RU2716078C1 - Virtual impactor - Google Patents

Abstract

FIELD: instrument engineering.

SUBSTANCE: invention relates to instrument-making, in particular to devices for sampling aerosols from air for further physical-chemical or microbiological analysis. Virtual impactor, comprising housing, filter substrate with filter, is characterized in that housing is divided into input section, middle section, outlet section, inlet and outlet sections along connecting circuit have external thread, and middle section by connecting contours has internal thread, forming threaded connection between sections; Intake section inlet channel has accelerating nozzle; middle section in inner space on the side of inlet section has substrate for filter of coarse particles with filter, and behind substrate there is accelerating nozzle; outlet section in inner space includes shell with space around its walls for air movement; in structural space of shell on side of middle section in grooves there is a substrate of baffle of fine particles, which is directed by recess for filter with filter of small particles towards accelerating nozzle of middle section; barrel at outlet end is conjugated with mesh structure.

EFFECT: improved technical characteristics of the device for aerosol sampling and improved efficiency of aerosol trapping and reliability of information on the state of the monitored medium.

7 cl, 4 dwg

Description

The invention relates to instrumentation, in particular, to devices for sampling aerosols from the air for subsequent physico-chemical or microbiological analysis.

Known solution RU 63539 U1 “Device for sampling aerosols”, IPC G01N 27/00, containing a cylindrical body, a filter, a flow meter, a flow controller with flow separation and a flow inducer. In this case, the flow regulator is installed at the device inlet in front of the filter, and the flowmeter output through the control unit is connected to the flow inducer. In the process, only the required part of the air pumped by the flow inducer is sucked through the aerosol filter, and the other part of the air passes through an adjustable hole in the device body. The flow meter only measures the air flow through the filter. When passing the required volume of air, the control unit gives a command to turn off the inducer of air flow, after which the filter is sent for analysis.

The disadvantage of this technical solution is that with the help of an aerosol sampling device, incomplete information on the state of the controlled medium is obtained, since it does not separate aerosol particles due to sorption by two eluators for large and small particles. (RU 63539 U1, http://new.fips.ru).

The known solution RU 2089870 C1 “Device for sampling aerosols”, IPC G01N 1/22, containing a cylindrical body (CC) installed at the inlet of the CC filter holder with a filter, flow inducer, flow meter and flow controller. The latter is installed behind the flow meter and is made in the form of a sleeve with a hole mounted with the possibility of rotation on the Central Committee. In the place of installation of the sleeve on the Central Committee made a hole corresponding to the hole in the sleeve. The flow meter is installed in the Central Committee behind the filter holder.

The disadvantage of this technical solution is that due to the large number of structural units, the device has a large mass, this negatively affects the flight characteristics of an unmanned aerial vehicle (UAV). (RU 2089870 C1, http://new.fips.ru).

Of the known technical solutions, the closest in purpose and technical nature to the claimed object is the solution SU 1096526 A1 “Device for sampling aerosol”, IPC G01N 1/22, containing a filter holder with a filter installed in the housing, the filter holder with the filter is installed coaxially relative to the housing, while the lower part of the housing is equipped with a bell, the upper is made in the form of a cylinder, and the filter holder is in the form of a truncated cone, and the filter is located in the plane of mating of the cylinder and the bell of the housing, and the housing and filter The holder is made with the outer surface covered with a film that absorbs thermal radiation.

The disadvantage of this technical solution is that with a high linear velocity of the air flow inside the device body, a filter may break through, which is installed in the upper plane of the filter holder, which will lead to losses of the taken aerosol sample. In addition, the structure of the rotating air flow inside the device does not allow to obtain a high efficiency of collecting aerosol particles from the air stream. (SU 1096526 A1, http://new.fips.ru).

SUMMARY OF THE INVENTION

The problem the claimed solution is aimed at is increasing the efficiency of aerosol capture by sorbing particles with two substrates with filters for large and small particles, creating a simple and lightweight virtual impactor design that does not require energy consumption for its operation and allows you to place the device on an unmanned aerial vehicle (UAV).

The impactor has a composite body of FIG. 1, including the input section (1) of FIG. 1, the middle section (2), the output section (3). The middle section is the connecting base for the input (1) and output (3) sections. The inlet (1) and outlet (3) sections along the connecting circuit have an external thread, and the middle section (2) along the connecting circuits has an internal thread of FIG. 2. Due to what the threaded connection between the sections is carried out.

The inlet section (1) of FIG. 2 is made on the basis of a cone, which increases streamlining and reduces the resistance to movement of the device to meet the air flow.

The inlet section (1) inside has an intake channel (1.1) of FIG. 2, nozzle (1.2), fractionating cascade for large particles (1.3).

The intake channel (1.1) of FIG. 2 of the input section (1) has a circular cross section and is located coaxially with the longitudinal axis of the section (1).

The accelerating nozzle (1.2) is made on the basis of the disk and is interfaced with the housing of the inlet section (1) of FIG. 2.

The middle section (2) of FIG. 1, 2 is made on the basis of a cylinder with an internal structural space in which, on the side of the inlet section, it has a coarse particle chipper substrate (2.1), a coarse particle chipper filter (2.1.1), and an accelerating nozzle (2.2) behind the filter substrate.

The accelerating nozzle (2.2) is made on the basis of the disk and is interfaced with the housing of the middle section (2) of FIG. 2.

The substrate of the chipper large particles (more than 10 microns) (2.1) Fig. 2, 3 includes a round base with a recess for the filter of large particles (2.1.1), conjugated with a cross, the return ends (2.1.2) of which are installed in grooves in the inner surface of the middle section (2) of FIG. 2.

Coarse particle stripper substrate (2.1) of FIG. 2 is directed by a recess for the filter of large particles towards the nozzle (1.2). In the recess of the base (2.1) of FIG. 2, 3, a large particle filter is installed (2.1.1).

The output section (3) of FIG. 1, 2 includes a glass (3.2) of FIG. 2 representing a hollow part, repeating the contours of the walls of the working fractionation cascade for small particles (3.3).

The beaker (3.2) of FIG. 2 is installed in the structural space of the fractionation cascade for small particles (3.3) so that between the walls of the cup (3.2) and the fractionation cascade for small particles (3.3) there is space for air movement. The glass (3.2) at the output end is interfaced with the mesh structure (3.2.1).

Installing the beaker in the outlet section (3) of FIG. 1, 2 is implemented due to the mesh structure (3.2.1) mating with the outlet (3.4) of the output section (3).

In the structural space of the glass (3.2) of FIG. 2 from the side of the middle section (2) of FIG. 1, in the grooves there is a substrate for the fenders of small particles (3.1) (less than 10 microns), which is directed by a recess for the filter of small particles (3.1.1) towards the accelerating nozzle (2.2) of the middle section.

The substrate for the fines eliminator (3.1) includes a round base with a recess for the filter for fines (3.1.1), conjugated with a cross, the return ends (3.1.2) of which are installed in grooves in the inner surface of the cup (3.2) of FIG. 2.

The filter of large particles (2.1.1) and small particles (3.1.1) is an AFA - VP - 20 filter moistened with glycerin as an eluting liquid.

Impactor and its structural elements are made of polymer material.

The technical result consists in improving the technical characteristics of the device for sampling aerosols by creating a simple and lightweight virtual impactor design that does not require energy for its operation and allows you to place the device on an unmanned aerial vehicle (UAV), in increasing the efficiency of aerosol capture due to sorption of particles by two substrates with filters for large and small particles and the reliability of information about the state of the controlled environment.

Brief Description of the Drawings:

in FIG. 1 is a schematic illustration of a virtual impactor. General form;

in FIG. 2 is a schematic illustration of a virtual impactor. Lengthwise cut;

in FIG. 3 is a schematic representation of the substrate of a chipper of large particles. General form;

in FIG. 4 is a schematic illustration of the substrate of the fenders of small particles. General form;

A brief description of the structural elements:

1 - input section;

1.1 - intake canal;

1.2 - nozzle;

1.3 - working fractionation cascade for large particles;

2 - middle section;

2.1 - substrate chipper large particles;

2.1.1 - filter striker large particles;

2.1.2 - the end of the cross;

2.2 - accelerating nozzle;

3 - output section;

3.1 - substrate fenders of small particles (less than 10 microns);

3.1.1 - filter fenders of small particles (less than 10 microns);

3.1.2 - the end of the cross;

3.2 - a glass;

3.2.1 - mesh design;

3.3 - working fractionation cascade for small particles;

3.4 - outlet;

Implementation of the claimed decision:

A virtual impactor, designed to take samples of biological aerosols from the air for subsequent analysis aimed at establishing the type of biological attacking agent.

This sampling device is placed on an unmanned aerial vehicle (UAV). Air is taken into the sampling device by means of an oncoming air flow, which is created when the UAV moves.

Aerosol aspiration occurs due to the oncoming air flow resulting from the flight of a UAV along a horizontal path. The flow rate is in the range from 20 to 200 l / min. The aerosol enters in the form of an axial jet into the inlet section (1) of FIG. 1, 2 through the intake channel (1.1) of FIG. 2 and falls into the working fractionation cascade for large particles (1.3), which divides the aerosol stream into two components: axial and radial. Then the aerosol stream meets the filter of the coarse particle chipper (more than 10 microns) (2.1.1), which is installed in the recess of the base of the coarse particle chipper (more than 10 microns) (2.1) of FIG. 2, 3. On the fibrous surface of the filter of the chipper of large particles (more than 10 μm) (2.1.1) of FIG. 2, which is an AFA - VP - 20 filter moistened with glycerin as an eluting liquid, inertial impaction of aerosol particles larger than 10 micrometers takes place.

The large particles (more than 10 μm) reflected from the chipper filter (2.1.1), a fan-shaped aerosol stream containing mainly particles smaller than 10 μm, acquires a radial (in radius) direction from the axis to the periphery (to the walls of the inlet section (1) Fig. 1). Then, inside the space of this section (1), the flow again changes its radial direction, is drawn in by the flow of incoming air into the funnel-shaped part of the section, and enters the virtual impacting unit (middle section) (2).

In the accelerating nozzle 2.2 of FIG. 2, the aerosol is focused into an axial high-speed jet, which is divided into two components - axial and radial in a ratio of 1: 9 with air flow rates of 20 l / min and 180 l / min, respectively.

The bulk of the particles of the dispersed phase, acquiring significant inertia at the exit from the accelerating nozzle (2.2), is concentrated in the axial flow and, following it, enters the working fractionation cascade for small particles (3.3), where it impinges small particles on the filter surface (less than 10 μm) (3.1.1), which is installed in the recess of the substrate base of the fenders of small particles (less than 10 μm) (3.1).

At the same time, the radial component of the flow of 180 l / min and containing a small amount of aerosol particles with a size of less than 1.5 μm falls into the inner space of the outlet section (3) of FIG. 1, where it is mixed with the air flow at the outlet of the working fractionation cascade for small particles (3.3) of FIG. 2 and is released into the atmosphere through the outlet (3.4).

Claims (7)

1. A virtual impactor, comprising a housing, a filter substrate with a filter, characterized in that the housing is divided into an inlet section, a middle section, an outlet section, the inlet and outlet sections along the connecting circuit have an external thread, and the middle section along the connecting circuits has an internal thread forming a threaded connection between sections; the intake channel of the input section at the output has an accelerating nozzle; the middle section in the inner space from the inlet section has a substrate for a filter of large particles with a filter, and an accelerating nozzle behind the substrate; the outlet section in the inner space includes a glass with a space around its walls for air movement; in the structural space of the glass from the side of the middle section in the grooves, a substrate for the fenders of small particles is installed, which is directed by a recess for the filter with a filter of small particles towards the accelerating nozzle of the middle section; the glass at the output end is paired with a mesh structure. 2. The impactor according to claim 1, characterized in that the inlet section is made on the basis of a cone and includes an intake channel that has a circular cross section and is located coaxially with the longitudinal axis of the section. 3. The impactor according to claim 1, characterized in that the accelerating nozzle of the inlet section is made on the basis of the disk and is coupled to the body of the inlet section. 4. Impactor according to claim 1, characterized in that the middle section is made on the basis of a cylinder. 5. Impactor according to claim 1, characterized in that the accelerating nozzle of the middle section is made on the basis of the disk and is interfaced with the housing of the middle section. 6. The impactor according to claim 1, characterized in that the substrate for the stripper of large particles includes a round base with a recess for the filter of large particles, mated with a cross, the return ends of which are installed in grooves in the inner surface of the middle section, and is directed by a recess for the filter of large particles in side of the nozzle. 7. The impactor according to claim 1, characterized in that the substrate of the fenders of small particles includes a circular base with a recess for the filter of small particles, mated with a cross, the return ends of which are installed in grooves in the inner surface of the glass, and directed by the recess for the filter of small particles to the side middle section.

Images