SU1284996A1 - Device for microbiological analysis of air - Google Patents

Abstract

The invention relates to sampling devices for trapping bacteria and viruses from air and can be used in veterinary medicine and medicine for sanitary and biological. control of the air environment. The purpose of the invention is to increase the degree of trapping the dispersed phase from the air and reducing the entrainment of the sorption liquid. The device contains a vertical cylindrical body 1 with a hopper 2 for sorption liquid;, ti 3, an inlet 4 with a screw-shaped plate 5 and a nozzle 6, with a tube 7 connected with the bunker 7. On the end surface of the inlet 4, in its upper part, in the form of a truncated cone, a perforated impacting element 8 is placed. The nozzle 4 is provided with a deaf staple 9 which surrounds it outside, in the side surface 10 of which the longitudinal slots 11 are located tangentially and the holes 12 are below. 1, an air-guided cylinder 13 is installed, on which it is tangential. the outlet 14 is fixed. The nozzle 6 is located in the minimum cross-section of the emergency valve -4. Area se§ W o 00 4 CO O5 (PuB.f

Description

for the passage in the device, the nozzle k at the location of the flow stream is equal to the cross section of the entrance section bi 13. 13. Clause 5, table 5 3 il.

one

The invention relates to sampling devices for trapping bacteria and viruses from the air and can be used in veterinary medicine and medicine for sanitary and biological control of the air environment.

The purpose of the invention is to increase the degree of trapping the dispersed phase from the air and reducing the entrainment of the sorption liquid.

FIG. 1 shows the device, a general view; in fig. 2 shows section A-A in FIG. one; in fig. 3 shows a section BB in FIG. one.

The device contains a vertical cylindrical body 1 with a hopper 2 for sorption liquid 3, an inlet 4 with a screw plate 5 and a nozzle 6 connected to the hopper 2 by a tube 7. On the end surface of the inlet 4 in its upper part, made in the form of a truncated a cone, a perforated activating element 8 is placed, P4 of the tube 4 is provided with a deaf cup 9 that clings to it outside, in the side surface 10 of which longitudinal slots 11 are tangentially located, and below are holes 12. ene air- discharging cylinder 13 on which is mounted tangentially outlet 14. The nozzle 6 is located at the minimum section of the inlet pipe 4.

The diameter of the holes in the perforation of the activating element 8 is 1 mm, which corresponds to the size of the maximum particles of coarse aerosols.

The cross-sectional area for the flow-through device B is equal to the cross-sectional area of the inlet nozzle 4 at the location of the nozzle 6, which is necessary to avoid limiting the sampling rate and the efficiency of the centrifugal separation process at the maximum degree of aerosol deposition on the catching surface.

s

ABOUT

five

0

five

0

For this same purpose, the diameter of the outlet nozzle 14 is equal to the diameter of the inlet nozzle 4 at the location of the nozzle 6.

To develop a circular motion. the current at the outlet of the device and the provision of its centrifugal separation, the diameter of the suction cylinder 13 is twice the diameter of the outlet nozzle 14.

With a distance between the holes in the impacting element 8 equal to three of their diameters, the interaction of the individual jets of flow is prevented, resulting in a decrease in the degree of trapping.

The angle of the cone of the inlet 4 corresponds to the opening angle of the torch.

The device works as follows.

Under the action of a discharge created by an external aspirator connected to the outlet 14, the air flow under study enters the inlet 4, passes through the screw-shaped screw 5 and the nozzle 6, after which the dispersed particles in the gas stream are captured by drops of sorption liquid 3 the spray gun in the conical part of the nozzle 4. Drops of the sorption fluid e trapped by dispersed particles in the flow pass the holes of the activating element 8 and due to the inertia forces are deposited on the trap The interior of the gripping nozzle 4 of the cup 9 flows along its walls and through the holes 12 is sent to the hopper 2. Recirculation of the sorption fluid is ejected by the nozzle 6 through the tube 7 lowered into the liquid in the hopper 2, which provides the necessary for analysis . the degree of concentration of the captured dispersed phase of the air flow.

Part of the sorption fluid leaving the flow through the tangential

slit 11, settles on the walls of the hull and, gathering in it. the lower sloping part, also flows into the hopper 2.

The final separation of the flow is provided by the air exhaust ply cylinder 13.

The color intensity is dissolved using a fluorometer (the color intensity of the solution is proportional to the mass of the dispersed phase in the sediment). The total mass of sediment in the bunker, on the surfaces of the device and on the filter is taken as 100%, the ratio of the mass of sediment in the bunker to the total mass is expressed as a percentage and is determined

Example. In a 12 m chamber

create a dry aerosol obtained by Q to the degree of dispersion of the dispersed when dispersing the lyophilized by the instrument, equal to the ratio of the mass of biological material from the dispersed phase to the accumulated phase sodium), and a fan equal to the ratio of the analysis, which entered the input room, are distributed to the whole volume. f5 is about ;; device version Samples of labeled aerosol are taken from the aerodynamic resistance,

those. the energy consumption for the selection of equal sample volumes, determined by the flow areas of the instruments, is chosen to be equal for both devices, which allows to compare their trapping rates depending only on the end

chambers for 2 min at the same time offered by the device for microbiological analysis of air and known, and then the mass is determined. sediments of the dispersed phase in the bunker, on the inner surfaces of the body and on the filter installed behind the device, using washings from these elements p equal amounts of solvent - 25 50 ml (the liquid from the bunker is also brought to volume. 50 ml) and O11 limits of instrumental features .

The distribution of precipitation and the volumetric velocities of the devices, depending on the regulated vacuum of the aspirator, are shown in Table. 1.In the bunker,%

ten

Dependence of the degree of capture of dispersed particles on the diameter (D is the diameter of the upper cylinder

 The degree of capture,%

The dependence of the degree of capture of dispersed particles in the device from

The color intensity is dissolved using a fluorometer (the color intensity of the solution is proportional to the mass of the dispersed phase in the sediment). The total mass of sediment in the bunker, on the surfaces of the device and on the filter is taken as 100%, the ratio of the mass of sediment in the bunker to the total mass is expressed as a percentage and is determined

to the degree of capture dispersed by the device, equal to the ratio of the mass of the dispersed phase accumulated in the bunker, to the mass of particles, directed to the analysis received in the input about ;; device version. Aerodynamic resistance

20

, 25 structural features.

The distribution of precipitation and the volumetric velocities of the devices, depending on the regulated vacuum of the aspirator, are shown in Table. 1.Tablicea 1

Known device 89 93 85

71

43

The meter outlet pipe of the air withdrawing cylinder is shown in Table. 2. Table2

1.5D

2D

3D

4D

92

96

95

91

the angle of the cone of the inlet pipe is shown in Table. 3

Angle of the nozzle,

grad25

The degree of capture,% 96

The dependence of the degree of trapping of the packing element (d is the diameter of the dispersed particles on the distance between the perforation holes) is shown in the center of the perforation holes of the impeller. .four.

Table4

The distance between from. Dependence of dispersed phase trapping degree, on its content

Cell concentration

in liquid, cells / ml 1x10 1x10

Cell concentration in liquid, g / l

The degree of capture,%

The device makes it possible to increase the determination of the concentration of the dispersed phase in air and the selection of a representative sample in a short period of time at low and background values of the microbial contamination of the air environment.

Claims (1)

1. A device for microbiological analysis of air, containing a cylindrical body with a hopper for sorption liquid and a dispersed phase trapped in it, an inlet with a spiral plate and a nozzle connected to the hopper by a tube immersed in a sorption liquid, perforated by impact, an element located opposite catching surface at a distance of from 0.5 to 5 diameters of perforation offsets, outlet nozzle, on the table 30 96 35 94 40 90 in the sorption liquid is shown in table. 5. 25Table5 5x10 1x10 2x10 " thirty .50 100 200 96 91 32 12 In order to increase the degree of capture of the dispersed phase from the air and reduce entrainment of the absorption liquid, the casing is installed vertically, the impacting element is placed on the end surface of the inlet nozzle, while the latter is made in the form of a truncated cone and is equipped with a glass outside and having tangentially located longitudinal slots in the lateral surface, an air discharge cylinder is installed in the upper part of the body, and the outlet nozzle is fixed on it tangentially. 2, the apparatus according to claim 1, characterized in that the nozzle is installed at the minimum cross section of the inlet nozzle, the diameter of the outlet nozzle is equal to the diameter of the inlet in this cross section and is half the diameter of the air vent cylinder.