RU2356633C1 - Dust catcher - Google Patents

Abstract

FIELD: instrument making.

SUBSTANCE: invention relates to devices designed to separate dispersed particles from gases or vapours. The proposed dust catcher comprises a casing to house a ring, at least, a part of which is perforated. The slit nozzle designed to let polluted gas in, is brought inside the casing and attached to the ring top part, tangentially to its inner surface. Note here that the nozzle is arranged at an angle to the ring horizontal section plane and directed towards its lower part. Dust collector bin is attached to the casing bottom, while the casing top part has a purified gas outlet. The space between the casing and ring serves to lift purified gas, the said space volume exceeding that inside the ring.

EFFECT: higher efficiency of separating finely dispersed dust.

5 cl, 5 dwg

Description

The invention relates to devices for separating dispersed particles from gases or vapors using gravitational inertial or centrifugal forces with a change in the direction of the stream being cleaned.

Known devices for cleaning gases from dust, in which cleaning occurs through the use of inertial forces. The attractiveness of such devices lies in the fact that they are structurally simple, but the efficiency of dust cleaning in these devices is not always sufficient.

It is especially difficult in such devices to purify the gas stream from light dust fractions.

Inertial dust collector designs are known in which perforated inserts and shells are used.

The patent GB 1283842 “Centrifugal separator”, publication 02.09.1972, B04C 5/103, describes the design of the separator, which contains the inlet pipe (10), chippers (16), directing the flow to the walls of the separator and a perforated screen (34). The purified stream partially passes through the openings of the screen and is discharged through the pipe (30). Folds (36) are made on the perforated screen, which serve to slow down the flow.

In this design, there is no sharp slowdown of the flow behind the perforated screen, therefore this design does not sufficiently capture light dust fractions.

Also known patent US 4778494, publication 18.10.1988, B01D 19/00 and patent RU 2302296, publication 10.07.2007, B04C 5/00.

US 4,778,494 discloses a cyclone separator for separating gas from a liquid. This separator uses a perforated insert. RU 2302296 shows the design of a vortex chamber for separating multiphase flows, which contains a cylindrical body with tangential inlet nozzles. An insert is installed in the housing in the form of a truncated conical surface with a perforated upper part that separates the housing into a working and receiving cavity. The swirl chamber is equipped with fittings for the removal of gases, solid and liquid products.

However, these perforated elements are used in devices designed to separate liquid from gas.

The following dust collector designs are also known: patent for the invention of the Russian Federation No. 2174452 “dust collector”, priority 10.10.2000, patent for a utility model of the Russian Federation No. 33879 “dust collector”, priority 10.11.2002, which describes the design of the dust collector containing a cylindrical housing in the upper part which tangentially to the inner generatrix of the housing has a slotted nozzle for introducing contaminated gas. Pockets are made along the generatrix of the case; the closest wall in the direction of flow is the wall of each of the pockets made in the form of a ledge. The space in the center of the casing is connected with the outlet pipe via a vertical pipe, and a dust collection bin is attached to the lower part of the casing.

These designs are quite effective, especially for the capture of coarse dust, but there is always the problem of efficient capture of fine dust as well. Creating a design in which the finely dispersed dust fraction was effectively captured is a difficult and urgent task.

The present invention solves the problem of increasing the efficiency of collecting fine dust fractions.

The inventive dust collector comprises a housing inside which a shell is installed, at least a portion of the shell is perforated.

A slit nozzle for introducing contaminated gas is introduced into the housing and is attached tangentially to its inner surface in the upper part of the shell, while the slot nozzle is directed at an angle to the horizontal plane of the shell with the orientation toward its lower part.

A dust bin is attached to the bottom of the housing.

In the upper part of the housing, the outlet of the purified gas is made.

The space between the housing and the shell is designed to lift the purified gas and is larger in volume than the space inside the shell.

The input stream of contaminated gas enters through the slotted nozzle and “sticks” to the inner surface of the shell. Further, the flow propagates along this inner surface down a spiral. During the passage of a contaminated gas stream, the particles of dirt rub against the walls of the shell, lose mechanical energy and settle down, gathering in the dust collection bin. Fine dust, moving down, also enters the hopper. Gas penetrates through the perforation of the shell and exits through the outlet of the purified gas located in the upper part of the housing. The gas stream is also cleaned of dust due to the fact that the volume inside the shell where the dusty stream moves is less than the volume between the shell and the body where the cleaned air rises. Therefore, the flow rate inside the shell is higher than the speed of the purified air rising to the outlet, which prevents the manifestation of the effect of "suction" of dust particles in the volume between the shell and the housing into the perforation holes.

Inside the shell, a cylindrical reflector can be additionally installed, which allows you to adjust the volume inside the shell without changing its diameter and creating the necessary ratio of volumes inside and outside the shell. In addition, a cylindrical reflector presses the flow against the wall of the shell, improving the braking conditions of dust particles.

Additionally, the volume of the said hopper can be isolated from the volume between the inner surface of the housing and the outer surface of the shell, for example, a washer. The installation of such insulation prevents the penetration of dust from the hopper into the volume between the shell and the housing where the purified gas rises.

For more efficient cleaning of the dusty stream inside the shell, pockets can be made on the inner surface of the shell, the closest wall of each pocket in the direction of the incoming gas stream is made in the form of a step.

On the way of a flat vertical gas flow on the surface of the shell there are ledges. A zone of reduced pressure arises behind each step, due to which the flat main vertical flow, according to the Coanda effect, deviates to the wall of the shell, as if “sticks” to it. Behind each step, in the zone of reduced pressure, a vortex circulation flow arises. Thanks to this design, the flow of dusty gas is always located at the inner wall of the shell, making a spiral motion, dropping down. The formation of a flow falling down the shell contributes to the location at an angle to the plane of the horizontal section of the slit nozzle body, with the orientation towards the lower part of the body. At the same time, the purified air passes through the perforation holes into the shells and rises up at a low speed.

The slotted nozzle can be oriented at an angle to the plane of the horizontal section of the shell in the range of angles 10-20 °.

This design of the dust collector allows you to capture coarse and medium dispersed dust particles, but is especially effective for fine dust particles. The greater the difference in volume inside the shell and the volume between the body and the shell, the lower the rate of rise of the purified gas inside the last space and the more efficient the cleaning of the finely divided fraction.

The invention is illustrated by drawings. Figure 1 shows a General view of the dust collector, figure 2 is a cross section of the upper part of the dust collector, figure 3 is a diagram of air and dust in the dust collector. Figure 4 is a cross section of the upper part of the dust collector for shell with pockets. Figure 5 shows only a shell with an attached slot nozzle.

The dust collector (FIG. 1-FIG. 3) contains a housing 1, inside of which a shell 2 is installed. A part or all of the area of the shell 2 is perforated 10. A slit nozzle 3 for introducing contaminated gas is introduced into the housing 1 and tangentially attached to the upper part of the shell 2 the inner surface and is directed at an angle A to the plane of the horizontal section of the shell 2. To the lower part of the housing 1 is attached a hopper 4 for collecting dust. In the upper part of the housing 1, an outlet 5 of purified gas is made. The space 6 between the housing 1 and the shell 2 is designed to lift the purified gas and is larger in volume than the space inside the shell 2. Inside the shell 2, a cylindrical reflector 11 is installed along its axis. The space of the hopper 4 is isolated from the space 6 between the inner surface of the shell and the outer surface of the shell washer 7.

Perforation 10 of the shell 2 can be performed in various ways, for example, holes can be located in the lower part of the shell or on its entire surface. The shape and direction of the holes relative to the surface can also be different. The total area of the holes in the shell with respect to the entire area of the perforated surface of the shell is controlled depending on the dusty nature of the gas stream, and may, for example, be about 50% of the area of the perforated surface of the shell.

When a dusty gas is supplied through a slotted nozzle 3 by means of a blowing fan, the flow is tangential to the inner surface of the shell 2, dust particles are braked on the inner surface and fall into the hopper 4. The purified gas penetrates through the perforation 10 of the shell 2, rises in space 6 and exits through yield 5 purified gas. The speed in the volume of the shell 2 and the speed of the gas rising inside the space 6 between the shell and the housing may differ, for example, ten times. This allows in this design of the dust collector to clean light fractions of dust that are entrained by the flow into the hopper 4. Dust from the hopper does not enter the space 6, since the path is blocked by the washer 7.

On the inner surface of the shell 2 in a more efficient embodiment (FIG. 4), pockets 8 are made in the shell 2, and the wall of each pocket is the closest in the direction of the incoming gas flow in the form of a step 9.

The contaminated gas is fed through the slotted nozzle 2 into the shell 2 using a blower fan. The gas flow is twisted inside the shell 2 into a decreasing spiral, while a vacuum is created in the zone of ledges 9. The vortex flows in the pockets 8 help to reduce the speed of dust particles, which along the generatrices of the pockets 8 fall into the hopper 4. In this case, the dust is more effectively captured in the pockets 8. The purified gas also leaves through the perforation holes 10 into space 6 and rises.

Claims (5)

1. A dust collector, characterized in that it contains a housing inside which the shell is mounted, at least part of the shell is perforated, a slotted nozzle for introducing contaminated gas is introduced into the housing and attached tangentially to its inner surface in the upper part of the shell, while the slotted nozzle is directed at an angle to the plane of the horizontal section of the shell with the orientation towards the bottom, a dust bin is attached to the bottom of the case, and the outlet is cleaned at the top of the case of gas, the space between the shell and the shell is intended for lifting the cleaned gas and the volume is greater than the space inside the sleeve. 2. The dust collector according to claim 1, characterized in that a cylindrical reflector is additionally installed inside the shell. 3. The dust collector according to claim 1, characterized in that the volume of the said hopper is isolated from the volume between the inner surface of the housing and the outer surface of the shell, for example, a washer. 4. The dust collector according to claim 1, characterized in that pockets are made on the inner surface of the shell, the wall of each of the pockets closest in the direction of the incoming gas stream is made in the form of a step. 5. The dust collector according to claim 1, characterized in that the said slotted nozzle is oriented at an angle to the plane of the horizontal section of the shell in the range of angles 10-20 °.

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