WO2014013243A1

WO2014013243A1 - Consumable cartridge suitable for holding unstable liquids

Info

Publication number: WO2014013243A1
Application number: PCT/GB2013/051901
Authority: WO
Inventors: Abdelouahed Ezbiri
Original assignee: Moving Sun Ltd
Current assignee: Moving Sun Ltd
Priority date: 2012-07-16
Filing date: 2013-07-16
Publication date: 2014-01-23
Anticipated expiration: 2015-01-16
Also published as: GB201212607D0

Description

Consumable Cartridge Suitable for Holding Unstable Liquids

Field. of the Invention The present invention relates a consumable cartridge for connection to an operative device, wherein the consumable cartridge contains a liquid reactant for use in the device. In particular, the invention relates to the containment of unstable liquid reactants within a consumable cartridge. Background to the Invention

The use of hydroxyl radicals as an airborne disinfectant in hospitals and other indoor environments is now becoming widespread. The disinfectant property of hydroxy! radicals has been known since the publication of research conducted in the 1960s at Porton Down in the UK and TNO in

The Netherlands. Air based disinfection using hydroxyl radicals mimics a naturally occurring process in the outdoor environment, and so the

concentration of hydroxyl radicals in the air is sometimes referred to as the "open air factor".

One example of an apparatus for generating hydroxyl radicals for airborne disinfectant is described in WO 2005/026044. A further apparatus is described in WO 2008/125879. The essential components of the apparatuses described in these documents are a supply of a reactant, specifically a supply of olefin, such as terpene, and a supply of ozone. An olefin vapour is produced from the supply of olefin and is mixed and reacts with the ozone to produce hydroxyl radicals. Hydrogen peroxide is an alternative reactant that can be used to react with ozone to produce hydroxyl radicals. The reactant supply is consumed and will become exhausted during use. It therefore needs to be replenished. The reactant is typically supplied in a consumable cartridge. The rate at which the reactant supply is used up depends on the pattern of usage of the apparatus and the size of the supply, but in view of a number of factors, including the physical size of the device, a reactant refill is typically designed to last a few months. In the system as described in WO 2008/125879, for example, cartridges containing a supply of olefin sufficient to last approximately three months. These cartridges have to maintain the reactant in good condition both during use and prior to use, while in storage.

One problem with existing cartridges is leakage of reactant before and during use. The cartridges are typically formed from rigid plastic and are shaped to fit into a particular slot in a base unit that provides the necessary airflow and power to generate ozone. Ultrasonic welding is used to seal the walls of the cartridge and this needs extremely high precision parts and fixtures. Any variability in the parts can result in bad welds and in turn in leaking cartridges.

It is an object of the present invention to address the containment of liquid reactants inside cartridges for use in operative devices, such as devices for generating hydroxyl radicals.

Summary of the Invention The present invention is defined in the appended independent claims, to which reference should be made. Preferred features of the invention are set out in the dependent claims.

In a first aspect, the invention provides a consumable cartridge comprising: a rigid housing, the rigid housing configured to engage an operative device; and

a flexible bag fixed to the rigid housing and containing a liquid for use in the operative device, wherein the flexible bag is liquid tight and is formed, at least in part from a material that is gas permeable.

The flexible bag is preferably disposed within the rigid housing. The flexible bag may comprise an outlet accessible from outside the rigid housing. The outlet may comprise a rigid spout element. The spout element may be snap fitted or otherwise mechanically fixed to the rigid housing. The flexible bag may further comprise a removable cap covering the outlet to maintain the bag liquid tight prior to use. Liquid tight bags having a spout, around which the bag is sealed, are widely available and the sealing process is a well established technology. It is possible to produce these bags relatively inexpensively when compared to the cost of producing a liquid tight rigid cartridge housing.

The flexible bag may further comprise a capillary wick to draw the liquid to the outlet.

The flexible bag may comprise one or more walls formed from a breathable material or materials. The flexible bag may be formed from a plurality of layers of material.

The liquid may contain a reagent that reacts with ozone to provide hydroxy I radicals, such as an olefin (for example D-limonene) or hydrogen peroxide.

The consumable cartridge may further comprise an ozone generator fixed to the rigid housing. Preferably, the ozone generator is an electrically powered ozone generator, such as a corona discharge ozone generator or a plasma ion generator. Other types of electrically powered ozone generator can be used, for example a cold plasma ozone generator, a UV type ozone generator, or a stainless steel filament in a dielectric tube. Preferably, the consumable cartridge includes at least one electrical contact configured to allow connection of an external power supply to the ozone generator.

The consumable cartridge may include a transformer and other electronic components. The transformer is used to provide the required voltage to the ozone generator, which is typically between 10 and 20 kV, Alternatively, the consumable cartridge may be configured for use with an operative device which contains an appropriate high voltage power source or a transformer for converting an external or battery supply voltage. As an alternative, the consumable cartridge may include a battery together with a suitable transformer.

When the reactant is hydrogen peroxide the consumable cartridge or the operative device unit may advantageously further comprise an ion generator. The interaction of ions with ozone and hydrogen peroxide increases the yield of hydroxy! radicals and so reduces both the amount of ozone that needs to be generated and the amount of ozone that remains unreacted with the hydrogen peroxide.

The ion generator may be a separate device to the ozone generator and may be in the operative device or in the consumable cartridge. However, advantageously, the ion generator may be the same device as the ozone generator. In this case, the ozone generator may be a plasma ion generator. in a second aspect, the invention provides a method of manufacturing a consumable cartridge, comprising:

forming a liquid tight flexible bag, the flexible bag being gas permeable and having an outlet;

filling the flexible bag with a liquid reagent; and

fixing the bag to a rigid cartridge housing.

The method may further comprise the step of placing a capillary wick inside the flexible bag. The step of fixing the bag to the rigid housing may comprise snap fitting a spout or collar on the bag with a corresponding feature on the rigid housing.

In a third aspect, the invention provides a hydroxy! radical generating apparatus, comprising;

a consumable cartridge and a base unit, the consumable cartridge configured to engage the base unit and containing a liquid comprising a reagent that reacts with ozone to produce hydroxy! radicals;

a supply of ozone disposed in the base unit or in the consumable cartridge or in a second cartridge; wherein the consumable cartridge comprises a rigid housing, the rigid housing configured to engage the base unit; and

a flexible bag fixed to the rigid housing and containing the liquid, wherein the flexible bag is liquid tight and is formed, at least in part from a material that is gas permeable.

The reagent may be an olefin (for example D-limonene) or hydrogen peroxide.

The invention also provides a consumable cartridge comprising:

a rigid housing, the rigid housing configured to engage an operative device; and

a inner container fixed to the rigid housing and containing a liquid for use in the operative device, wherein the inner container is liquid tight and is formed, at least in part from a material that is gas permeable.

The invention also provides a consumable cartridge comprising:

a flexible bag having an outlet aperture and containing a liquid; and a capillary wick coupled to the outlet aperture. The flexible bag is liquid tight and may advantageously be formed, at least in part, from a material that is gas permeable. The flexible bag preferably comprises a rigid spout or collar for engagement with a rigid housing. The rigid spout may also retain the wick.

The invention provides a consumable cartridge comprising:

a flexible bag fixed to the rigid housing and containing a liquid for use in the operative device, wherein the flexible bag Is liquid tight and has a sealable outlet spout. A capillary wick may be provided within the bag and coupled to the outlet spout.

Brief description of the drawings

Embodiments of the present invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is an exploded view of a cartridge in accordance with an embodiment of the invention; Figure 2 is a perspective view of the cartridge of Figure 1 , in an assembled condition;

Figure 3 is a perspective view of the cartridge of Figure 1 , in an assembled condition, with the cap removed; and

Figure 4 is an exploded perspective view of a cartridge as shown in Figures 1 to 3 together with a base unit and cover into which the cartridge is received in use. Detailed description

Figure 1 is an exploded view of a cartridge in accordance with an embodiment of the invention. The cartridge comprises a flexible bag 10 formed from a three layer construction of breathable films. The bag comprises an inner layer of cast extruded polypropylene film, which is 80 micron thick, an intermediate layer of Nylon, which is 15 microns thick, and an outer layer of Polyethylene terephthalate film, which is 12 microns thick. The bag is liquid tight and sealed around a plastic spout 12 through which liquid in the bag can pass to and from the interior of the bag. The spout 12 is closed by a cap 16, which fits to the spout using a screw fitting or a snap fitting. The cap is formed from moulded plastic. The design of the bag is consistent with a commonly used packaging product, generically known as a spout bag.

The spout moulding 12 is designed to retain a wick 14. The lower end of the wick 14 protrudes into the bag and is in contact with a liquid reagent in the bag 10. The wick 14 may be formed from any suitable fibrous material, such as polypropylene fibre. In an assembled state, the top of the wick 14 protrudes from the top surface of the spout moulding12, but is retained within the cap 16. The bag is received within a main body 18 of a rigid cartridge housing. The spout moulding is designed to be securely attached to the underside of a lid 20 of the rigid cartridge housing using a snap fit detail on the moulding of the spout moulding and a corresponding moulded detail on the lid moulding. This also locates the spout moulding vertically into the lid moulding. The spout moulding incorporates a feature that engages with a feature on the underside of the lid moulding so that when in position the spout moulding is prevented from moving in a radial fashion such as when removing the cap with a twisting motion.

This design allows for the spout bag 10 to be filled through the spout moulding 12 with a liquid reagent. The wick 14 is then inserted into the neck of the spout moulding 12 and the spout bag closed with the cap 16. The filled bag is then assembled onto the underside of the lid moulding 20 and the lid moulding 20 retaining the spout bag 10 secured inside the cartridge body 18 so that the spout bag assembly is contained within the cartridge. Figure 2 is a perspective view of the cartridge in an assembled condition.

The spout moulding and lid moulding are designed so that when the two are assembled the top surface of the spout moulding is coincident with the top surface of the lid when the closure cap is removed. This is illustrated in Figure

3.

In this example, the cartridge is intended for use with a base unit device to produce hydroxyl radicals and dispense them into the surrounding

environment. The cartridge and base unit are of the same type as those described in WO2012059726, the contents of which are incorporated herein by reference. Figure 4 is an exploded view of the cartridge and base unit, illustrating how they engage with each other.

The bag 10 contains a hydrogen peroxide solution. Hydrogen peroxide reacts with ozone to produce hydroxyl radicals. In this example an ozone generator is also provided in the cartridge. However, the ozone generator may be provided in the base unit. The ozone generator is a corona discharge ozone generator that generates ions as weii as ozone in operation, Suitable corona discharge ozone generators, such as plasma ion generators, are available from Trump Electronics of East Yongfu Road, Tianchang, China 201 100

(www.trumpxp.cQm) and may be formed from aluminium oxide or calcium silicate for example. The cartridge includes electrical contacts 22 for connecting to power supply in the base unit. The base unit includes a power supply socket for connection to a power supply, typically a 12V DC supply adapted from the mains. The power socket is electrically connected to contacts on the base unit that interface with the contacts 22 on the cartridge. A suitable configuration for the base unit 30 is described in detail in WO2012059726.

The generation of ions as well as ozone is beneficial when using hydrogen peroxide as a reactant. The ozone reacts with the hydrogen peroxide in a process referred to as the peroxone process. But the ions speed the reaction and provide another reaction pathway. Accordingly the cartidge may include an Ion generator, as described in WO2012059726.

The cap 16 is first removed from the cartridge before the cartridge is inserted into a slot 34 in the base unit 30. A covering shell 32 is fitted over the cartridge to provide a more aesthetically pleasing appearance. In use, hydroxy! radicals are dispensed from the base unit through outlet 36. The operation of the base unit in conjunction with a cartridge of this type is described in detail in

WO2012059726. Hydrogen peroxide is unstable and decomposes spontaneously into water and hydrogen. The speed of decomposition may depend on impurities in the solution, but it is inevitable that there will be some gas developed with the bag 10, and depending on the length of time between filling of the bag and exhaustion of the hydrogen peroxide, can be significant. For this reason at least a portion of the bag 10 is formed from a breathable, i.e. gas permeable, material. In the described embodiment the flexible material of the bag 10 is entirely formed from breathable films. The outer layer of polyethylene terephfhalate film is chosen to provide an aesthetically pleasing outer surface that is easy to print onto. The intermediate layer of Nylon provides mechanical strength and barrier properties. The inner layer of polypropylene is chosen for barrier properties and compatibility with hydrogen peroxsde. It is important that the bag or a portion of the bag is breathable so thai gases generated within the bag can escape. Otherwise the bag could burst.

Different materials may be chosen for the bag depending on the liquid reagents being contained. In another example, the liquid contains D-iimonene, which reacts with ozone to produce hydroxy! radicals, in this example the bag is again formed from a three layer construction, with the same outer and intermediate layers as described in the example above. However, the inner layer is formed from 100 micron thick low density polyethylene film.

Claims

1. A consumable cartridge comprising:

2. A consumable cartridge according to any preceding claim, wherein the liquid contains a reagent that reacts with ozone to provide hydroxy I radicals.

3. A consumable cartridge according to claim 1 or 2, wherein the flexible bag is disposed within the rigid housing.

4. A consumable cartridge according to claim 3, wherein the flexible bag comprises an outlet accessible from outside the rigid housing.

5. A consumable cartridge according to claim 4, wherein the outlet comprises a rigid spout element.

6. A consumable cartridge according to claim 5 or 6, further comprising a removable cap covering the outlet.

7. A consumable cartridge according to any preceding claim, wherein the flexible bag comprises a capillary wick.

8. A consumable cartridge according to any preceding claim, wherein the flexible bag comprises one or more walls formed from a breathable material.

9. A consumable cartridge according to any preceding claim, wherein the liquid contains hydrogen peroxide.

10. A consumable cartridge according to any preceding claim, further comprising an ozone generator fixed to the rigid housing.

1 1 . A method of manufacturing a consumable cartridge, comprising:

filling the flexible bag with a liquid reagent; and

fixing the bag to a rigid cartridge housing.

12. A method according to claim 1 1 , wherein the liquid reagent is a reagent that reacts within ozone to produce hydroxyl radicals.

13. A method according to claim 1 1 , further comprising the step of placing a capillary wick inside the flexible bag.

14. A hydroxyl radical generating apparatus, comprising:

a supply of ozone disposed in the base unit or in the consumable cartridge or in a second cartridge;

wherein the consumable cartridge comprises a rigid housing, the rigid housing configured to engage the base unit; and

15. A hydroxyl radical generating apparatus according to claim 14, wherein the reagent is hydrogen peroxide.