RU2846565C1 - Aerosol generator - Google Patents

Abstract

FIELD: aerosol generators.

SUBSTANCE: invention relates to devices for generating aerosols and can be used in nuclear power facilities, medical institutions, pharmaceutical enterprises, microelectronics and in other industries, where there are high requirements for air cleaning to ensure special production conditions or high requirements for radiation and chemical safety. Aerosol generator comprises a noise absorber, air supply lines, flow meter, valve, compressor for supplying compressed air, HEPA filter, vessel with liquid test substance and sprayer in the form of nozzle with two-component nozzle directed to glass surface. Sprayer, in the form of a two-jet nozzle, is provided with a housing in which there is a channel for feeding compressed air, a channel for injecting the test substance, a channel for outlet of the obtained aerosol and a channel for releasing excess pressure of the aerosol. Sprayer has three interconnected cylindrical diffusers. Two of them are oriented vertically, and one serving as a mixing chamber is oriented horizontally. First diffuser top part is communicated with compressed air feed channel. Its lower part is connected via cylindrical ejector with second diffuser that doubles as mixing chamber. Third diffuser is connected to said chamber from below to feed test fluid from its container. Mixing chamber serves to produce aerosol by creating two colliding jets in spraying compressed air jet and fed test fluid. Finally, for impact under pressure of the obtained aerosol from the mixing chamber, the wall of the test liquid container is used, while obtaining an aerosol with particle size of 0.1-0.5 mcm, which is released through the aerosol outlet channel. Some part of aerosol, when its excess pressure is created in the reservoir for test liquid, is removed through the channel for its discharge, which is equipped with a nozzle, with a check valve and a sound wave damper.

EFFECT: high stability of the size of aerosol particles and their concentration by controlling dispersity thereof.

1 cl, 4 dwg

Description

The invention relates to devices for generating aerosols and can be widely used at nuclear power facilities (NPF), in medical institutions (oncology centers using beam and radiation technologies for diagnostics and treatment), at pharmaceutical, microelectronics and other industries where high demands are placed on air purification to ensure special production conditions, or high demands on radiation and chemical safety. Known is a "Method for producing an aerosol and a generator for producing it", comprising a container for an aerosol-forming composition and an outlet pipe for ejecting an aerosol, characterized in that it is equipped with a suspension module, a high-pressure pump, and the container for the aerosol-forming composition is made in the form of a reactor with inlet openings for feeding activated aluminum and water into it and an outlet pipe for ejecting an aerosol, wherein the reactor is connected to the suspension module using a high-pressure pump. Russian Federation Patent for Invention No. 2254314, IPC: C06D 3/00, publ. 20.06.2005

Known is an "aerosol generator mounted on a transport base and containing thermomechanical and pneumatic circuits connected to a pressure gauge connected via a first flow sensor to a first disperser spraying the working fluid of the exhaust gas flow of a gas turbine engine, wherein via a second flow sensor a working fluid supply line is connected to a second disperser located at the outlet of the compressed air line, characterized in that it contains a cooling circuit including a coolant tank via a third pump and a fifth valve connected to a sixth valve and a third flow sensor with a first coolant supply manifold into the exhaust gas flow, and the fifth valve is connected via a seventh valve and a fourth flow sensor with a second coolant supply manifold into the compressed air flow with the possibility of regulating the compressed air supply damper.

RF patent for invention No. 2236131, IPC: A01M 7/00, publ. September 20, 2004

Known is a "Universal aerosol generator comprising a sprayer with gas and liquid channels, an outlet pipe, a reservoir for medicinal liquid and a housing, characterized in that it is provided with an additional pipe having a narrowed outlet opening and external and internal conical seats and forming an articulated condensate collector with an outlet pipe provided with a steam supply nipple, wherein both pipes are installed in the housing coaxially with each other and with the axis of the sprayer, and the housing is made in the form of a hollow cylinder with right and left conical seats at opposite ends and a third threaded seat located in the center at an angle to the axis of the cylinder, wherein the sprayer is installed in the left conical seat of the housing and is provided with a separator in the form of a removable sleeve or a rotary flag with a cylindrical part protruding towards the aerosol flow, installed coaxially with the outlet opening of the sprayer at a distance of 3-5 diameters of the outlet opening from its cut to the end of the cylindrical part, the diameter of which is equal to 3-4 diameters of the outlet opening, the outlet and additional pipes are installed in the right conical seat, and the reservoir for the medicinal liquid is on the threaded seat.

RF patent for invention No. 2145886, IPC A61M 11/00, publ. 02/27/2000.

The closest technical solution to the device is the "Topas ATM 226 aerosol generator, which contains a noise absorber, air supply lines, a flow meter, a valve, a compressor for supplying compressed air, a HEPA filter, a vessel with a liquid test substance and a sprayer in the form of a nozzle with a two-component nozzle directed at a glass surface. The Topas ATM 226 aerosol generator is used to obtain test aerosols with specified properties, and the main unit of the generator is the sprayer, in which there is a two-component nozzle operating as an injector, directed at a glass surface. This glass surface acts as a trap and serves to immediately return large droplets that arise during the spraying process. (WWW. Topas-gmbh.de Aerosol Generator АТМ-226-Topas GmbH; Manufacturer: TopasGmbH DE - 01237 Dresden, GERMANY )

The technical result consists in ensuring high stability of the sizes of aerosol particles and their concentration by regulating their dispersion using a sprayer design with three cylindrical diffusers connected to each other, an ejector between the diffuser for supplying compressed air and a diffuser serving as a mixing chamber and a third diffuser serving to suck in test liquid from a container for it, as well as using the walls of a container for the test liquid as a glass surface for impacting it under pressure of the aerosol obtained from the mixing chamber, and thereby obtaining an aerosol with a particle size of 0.1-0.5 μm.

The technical result is achieved by the fact that the "Aerosol generator contains a noise absorber, air supply lines, a flow meter, a valve, a compressor for supplying compressed air, a HEPA filter, a vessel with a liquid test substance and a sprayer in the form of a nozzle with a two-component nozzle directed at a glass surface. In this case, the sprayer, in the form of a two-jet nozzle, is provided with a body in which a channel for supplying compressed air, a channel for sucking in the test substance, a channel for removing the resulting aerosol and a channel for relieving excess aerosol pressure are made. And the sprayer is also provided with three cylindrical diffusers connected to each other, wherein two of them are oriented vertically, and one, serving as a mixing chamber, is oriented horizontally and is located at an angle of 90° with respect to the other two. Moreover, the upper part of the first diffuser is connected to the compressed air supply channel, and its lower part, through a cylindrical ejector, is connected to the second diffuser serving as a mixing chamber, to which, in turn, a third diffuser is connected from below, serving to supply the test liquid from the container for it. The mixing chamber in this case serves to obtain an aerosol by creating two jets colliding with each other during spraying of the compressed air stream and the supplied liquid. Finally, as a glass surface, for impact against it under the pressure of the obtained aerosol from the mixing chamber, the wall of the container for the test liquid is used, thereby obtaining an aerosol with a particle size of 0.1-0.5 μm, which is released through the channel for the aerosol discharge. Part of the aerosol, when its excess pressure is created in the container for the test liquid, is discharged through the channel for its discharge. The latter is equipped with an outlet nipple, in which, in turn, a check valve and a sound wave damper are made. In addition, the aerosol generator is equipped with a power supply unit with fuses against network overload and regulators for switching the device on and off, and a rotameter is used as a flow meter. In this case, the diameters of the diffusers and the ejector are in the following ratio to each other, equal to D ₁ = D ₃ = 1.5 mm, D ₂ = 1/3 D ₁ , and D ₄ = 2/3 D ₁ where:

D ₁ - diameter of the diffuser for supplying compressed air;

D2 - ejector diameter;

D3 - diameter of the diffuser serving as a mixing chamber;

D4 - diameter of the diffuser for supplying test liquid.

The "aerosol generator" is illustrated by the drawings in Figs. 1, 2, 3 and 4.

Fig. 1 - Aerosol generator (general drawing-diagram);

Fig. 2 - Aerosol generator (longitudinal section of the aerosol sprayer along the vertical plane;

Fig. 3 - Aerosol generator (enlarged cutout of a longitudinal section of an aerosol sprayer along a vertical plane);

Fig. 4 - Aerosol generator (cross-section along the horizontal axis of the channels for removing the resulting aerosol and for releasing excess aerosol pressure).

According to Fig. 1, 2, 3 and 4, the "Aerosol Generator" comprises a muffler 1, a flow meter for the supplied air pressure (rotameter) 2, a throttle 3, a compressor 4, a power supply 5, a HEPA filter 6, a sprayer 7 and a container for the test substance 8. In this case, the sprayer 7 is provided with a housing 9, in which a channel 10 for supplying compressed air, a channel 11 for sucking in the test substance, a channel 12 for removing the obtained aerosol and a channel 17 for releasing excess aerosol pressure are made. The sprayer 7 is also provided with three cylindrical diffusers connected to each other. The diffuser 13 is vertically oriented and is connected with its upper part to the channel 10 for supplying compressed air, its lower part, through the cylindrical ejector 14, is connected to the second diffuser 15, which serves as a mixing chamber, to which the third diffuser 16 is connected from below, which serves to supply the test liquid from the channel 12 and suck it from the container 8. The wall of the container 8 for the test liquid is used as a glass surface, thereby obtaining an aerosol with a particle size of 0.1-0.5 μm, which is released through the channel 11 for the aerosol discharge. Part of the aerosol, when its excess pressure is created in the container 8 for the test liquid, is discharged through the channel 17 for its discharge. Channel 17 is equipped with a fitting 18, in which a check valve 19 and a sound wave damper 20 are made. The aerosol generator is equipped with a power supply 5 with fuses against network overload and regulators for turning the device on and off, and a rotameter 2 is used as a flow meter.

In this case, the diameters of the diffusers and the ejector are in the following relationship with each other, equal to D ₁ = D ₃ = 1.5 mm,

D ₂ = 1/3 D ₁ = 0.5 mm, a D ₄ = 2/3 D, = 1 mm where:

D ₁ - diameter of the diffuser for supplying compressed air;

D ₂ - ejector diameter;

D3 - diameter of the diffuser serving as a mixing chamber;

D4 - diameter of the diffuser for supplying test liquid.

The aerosol generator operates as follows: a silencer 1 is installed at the inlet, which is designed to reduce noise and serves as a pre-filter for the pneumatic line. Air from the main line is fed through the rotameter 2 and through the throttle 3 into the compressor 4, which produces compressed air, and the rotameter provides its required pressure and flow rate, then the compressed air through the HEPA filter 6, which ensures the purity of the air supplied to the sprayer 7, enters the channel 10 for supplying compressed air, and then into the upper part of the diffuser 13. Then through the cylindrical ejector 14 it enters the second diffuser 15, which serves as a mixing chamber, to which the third diffuser 16 is connected from below, which serves to supply the test liquid from the suction channel 12, lowered into the test liquid of the container 8. The ejector 14, working according to Bernoulli's law, creates a reduced pressure of the air medium in its narrowing section, which causes the suction of a stream of liquid medium from the diffuser 16 into the mixing chamber 15, connected through the suction channel of the test substance 11 with the container 8, wherein an aerosol with particles of 0.1-0.5 μm in size is formed in the mixing chamber 15, which is ensured by the optimal ratio of the diameters of the diffusers and the ejector. Then the resulting aerosol is ejected from the mixing chamber 15 into the air space of the container 8 for the test liquid. After the aerosol jet hits the side glass wall, its large particles slide back into the liquid of the container 8, and the aerosol with particles of 0.1-0.5 μm in size is released through the channel 11 for its discharge. In this case, part of the aerosol, when its excess pressure is created in the container 8 for the test liquid, is discharged through the channel 17 for its discharge, equipped, in turn, with a fitting 18, in which a check valve 19 and a sound wave damper 20 are made.

Examples of selecting the optimal sizes of the diffuser and ejector diameters to obtain an aerosol with the required particle sizes in the range of 0.1-0.5 µm, as well as test graphs are summarized in tables and graphs 1, 2 and 3, from which it is clear that the optimal ratio of the diffuser and ejector diameters corresponds to table and graph 2.

Table 4 shows the “Technical characteristics of the “Aerosol Generator”

Table 5 shows the “Concentration distribution of the test aerosol (DEHS aerosol liquid) at an average generator flow rate of 180 l/h (3 l/min).”

The aerosol generator can work with aerosol liquids other than DEHS (DOS). Such substances can be: low-viscosity paraffin oil, DOP, Emery 3004. With the help of this Generator, Latex aerosols and salt aerosols (NaCl solution and other materials) can also be produced with the additional connection of a diffusion dryer.

The proposed "Aerosol Generator" invention allows for high stability of aerosol particle sizes and their concentration, solves the problem of regulating the size of aerosol particles when creating test aerosols, and is also easy to operate and compact.

Claims (5)

An aerosol generator comprising a noise absorber, air supply lines, a flow meter, a valve, a compressor for supplying compressed air, a HEPA filter, a vessel with a liquid test substance and a sprayer in the form of a nozzle with a two-component nozzle directed at a glass surface, characterized in that the sprayer in the form of a two-jet nozzle is provided with a housing in which a channel for supplying compressed air, a channel for sucking in the test substance, a channel for removing the resulting aerosol and a channel for relieving excess aerosol pressure are made, wherein the sprayer is provided with three cylindrical diffusers connected to each other, wherein two of them are oriented vertically, and one, serving as a mixing chamber, is oriented horizontally and is located at an angle of 90° with respect to the other two, wherein the upper part of the first diffuser is connected to the compressed air supply channel, and its lower part, through a cylindrical ejector, is connected to the second diffuser, serving as a mixing chamber, to which in turn a third is connected from below a diffuser used to feed the test liquid from a container for it, wherein the mixing chamber serves to obtain an aerosol by creating two jets colliding with each other when spraying a compressed air stream and the supplied test liquid, finally, as a glass surface, for impact against it under the pressure of the obtained aerosol from the mixing chamber, use the wall of the container for the test liquid, thereby obtaining an aerosol with a particle size of 0.1-0.5 μm, which is released through a channel for removing the aerosol, and part of the aerosol, when creating its excess pressure in the container for the test liquid, is removed through a channel for its discharge, for this purpose the latter is equipped with an outlet fitting, in which in turn a check valve and a sound wave damper are made, in addition, the aerosol generator is equipped with a power supply with fuses from network overload and regulators for turning the device on and off, and a rotameter is used as a flow meter, wherein the diameters of the diffusers and the ejector are in the following ratio to each other, equal to D ₁ = D ₃ =1.5 mm, D ₂ =1/3 D ₁ , a D ₄ =2/3 D ₁ , where D ₁ is the diameter of the diffuser for supplying compressed air; D ₂ - ejector diameter; D ₃ - diameter of the diffuser serving as a mixing chamber; D ₄ - diameter of the diffuser for supplying test liquid.