SU1632471A1 - Scrubber for cleaning dust-laden gases - Google Patents

Abstract

The invention relates to the wet cleaning of dusty hot gases from water wettable dust and can be used to clean gases after drying installations in the medical, food and chemical industries. The purpose of the invention is to increase the efficiency of the scrubber and the operational reliability of the scrubber. The invention achieves this goal due to the fact that the scrubber plates 8 are configured to synchronously rotate around the longitudinal axes 11 of rotation, which divide each plate into two parts so that the ratio of the length of the first part of the plate along the gas direction to the second lies within 1 5-2.5. Thus, water enters chamber 3 in the form of jets of a large cross section, which prevents their crushing by air and their further entrainment. 1 hp f-ly, 13 ill.

Description

The invention relates to the wet cleaning of dusty hot gases from wettable water. Dust and can be used to clean gases after drying plants in the medical, food and chemical industries.

The aim of the invention is to increase the efficiency of gas cleaning from dust and increase the operational reliability of the scrubber.

Figure 1 is a schematic representation of the structure of a scrubber; Figures 2 and 3 are embodiments of the plates of the last row; figure 4 - scrubber, top view; Figures 5-7 show the layouts of the plates at different positions of the axis of rotation of the plates; Figures 8-12 show the layouts of the plates at their angles of inclination to the vertical of 10, 20, 30, 45, and 60 °, respectively; on Fig is a graph of the dependence of gas cleaning efficiency on the angle of inclination of the blades. °

The scrubber contains an irrigation system 1, packages of 2 rotary plane-parallel plates, installed in the gas flow direction, separation chamber 3, gas distributor 4, inlet 5 and outlet 6 nozzles, outlet 7 of the liquid outlet. The plates 8 of the package 2 are divided into two parts 9 and 10 of different lengths by the axis 11 and are installed with the possibility of synchronous rotation, in one direction within the package 2 and in opposite directions in even and odd rows. The ratio of the length of the first in the course of the gas part of the plate to the length of the other part is 1.5-2.5.

The gas distributor 4 is made in the form of a hollow cylinder with louvered slits.

12 and placed coaxially discharge pipe 6.

All elements are placed in the housing 13.

Scrubber works as follows ..

The dust-laden gas is supplied to the nozzles of the irrigation system 1 through the inlet pipe 5 and mixed with dispersed water. In this zone there is a wetting of dust particles and, accordingly, an increase in their mass. After that, the gas-liquid mixture is directed onto the stack of 2 plane-parallel plates 8. On the inclined plates 8 of the stack 2, the wetted dust and water particles are precipitated. Stack on the plates in the form of a film, water washes away precipitated dust particles from one row of plates to another.

Due to the inertial forces resulting from a change in the direction of the gas-liquid flow, effective separation of solid and liquid particles from the gas-liquid flow is achieved. To prevent deposits of dust on the lower surfaces of the plates, the latter are periodically shifted to a position symmetrical with respect to vertical planes passing through the axes of rotation of the plates. In this case, a film of water washes the reverse side of each plate.

8, the separation chamber 3 water enters the form of jets formed on the edge of the lower row of plates, which prevents the water from splitting into small droplets by air flow and carried away from the apparatus. This contributes to the implementation of the lower edge of the gear (Figures 2 and 3).

The plane-parallel plates 8 serve to form a labyrinth of the ploshchadny type, on the wetted surfaces of which sedimentation of suspended particles occurs, 8 the working position of the plate is set at an angle of 30 ° to the vertical in one direction or the other.

The operation time of the plates in one position depends mainly on the properties of the material being caught and is from tens of minutes to several hours. A graph of gas cleaning efficiency versus plate inclination is shown in FIG. 13.

In order to ensure the switching of the plates 8 from one position to another, it is necessary to ensure a distance between the axes of the adjacent plates that are equal in size or greater than their length.

Water with dissolved or suspended dust is discharged through pipe 7,

The gas containing small water droplets that do not fall on the plates, the passage through the separation chamber 3, is cleared of droplets

due to a sharp decrease in the flow rate, flows through the gas distributor 4 into the region of the purified gas and leaves the apparatus.

The gas distributor 4 serves to disperse the cleaned gas outlet by leveling the gas velocities both in the vertical and horizontal sections of the separation chamber. This contributes to a more complete deposition of droplets and suspended particles. Partially this device performs the role of the second stage of separation. .

The constructive execution of the gas distributor (Fig. 4) makes it possible to get it compact, working across the entire side surface.

Figure 5-7 shows the schemes of the plates with different lengths of the blades -t-2 and

with extreme values

From the diagram it can be seen that when -t-2 provides 4, where a is the length of the first part of the 10 plates along the gas flow; b - the length of the second in the course of the gas part 9 plates.

but

b

The overflow of the liquid film from the plates of the upper row to the plates of the lower one, while the plates of the lower row are almost completely washed by the fluid, i.e. Provides conditions for the effective operation of the apparatus. With 1 film overflow

fluid is poorly supplied. Most of the lower plates are practically not bathed in liquid. In addition, the liquid from the extreme plates can flow onto the side walls, which leads to the formation of material deposition on them.

4, a significant portion of the surface of the f plates is not bathed in liquid. In addition, in this case, the non-uniformity of the gas flow in the area of the plane increases (allele plates and one of the extreme plates of the first row, as can be seen from Fig. 7, has a significantly greater load.

Thus, the optimum is

The range of the ratio of the length is $ - 1.5-2.5.

Outside of this ratio, the package is less efficient.

Figures 8-12 show diagrams showing the positions of the plates at angles of inclination to the vertical of 10, 20, 30, 45, and 60 °.

As can be seen from Fig. 8, at an angle of inclination, the channel between them has a small curvature. The forces of inertia of suspended particles with a deviation of flow of 10 ° small plates of 10 °

shiv, a significant breakthrough of them is possible, especially since in this case it is difficult to ensure the flow of a liquid film over the entire surface. To prevent the flow of suspended particles, it is necessary that the channels be narrow.

At an inclination angle of the plates of 20 ° (Fig. 9), the particle trapping efficiency is higher than at an inclination angle of 10 °, since the inertia of the particles is higher. However, in this case there are the same drawbacks as in the previous

When the angle of inclination of the plates is 30 °, the degree of purification is highest (Fig. 13). In this case, a liquid film is easily achieved over the entire surface of the plate, and the inertia forces of the suspended particles are quite large, since the upper plates onto the lower films and the flux flow at an angle of 60 °. This ensures the normal movement of the gas stream and the liquid film.

When the plates are inclined at an angle of 45 °, the cleaning degree drops and the working conditions deteriorate. This is due to the fact that the flow from the top plate to the bottom runs at an angle of 90 °, the formation and flow of the liquid film is disturbed, and a part of the liquid moves up the plate and is thrown over its upper edge.

At an inclination angle of the plates of 60 °, the degree of cleaning is even lower, since the flow from the top to the bottom plate runs at an angle of 120 ° and the liquid film is blown up, the film flow along the plate is disturbed. In that

If, in all other cases, with the inclination angle of the plates over 45 °, the cleaning efficiency of dusty streams is low.

Thus, optimal conditions

cleaning of dusty gases, caused by the conditions for the formation of a liquid film and the necessary inertial force of suspended particles, is realized at the angles of inclination of the plates to the vertical close to 30 °.

Claims (2)

1. Scrubber for cleaning dusty gases, including the housing in which the rotating packages are installed plane-parallel plates, inlet and outlet nozzles, irrigation system, gas distributor, characterized in that, in order to increase the efficiency of gas cleaning from dust and increase operational reliability, the packages of plane-parallel plates are placed on the bottom along the gas flow, and the plates are fixed with the possibility of simultaneous rotation one way within each package and in opposite sides in even and odd rows of packets, each plate being divided by an axis of rotation into two parts with the ratio of the length of the first part of the plate along the gas flow to the length of the other parts 1.5-2.5. 2. Scrubber pop-1, characterized in that the gas distributor is made in the form of a hollow cylinder with louvered slits and is placed coaxially with the gas outlet nozzle. 1 FIG. 2 FIG. five B my UWE91 angle 10 ° FIG B angle of 20 ° Fig.9 In FIG. 7 I; 1} DGM AsZo Fig.Yu i ugo / to 450 FS.11 thirty SOZO & Angle of Lobe% Zrad angle a - 60 ° (Rig. / 2