SU902795A2 - Scrubber - Google Patents

Description

(5) DEVICE FOR WET GAS CLEANING

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The invention relates to a technique for cleaning gases from dust of liquid aerosols and can be used in chemical, petrochemical, metallurgical, energy and other industries that need to be cleaned before they are released into the atmosphere.

A device for wet gas cleaning is known, which includes a coagulation chamber equipped with coaxially mounted sound pipes for supplying dusty gas, which are equipped with nozzles for spraying liquids, swirlers, annular nozzles installed coaxially to the inlet ends of the accelerating tubes, and With branch pipe C 1.

A disadvantage of the known device is the low efficiency of dust collection, especially of its fine fractions, due to the sharp expansion of oncoming gas flows at the entrance to the chamber and the decrease in density.

irrigation of the gas to be cleaned with washing liquid to the zone of jets impact.

By bus Nb5b6 6 a device for wet gas cleaning is known, which includes a coagulation chamber, acceleration channels of dusty air directed towards each other, made narrowing along the length, the outlet openings of which are located at a distance from each other in one plane inside the coagulation chamber, and the nozzle for spraying liquids located in the narrowing parts of the accelerating channels C 23.

A disadvantage of this device is the low intensity of the dust capture of the low energy of the gas phase pulsations in the zone of the jet impact due to the sharp expansion of the gas flow upon entering the coagulation chamber, i.e. fast conversion of the kinetic energy of the streams to the potential, as well as from

for a sharp decrease in the Oroshe density. and the wash liquid of the expanding jet of gas to be purified, since the particles of the sprayed liquid of a larger size do not have time to deviate from the flow axis and therefore are concentrated in the center of the jets, as well as incomplete use of the washing liquid caused by the formation of a liquid film on the wall a narrowing part of the acceleration channels, which is carried by the gas flow into the coagulation chamber and flows in the form of streams or splashes from the exit edges of the channels.

The aim of the invention is to intensify and stabilize the gas cleaning process.

The goal is achieved by the fact that the device is provided with cylindrical rings mounted coaxially with the outlet openings of the acceleration channels with the possibility of axial movement.

Figure 1 shows the proposed device, a longitudinal section; figure 2 - the same cross section.

The proposed device for wet gas cleaning includes a coagulation chamber 1, accelerating channels 2 in the form of diffusionless Venturi tubes, consisting of a confuser 3 and necks C. In the confusers 3, nozzles 5 are installed for spraying the washing liquid. Coaxially to the necks k closer to the output edge, cylindrical rings 6 with a diameter greater than the outer diameter of the neck are installed. To the outer wall of the ring 6, the connecting rods 7 are attached to the axial movement mechanism 8. The mechanism 8 moves the ring 6 relative to the throat, thereby changing the aerodynamics of the expanding jet of gas to be cleaned. The coagulation chamber 1 is provided with a venting pipe 9 and a pipe 10 for draining sludge.

The stabilization of the cleaning process is achieved by improving the aerodynamics of the occurring jets of gas to be cleaned and crushing the wash liquid film that forms on the wall of the converging portion of the accelerating channels 2 at the outlet of the gas flow to the coagulation chamber 1.

The proposed device for wet gas cleaning works as follows.

Dust-laden gases are directed into the acceleration channels 2, compressed into

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3) where dust wetting liquid is sprayed through the nozzles 5- Next, finer crushing occurs in the throat

liquid drops due to high velocities of gases in throat k, and particles of liquid acquire high speeds of movement, which allows them to coagulate intensively

with dust particles in the interfacing space of accelerating channels 2 inside chamber 1. At the exit from the neck k, the gas flow passes through a cylindrical ring 6, where the ejection sy-,

The jet stream is used to form the recirculation of an already purified gas inside chamber 1 to the jet being cleaned in the direction from the confuser 3 to the collision zone.

jets through the annular gap between the throat k and the ring 6. This achieves an additional compression of the jets of the gas to be purified and increases the energy of the pulsations of the gas flows into the gas without impacting the jets.

In addition, the part of the liquid that forms the film on the walls of the confuser 3 and the neck C, in the ring 6, is crushed by gas that is sucked into the jet

O through the annular gap between the ring 6 and the neck 4, thereby increasing the irrigation density with the washing liquid of the gas being purified in the core of each jet, i.e. on the plot from

- the output end of the neck k to the area of the impact of the jets.

Gas purification from dust occurs as a result of intensive coagulation of the liquid and solid dispersed phases in the gas jet and in the meeting area of the flows. The dust caught in the liquid droplets in the form of sludge is discharged from the apparatus through the drain pipe 10, and the purified gas through the gas outlet pipe 9 enters the droplet separator.

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The degree of compression of the jet and the amount of gas recirculated through the annular gap between the neck k and the ring 6 depends on the location of the ring 6 relative to the outlet edge of the neck k, and therefore, in order to adjust the gas cleaning efficiency, it is possible to make the ring 6 movable relative to the neck 4, securing it On tgakh 7 and those, in turn, connect to the mechanism 8 ocejc o movement.

On a laboratory prototype of the proposed device with a throat diameter of accelerating channels 2 equal to 10 mm, investigations were carried out on cleaning air from tobacco smoke aerosols with an initial concentration of 0.9-0.8 g / nm, which showed that when installing a cylindrical ring with an annular gap with respect to the outer diameter of the neck 4 equal to 1.25 mm in the range of velocities of the purified air at the outlet of the neck k equal to m / s, the overall efficiency of air purification was 9-15% higher. It was noted that the hydraulic resistance of the apparatus increased by, 5 and the amount of gas recirculated through the annular gap was approximately 8-15% of the total amount of gas passing through the cross section of the throat of the accelerating channel. Water was used as a washing liquid.

; The advantage of the proposed device in comparison with the known method, which allows to increase the intensity and stabilization of the gas cleaning process, is to increase the energy of the gas phase pulsations in the jet impact zone and the increased degree of utilization of the washing liquid in the apparatus, as well as the ability to control the intensity of the dust collection process the edges of the neck of the cylindrical ring forming an annular gap with the neck and connected to the axial movement mechanism.

If it is necessary to clean the gas from dust and vapor-gas impurities, it is necessary to spray liquid reactants in the accelerating channels, which facilitate the removal of vapor-gas impurities.

A positive effect with the widespread introduction of the proposed device in all branches of the national economy is to create highly efficient and cost-effective devices for cleaning smoke and ventilation debris before being released into the atmosphere, to reduce the concentration of harmful substances in the surface air layer of industrial sites of enterprises.

Claims (2)

1. USSR author's certificate No. 659173, class On 01 D, 1976 2. USSR author's certificate number 6566A6, cl. In 01 Oh, 1977.