DE20122041U1 - Aerosol production appliance incorporates container, injector, throttle controlled by control unit, and sensor determining difference in pressure between container's pressure and supply pressure - Google Patents

Abstract

The pressurized container (4) contains the injector (5) and in it is produced an aerosol from a liquid and from a carrier gas supplied under pressure. the quantities of carrier gas and liquid in the injector are controlled by being supplied via at least one throttle (8,9). The throttle is controlled by a control unit (10).The difference in pressure between the container's pressure and the supply pressure is determined by a sensor (11).

Description

The invention relates to a device for aerosol generation according to the generic term of claim 1.

Such a device is from the DE 196 543 21 (A1) known. The aerosols produced in this way can be used in inhalers in medical technology, humidifiers in household technology and in particular for the cooling and lubrication of tools or workpieces.

The device of the DE 196 543 21 comprises an injector device arranged in a pressure vessel for generating an aerosol from a liquid and a carrier gas. The liquid forming a lubricant, preferably oil, is sucked in by means of a vacuum and atomized in a jet of the carrier gas, preferably air. The carrier gas is introduced under pressure into a chamber of the injector device, a vacuum being created as a result of the enlargement of the cross section, which conveys the liquid from its line, which also opens into the chamber, and feeds the carrier gas stream at high speed. The liquid is carried along with the carrier gas flow and is distributed finely distributed on the structured surface of an impact body. The liquid film is atomized into an aerosol of small particle size on the surface of the impact body.

In the lid of the pressure vessel a connecting line forming an aerosol outlet is provided, via which Aerosol from the pressure vessel is removed to at least one tool or workpiece for cooling and for lubrication.

The supply of the liquid and the carrier gas to the injector device takes place via a line in which a control valve is provided. Via the control valves a pressure control, both when supplying the liquid as well as when feeding of the carrier gas.

With the device designed in this way continuous aerosol generation is guaranteed as long as the Aerosol outlet a sufficiently large amount of aerosol from the pressure vessel promoted becomes. This is the case if those connected to the aerosol outlet Tools have at least a minimum diameter, which is typically is 10 mm.

With smaller tool diameters the amount of aerosol withdrawn per unit of time is so small that the tank pressure inside the pressure vessel increases continuously, with the tank pressure becoming asymptotic the supply pressure with which the carrier gas is supplied via an external carrier gas supply is fed to the injector device, approaches.

This increase in pressure can over the Pressure regulation on the control valves cannot be prevented. Especially about that Control valve for the carrier gas supply pressure control can no longer be carried out because the supply pressure for the carrier gas according to the design of the external carrier gas supply is.

This makes it independent of the pressure control through the control valve to supply liquid to the Differential pressure between supply pressure and tank pressure so low that the flow rate of the carrier gas supplied to the injector device is no longer large enough is to fluid to suck. This means that only carrier gas without liquid is left fed to the injector device, so that the aerosol generation breaks off.

In such cases a Maintaining aerosol generation is known in devices in the pressure vessels a bypass installed. about the bypass becomes inadmissible pressure increase in the pressure vessel Aerosol discharged, which causes the container pressure to drop again.

Apart from the fact that from the pressure vessel rejected aerosol for tool lubrication is no longer available and undesirably reduces the yield of aerosol generation such a bypass subordinate procedural steps to catch and discarding the rejected aerosol. This makes the constructive The effort of the device for aerosol generation undesirably increased.

The invention has for its object a To design the device of the type mentioned in such a way that for as possible wide range of aerosol withdrawals a reliable aerosol generation guaranteed is.

To solve this task are the Features of claim 1 provided. Advantageous embodiments and appropriate further training the invention are described in the subclaims.

In the device according to the invention for aerosol generation, an injector device in a pressure vessel and used at least one choke. In the injector device from a carrier gas supplied under a supply pressure and a liquid creates an aerosol. The carrier gas and the liquid the injector device is in each case via at least one throttle of the throttle system.

By opening and closing the invention Throttle system depending of the differential pressure between the supply pressure and the pressure in pressure vessel becomes one equally reliable Obtain aerosol generation with both small and large aerosol withdrawals. It is particularly advantageous that in the entire area of Aerosol purchase quantities are the proportion of carrier gas and liquid can be specified in a targeted and reproducible manner in the aerosol.

This advantage is essentially based on the feeder of carrier gas and liquid optimally in the injector device to the aerosol withdrawal process is adjusted.

The units supplied with aerosol, tools in particular, are about at least one aerosol outlet connected to the device. The connection of a tool to an aerosol outlet has one effective aerosol acceptance cross-section, depending on the training and operating mode of the tool a certain volume flow of aerosol guided becomes. The tool itself forms a throttle, via which a certain volume flow of aerosol is promoted.

The basic idea of the invention is by means of a differential pressure control via the throttle system, the volume flows of the carrier gas and the liquid, which are introduced into the injector device to adapt to the aerosol withdrawal amounts. The pressure of the carrier gas is not regulated nor the pressure of the liquid. Rather, there is a dynamic pressure change on the throttle system in the carrier gas supply and the hydration.

This dynamic pressure change has a stabilizing effect on aerosol production and supply of the connected tool. Self-stabilization takes place in particular aerosol generation and supply in the event of changes over time Aerosol withdrawal amounts.

For example, at the aerosol outlet as a tool to be cooled and the drill to be lubricated is connected via the Aerosol discharge promoted a constant amount of aerosol as long as its operating state unchanged remains. Accordingly, over the throttle system determines certain volume flows of carrier gas and liquid promoted. Changes the operating state of the drill, for example in that it into a workpiece penetrates, so the aerosol decrease cross section, so that a smaller amount of aerosol is added to the tool. Because the supply of liquid and carrier gas not pressure-controlled to the injector device, but quantity-controlled done, increased the aerosol pressure before the aerosol outlet, causing a larger volume flow aerosol to the tool becomes, which in turn leads to pressure stabilization inside the device leads to aerosol generation.

The quantity control depends on the differential pressure monitoring. This comprises a sensor which measures the pressure difference ΔP between the supply pressure P _V with which the carrier gas is supplied to the injector device and the container pressure P _B in the pressure container in which the injector device is arranged.

If the differential pressure ΔP is above a first limit value ΔP ₀ , corresponding volume flows of carrier gas and liquid are supplied to the injector device with a predetermined setting of the throttle system. If the differential pressure ΔP drops so that it is below ΔP ₀ , the throttle system is closed and aerosol generation is prevented. Aerosol generation is only resumed when the differential pressure exceeds a further limit value ΔP ₁ , which is above ΔP ₀ . The difference between ΔP ₁ and ΔP ₀ forms a switching hysteresis. This prevents unnecessary switching operations and thus leads to stabilization of aerosol generation.

This control makes it long-term stable Aerosol generation, both for very small as well as very large Obtained aerosol withdrawals. Accordingly, can the aerosol outlets both Tools with large as well as small aerosol acceptance cross sections. there can in particular also tools with tool diameters of less than 1.5 mm, which are used for example in deep hole drilling, reliable be supplied with aerosol. In particular, it is excluded that in the pressure vessel pressure conditions rule that make aerosol generation impossible.

It is also particularly advantageous that the volume flows of the carrier gas and the liquid over a fixed predetermined setting of the throttle system can be specified and while the operation of the device need not be changed.

In an advantageous embodiment the invention is the control of the device and in particular the setting of the throttle system centrally via a control unit.

The throttle system includes from the control unit controlled diaphragm arrangements with one predetermined number of apertures, the above the control unit selectively opened or can be closed.

There is at least one nozzle with an orifice arrangement for the supply of carrier gas and at least one other nozzle with a further aperture arrangement for the supply of liquid intended.

Another major advantage of the method according to the invention is that with this aerosol at predetermined time intervals can be removed without the device in one unstable condition.

Such modes are for example cooling and lubrication of drills necessary, which at predetermined time intervals Aerosol supplied must become. For this purpose, a closure means is arranged on the aerosol outlet, which is formed, for example, by a controlled ball valve is. By controlling the ball valve accordingly, the Aerosol removal can be started or stopped abruptly.

This interval operation changes the pressure conditions in the pressure vessel. A pressure-controlled supply of carrier gas and liquid would be too slow to follow these changes due to the system-related control times. In contrast, no pressure control takes place in the device according to the invention, so that even when the ball closes hahns the aerosol continues to be produced with unchanged parameters of the throttle system. The aerosol generated in this way can escape suddenly when the ball valve is opened and is thus immediately available to the tool.

The invention is set out below explained using the drawings. Show it:

1 Block diagram of an embodiment of the device for aerosol generation according to the invention.

2 Detailed representation of a section of a second embodiment of an apparatus for aerosol generation.

3 Embodiment of a panel arrangement for the device according to 1 ,

1 shows schematically the basic structure of a device 1 for aerosol generation. That by means of the device 1 generated aerosol 2 is used in the present example for cooling and lubricating tools 3 , Workpieces as well as gears and machines. In principle, such devices 1 also for the production of aerosols 2 for inhalers in medical technology, humidifiers in household technology and the like.

The device 1 according to 1 includes a pressure vessel 4 in which an injector device 5 is arranged. The injector device 5 is via a first line 6 Carrier gas and a second line 7 fed a liquid. The carrier gas consists of air and is provided via a compressed air supply, not shown, with a supply pressure P _V , which is typically in the range 6 bar P P _V 10 10 bar. The liquid serves as a lubricant and, in the present exemplary embodiment, is formed by oil that flows into the line via an oil reservoir 7 is fed. Alternatively, synthetic esters or the like can also be used.

Both the air and the oil are each via a throttle 8th . 9 the injector device 5 fed. The throttles forming a throttle system 8th . 9 are via a control unit 10 controlled. The control unit 10 is formed by an electrical circuit or the like. In addition to the chokes 8th . 9 is a sensor via supply lines, not shown 11 to the control unit 10 connected. The sensor designed as a differential pressure sensor 11 measures the differential pressure ΔP = P _V - P _B , where P _{B is} the pressure in the interior of the pressure vessel 4 prevails.

The injector device 5 has an injector block 12 on in which an injector chamber 13 is arranged. The injector chamber 13 is widened in the area of its outlet towards the lower end. There is a conical baffle below the outlet 14 arranged, the lateral surface of a staircase structure with a plurality of successive steps 15 having.

Via a bracket 16 is the impact body 14 at a predetermined distance from the outlet of the injector chamber 13 arranged, this distance is preferably adjustable.

Over the chokes 8th . 9 air and oil into the injector chamber 13 introduced, when entering the injector chamber 13 Due to the enlargement of the cross section, a negative pressure is created, through which oil is sucked in and mixed with the compressed air. The gas jet thus obtained with liquid droplets contained therein is applied to the impact body 14 led, on which liquid droplets initially settle. The air of the gas jet flowing in at high speed with further liquid droplets leads to the formation of very fine droplets of the oil upon impact of these droplets, so that an aerosol is formed 2 with very fine oil particles.

The aerosol 2 with the fine oil particles it is deflected laterally and via an aerosol outlet 17 , in the present example on the ceiling of the pressure vessel 4 is arranged, executed from this and a tool 3 fed. In principle, several aerosol outlets can also be used 17 for connecting a specified number of tools 3 be provided.

The heavy oil particles sink to the bottom of the pressure vessel 4 in which an oil supply 18 is arranged, which is advantageously used as an oil for aerosol generation.

A size selection of the oil droplets in the aerosol 2 can get in the area before the aerosol outlet 17 Cage structures, not shown, can be arranged which force an approximately right-angled deflection of the aerosol flow. Larger oil drops cannot follow this deflection, so that only the smallest oil droplets in the aerosol flow via the aerosol outlet 17 from the pressure vessel 4 be performed.

In addition, a further nozzle, not shown, for feeding be provided by additional air.

Between aerosol outlet 17 and tool 3 is a locking device controlled by an external control 19 intended. The fastener 19 is preferably formed by a compressed air controlled ball valve. This can be closed and opened via the control with short response times, so that the supply of aerosol 2 to the tool 3 can be activated and deactivated abruptly.

2 shows an embodiment of an injector device 5 , which essentially according to the embodiment 1 equivalent. In particular, the injector device 5 another injector chamber 13 on that at a distance from the impact body 14 opposite, the impact body 14 by means of the bracket 16 at a specified distance from the injector chamber 13 is fixed.

In contrast to the exemplary embodiment according to 1 are in accordance with the arrangement 2 two sets of nozzles, each with two nozzles 20 . 21 . 22 . 23 provided for the supply of air and Oil in the injector device 5 serve.

The first set of nozzles has two close to the injector chamber 13 adjacent nozzles 20 . 21 on, passing through the first nozzle 20 Air and over the second nozzle 21 Oil in the injector chamber 13 is directed.

The second set of nozzles lies above the first set of nozzles and also has a nozzle 22 for feeding air and a second nozzle 23 for feeding in oil.

The supply of oil and air through the various nozzles is quantity-controlled via one in each 2 throttle, not shown 8th . 9 , the chokes 8th . 9 form the throttle system.

Control of the throttle system and the supply of oil and air to the injector device 5 again takes place via the control unit 10 ,

Depending on how large the oil requirement for aerosol production is, oil and air are preferably introduced into the injector device either only via the first nozzle system or via both nozzle systems 5 directed. The air supply can be further adjusted using the additional nozzle.

The thrushes 8th . 9 of the throttle system are designed in the form of diaphragm arrangements. An embodiment of such a throttle designed as an orifice arrangement 8th for air supply is in 3 shown.

The diaphragm arrangement comprises a diaphragm body 24 , in which a predetermined number of diaphragm openings lie next to each other at a distance 25 is incorporated. The aperture openings 25 each have a circular cross section. The diameters of the apertures 25 are preferably different in each case and are in the range from less than one millimeter to a few millimeters. In the 3 The diaphragm arrangement shown serves for the supply of air and has four diaphragm openings lying side by side 25 on. Before every aperture 25 there is a valve 26 , over which air of the respective aperture 25 is fed.

The diameter of the aperture 25 are large compared to the thickness of the panel body 24 , In any case, the diameters are at least one third of the thickness of the diaphragm body. This is the longitudinal extent of the aperture 25 considerably smaller, but at least not significantly larger than their cross-section. As a result, a largely constant and homogeneous velocity profile is obtained even with different air flow velocities across the orifice cross section.

The aperture 25 each panel arrangement can be selectively controlled by the control unit 10 be closed or opened. Depending on which aperture openings 25 closed or open, there are different cross sections of the throttle 8th . 9 , in the present case fifteen different cross sections are adjustable.

The diaphragm arrangements for supplying oil have a structure which essentially corresponds to the structure of the diaphragm arrangement 3 equivalent. The diaphragm arrangement for supplying oil in the present case has only two different diaphragm openings 25 on.

The diaphragm arrangement for the additional air has three diaphragm openings in the present case 25 with different cross sections.

The control of the device 1 for aerosol generation takes place centrally via the control unit 10 ,

Depending on the type of aerosol outlet 17 connected tool 3 for the individual panel arrangements each via the control unit 10 specified which aperture 25 closed and which ones are open. This takes place depending on the aerosol outlet 17 from the pressure vessel 4 executed aerosol withdrawal amount an adjustment of the oil and air volume flows, that of the injector device 5 be fed. By presetting these volume flows, dynamic pressure control takes place inside the pressure vessel 4 , which leads in particular to self-stabilization of aerosol production. In particular, dynamic cross-sectional changes in the aerosol take-off cross section and associated changes in the aerosol withdrawal amounts lead to a pressure change in the interior of the pressure vessel 4 that counteract the respective change in the withdrawal quantity. Such dynamic processes occur in particular in the case of tools designed as drills 3 on, which are inserted into a workpiece and then executed again from this.

In this way, stable aerosol generation is obtained without having to adjust the throttle system during the operation of the device 1 needs to be changed. In particular, stable aerosol generation is guaranteed with aerosol withdrawal quantities that change over time.

The setting values of the throttle system are expediently in the control unit as parameter values or characteristic curves 10 saved or entered into them as required.

The essentially only requirement for stable aerosol generation is that the differential pressure ΔP = P _V - P _{B is} above a predetermined limit value ΔP ₀ . At a predetermined supply pressure P _V at the compressed air supply, the tank pressure P _B in the pressure tank is then allowed 4 do not exceed a specified limit. The limit value ΔP ₀ is in the range 2 bar Δ ΔP ₀ bar 2.5 bar and is preferably 2.2 bar. The differential pressure is measured using the sensor 11 recorded and as an input variable for the control of aerosol generation in the control unit 10 read.

If the differential pressure is above the limit value ΔP ₀ , this takes place in the injector device 5 continuous aerosol generation with those in the control unit 10 default settings of the Diaphragm arrangements.

If the differential pressure ΔP falls below the limit value ΔP ₀ , aerosol generation is prevented. For this purpose, all diaphragm arrangements are preferably closed. The aerosol outlet 17 remains open, however, so aerosol remains 2 from the pressure vessel 4 is promoted so that the container pressure P _B decreases over time.

Aerosol generation is only resumed as soon as the differential pressure ΔP exceeds a further limit value ΔP ₁ . The limit value ΔP ₁ is above the limit value ΔP ₀ . ΔP ₁ is preferably in the range 3 bar ≤ ΔP ₁ 3,5 3.5 bar and is particularly advantageously 3.4 bar.

The difference .DELTA.P between the limit values .DELTA.P ₀ and .DELTA.P ₁ forms a switching hysteresis for the control of the aerosol generation, by means of which unnecessary switching operations, ie starting and interrupting the aerosol generation, are avoided. This prevents the system from swinging up.

Particularly in the case of tools designed as drills 3 it is necessary that the particular tool 3 aerosol only at fixed time intervals 2 is fed.

For example, it is expedient to limit the aerosol supply to the time intervals in which the drill is inserted into a workpiece. In contrast, aerosol generation should be prevented if the tool 3 is carried out from the workpiece to prevent unnecessary contamination of the workpiece with oil.

For this purpose, the ball valve is actuated via an external control, whereby the aerosol delivery to the tool 3 can be activated or deactivated abruptly.

(1)

Vorrichtung

(2)

Aerosol

(3)

Werkzeuge

(4)

Druckbehälter

(5)

Injektorvorrichtung

(6)

Erste Leitung

(7)

Zweite Leitung

(8)

Drossel

(9)

Drossel

(10)

Steuereinheit

(11)

Sensor

(12)

Injektorblock

(13)

Injektorkammer

(14)

Prallkörper

(15)

Stufen

(16)

Halterung

(17)

Aerosolabgang

(18)

Ölvorrat

(19)

Verschlussmittel

(20)

Düse

(21)

Düse

(22)

Düse

(23)

Düse

(24)

Blendenkörper

(25)

Blendenöffnungen

(26)

Ventil

LIST OF REFERENCE NUMBERS

(1)

contraption

(2)

aerosol

(3)

Tools

(4)

pressure vessel

(5)

injector

(6)

First line

(7)

Second line

(8th)

throttle

(9)

throttle

(10)

control unit

(11)

sensor

(12)

injector block

(13)

injector chamber

(14)

baffle

(15)

stages

(16)

bracket

(17)

aerosol outlet

(18)

oil supply

(19)

closure means

(20)

jet

(21)

jet

(22)

jet

(23)

jet

(24)

visor body

(25)

apertures

(26)

Valve

Claims (19)

Device for producing an aerosol, with at least one throttle ( 8th . 9 ), a pressure vessel ( 4 ) and an injector device arranged in the pressure container ( 5 ), wherein a carrier gas can be fed to the injector device via the at least one throttle and can be mixed in the injector device with a liquid to form an aerosol, characterized in that a sensor ( 11 ) is provided, through which the pressure difference (ΔP) between the supply pressure (P _V ) of the supplied carrier gas and the pressure (P _B ) in the pressure vessel can be detected, and that the at least one throttle ( 8th . 9 ) is designed to be openable and closable depending on the pressure difference (ΔP). Device according to claim 1, characterized in that the sensor ( 11 ) is designed as a differential pressure valve. Device according to claim 1 or 2, characterized in that at least one further throttle ( 8th . 9 ) is provided, through which the liquid is passed to the injector device. Device according to one of the above claims, characterized in that a control unit ( 10 ) to which the Sensor ( 11 ) is connected and via which the at least one choke ( 8th . 9 ) is controllable. Device according to one of the above claims, characterized in that the at least one throttle as an aperture ( 25 ) is trained. Apparatus according to claim 5, characterized in that a predetermined number of diaphragm openings ( 25 ) is provided. Apparatus according to claim 5 or 6, characterized in that a valve ( 26 ) lies over which air of the respective aperture ( 25 ) is supplied. Apparatus according to claim 6 or 7, characterized in that each aperture ( 25 ) a valve ( 26 ) assigned. Device according to one of claims 5 to 8, characterized in that each aperture ( 25 ) selectively via a control device ( 10 ) can be opened and closed. Device according to one of claims 5 to 9, characterized in that the diaphragm openings ( 25 ) have a circular cross section. Device according to one of claims 5 to 10, characterized in that the diaphragm openings ( 25 ) are provided with diameters in the range from less than one millimeter to a few millimeters. Device according to one of claims 5 to 11, characterized in that the longitudinal extension of the aperture ( 25 ) is not significantly larger than their cross-section. Device according to one of claims 5 to 12, characterized in that the diaphragm openings ( 25 ) are designed to be selectively openable and closable. Device according to one of the above claims, characterized in that the injector device ( 5 ) two nozzle sets ( 20 . 21 . 22 . 23 ) through which air and oil can be fed into the injector device. Device according to one of the above claims, characterized characterized that a nozzle is provided, through which additional air can be fed into the pressure vessel is. Device according to one of the above claims, characterized in that the carrier gas and / or the liquid in the throttle system through an orifice arrangement with a predetermined number of separately closable orifices ( 25 ) are directed. Device according to one of the above claims, characterized in that the at least one throttle is designed to be closable when the pressure falls below a predetermined limit value (ΔP ₀ ). Device according to one of the above-mentioned claims, characterized in that predetermined aperture openings ( 25 ) are designed to be openable if a predetermined limit value ΔP ₁ , which is greater than ΔP _0, is exceeded. Device for aerosol generation according to one of the above claims, characterized in that when the differential pressure ΔP is above the limit value ΔP ₁ , a number of orifices ( 25 ) is opened, which from the via at least one aerosol outlet from the pressure vessel ( 4 ) delivered amount of aerosol depending on the control device ( 11 ) is specified.