RU2844066C1 - Hookah device with dielectric heater - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: group of inventions relates to aerosol-generating devices. Hookah device comprises a liquid cavity comprising a liquid volume through which the aerosol generated by the hookah device passes before inhalation by the user, an article cavity configured to receive an aerosol-generating article comprising an aerosol-forming substrate, electromagnetic field generator configured to generate a radio frequency (RF) electromagnetic field in the product cavity. Fluid chamber has a free space outlet. Article cavity is in fluid communication with liquid cavity. Electromagnetic field generator comprises a magnetron or a solid-state RF transistor. Cavity for article comprises one or more outer walls formed from material which is impermeable to RF-electromagnetic field, wherein one or more slots are formed in one or more outer walls.

EFFECT: uniform controlled heating of the aerosol-forming substrate is provided, the electromagnetic field is retained in the cavity for the article for effective heating and radiation leakage is prevented.

14 cl, 9 dwg

Description

The present invention relates to a hookah system for generating an aerosol from an aerosol-forming substrate (aerosol-forming substrate). In particular, the present invention relates to a hookah system, a hookah device, and a hookah article for use with a hookah device.

Traditional hookah devices are sometimes referred to in the art as a hookah, chillum, grill, or shisha. Traditional hookah devices differ from other aerosol-generating devices in that the volatile compounds released from a heated substrate in the hookah device pass through a liquid reservoir before being inhaled by the user. Traditional hookah devices may contain a single outlet or more than one outlet so that the device can be used by more than one user at a time.

Traditional hookahs are typically used in combination with a hookah substrate, sometimes referred to in the art as hookah tobacco, tobacco molasses, or simply molasses. Traditional hookah substrates are characterized by a relatively high sugar content, which in some cases amounts to approximately 50 percent, compared to approximately 20 percent that may be found in standard combustible cigarettes.

Traditional hookah devices also use charcoal to heat or sometimes burn the hookah substrate to generate an aerosol for the user to inhale. Using charcoal to heat the hookah substrate can cause the tobacco and other ingredients in the hookah substrate to be completely or partially burned.

Various types of electric hookah systems are known to date. In electric hookah systems, the charcoal-based heat source used in a traditional hookah device is replaced by an electrically powered heater. Almost all proposed electric hookah systems heat an aerosol-forming substrate by one or more of the following: heat transfer from a heating element to an aerosol-forming substrate, heat radiation from a heating element to an aerosol-forming substrate, or heated air passing through an aerosol-forming substrate. Typically, heating is accomplished by passing an electric current through an electrically resistive heating element, which results in Joule heating of the heating element. Induction heating systems have also been proposed, in which Joule heating occurs as a result of eddy currents induced in a heating element of a current collector.

One problem with previously proposed electric hookah devices is that these devices can cause uneven heating of the aerosol-forming substrate. The portion of the aerosol-forming substrate that is closest to the heating element heats up faster or to higher temperatures than those portions of the aerosol-forming substrate that are further from the heating element.

It would be desirable to be able to provide uniform heating of the aerosol forming substrate in a manner that allows greater design flexibility and also provides heating control.

According to the present invention, a hookah device is proposed for heating an aerosol-forming substrate (aerosol-forming substrate) to generate an aerosol. The hookah device may comprise a cavity for liquid, configured to accommodate a certain volume of liquid therein. The cavity for liquid may have an outlet opening for free space. The hookah device may comprise a cavity for an article, configured to accommodate an aerosol-forming substrate therein. The cavity for the article may be in fluid communication with the cavity for liquid. The hookah device may comprise: an electromagnetic field generator configured to generate a radio frequency (RF) electromagnetic field in the cavity for the article.

In particular, according to the present invention, a hookah device is proposed for heating an aerosol-forming substrate to generate an aerosol, wherein said hookah device comprises: a cavity for liquid, made with the possibility of placing a volume of liquid in it, wherein said cavity for liquid has an outlet opening for free space; a cavity for an article, made with the possibility of placing an aerosol-forming substrate in it, wherein said cavity for an article is in fluid communication with the cavity for liquid; and an electromagnetic field generator made with the possibility of generating a radio frequency (RF) electromagnetic field in the cavity for an article.

Such a hookah device is designed to provide dielectric heating of the aerosol-forming substrate. Dielectric heating can be uniform throughout the volume of the aerosol-forming substrate without creating hot spots. In addition, dielectric heating does not require contact between the heating element and the aerosol-forming substrate. This means that there is no need to clean the heating element, unlike standard arrangements in which aerosol residues can accumulate on the surface of electric heating elements. The hookah device provides significant design flexibility in terms of the shape, volume and composition of the aerosol-forming substrate, and accordingly the shape and volume of the cavity for the product.

The electromagnetic field generator may refer to any suitable type of electromagnetic field generator that is configured to generate a radio frequency (RF) electromagnetic field in a cavity for an article.

Preferably, the electromagnetic field generator comprises a solid state RF transistor.

The use of a solid-state RF transistor allows for the compactness of the hookah device. The standard means for generating RF radiation for heating, such as in household microwave ovens, is a magnetron. Magnetrons are bulky and require high voltage to operate. In addition, magnetrons have a relatively unstable output frequency and are characterized by a relatively short service life. An RF transistor can provide stable operation over many cycles of use and requires much lower operating voltages.

Advantageously, the solid-state RF transistor can be designed to generate and amplify the RF electromagnetic field. Using a single transistor to generate and amplify the RF electromagnetic field allows the hookah device to be compact. The solid-state RF transistor can be, for example, an LDMOS transistor, a gallium arsenide field-effect transistor, a silicon carbide field-effect transistor with a Schottky gate, or a gallium nitride heterostructure field-effect transistor.

Although it is preferred that the electromagnetic field generator comprise a solid state RF transistor, it is envisaged that in some embodiments the electromagnetic field generator may comprise a magnetron or other suitable electromagnetic field generator capable of generating an RF electromagnetic field.

In the context of this document, the term "radio frequency" (RF) shall be understood to mean a frequency from about 3 hertz (Hz) to about 3 terahertz (THz). Accordingly, in the context of this document, RF frequencies include microwave frequencies. Preferably, the RF electromagnetic field has a frequency from about 1 megahertz (MHz) to about 50 gigahertz (GHz). More preferably, the RF electromagnetic field has a frequency from about 4 megahertz (MHz) to about 30 gigahertz (GHz). The RF electromagnetic field can have a frequency from about 100 megahertz (MHz) to about 10 gigahertz (GHz). In one embodiment, the RF electromagnetic field has a frequency of about 4 megahertz (MHz). In one embodiment, the RF electromagnetic field has a frequency of about 3 gigahertz (GHz). In one embodiment, the RF electromagnetic field has a frequency of approximately 2.4 gigahertz (GHz).

In the context of this document, the term "aerosol-forming substrate" means a substrate capable of releasing volatile compounds that can form an aerosol. Such volatile compounds can be released by heating the aerosol-forming substrate. The aerosol-forming substrate is typically part of an aerosol-generating article. For example, the aerosol-forming substrate may be an aerosol-forming hookah substrate.

The aerosol-forming substrate for hookah may sometimes be referred to in the art as hookah tobacco, tobacco molasses, or simply molasses. The aerosol-forming substrate for hookah may have a relatively high sugar content compared to standard combustible cigarettes or tobacco-based consumable products that are designed to heat without burning to simulate the sensation of smoking. The aerosol-forming substrate will be described in more detail below.

In the context of this document, the term "aerosol generating article" refers to an article containing an aerosol forming substrate that is capable of releasing volatile compounds that can form an aerosol. For example, the aerosol generating article can be a cartridge for a hookah device. The cartridge for a hookah device contains an aerosol forming substrate. Preferably, the cartridge for a hookah device contains an aerosol forming substrate for a hookah. The cartridge for a hookah device is configured to be placed in a hookah device and to be operable with the hookah device to generate an aerosol that can be inhaled by a user who inhales or puffs through a mouthpiece of the hookah device. The aerosol generating article can be disposable.

In the context of this document, the term "hookah device" refers to a device that interacts with an aerosol-forming substrate to generate an aerosol. The hookah device is separate from the aerosol-forming substrate. The hookah device is configured to be combined with the aerosol-forming substrate to heat the aerosol-forming substrate. The aerosol-forming substrate may be provided as part of an aerosol-generating article. The hookah device is separate from the aerosol-generating article. The hookah device is configured to be combined with the aerosol-generating article to heat an aerosol-forming substrate that is part of the aerosol-generating article. Hookah devices differ from other aerosol-generating devices at least in that volatile compounds released from the heated substrate pass through a liquid reservoir of the hookah device before entering the respiratory tract of the user. Hookah devices may contain more than one outlet so that the device can be used by more than one user at a time. The hookah device may contain an air flow channel, such as a mouthpiece tube, to direct volatile compounds released from an aerosol-forming substrate into a liquid reservoir.

In the context of this document, the term "hookah system" refers to a combination of a hookah device with an aerosol-forming substrate or an aerosol-generating article that contains an aerosol-forming substrate. In a hookah system, an aerosol-forming substrate or an aerosol-generating article that contains an aerosol-forming substrate interacts with a hookah device to generate an aerosol.

A hookah device differs from other aerosol generating devices in that the aerosol generated by the hookah device passes through a volume of liquid, typically water, before said aerosol enters the respiratory tract of the user. More specifically, when a user of the hookah device takes a drag, volatile compounds released from a heated aerosol-forming substrate enter through an air flow channel of the hookah device into a volume of liquid. The volatile compounds enter from said volume of liquid into a headspace of the hookah device, where the volatile compounds form an aerosol. The aerosol located in the headspace is then drawn out of said headspace through an outlet opening of the headspace for inhalation by the user. The volume of liquid, typically water, is intended to reduce the temperature of the volatile compounds and may increase the water content of the aerosol formed in the headspace of the hookah device. This process adds distinctive characteristics to the process of using the hookah device by the user, and also imparts distinctive characteristics to the aerosol generated by the hookah device and inhaled by the user.

In some preferred embodiments, the hookah device comprises an air flow channel for transferring volatile compounds released from the heated aerosol-forming substrate from the article cavity to the liquid cavity. More specifically, the hookah device may comprise an air flow channel configured to transfer volatile compounds released from the heated aerosol-forming substrate from the article cavity to a volume of liquid located in the liquid cavity. Typically, the air flow channel is configured to transfer the aerosol from the article cavity to a location located below the liquid filling level in the liquid cavity. The liquid filling level in the liquid cavity is the level to which the liquid cavity must be filled with liquid so that the hookah device can optimally function. The air flow channel may be characterized by the presence of an opening leading into the liquid cavity and located below the liquid filling level of the liquid cavity.

The hookah device comprises a headspace outlet. The headspace outlet is an outlet through which the aerosol can be discharged from the liquid cavity. The headspace outlet can be located above the liquid filling level of the liquid cavity. The space located above the liquid filling level of the liquid cavity is called headspace. The headspace in the liquid cavity is a space in which volatile compounds drawn from the product cavity and through the liquid volume into the liquid cavity can condense to form an aerosol that is suitable for inhalation by the user. The headspace in the liquid cavity should not contain any volume of liquid located in the liquid cavity. Accordingly, the headspace can be located above the liquid filling level of the liquid cavity, which is the level to which the liquid cavity must be filled with liquid. The headspace outlet can be located in such a way as to ensure the possibility of removing the aerosol from the liquid cavity. The headspace outlet can communicate with the headspace via a fluid medium.

The mouthpiece may be in fluid communication with the headspace outlet. The mouthpiece may be designed so that the user can puff and receive the aerosol generated by the hookah device. In some embodiments, the mouthpiece may be fixed in the headspace outlet. In other words, the mouthpiece may be attached to the headspace outlet, as a result of which the mouthpiece cannot be removed from the headspace outlet without damaging the mouthpiece and/or the headspace outlet. The mouthpiece may be removably connected to the headspace outlet. In other words, the mouthpiece may be designed to be connected to the headspace outlet and removed from the headspace outlet. In some embodiments, the mouthpiece may be interchangeable with a removable one-way air valve. Thus, if more than one headspace outlet is provided, the number of mouthpieces can be adjusted to suit the number of users during any given use session without adversely affecting the resistance to draw (RTD) of the device. The mouthpiece may comprise a hose that is connected to the headspace outlet. The hose may be a flexible hose.

The mouthpiece may comprise an actuation element. The actuation element may comprise a switch activated by the user. The mouthpiece may comprise a puff sensor designed to detect a puff by the user through the mouthpiece. The actuation element may comprise both a switch activated by the user and a puff sensor. The actuation element may be operatively connected to the control circuit of the hookah device. The actuation element may be connected to the control circuit of the hookah device via a wireless connection. Activation of the actuation element may cause activation of the heating element by means of the control circuit of the hookah device instead of a constant supply of energy to the heating element. Accordingly, the use of the actuation element may contribute to energy savings compared to devices in which such elements are not used to provide heating on demand instead of constant heating.

The hookah device may comprise a plurality of headspace outlets. For example, the hookah device may comprise two, three, four, five, or six headspace outlets. Having more than one headspace outlet may allow more than one user to simultaneously draw aerosol from the liquid cavity. In other words, having a plurality of headspace outlets may allow multiple users to simultaneously use the hookah device.

The hookah device comprises a cavity for the product, designed with the possibility of placing therein an aerosol-generating product, which contains a substrate that forms the aerosol.

It is desirable that the electromagnetic radiation generated by the electromagnetic field generator is contained in the product cavity. This is necessary both to ensure efficient heating and to prevent radiation leakage. Such radiation leakage may cause damage to other components of the system, including the electromagnetic field generator itself. In addition, it is desirable to minimize the user's exposure to RF radiation. Advantageously, the product cavity may comprise one or more outer walls formed of a material impermeable to the RF electromagnetic field. One or more outer walls of the product cavity may comprise any suitable material that is impermeable to RF radiation, such as aluminum, stainless steel, silver or gold. One or more outer walls of the product cavity may be characterized by the presence of a polished surface to improve the reflection of RF radiation inside the cavity.

In addition, the radiation must be able to enter the cavity for the product. Accordingly, one or more slits can be formed in one or more outer walls to allow the electromagnetic field to enter the cavity for the product. The presence of one or more slits through which the electromagnetic field can pass provides the ability to penetrate the electromagnetic field into the cavity for the product. One or more slits can be characterized by any suitable shape and size to allow the electromagnetic field to enter the cavity for the product. For example, at least one of the one or more slits can be characterized by an L-shape, an S-shape, a T-shape, or an I-shape.

The cavity for the article may comprise one or more walls that are permeable to the RF electromagnetic field. In particular, the cavity for the article may comprise one or more walls that are permeable to the RF electromagnetic field, wherein the aerosol-forming substrate is enclosed in a wrapper or container made of a material that is impermeable to the RF electromagnetic field. One or more slits may be made in the wrapper or container that surrounds the aerosol-forming substrate to allow the electromagnetic field to penetrate.

The cavity for the product may be characterized by any suitable shape and size. In particular, the cavity for the product may be characterized by a shape and size that are selected in accordance with the shape and size of the aerosol-generating product.

The product cavity may have any suitable cross-section. For example, the product cavity may have a circular, oval, rectangular, square, triangular, or any other polygonal cross-sectional shape.

In some embodiments, the article cavity is substantially cylindrical.

In some embodiments, the article cavity has a substantially truncated cone shape. In some embodiments, the width or diameter of one end of the article cavity exceeds the width or diameter of the other end of the article cavity. In other words, the article cavity may taper from one end to the other. Having one end of the article cavity that is narrower than the other end may allow the article cavity to retain the aerosol-generating article in the article cavity by gravity alone.

The cavity for the article may comprise an opening. The cavity for the article may be designed to accommodate an aerosol-forming article therein, which contains an aerosol-forming substrate, through the opening. The cavity for the article may comprise an open end. The cavity for the article may be designed to accommodate an aerosol-forming article therein, which contains an aerosol-forming substrate, through the open end.

In some embodiments, the article cavity may comprise a movable closure. The movable closure may be configured to substantially close the open end of the article cavity. When the movable closure is positioned to substantially close the open end of the article cavity, the movable closure may substantially prevent the aerosol-forming article from being removed from the article cavity. The movable closure may be configured to rotate to close the open end of the article cavity. The movable closure may be configured to slide to close the open end of the article cavity. The movable closure may be removably attached to the open end of the article cavity to substantially close the open end of the article cavity.

In some embodiments, the article cavity may comprise two open ends. For example, the article cavity may comprise an open first end and an open second end located opposite the first end. Advantageously, providing the article cavity with two open ends may allow air to pass through the article cavity from one open end to the other.

In some embodiments, the article cavity may comprise an open end and a closed end. The closed end may allow the article cavity to retain the aerosol-generating article in the article cavity.

In some highly preferred embodiments, the article cavity has a substantially truncated cone shape, in which the first end is narrower than the second end. In these embodiments, the first end of the article cavity may be open, while the second end of the article cavity may also be open. This may allow air to flow through the article cavity from the first end to the second end. In these embodiments, the aerosol-generating article, which is configured to be placed in the article cavity, may comprise a fluid-permeable first end outer surface and a fluid-permeable second end outer surface. The fluid-permeable first and second end outer surfaces of the aerosol-generating article may allow air to flow through the article cavity between the first end and the second end when the aerosol-generating article is positioned in the article cavity. In these embodiments, preferably, the fluid-permeable first and second end outer surfaces of the aerosol-generating article are permeable to the RF electromagnetic field. For example, the first and second end outer surfaces permeable to a fluid medium may be formed from a metal mesh.

The article cavity may be characterized by any suitable shape and dimensions. The article cavity may have a length of about 10 millimeters to about 100 millimeters, about 20 millimeters to about 90 millimeters, or about 25 millimeters to about 80 millimeters. In some preferred embodiments, the article cavity may have a length of about 33 millimeters, about 34 millimeters, about 35 millimeters, about 36 millimeters, about 37 millimeters, about 38 millimeters, 39 millimeters, about 40 millimeters, about 41 millimeters, or about 42 millimeters. The article cavity may have a width or diameter of about 5 millimeters to about 70 millimeters, about 10 millimeters to about 60 millimeters, or about 10 millimeters to about 50 millimeters. In some preferred embodiments, the article cavity may have a width or diameter of about 35 millimeters, about 36 millimeters, about 37 millimeters, about 38 millimeters, 39 millimeters, about 40 millimeters, about 41 millimeters, about 42 millimeters, about 43 millimeters, about 44 millimeters, or about 45 millimeters.

As used herein, the term "length" means the maximum longitudinal dimension between the base or lower end and the upper end of a hookah device, a component of a hookah device, an aerosol-generating article, or a component of an aerosol-generating article. As used herein, the term "width" or "diameter" means the maximum transverse dimension of a hookah device, a component of a hookah device, an aerosol-generating article, or a component of an aerosol-generating article. For example, when an aerosol-generating article has the shape of a truncated cone, the width or diameter of the aerosol-generating article is the width or diameter of the base of the truncated cone that is the widest part of the aerosol-generating article, at any point along the length of the aerosol-generating article. The transverse dimension is the dimension measured in a direction transverse to the longitudinal direction, where the longitudinal direction is the direction in which the longitudinal dimensions are measured. In the context of this document, the term "cross-section" means a section taken along a transverse plane.

In the context of this document, the terms "upper" and "lower" mean the relative positions of elements or parts of elements of a hookah device, a component of a hookah device, an aerosol-generating article, or a component of an aerosol-generating article.

The cavity for the article may be located in the heating unit. The heating unit may comprise the cavity for the article and an electromagnetic field generator. The heating unit may further comprise one or more of the following: a control circuit, a power supply unit, and electromagnetic field manipulators such as waveguides and antennas, which is described in more detail below. The heating unit may further comprise one or more electrical connectors for electrically connecting one or more electrical components to the heating unit, such as the control circuit, the power supply unit, and the electromagnetic field manipulators.

The heating unit may comprise one or more outer walls formed from a material impermeable to the RF electromagnetic field. Preferably, all outer walls of the heating unit are formed from a material impermeable to the RF electromagnetic field. The heating unit may comprise an opening for providing insertion of an aerosol-generating article into the article cavity. The heating unit may comprise a movable closure, such as a lid or a door, which is configured to move between an open position and a closed position. The open position may provide the possibility of insertion of the aerosol-generating article into the article cavity, and the closed position may substantially prevent or impede the removal of the aerosol-generating article from the article cavity. The movable closure may be connected with the possibility of movement, for example with the possibility of rotation or sliding, to the outer wall of the heating unit. The movable sealing means can be attached in a removable manner to the outer wall of the heating unit.

The aerosol generating device may additionally comprise a volume resonator located between the cavity for the article and the electromagnetic field generator. In the context of this document, the term "volume resonator" means a structure that can retain electromagnetic waves of a given frequency. In this case, the selected frequency of electromagnetic waves corresponds to the RF spectrum region. To retain electromagnetic waves, the volume resonator is made of a reflective material selected specifically for this frequency, such as metals. The structure may be either hollow or filled with a dielectric material. The task of the volume resonator is to ensure the reflection of electromagnetic waves in the forward and backward directions in the internal volume in order to enhance the formation of standing waves and minimize power losses.

The cavity resonator amplifies the RF electromagnetic field at the resonant frequency and can be designed to match the impedance of the electromagnetic field generator and the load, which in this case is the aerosol-forming substrate in the product cavity, to optimize energy absorption by the load and minimize radiation reflection from the load. This improves heating efficiency and minimizes radiation leakage from the system. The cavity resonator can be located between the electromagnetic field generator and the product cavity.

The hookah device may comprise a waveguide. The waveguide may be located adjacent to the cavity for the product. The waveguide may be provided to provide the ability for the RF electromagnetic field to penetrate into the cavity for the product through one or more slots or entry points. RF radiation may freely propagate inside the waveguide. The waveguide may be characterized by the presence of outer walls that are impermeable to RF electromagnetic radiation. The waveguide may be located between the electromagnetic field generator and the cavity for the product. The waveguide may be located between the electromagnetic field generator and the cavity resonator.

The aerosol generating device may further comprise an antenna connected to the electromagnetic field generator and configured to direct the RF electromagnetic field. The aerosol generating device may further comprise a plurality of antennas that are connected to the electromagnetic field generator and configured to direct the RF electromagnetic field. One or more antennas may be located at least partially in the cavity for the article. In use, one or more antennas may be located at least partially with the aerosol-forming substrate in the cavity for the article. In use, one or more antennas may be configured to pierce the container or wrapper in which the aerosol-forming substrate is enclosed. One or more antennas may pass through a slit in the outer wall of the cavity for the article. One or more antennas may be connected to a waveguide. One or more antennas may be connected to a waveguide that is connected to the electromagnetic field generator. One or more antennas may be located at least partially inside the cavity resonator. One or more antennas may be located between the electromagnetic field generator and the cavity for the article. One or more antennas may be located between the waveguide and the cavity for the article. One or more antennas may be located between the waveguide and the cavity resonator.

The presence of an antenna to direct the radiation generated by the electromagnetic field generator can improve the efficiency of the device. One or more antennas may contain an electrically conductive pin.

The hookah device may comprise an air inlet. The air inlet may provide for drawing in ambient air into the hookah device. The hookah device body may comprise an air inlet. The air inlet may provide for drawing in ambient air into the product cavity. In embodiments in which one or more ends of the product cavity are located on the outer surface of the hookah device, the product cavity may comprise an air inlet. In embodiments in which the product cavity comprises an open end for accommodating an aerosol-generating product therein, the open end may form an air inlet.

The air flow path can be defined between the air inlet and the outlet of the free space. The air flow path can pass through the cavity for the product. The air flow path can pass through the cavity for the product into the cavity for the liquid. The air flow path can pass from the cavity for the product through the air flow channel and then into a place of the cavity for the liquid located below the level of filling the cavity for the liquid with liquid. The air flow path can pass from a place located below the level of filling the cavity for the liquid with liquid into the free space of the cavity for the liquid and then from the outlet of the free space.

The air flow path may comprise one or more labyrinth-shaped portions passing by one or more radiation protection elements. In embodiments in which the air flow path passes through a cavity for an article or through a generated RF electromagnetic field, the air flow path may comprise a labyrinth-shaped portion after one or more radiation protection elements to prevent RF radiation from leaking through an air inlet or an air outlet. One or more fluid-permeable radiation protection elements may be installed in the air flow path. For example, a metal mesh may be installed in the air flow path.

In some embodiments, the article cavity is configured such that the air flow path through the article cavity is aligned with the air flow channel. In some embodiments, the article cavity is configured such that the air flow path through the article cavity substantially coincides with the direction in which the RF electromagnetic field penetrates the cavity. In some embodiments, the article cavity is configured such that the air flow path through the article cavity passes substantially across the direction in which the RF electromagnetic field penetrates the cavity.

In some embodiments, the article cavity comprises a first end, a second end opposite the first end, and a side wall extending between the first end and the second end. In these embodiments, the article cavity may be configured to provide air flow through the article cavity between the first end and the second end. In these embodiments, the article cavity may be configured to provide RF electromagnetic energy penetration into the article cavity from the side. For example, one or more slits may be provided in the side wall of the article cavity, which is made of a material impermeable to the RF electromagnetic field. For example, the side wall of the cavity may comprise a material that is substantially permeable to the RF electromagnetic field.

In some embodiments, the cavity for the article comprises a first end, a second end located opposite the first end, a first side wall extending between the first end and the second end, and a second side wall located opposite the first side and extending between the first end and the second end. The cavity for the article may be configured to provide air flow through the cavity for the article between the first side wall and the second side wall. The cavity for the article may be configured to provide penetration of RF electromagnetic energy into the cavity for the article from at least one of the first end and the second end.

When using an RF transistor to generate an RF electromagnetic field, a closed-loop control circuit can be used. The hookah device can comprise a sensor located in the cavity for the product or adjacent to it, wherein said sensor provides a signal characterizing the temperature in the cavity for the product, and a controller connected to receive a signal from the sensor and connected to control the electromagnetic field generator depending on the signal coming from the sensor.

The sensor may comprise a temperature sensor that directly measures the temperature. The sensor may comprise a sampling antenna or a plurality of sampling antennas configured to detect a disturbance of the electromagnetic field in the cavity for the article that characterizes the temperature in the cavity for the article. The dielectric properties of the aerosol-forming substrate change depending on the temperature. The frequency and/or amplitude of the electromagnetic field may be regulated by a controller based on a signal from the sensor for controlling the heating performed by the device.

The sensor can detect both excess and insufficient heating. The frequency and amplitude of the electromagnetic field can be adjusted accordingly depending on whether excess or insufficient heating is detected. The control circuit of the hookah device can be configured to adjust at least one of the frequency or amplitude of the electromagnetic field based on whether excess or insufficient heating is detected by the sensor.

The sensor can detect failures. If a failure is detected, the hookah device can be automatically switched off. In addition, it is possible to detect the presence of unsuitable materials in the cavity for the product. If an unsuitable material is detected in the cavity for the product, the hookah device can be automatically switched off. Similarly, if the sensor signal indicates the absence of an aerosol-forming substrate in the cavity for the product, the device can be automatically switched off. To automatically switch off the hookah device, the hookah device control circuit can be designed with the ability to interrupt the supply of electrical energy to the electromagnetic field generator. This type of control is not possible if a magnetron is used to generate RF radiation.

It may be desirable to maintain the temperature within the article cavity within a predetermined temperature range. It may be desirable to maintain the temperature of the aerosol-forming substrate below the temperature at which the aerosol-forming substrate ignites.

The ability to control the degree of heating performed by the hookah device based on the feedback signal also allows the use of different aerosol-forming substrates. Different aerosol-forming substrates may need to be heated to different temperatures. Accordingly, the presence of a temperature control mechanism allows for optimal conditions to be achieved for different aerosol-forming substrates or different designs of aerosol-forming products.

The hookah device may comprise a puff detector configured to detect when a user of the hookah device takes a puff. In the context of this document, the term "puff" means drawing in the hookah system by the user to obtain an aerosol. The puff detector may comprise a temperature sensor. The puff detector may comprise a pressure sensor. The puff detector may comprise both a temperature sensor and a pressure sensor.

The hookah device may contain a control circuit. The control circuit may be configured to control the power supply to the electromagnetic field generator. The control circuit may contain one or more of the following: a microprocessor, a programmable microprocessor, a microcontroller, and an application-specific integrated circuit (ASIC) or other electronic circuit capable of providing control. The control circuit may contain additional electronic components. For example, in some embodiments, the control circuit may contain one or more of the following: sensors, switches, and display elements. The control circuit may contain an RF power sensor. The control circuit may contain a power amplifier.

In some embodiments, the hookah device is designed to be connected to an external power source. For example, the hookah device may be designed to be connected to a power source from the electrical network.

In some embodiments, the hookah device comprises a power source. The power source may be a DC power source. The power source may comprise a battery or another type of charge storage device, such as a capacitor. The power source may comprise a rechargeable lithium-ion battery. In some embodiments, the power source is a rechargeable power source. The hookah device may be configured to be connected to an external power source to recharge the rechargeable power source.

The control circuit may be configured to control the power supplied to the electromagnetic field generator from the power source.

The power source may provide power in the range of about 0.5 watts to about 50 watts. In some embodiments, the power source may provide power in the range of about 1 watt to about 40 watts or about 2 watts to about 30 watts.

If the electromagnetic field generator is a solid-state RF transistor, the impedance of the electromagnetic field generator may be less than or equal to approximately 100 ohms. The impedance of the electromagnetic field generator may be less than or equal to 75 ohms. The impedance of the electromagnetic field generator may be greater than approximately 1 ohm. The impedance of the electromagnetic field generator may be greater than approximately 10 ohms. The impedance of the electromagnetic field generator may be in the range of 50 ohms to 75 ohms.

If the electromagnetic field generator is a solid state RF transistor, the forward voltage across the electromagnetic field generator may be less than or equal to approximately 100 V. The forward voltage across the electromagnetic field generator may be greater than or equal to approximately 1 V. The forward voltage across the electromagnetic field generator may be in the range of approximately 1 V to approximately 100 V.

The hookah device may comprise a vessel. The cavity for liquid may be an internal volume of the vessel. The vessel may be configured to accommodate liquid therein. The vessel may define a cavity for liquid. The vessel may comprise a free space outlet. The vessel may define a liquid filling level. For example, the vessel may comprise a liquid filling level limiting element. The liquid filling level limiting element is an indicator provided in the vessel to indicate a desired level to which the cavity for liquid should be filled with liquid. The free space outlet may be located above the liquid filling level. The free space outlet may be located above the liquid filling level limiting element. The vessel may comprise an optically transparent portion. The presence of an optically transparent portion may allow the user to see the contents of the vessel. The vessel may be made of any suitable material. For example, the vessel may be made of glass or a rigid plastic material. In some embodiments, the vessel is configured to be detachable from the rest of the hookah assembly. In some embodiments, the vessel is detachable from the aerosol-generating portion of the hookah assembly. Advantageously, the presence of a removable vessel allows the user to fill the liquid cavity with liquid, remove the liquid from the liquid cavity, and clean the vessel.

The user may fill the vessel to the fill level with liquid. Preferably, the liquid comprises water. The liquid may comprise water with one or more colorings or flavorings added. For example, one or both of the plant or herbal supplements may be added to the water.

The vessel may be of any suitable shape and size. The cavity for the liquid may be of any suitable shape and size. The free space may be of any suitable shape and size.

Typically, during use, the hookah device according to the present invention is intended to be placed on a flat surface, and not to be held by the user. Accordingly, the hookah device according to the present invention may have a specific operating orientation or a series of orientations in which the device is to be located during use. Accordingly, in the context of this document, the terms "above" and "below" mean the relative positions of the elements of the hookah device or hookah system when the hookah device or hookah system is in the operating orientation.

In some embodiments, the article cavity is located above the liquid cavity. In these embodiments, the air flow channel may extend from the article cavity to a location below the liquid filling level of the liquid cavity. Advantageously, this may ensure that the volatile compounds released from the aerosol-forming substrate in the article cavity are delivered from the article cavity to the liquid volume in the liquid cavity, rather than to the free space above the liquid cavity. In these embodiments, the air flow channel may extend from the aerosol cavity to the liquid cavity through the free space in the liquid cavity above the liquid filling level and further into the liquid volume below the liquid filling level. The air flow channel may extend into the liquid cavity through the upper part or the upper end of the liquid cavity.

In some embodiments, the article cavity is located below the liquid cavity. In these embodiments, the one-way valve may be located between the article cavity and the liquid cavity. The one-way valve may prevent liquid from entering the liquid cavity from the liquid cavity into the article cavity under the action of gravity. In these embodiments, the one-way valve may be located in the air flow channel extending from the article cavity to the liquid cavity. In these embodiments, the air flow channel may extend into the liquid cavity to a location below the liquid filling level. The air flow channel may extend into the liquid cavity through the lower end of the liquid cavity.

According to some particularly preferred embodiments of the present invention, a hookah device is provided for heating an aerosol-forming substrate to generate an aerosol, wherein said hookah device comprises: a liquid cavity configured to accommodate a volume of liquid therein, wherein said liquid cavity has a free space outlet; a product cavity configured to accommodate an aerosol-forming substrate therein, wherein said product cavity is in fluid communication with the liquid cavity; and an electromagnetic field generator configured to generate a radio frequency (RF) electromagnetic field in the product cavity, wherein said electromagnetic field generator comprises a solid-state RF transistor.

According to some particularly preferred embodiments of the present invention, a hookah device is proposed for heating an aerosol-forming substrate to generate an aerosol, wherein said hookah device comprises: a liquid cavity configured to accommodate a volume of liquid therein, wherein said liquid cavity has a free space outlet; an article cavity configured to accommodate an aerosol-forming substrate therein; an air flow channel extending between the article cavity and the liquid cavity, wherein said air flow channel fluidly connects the article cavity and the liquid cavity; a mouthpiece in fluid communication with the free space outlet of the liquid cavity; and an electromagnetic field generator configured to generate a radio frequency (RF) electromagnetic field in the article cavity.

According to some particularly preferred embodiments of the present invention, a hookah device is proposed for heating an aerosol-forming substrate to generate an aerosol, wherein said hookah device comprises: a liquid cavity configured to accommodate a volume of liquid therein, wherein said liquid cavity has a free space outlet; a heating unit comprising a product cavity configured to accommodate an aerosol-forming substrate therein and an outer housing made of a material impermeable to an RF electromagnetic field; an air flow channel extending between the product cavity and the liquid cavity, wherein said air flow channel fluidly connects the product cavity and the liquid cavity; a mouthpiece in fluid communication with the free space outlet of the liquid cavity; and an electromagnetic field generator configured to generate a radio frequency (RF) electromagnetic field in the product cavity.

The present invention also provides an aerosol generating article for use with the hookah device described above.

An aerosol-generating article may be any suitable type of aerosol-generating article for use with a hookah device. An aerosol-generating article that is specifically designed for use with a hookah device may be referred to as a hookah device cartridge. An aerosol-generating article that is specifically designed for use with a hookah device equipped with an electromagnetic field generator may be referred to as a hookah device cartridge equipped with an electromagnetic field generator.

The aerosol generating article may have any suitable shape and size. In particular, the aerosol generating article may have a shape and size that are selected in accordance with the shape and size of the cavity for the hookah device article.

The aerosol generating article may have any suitable cross-section. For example, the aerosol generating article may have a circular, oval, rectangular, square, triangular or any other polygonal cross-sectional shape.

In some embodiments, the aerosol generating article is substantially cylindrical.

In some embodiments, the aerosol-generating article has a substantially truncated cone shape. In some embodiments, the width or diameter of the first end of the aerosol-generating article exceeds the width or diameter of the second end of the aerosol-generating article, which is opposite the first end. In other words, the aerosol-generating article may taper from the first end to the second end. Having a second end of the aerosol-generating article, which is narrower than the first end, may ensure that the aerosol-generating article is retained in the complementary cavity for the article by gravity.

The aerosol-generating article may have a length of about 10 millimeters to about 100 millimeters, about 20 millimeters to about 90 millimeters, or about 25 millimeters to about 80 millimeters. In some preferred embodiments, the aerosol-generating article may have a length of about 33 millimeters, about 34 millimeters, about 35 millimeters, about 36 millimeters, about 37 millimeters, about 38 millimeters, 39 millimeters, about 40 millimeters, about 41 millimeters, or about 42 millimeters. The aerosol-generating article may have a width or diameter of about 5 millimeters to about 70 millimeters, about 10 millimeters to about 60 millimeters, or about 10 millimeters to about 50 millimeters. In some preferred embodiments, the aerosol-generating article may have a width or diameter of about 35 millimeters, about 36 millimeters, about 37 millimeters, about 38 millimeters, 39 millimeters, about 40 millimeters, about 41 millimeters, about 42 millimeters, about 43 millimeters, about 44 millimeters, or about 45 millimeters.

An aerosol-generating article comprises an aerosol-forming substrate. The aerosol-forming substrate may be enclosed in a wrapper or container. In some embodiments, the aerosol-forming substrate may have a coating.

The wrapper may define a substrate cavity. The aerosol-forming substrate may be located in the substrate cavity within the wrapper.

In some embodiments, the wrapper may comprise a material that is impermeable to the RF electromagnetic field. In some embodiments, at least a portion of the wrapper comprises a material that is impermeable to the RF electromagnetic field. In some embodiments, the entire wrapper may comprise a material that is impermeable to the RF electromagnetic field.

One or more slits may be formed in the wrapper to allow the RF electromagnetic field to penetrate into the aerosol-forming substrate. In particular, when all parts of the wrapper comprise a material impermeable to the RF electromagnetic field, one or more slits may be formed in the wrapper to allow the electromagnetic field to penetrate into the aerosol-forming substrate.

At least a portion of the wrapper may be fluid-permeable. The fluid-permeable portion of the wrapper may allow volatile compounds released from the aerosol-forming substrate to be released from the aerosol-generating article. The portion of the wrapper comprising a material impermeable to the RF electromagnetic field may also be fluid-permeable. For example, the fluid-permeable material that is impermeable to the RF electromagnetic field may be a metal mesh. Accordingly, at least a portion of the wrapper may be formed from a metal mesh. In some embodiments, the wrapper may be formed from a metal mesh.

The aerosol-forming substrate may be contained in a container. The container may define a substrate cavity. The aerosol-forming substrate may be located in a substrate cavity within the container.

In some embodiments, the container may comprise a material that is impermeable to RF electromagnetic fields.

In some embodiments, the container may comprise one or more walls. At least one wall of the container may comprise a material that is impermeable to an RF electromagnetic field. All walls of the container may comprise a material that is impermeable to an RF electromagnetic field.

The container may comprise a top wall, a bottom wall, and a side wall extending between the top wall and the bottom wall. The top wall may consist of a material impermeable to an RF electromagnetic field. The bottom wall may consist of a material impermeable to an RF electromagnetic field. The side wall may consist of a material impermeable to an RF electromagnetic field. In some embodiments, each of the top wall, bottom wall, and side wall comprises a material impermeable to an RF electromagnetic field.

One or more slits may be formed in the container to allow the RF electromagnetic field to penetrate. In particular, when each of the top wall, bottom wall and side wall of the container comprises a material impermeable to the RF electromagnetic field, one or more slits may be formed in the container to allow the RF electromagnetic field to penetrate into the aerosol-forming substrate.

In some embodiments comprising a container, the top and bottom walls of the container comprise a material impermeable to the RF electromagnetic field. In some of these embodiments, the side wall does not comprise a material impermeable to the RF electromagnetic field to allow the RF electromagnetic field to penetrate into the areas of the side wall.

In some embodiments comprising a container, the side wall of the container comprises a material impermeable to the RF electromagnetic field. In some of these embodiments, the top wall comprises a material impermeable to the RF electromagnetic field, and the bottom wall does not comprise a material impermeable to the RF electromagnetic field, to allow the RF electromagnetic field to penetrate into the regions of the bottom wall. In some of these embodiments, the bottom wall comprises a material impermeable to the RF electromagnetic field, and the top wall does not comprise a material impermeable to the RF electromagnetic field, to allow the RF electromagnetic field to penetrate into the regions of the top wall.

In some embodiments comprising a container in which each of the top wall, the bottom wall and the side wall comprises a material impermeable to the RF electromagnetic field, one or more slits are formed in the wall of the container to allow the electromagnetic field to penetrate. In some of these embodiments, one or more slits are formed in the top wall. In some of these embodiments, one or more slits are formed in the bottom wall. In some of these embodiments, one or more slits are formed in the side wall.

At least a portion of the container may be fluid-permeable. The fluid-permeable portion of the container may allow volatile compounds released from the aerosol-forming substrate to be released from the aerosol-generating article. The container wall comprising a material impermeable to the RF electromagnetic field may also be fluid-permeable. For example, the fluid-permeable material that is impermeable to the RF electromagnetic field may be a metal mesh. Accordingly, at least a portion of the container may be formed from a metal mesh. In some embodiments, the container may be formed from a metal mesh.

In some embodiments, at least a portion of the aerosol-forming substrate has a coating. As used herein, the term "coating" means a layer of material that covers and adheres to the aerosol-forming substrate. The coating may be applied to cover and adhere to the surface of at least a portion of the aerosol-forming substrate by any suitable methods known in the art, including, but not limited to, spraying, vapor deposition, dipping, material transfer (e.g., brushing or gluing), electrostatic deposition, or any combination thereof.

In some embodiments, the coating may comprise a material that is impermeable to RF electromagnetic fields.

One or more areas of the outer surface of the aerosol-generating substrate may be exposed. That is, one or more areas of the outer surface of the aerosol-generating substrate may not contain any coating. This may ensure that volatile compounds released from the aerosol-generating substrate are able to escape from the aerosol-generating article. If the coating contains a material that is impermeable to the RF electromagnetic field, this may also facilitate the penetration of the RF electromagnetic field to the aerosol-generating substrate.

In some embodiments, the coating may comprise a fluid-permeable material.

In some embodiments, one or more regions of the outer surface of the aerosol-forming substrate may be coated with a first coating, and one or more regions of the outer surface of the aerosol-forming substrate may be coated with a second coating. One of the first coating and the second coating may comprise a material that is impermeable to the RF electromagnetic field. One of the first coating and the second coating may comprise a material that is permeable to the fluid. In some preferred embodiments, one of the first coating and the second coating comprises a material that is impermeable to the RF electromagnetic field, and the other of the first coating and the second coating comprises a material that is permeable to the fluid. This may provide penetration of the RF electromagnetic field into the aerosol-forming substrate in one region of the aerosol-forming substrate, and may provide passage of air through the aerosol-forming substrate in another region of the aerosol-forming substrate, without the RF electromagnetic field escaping from the aerosol-forming substrate in this region.

In some embodiments, at least a portion of the wrapper or container that contains the aerosol-forming substrate has a coating. The coating may comprise a material that is impermeable to an RF electromagnetic field.

The aerosol-forming substrate may be any suitable substrate capable of releasing volatile compounds upon heating.

In some preferred embodiments, the aerosol-forming substrate is in the form of a suspension. For example, the aerosol-forming substrate may comprise molasses. As used herein, "molasses" means a composition of the aerosol-forming substrate comprising a suspension having at least about 20 percent by weight sugar. For example, molasses may comprise at least about 25 percent by weight sugar, such as at least about 35 percent by weight sugar. Typically, molasses will comprise less than about 60 percent by weight sugar, such as less than about 50 percent by weight sugar.

Preferably, the aerosol-forming substrate is a hookah substrate. In the context of this document, "hookah substrate" refers to an aerosol-forming substrate composition comprising at least about 20 percent by weight of sugar. The hookah substrate may comprise molasses. The hookah substrate may comprise a suspension having at least about 20 percent by weight of sugar.

The aerosol-forming substrate may be solid or liquid, or contain both solid and liquid components.

The aerosol-forming substrate may contain nicotine. The nicotine-containing aerosol-forming substrate may contain a nicotine salt matrix. The aerosol-forming substrate may contain a plant-based material. The aerosol-forming substrate preferably contains tobacco. The tobacco-containing material preferably contains volatile tobacco flavor compounds that are released from the aerosol-forming substrate upon heating. The aerosol-forming substrate may contain homogenized tobacco material. The homogenized tobacco material may be formed by agglomerating tobacco in the form of particles. The aerosol-forming substrate may contain a material that does not contain tobacco. The aerosol-forming substrate may contain homogenized plant-based material.

The aerosol-forming substrate may comprise, for example, one or more of: powder, granules, pellets, pieces, fine threads, strips or sheets. The aerosol-forming substrate may comprise one or more of: grass leaf, tobacco leaf, tobacco rib fragments, reconstituted tobacco, homogenized tobacco, extruded tobacco and expanded tobacco. The tobacco may be fire-cured tobacco.

The aerosol-forming substrate may comprise at least one aerosol-forming substance. Suitable aerosol-forming substances include compounds or mixtures of compounds that facilitate the formation of a dense and stable aerosol upon use and that are substantially resistant to thermal decomposition at the operating temperature of the hookah device. Suitable aerosol-forming substances are well known in the art and include, but are not limited to: polyhydric alcohols such as triethylene glycol, 1,3-butanediol and glycerol; esters of polyhydric alcohols such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Particularly preferred aerosol-forming substances are polyhydric alcohols or mixtures thereof such as triethylene glycol, 1,3-butanediol and most preferably glycerol. The aerosol former may be propylene glycol. The aerosol former substrate may contain any suitable amount of the aerosol former. For example, the aerosol former content of the substrate may be equal to or greater than 5 percent by dry weight, and preferably greater than 30 percent by weight by dry weight. The aerosol former content may be less than about 95 percent by dry weight. Preferably, the aerosol former content is up to about 55 percent by dry weight.

The aerosol-forming substrate preferably comprises nicotine and at least one aerosol-forming agent. In some embodiments, the aerosol-forming agent is glycerol or a mixture of glycerol and one or more other suitable aerosol-forming agents, such as those listed above. In some embodiments, the aerosol-forming agent is propylene glycol.

The aerosol-forming substrate may contain other additives and ingredients, such as flavorings. In some examples, the aerosol-forming substrate contains one or more sugars in any suitable amount. Preferably, the aerosol-forming substrate contains invert sugar. Invert sugar is a mixture of glucose and fructose obtained by separating sucrose. Preferably, the aerosol-forming substrate contains from about 1 percent to about 40 percent by weight of a sugar, such as invert sugar. In some example, one or more sugars can be mixed with a suitable carrier, such as corn starch or maltodextrin.

In some examples, the aerosol-forming substrate contains one or more sensory enhancing agents. Suitable sensory enhancing agents include flavors and sensory affecting agents such as cooling agents. Suitable flavors include natural or synthetic menthol, peppermint, spearmint, coffee, tea, spices (such as cinnamon, cloves, ginger, or combinations thereof), cocoa, vanilla, fruit flavors, chocolate, eucalyptus, geranium, eugenol, agave, juniper, anethole, linalool, and any combination thereof.

Any suitable amount of aerosol-forming substrate, such as molasses or tobacco substrate, can be provided in the aerosol-generating article. In some preferred embodiments, from about 3 g to about 25 g of aerosol-forming substrate is contained in the aerosol-generating article. The cartridge can contain at least 6 grams, at least 7 grams, at least 8 grams, or at least 9 grams of aerosol-forming substrate. The cartridge can contain up to 15 grams, up to 12 grams, up to 11 grams, or up to 10 grams of aerosol-forming substrate. Preferably, from about 7 grams to about 13 grams of aerosol-forming substrate is contained in the aerosol-generating article.

The aerosol-forming substrate may be provided on or embedded in a thermally stable carrier. The term "thermostable" is used here to denote a material that does not substantially decompose at temperatures to which the substrate is typically heated (e.g., from about 150 °C to about 300 °C). The carrier may comprise a thin layer on which the substrate is applied to a first major surface, to a second major outer surface, or to both the first and second major surfaces. The carrier may be formed, for example, from paper or a paper-like material, a non-woven mat of carbon fibers, a lightweight open-cell metal mesh, or a perforated metal foil, or any other thermally stable polymer matrix. Alternatively, the carrier may be in the form of powder, granules, beads, grains, thin tubes, strips, or sheets. The carrier may be a non-woven web or a bundle of fibers in which tobacco components are incorporated. The nonwoven web or bundle of fibers may contain, for example, carbon fibers, natural cellulose fibers or fibers from cellulose derivatives.

In some preferred embodiments, the aerosol-forming substrate may comprise tobacco, sugar, and an aerosol forming agent. In these embodiments, the aerosol-forming substrate may comprise 10 percent to 40 percent by weight of tobacco. In these embodiments, the aerosol-forming substrate may comprise 20 percent to 50 percent by weight of sugar. In these embodiments, the aerosol-forming substrate may comprise 25 percent to 55 percent by weight of an aerosol forming agent. In some particularly preferred embodiments, the aerosol-forming substrate comprises 20 percent to 30 percent by weight of tobacco, 30 percent to 40 percent by weight of sugar, and 35 percent to 45 percent by weight of an aerosol forming agent. In some particularly preferred embodiments, the aerosol-forming substrate may comprise about 25 percent by weight of tobacco, about 35 percent by weight of sugar, and about 40 percent by weight of an aerosol forming agent. In these preferred embodiments, the tobacco may be fire-cured tobacco leaf. In these preferred embodiments, the sugar may be sucrose or invert sugar. In these preferred embodiments, the aerosol forming agent may be propylene glycol.

According to some particularly preferred embodiments of the present invention, an aerosol-generating article is provided for a hookah system, wherein said aerosol-generating article comprises: an aerosol-forming substrate composition that comprises a suspension having at least about 20 percent by weight of sugar; and one or more outer surfaces formed from a material impermeable to an RF electromagnetic field.

According to some particularly preferred embodiments of the present invention, an aerosol-generating article is provided for a hookah system, wherein said aerosol-generating article comprises: an aerosol-generating substrate; and a coating applied to at least a portion of the outer surface of the aerosol-generating substrate made of a material impermeable to an RF electromagnetic field.

According to some particularly preferred embodiments of the present invention, an aerosol-generating article is provided for a hookah system, wherein said aerosol-generating article comprises: an aerosol-generating substrate; and a wrapper enclosing the aerosol-generating substrate, wherein said wrapper comprises one or more fluid-permeable regions and one or more regions formed from a material impermeable to an RF electromagnetic field.

According to the present invention, a hookah system is proposed, comprising a hookah device, as described above, and an aerosol-generating article, which contains an aerosol-forming substrate.

In particular, according to the present invention, a hookah system is proposed, comprising a hookah device described above and an aerosol generating article described above.

In particular, according to the present invention, a hookah system is proposed, comprising a hookah device and an aerosol-generating article. The hookah device comprises: a cavity for liquid, made with the possibility of placing a volume of liquid in it, wherein said cavity for liquid has an outlet opening of free space; a cavity for an article, made with the possibility of placing an aerosol-forming substrate in it, wherein said cavity for an article is in fluid communication with the cavity for liquid; and an electromagnetic field generator, made with the possibility of generating a radio frequency (RF) electromagnetic field in the cavity for an article. The aerosol-generating article contains an aerosol-forming substrate.

In some of these embodiments, the cavity for the article comprises one or more walls formed from a material impermeable to the RF electromagnetic field, and an opening for allowing the insertion of an aerosol-generating article into the cavity for the article. In these embodiments, the aerosol-generating article may comprise an outer surface that is formed from a material impermeable to the RF electromagnetic field. The outer surface of the aerosol-generating article may be designed such that, when the aerosol-generating article is placed in the cavity for the article, one or more walls of the cavity for the article formed from a material impermeable to the RF electromagnetic field are aligned with the outer surface of the aerosol-generating article that is formed from a material impermeable to the RF electromagnetic field, to form a shell around the aerosol-generating substrate that is limited by surfaces that are formed from materials impermeable to the RF electromagnetic field.

It should be noted that the features described in relation to the hookah device or aerosol generating article can be applied to the hookah system according to the present invention.

It should also be borne in mind that individual combinations of the various features described above may be independently implemented, provided and used.

Embodiments of the present invention will now be described solely as examples with reference to the accompanying drawings, where:

Fig. 1 shows a schematic representation of a dielectric heating system;

Fig. 2 shows a schematic representation of a closed loop control system for a hookah system with a dielectric heating system according to embodiments of the present invention;

Fig. 3 shows a schematic representation of an embodiment of a hookah system with a dielectric heating system;

Fig. 4 is a schematic illustration of a heating unit of a hookah device and an aerosol generating article adapted for use with the hookah device according to one embodiment of the present invention;

Fig. 5 shows a schematic representation of heating units of different embodiments of a hookah device according to embodiments of the present invention;

Fig. 6 shows a schematic illustration of a heating unit of a hookah device and an aerosol generating article adapted for use with the hookah device according to one embodiment of the present invention;

Fig. 7 is a schematic illustration of a heating unit of a hookah device and an aerosol generating article adapted for use with the hookah device according to one embodiment of the present invention;

Fig. 8 shows a schematic illustration of a heating unit of a hookah device and an aerosol generating article adapted for use with the hookah device according to one embodiment of the present invention; and

Fig. 9 shows a schematic representation of an embodiment of a hookah system with a dielectric heating system.

Fig. 1 shows a schematic diagram of a system for implementing heating using radio frequency (RF) electromagnetic radiation, which is sometimes called dielectric heating. The system includes a radio frequency signal generator 10, a power amplifier 12 connected to the signal generator for amplifying the radio frequency signal, and antennas 16 located inside a cavity 14 for an article, wherein the antennas 16 are connected to the output of the power amplifier 12. The output of the power amplifier 12 is fed back to the signal generator 10 to provide closed-loop control. An article 18 that is to be heated is placed in the cavity 14 for an article and exposed to radio frequency electromagnetic radiation. Polar molecules inside the article 18 are matched to the oscillating electromagnetic field, so that the polar molecules oscillate under the influence of the oscillating electromagnetic field. This causes the temperature of the product to rise 18. This type of heating has the advantage of being uniform throughout the product (provided that the polar molecules are uniformly distributed). Another advantage is that dielectric heating is a non-contact form of heating that does not require heat conduction or convection from a high-temperature heating element.

Fig. 2 shows a control circuit that can be used in any of the embodiments described in Figs. 3-9. As described above, the system comprises a control circuit for an electromagnetic field generator. In the example shown in Fig. 2, the electromagnetic field generator 11 comprises a solid-state RF transistor of the LDMOS type, which performs the function of both an RF signal generator 10 and a power amplifier 12 for amplifying the generated RF electromagnetic signal. The output from the solid-state RF transistor is supplied to a radiating antenna 16, located for irradiating an aerosol-forming substrate 20, which is located inside an aerosol-generating article 18, which is located in a cavity 14 for the article.

The control circuit comprises a microcontroller 26 which can control both the frequency and the output power of the solid-state RF transistor. One or more sensors provide input data for the microcontroller 26. The microcontroller 26 regulates the frequency or the output power or the frequency and the output power of the electromagnetic field generator 11 based on the input data of the sensors. In the example shown in Fig. 2, a temperature sensor 28 is shown, installed for measuring the temperature inside the cavity 14 for the article. An antenna 30 for sampling can be provided in the cavity 14 for the article as an alternative to the temperature sensor 28 or in addition to it. The antenna 30 for sampling is designed as a receiver and can detect a disturbance of the electromagnetic field in the cavity 14 for the article, which is an indicator of the efficiency of energy absorption by the substrate 20 forming the aerosol. In addition, an RF power sensor 32 is provided for determining the output power of the electromagnetic field generator 11.

The microcontroller 26 receives signals from the RF power sensor 32, the temperature sensor 28 and the sampling antenna 30. These signals can be used to determine at least one of the following: whether the temperature is too low, whether the temperature is too high, whether a malfunction occurs, and whether there is no substrate or a substrate with inappropriate dielectric properties is used in the cavity 14 for the article.

Based on the determination made by the microcontroller 26, the frequency and power of the electromagnetic field generated by the solid-state RF transistor are adjusted, or the electromagnetic field is switched off. Typically, it is desirable to provide a stable and constant volume of aerosol, which is achieved by maintaining the aerosol-forming substrate within a certain temperature range. However, the desired target temperature may vary over time, since the composition of the aerosol-forming substrate changes, as well as the temperature of the surrounding system. In addition, the dielectric properties of the aerosol-forming substrate change with temperature, as a result of which it may be necessary to adjust the electromagnetic field as the temperature increases or decreases.

It should be clear that the features described with respect to one embodiment can be applied to other embodiments. The described embodiments provide the advantages of uniform, contactless heating of the aerosol-forming substrate in a controlled manner to produce an aerosol with certain desired properties. Compared to conventional microwave heating with a magnetron, the use of a solid-state RF transistor provides better frequency and power control, and also increases the service life.

In the embodiments described with reference to Figs. 3-8, the basic heating and control principles shown in Figs. 1 and 2 are used. In addition, in the embodiments described with reference to Figs. 3-8, a solid-state radio frequency (RF) transistor is used to perform the signal generation and power amplification functions, as shown in Fig. 1. However, it is possible to implement the described embodiments using an RF transistor for signal generation and a separate electronic component or components for providing power amplification. In addition, it is possible to implement the described embodiments using conventional microwave heating systems, such as systems that employ a magnetron.

Fig. 3 is a schematic representation of a hookah system according to one embodiment of the present invention.

The hookah device 50 comprises a vessel 52 defining a cavity 54 for liquid. The vessel 52 is configured to hold a volume of liquid in the cavity 54 for liquid and is made of a rigid optically transparent material, such as glass. In this embodiment, the vessel 52 has a substantially truncated cone shape and, when used, rests with its wide end on a flat horizontal surface, such as a table or shelf. The cavity 54 for liquid is divided into two sections: a section 56 for liquid for accommodating a volume of liquid and a free space 58 above the section 58 for liquid. The liquid filling level 60 is located on the boundary between the section 56 for liquid and the free space 58, wherein the liquid filling level 60 is designated on the vessel 52 by a dotted line marked on the outer surface of the vessel 52. The outlet opening 62 of the free space is provided on the side wall of the vessel 52 above the liquid filling level 60. The outlet opening 62 of the free space allows the fluid to be removed from the free space 58 of the cavity 54 for liquid. The mouthpiece 64 is connected to the outlet opening 62 of the free space by means of a flexible hose 66. The user can puff through the mouthpiece 64 to remove the fluid from the free space 58 for inhalation.

The hookah device 50 further comprises a heating unit 70 comprising an electromagnetic field generator in accordance with the present invention. Examples of different heating units will be discussed in more detail below with reference to Figs. 4, 5, 6, 7 and 8. The heating unit 70 is located above the vessel 52 by means of an air flow channel 72. In this embodiment, the heating unit 70 is supported above the vessel 52 by means of the air flow channel 72, however, it should be understood that in other embodiments, the heating unit 70 can be supported above the vessel 52 by means of the hookah device body or other suitable support. The air flow channel 72 extends from the heating unit 70 into the liquid cavity 54 of the vessel 52. The air flow channel 72 extends through the free space 58 and below the liquid filling level 60 into the liquid section 58. The air flow channel 72 is characterized by the presence of an outlet opening 74 in the liquid section 56 of the liquid cavity 54 below the liquid filling level 60. Such an arrangement allows air to be drawn from the heating unit 70 into the mouthpiece 64. Air can be drawn from the environment, which is outside the device 50, into the heating unit 70, through the heating unit 70, through the air flow channel 72 into the liquid volume located in the liquid section 56 of the liquid cavity 54, and then from the liquid volume into the free space 58, and then from the free space 58 of the vessel through the outlet opening 62 of the free space, through the hose 66 into the mouthpiece 64.

In use, the user can draw through the mouthpiece 64 of the hookah device 50 to obtain an aerosol from the hookah device 50. More specifically, the aerosol-generating article containing the aerosol-forming substrate can be located in a cavity for the article located inside the heating unit 70 of the hookah device 50. The heating unit 70 can operate to heat the aerosol-forming substrate inside the aerosol-generating article and to release volatile compounds from the heated aerosol-forming substrate. When the user draws through the mouthpiece 64 of the hookah device 50, a decrease in pressure occurs inside the hookah device 50, which causes the volatile compounds released from the aerosol-forming substrate to be drawn from the heating unit 70 into the air flow channel 72. Volatile compounds enter from the air flow channel 72 through the outlet opening 74 into the volume of liquid located in the section 56 for liquid of the cavity 54 for liquid. The volatile compounds are cooled in the volume of liquid and are released into the free space 58 above the liquid filling level 60. The volatile compounds in the free space 58 condense to form an aerosol, which is drawn from the free space through the outlet opening 62 of the free space and enters the mouthpiece 64 for inhalation by the user.

Fig. 4 shows schematic illustrations of the heating unit 70 of the hookah device 50 shown in Fig. 3 in combination with the aerosol generating article 90, which form a hookah system according to one embodiment of the present invention. Fig. 4a shows the heating unit 70 and the aerosol generating article 90 before the aerosol generating article 90 is inserted into the article cavity 14 of the heating unit 70. Fig. 4b shows the aerosol generating article 90 after being placed in the article cavity 14 of the heating unit 70.

As shown in Fig. 4a, the heating unit 70 comprises an outer housing 71. The outer housing 71 forms a cylindrical tube which is made open at one end for insertion of the article 90 generating an aerosol, and substantially closed at the opposite end. The outer housing 71 is formed from a material impermeable to RF electromagnetic radiation, such as aluminum.

The cavity 14 for the article is limited inside the outer housing 71 by means of the base 78 and the side wall 76, passing between the periphery of the base 78 and the open end of the outer housing 71. The cavity 14 for the article is designed with the possibility of accommodating the article 90 generating an aerosol in it, and is characterized by a shape and a size, which are selected in accordance with the shape and size of the article 90 generating an aerosol. The diameter of the base 78 of the cavity 14 for the article is smaller than the diameter of the open end of the outer housing 71, so that the side wall 76 is inclined relative to the cylindrical side wall of the outer housing 71. Accordingly, the cavity 14 for the article has essentially the shape of a truncated cone, which is open at its wide end for accommodating the article 90 generating an aerosol in it. The side wall 76 and the base 78 of the cavity 14 for the article are made of a material, which is impermeable to RF electromagnetic radiation, for example aluminum. However, the base 78 of the cavity 14 for the product contains a plurality of slots 79, configured to ensure the propagation of the RF electromagnetic field into the cavity 14 for the product through the base 78.

The cavity resonator 80 is located below the base 78 of the cavity 14 for the article. In this embodiment, the cavity resonator 80 is limited between the base 78 of the cavity 14 for the article, the substantially closed end of the outer housing 71 and the inner wall 82. The inner wall 82 extends between the periphery of the base 78 of the cavity 14 for the article and the substantially closed end of the outer housing 71. In this embodiment, the inner wall 82 is formed from a material that is impermeable to RF electromagnetic radiation, such as aluminum.

It should be understood that in other embodiments, the position of the inner wall 82 may be changed in order to change the size and shape of the cavity resonator 80. It may be necessary to change the position of the inner wall 82 in order to ensure resonation of an electromagnetic field of a particular frequency within the cavity resonator 80.

Preferably, the base 78 and the side wall 76 of the cavity 14 for the product, as well as the inner wall 82 and the outer housing 71 are characterized by the presence of polished surfaces to improve the reflection of RF radiation.

The heating unit 70 additionally comprises an electromagnetic field generator 11. The electromagnetic field generator 11 comprises a solid-state RF transistor of the LDMOS type, which performs the function of both an RF signal generator and a power amplifier for amplifying the generated RF electromagnetic signal. The output of the solid-state RF transistor is connected to the waveguide 15. The waveguide 15 passes into the volume resonator 80 through the substantially closed end of the outer housing 71. The waveguide 15 is connected to the antenna 16, which is located inside the volume resonator 80 and is configured to emit an RF electromagnetic field generated by the solid-state RF transistor into the volume resonator 80.

The electromagnetic field generator 11 is connected to a power supply unit (not shown) and a control circuit (not shown) of the hookah device, wherein the control circuit is configured to control the power supply from the power source to the electromagnetic field generator 11. In this embodiment, the power supply unit is a rechargeable lithium-ion battery, wherein the hookah device 50 comprises a power connector that allows the hookah device 50 to be connected to a power supply from the electrical network to recharge the power supply unit. Equipping the hookah device 50 with a power supply unit, such as a battery, ensures the portability of the hookah device 50 and allows it to be used outdoors or in places where power supply from the electrical network is unavailable.

The heating unit 70 is located above the vessel 52 of the hookah device 50 by means of an air flow channel 72. The air flow channel 72 is fixedly attached to the substantially closed end of the outer housing 71 of the heating unit 70. It should be noted that in other embodiments, the heating unit 70 can be removably attached to the air flow channel 72, as a result of which the heating unit 70 can be removed for cleaning or replacement, if necessary. In the substantially closed end of the outer housing 71, an opening 73 is provided for fluid communication of the volumetric resonator 80 with the air flow channel 72. A radiation shielding element (not shown) in the form of a metal mesh is arranged over the opening 73 of the outer housing 71 to substantially prevent the RF electromagnetic field from escaping from the cavity resonator 80 into the air flow channel 72 without significantly affecting the flow of fluid between the cavity resonator 80 and the air flow channel 72.

Accordingly, the heating unit 70 is designed in such a way that air can be drawn from the cavity 14 for the product into the volumetric resonator 80 through the slots 79 in the base 78, and then from the volumetric resonator 80 into the air flow channel 72 through the opening 73 and the radiation protection element.

The aerosol-generating article 90 comprises an aerosol-forming substrate 92. In this embodiment, the aerosol-forming substrate 92 is a hookah substrate containing molasses and tobacco. The aerosol-forming substrate 92 is enclosed in a container. The container has a substantially truncated cone shape that is selected in accordance with the shape of the cavity 14 for the article. The container comprises a bottom wall 94, an upper wall 96, and a side wall 98 extending between the bottom wall 94 and the upper wall 96. The bottom wall 94 and the side wall 98 of the container are formed from a material that is permeable to a fluid medium and substantially permeable to an RF electromagnetic field, such as perforated cardboard or a plastic material. This allows air to enter and exit the aerosol-generating article through the bottom wall 94 and the side wall 98, and also provides the possibility of penetration of the RF electromagnetic field into the aerosol-generating article through the bottom wall 94 and the side wall 98. The top wall 96 comprises a material impermeable to the RF electromagnetic field, such as a metal mesh. This allows air to enter the aerosol-generating article through the top wall 96 and prevents the RF electromagnetic field from penetrating beyond the aerosol-generating article through the top wall 96.

As shown in Fig. 4b, when the aerosol generating article 90 is placed in the article cavity 14 of the heating unit 70, the bottom wall 94 of the aerosol generating article 90 interacts with the bottom wall 78 of the article cavity 14, and the side wall 98 of the aerosol generating article 90 interacts with the side wall 76 of the article cavity 14. The top wall 96, formed from a material impermeable to the RF electromagnetic field, aligns and interacts with the side wall 76 of the article cavity 14, which is also formed from a material impermeable to the RF electromagnetic field. In this position, the aerosol-forming substrate 92 is surrounded by a material impermeable to the RF electromagnetic field in the region of the top wall 96 of the aerosol-generating article 90, as well as the side wall 76 and the base 78 of the cavity 14 for the article. The slots 79 in the base 78 of the cavity 14 for the article represent the only entry and exit point through which the RF electromagnetic field can penetrate into the aerosol-forming substrate 92 and leave it.

When the user takes a puff through the mouthpiece 64 of the hookah device 50, air is drawn into the hookah device 50 through the upper wall 96 of the aerosol-generating article 90. The air flow path through the aerosol-generating article 90 and the heating unit 70 is shown by arrows in Fig. 4b. Air is drawn into the aerosol-generating article 90 through the upper wall 96 of the aerosol-generating article 90, through the aerosol-forming substrate 92, and then into the volumetric resonator 80 of the heating unit 70 through the lower wall 94 of the aerosol-generating article 90 and the slits 79 in the lower wall 78 of the cavity 14 for the article. Then, from the volumetric resonator 80, air is drawn into the air flow channel 72 through the opening 73 in the outer housing 71 of the heating unit 70.

In use, electric power is supplied to the electromagnetic field generator 11 from the power supply unit when the user activates the hookah device 50. In this embodiment, the hookah device is activated by the user by pressing an activation button (not shown) provided on the outer surface of the heating unit 70. It should be understood that in other embodiments, the hookah device can be activated in another way, for example, when detecting the user taking a puff through the mouthpiece 64 by means of a puff sensor provided in the mouthpiece 64. When electric power is supplied to the electromagnetic field generator 11, the electromagnetic field generator 11 generates and amplifies an RF electromagnetic field with a frequency of 900 MHz to 2.4 GHz. The RF electromagnetic field is directed along the waveguide 15 and emitted into the cavity resonator 80 by means of the antenna 16. From the cavity resonator 80, the RF electromagnetic field propagates into the aerosol-forming substrate 92 of the aerosol-generating article 90 through the slots 79 in the lower wall 78 of the cavity 14 for the article and the lower wall 94 of the aerosol-generating article 90. The upper wall 96 of the aerosol-generating article 90 prevents the RF electromagnetic field from penetrating beyond the aerosol-generating article 90. The RF electromagnetic field causes dielectric heating of the aerosol-forming substrate 90, which releases volatile compounds. As described above, the temperature in the cavity 14 for the article can be controlled using a feedback control mechanism. In order to send a feedback signal to the control circuit of the hookah device 50, it is possible to measure the temperature inside the cavity 14 for the product or it is possible to measure another parameter indicating the temperature inside the cavity for the substrate. The control circuit is designed with the possibility of adjusting the frequency and/or amplitude of the RF electromagnetic field in order to maintain the temperature inside the cavity 14 for the product within the desired temperature range.

When the user takes a puff through the mouthpiece 64 of the hookah device 50, the volatile compounds released from the heated substrate 90 forming the aerosol are captured by the air flow through the aerosol generating article 90 and exit the aerosol generating article 90 through the volumetric resonator 80, entering the air flow channel 72. From the air flow channel, the volatile compounds are drawn through the hookah device 50 into the mouthpiece 66, and then from it, as described above.

Fig. 5 shows heating units 70 for a hookah device according to other embodiments of the present invention. The heating units 70 shown in Fig. 5 are substantially similar to the heating unit 70 shown in Fig. 4, and the same reference numerals are used to represent the same features.

The heating unit 70 shown in Fig. 5A differs from the heating unit 70 shown in Fig. 4 in that the base 78 of the cavity 14 for the article does not contain slots 79, as a result of which the RF electromagnetic field is not able to propagate from the cavity resonator 80 into the cavity 14 for the article through the base 78 of the cavity 14 for the article. In the embodiment shown in Fig. 5a, the slots 83 are formed in the inner wall 82, and the slots 77 are formed in the side wall 76 of the cavity 14 for the article. Accordingly, the RF electromagnetic field is able to penetrate into the cavity 14 for the article through the side wall 76 of the cavity 14 for the article and through the slots 83 in the inner wall 82. This arrangement changes the shape and size of the cavity resonator 80 compared to the cavity resonator 80 of the embodiment shown in Fig. 4. Changes in the size and shape of the cavity resonator 80 may be necessary when using an RF electromagnetic field with different frequencies to ensure that the RF electromagnetic field resonates within the cavity resonator 80.

The heating unit 70 shown in Fig. 5b differs from the heating unit 70 shown in Fig. 4 in that, in addition to the base 78 of the cavity 14 for the article containing the slots 79, the inner wall 82 also contains the slots 83, and the side wall 76 of the cavity 14 for the article contains the slots 77, as a result of which the RF electromagnetic field can penetrate into the cavity 14 for the article both through the base 78 and through the side wall 76 of the cavity 14 for the article. This arrangement makes it possible to create a cavity resonator 80 with an additional alternative size and shape, as a result of which a suitable cavity resonator for an RF electromagnetic field of an alternative frequency can be provided.

Fig. 6 shows a heating unit 70 for a hookah device and an aerosol generating article 90, which form a hookah system according to another embodiment of the present invention. The heating unit 70 and the aerosol generating article 90 shown in Fig. 6 are substantially similar to the heating unit 70 and the aerosol generating article 90 shown in Fig. 4, and the same reference numerals are used to represent the same features. Fig. 6a shows the heating unit 70 and the aerosol generating article 90 before inserting the aerosol generating article 90 into the article cavity 14 of the heating unit 70. Fig. 6b shows the aerosol generating article 90 after placing the heating unit 70 in the article cavity 14.

The heating unit 70 shown in Fig. 6 differs from the heating unit 70 shown in Fig. 4 in that the base 78 of the cavity 14 for the article, the side wall 76 of the cavity 14 for the article and the inner wall 82 are formed from a material that is substantially permeable to the RF electromagnetic field, such as a rigid plastic material, ceramic or clay. In this embodiment, each of the base 78 of the cavity 14 for the article, the side wall 76 of the cavity 14 for the article and the inner wall 82 is made permeable to a fluid medium, as a result of which air can pass through each of these walls. It should be understood that in other embodiments, the base 78 of the cavity 14 for the article may be permeable to the fluid, and the side wall 76 of the cavity 14 for the article and the inner wall 82 may be substantially impermeable to the fluid, or the side wall 76 of the cavity 14 for the article and the inner wall 82 may be permeable to the fluid, and the base 78 of the cavity 14 may be substantially impermeable to the fluid.

The aerosol generating article 90 shown in Fig. 6 differs from the aerosol generating article 90 shown in Fig. 4 in that the bottom wall 94 and the side wall 80 of the aerosol generating article are formed from a material impermeable to the RF electromagnetic field. In order to allow the RF electromagnetic field to enter the aerosol generating article 90 and heat the substrate 92 forming the aerosol, a plurality of slits 95 are provided in the bottom wall 94 and the side wall 90. It should be understood that in some embodiments, only one slit is provided on one of the bottom and top walls. In addition, it should be understood that the size and shape of one or more slits can vary depending on the geometry of the aerosol generating article and the hookah device. In these embodiments, the slots 95 also make the bottom wall 95 and the side wall 98 permeable to fluid so that air can be drawn through the aerosol generating article 90 and enter the heating unit 70 of the hookah device 50.

The advantage of providing the bottom wall and the side wall of the aerosol-generating article with a material that is impermeable to the RF electromagnetic field is that the number, size, shape and arrangement of the slits in the bottom wall and the side wall can be selected depending on the aerosol-generating substrate that is contained inside the aerosol-generating article. The number, size, shape and arrangement of the slits in the bottom wall and the side wall can affect the RF electromagnetic field inside the aerosol-generating article, which in turn affects the heating of the aerosol-generating substrate and the temperature to which the aerosol-generating substrate is heated.

Fig. 7 shows a heating unit 70 for a hookah device and an aerosol generating article 90 according to another embodiment of the present invention. The heating unit 70 and the aerosol generating article 90 shown in Fig. 7 are substantially similar to the heating unit 70 and the aerosol generating article shown in Fig. 4, and the same reference numerals are used to represent the same features.

The heating unit 70 shown in Fig. 7 comprises an outer housing 71 forming a cylindrical tube which is open at one end and substantially closed at the opposite end. The outer housing 71 is formed from a material which is impermeable to RF electromagnetic radiation.

The cavity 14 for the product is limited inside the outer housing 71 and has such dimensions and shape that allow the product 90 generating an aerosol to be placed therein. The heating unit is located above the vessel 52 of the hookah device 50 by means of a channel 72 for an air flow that passes into the substantially closed end of the outer housing 71 of the heating unit 70 for fluid communication of the cavity 14 for the product with the vessel 52 of the hookah device 50. A radiation protection element (not shown) made in the form of a metal mesh is located in the channel 72 for an air flow to prevent the RF electromagnetic field from escaping from the cavity 14 for the product through the channel 72 for an air flow.

The heating unit 70 shown in Fig. 7 differs from the heating unit 70 shown in Fig. 4 in that the heating unit 70 shown in Fig. 7 comprises a closure 75. The closure 75 is movable relative to the open end of the outer housing 71 of the heating unit 70 to substantially close said open end. The closure 75 comprises an outer housing similar to the outer housing 71 of the heating unit, which is made of the same material impermeable to the RF electromagnetic field, and has such a size and shape that it can be combined and engaged with the outer housing 71 to close the open end. The closure 75 is connected with the possibility of rotation to the outer housing 71 by means of a hinge and can rotate between an open position, as shown in Fig. 7a, and a closed position, as shown in Fig. 7b. When the closure 75 is in the open position, the open end of the outer body 71 is open for inserting the aerosol-generating article 90 into the cavity 14 for the article, and also for removing the aerosol-generating article 90 from the cavity 14 for the article. When the closure 75 is in the closed position, the cavity 14 for the article is surrounded by a material that is impermeable to the RF electromagnetic field, as a result of which the RF electromagnetic field cannot spread beyond the cavity 14 for the article.

In this embodiment, the closure 75 also comprises an electromagnetic field generator 11, implemented as a solid-state RF transistor of the LDMOS type, a waveguide 15, connected to the solid-state RF transistor, a cavity resonator 80 and an antenna 16, connected to the waveguide 16 and located in the cavity resonator 80. In this embodiment, the cavity resonator 80 comprises a substantially cylindrical body made of a dielectric material, enclosed in a metal outer package. The metal outer package of the cavity resonator 80 comprises a pair of slits 79, which allow the RF electromagnetic field, generated by the electromagnetic field generator 11 and directed into the cavity resonator 80, to propagate from the cavity resonator 80 into the cavity 14 for the article, when the closure 75 is in the closed position. A control circuit (not shown) and a battery (not shown) are also located within the closure 75 to provide a controlled supply of electrical energy to the electromagnetic field generator 11.

It should be understood that in some embodiments, the hookah device may contain electrical components in the vessel 50 or mouthpiece 64 that require power from a battery or control signals from a control circuit. In these embodiments, a flexible circuit or wire may extend from the control circuit and battery located in the closure 75 through the hinge to components located elsewhere in the hookah device 50.

In this embodiment, the closure 75 also comprises an air inlet (not shown) formed as a fluid-permeable region made of a material that is impermeable to an RF electromagnetic field. The air inlet allows air to be drawn into the cavity 14 for the article when the closure 75 is in the closed position.

This embodiment has an extremely advantageous configuration, since it is simple to manufacture and contains a relatively small number of components. In addition, since the cavity 14 for the article is completely covered with a material impermeable to the RF electromagnetic field, it is not necessary that any outer surfaces of the article 90 generating an aerosol be formed from a material impermeable to the RF electromagnetic field. Since the article 90 generating an aerosol is typically a disposable component of the hookah system, this can reduce the cost of manufacturing the article 90 generating an aerosol.

Fig. 8 shows a heating unit 70 for a hookah device 50 and an aerosol generating article 90 according to another embodiment of the present invention. The heating unit 70 and the aerosol generating article 90 shown in Fig. 8 are substantially similar to the heating unit 70 and the aerosol generating article 90 shown in Fig. 7, and the same reference numerals are used to represent the same features. Fig. 7a shows the heating unit 70 and the aerosol generating article 90 before inserting the aerosol generating article 90 into the article cavity 14 of the heating unit 70. Fig. 7b shows the aerosol generating article 90 after placing the heating unit 70 in the article cavity 14.

The heating unit 70 shown in Fig. 8 differs from the heating unit 70 shown in Fig. 7 in that the heating unit 70 shown in Fig. 8 comprises the electromagnetic field generator 11, the waveguide 15, the antenna 60 and the cavity resonator 80 in the outer housing 71, and not in the closure 75. In this embodiment, the closure 75 is simply a coating that covers the cavity 14 for the article to prevent the RF electromagnetic field from escaping from the cavity 14 for the article.

The volumetric resonator 80 of the heating unit 70 shown in Fig. 8 comprises a substantially ring-shaped body made of a dielectric material enclosed in a metal outer container. The volumetric resonator 80 comprises a conical internal passage which widens towards the open end of the outer housing 71. In this embodiment, the internal passage of the volumetric resonator 80 substantially defines a cavity 14 for an article which is designed to accommodate therein an article 90 generating an aerosol, substantially in the form of a truncated cone. A plurality of slots 79 are formed in the metal outer container of the volumetric resonator 80 on the side of the internal passage to allow the RF electromagnetic field to propagate into the cavity 14 for an article.

In this embodiment, the air flow path through the heating unit 70 extends substantially along the entire cavity 14 for the article in the direction of the air flow channel 72, wherein the RF electromagnetic field propagates from the cavity resonator 80 into the cavity 14 for the article in a direction substantially across the air flow. Such an arrangement ensures that the device generating the electromagnetic field is removed from the air flow path through the heating unit 70. This type of arrangement can facilitate the control of the draw resistance along the heating unit 70. This type of arrangement can also facilitate the control of the temperature of the device generating the electromagnetic field, since the temperature of the device generating the electromagnetic field is less likely to fluctuate during use as a result of the user puffing through the hookah device and drawing air through the device generating the electromagnetic field.

Fig. 9 shows a hookah system according to another embodiment of the present invention. This hookah system is similar to the hookah system shown in Fig. 3, and like reference numerals are used to represent like features.

The hookah device 50 comprises a vessel 52 defining a cavity 54 for liquid, which is divided into two sections, namely a section 56 for liquid containing a volume of liquid, and a free space 58 above the section for liquid. In this embodiment, the vessel 52 is substantially cylindrical. The liquid filling level 60 is defined along the boundary between the section 56 for liquid and the free space 58 and is indicated by a dotted line 60 on the outer surface of the vessel 52. The outlet opening 62 of the free space is provided on the side wall of the vessel 52 above the liquid filling level and is designed to ensure drawing of the fluid from the cavity for liquid through the free space 58. The mouthpiece 64 is connected to the outlet opening 62 of the free space by means of a flexible hose 66.

The vessel 52 is located on the heating unit 70, which in this embodiment is a cylindrical block characterized by a diameter that is substantially equal to the diameter of the vessel 52. Accordingly, when the vessel 52 and the heating unit 70 are combined with each other for use, the hookah device 50 forms a substantially cylindrical block.

The heating unit 70 is substantially similar to the heating unit shown in Fig. 7, and like reference numerals are used to represent like features.

The heating unit 70 comprises an outer housing 71 formed from a material impermeable to RF electromagnetic radiation. The outer housing 71 forms a cylindrical tube which is substantially closed at both ends. A door (not shown) is formed in a side wall of the outer housing 71 and is connected to the side wall by means of a hinge. The door is configured to rotate between an open position and a closed position so that aerosol-generating articles can be inserted into the heating unit 70 and removed from the heating unit 70. The door is configured to be locked in the closed position to ensure that the door does not open during operation of the hookah device 50, wherein the door is formed from a metal mesh impermeable to RF electromagnetic radiation, but permeable to a fluid medium, as a result of which ambient air can be drawn into the heating unit 70.

The cavity 14 for the article is defined inside the heating unit 70 for receiving the article 90 generating the aerosol therein. In this embodiment, the cavity 14 for the article has a substantially truncated cone shape, so that the cavity 14 for the article is configured to receive the article 90 generating the aerosol therein, which is substantially in the shape of a truncated cone. The cavity 14 for the article is located above the cavity resonator 80. In this embodiment, the cavity resonator 80 comprises a substantially cylindrical body made of a dielectric material, enclosed in a metal outer container. The metal outer container of the cavity resonator 80 comprises a pair of slits 79, which are provided to allow the RF electromagnetic field to propagate from the cavity resonator 80 into the cavity 14 for the article.

An electromagnetic field generator 11, implemented in the form of a solid-state RF transistor of the LDMOS type, is provided below the volumetric resonator 80. The output of the electromagnetic field generator 80 is connected to a waveguide 15, implemented in the form of a waveguide tube for directing electromagnetic waves. The waveguide 15 is intended for directing the RF electromagnetic field generated by the electromagnetic field generator 11 to the antenna 16, which is located in the volumetric resonator 80. With such an arrangement, the RF electromagnetic field generated by the electromagnetic field generator 11 is directed to the volumetric resonator 80 and spreads from the volumetric resonator 80 through the slots 79 into the cavity 14 for the article for heating the substrate forming the aerosol, located in the cavity 14 for the article. The electromagnetic field generator 11 is connected to a control circuit (not shown) and a lithium ion battery (not shown), which are arranged and configured to control the supply of electric power to the electromagnetic field generator 11 in order to control the RF electromagnetic field generated by the electromagnetic field generator 11.

An air flow passage 72 extends from the article cavity 14 into the vessel 52 to a location in the liquid section 56 that is below the liquid fill level 60. The air flow passage 72 fluidly connects the article cavity to the liquid section 56 of the vessel 52. In order to prevent liquid from flowing out of the liquid section 56 into the article cavity 14 through the air flow passage 72 under the action of gravity, a one-way valve (not shown) is located in the air flow passage 72 in the region of the opening 73 between the heating unit 70 and the vessel 52. The one-way valve does not allow fluid to flow from the vessel 52 into the heating unit 70, and a minimum pressure is required before fluid can flow from the heating unit 70 into the vessel 52.

In use, when the user takes a puff through the mouthpiece 64, ambient air is sucked into the hookah device 50 through the mesh door (not shown) and then into the cavity 14 for the product. A puff sensor (not shown) provided in the cavity 14 for the product and connected to the control circuit and the battery determines that the user takes a puff through the mouthpiece 64 when air enters the cavity 14 for the product. When the puff sensor detects that the user takes a puff through the mouthpiece 64, the control circuit supplies electric power from the battery to the electromagnetic field generator 11, which causes the RF electromagnetic field to spread into the cavity 14 for the product and heat the aerosol-forming substrate in the aerosol-generating article 90. As a result of heating the aerosol-forming substrate, volatile compounds are released. Air drawn into the cavity 14 for the article takes with it the released volatile compounds, wherein the captured volatile compounds pass through the channel 72 for the air flow, and then through the one-way valve into the section 56 for the liquid of the vessel 52. The volatile compounds are cooled in the volume of the liquid in the section 56 for the liquid and are released from the liquid into the free space 58, where they condense to form an aerosol. The aerosol is drawn from the free space 58 through the outlet opening 62 of the free space, passes through the hose 66 and then enters the mouthpiece 64 for inhalation by the user.

It should be understood that the embodiments described above are merely illustrative embodiments, and various other embodiments according to the present invention are also envisaged. For example, it should be understood that the embodiments of the heating unit described above can be used with any suitable configuration of a hookah device, such as the devices shown in Figs. 3 and 9. For example, it should also be understood that the vessels, aerosol-forming articles, and other elements of the hookah systems according to the present invention can have any desired shapes and sizes. For example, the liquid inside the liquid sections of the hookah devices is preferably water, but can be any other suitable liquid.

Claims (20)

1. A hookah device for heating an aerosol-forming substrate to generate an aerosol, wherein the hookah device comprises: a liquid cavity containing a volume of liquid through which the aerosol generated by the hookah device passes before being inhaled by the user, wherein said liquid cavity has a free space outlet; a cavity for an article configured to accommodate an aerosol-generating article containing an aerosol-forming substrate, wherein said cavity for an article is in fluid communication with the cavity for a liquid; and an electromagnetic field generator configured to generate a radio frequency (RF) electromagnetic field in a cavity for an article, wherein said electromagnetic field generator comprises a magnetron or a solid-state RF transistor, wherein the cavity for the article comprises one or more outer walls formed from a material impermeable to an RF electromagnetic field, and wherein one or more slots are formed in one or more outer walls. 2. A hookah device according to paragraph 1, characterized in that the electromagnetic field generator contains a solid-state RF transistor, wherein said solid-state RF transistor is designed with the ability to generate and amplify an RF electromagnetic field. 3. A hookah device according to any one of paragraphs 1-2, characterized in that the cavity for the article contains an open end for placing an aerosol-forming article, which contains an aerosol-forming substrate and a substantially closed end. 4. A hookah device according to any one of paragraphs 1-3, additionally containing an antenna connected to the electromagnetic field generator and configured to direct the RF electromagnetic field. 5. A hookah device according to item 4, characterized in that the antenna is located at least partially in the cavity for the product. 6. A hookah device according to any one of paragraphs 1-5, additionally containing a volumetric resonator between the cavity for the product and the electromagnetic field generator. 7. A hookah device according to any one of paragraphs 1-6, characterized in that it contains a sensor located in the cavity for the product or adjacent to it, wherein said sensor provides a signal characterizing the temperature in the cavity for the product, and a controller connected to receive a signal from the sensor and connected to control the electromagnetic field generator depending on the signal coming from the sensor. 8. A hookah system comprising a hookah device according to any one of paragraphs 1-7, and an aerosol-generating article that contains an aerosol-forming substrate. 9. A hookah system according to claim 8, characterized in that the aerosol-forming substrate contains tobacco. 10. A hookah system according to claim 8 or 9, characterized in that the aerosol-generating product contains one or more external surfaces formed from a material that is impermeable to an RF electromagnetic field. 11. A hookah system according to claim 10, characterized in that one or more slots are formed in one or more external surfaces formed from a material that is impermeable to an RF electromagnetic field. 12. A hookah system according to claim 10 or 11, characterized in that the material, impermeable to the RF electromagnetic field, forms a coating on one or more external surfaces. 13. An aerosol-generating article for a hookah system according to any of paragraphs 8-9, wherein said aerosol-generating article comprises: aerosol-forming substrate; and one or more outer surfaces formed from a material impermeable to an RF electromagnetic field, wherein said material impermeable to an RF electromagnetic field is permeable to a fluid medium. 14. An aerosol-generating article according to paragraph 13, characterized in that the material impermeable to the RF electromagnetic field is a metal mesh.