SU1220195A1 - Method of electric removal of dust from gases - Google Patents

Description

This invention relates to the field of electrical gas cleaning from dummies and can be used in various industrial zones to increase the efficiency of electric gas dosing from dips.

The aim of the invention is to increase the degree of purification of gases and reduce the size of electrostatic precipitators.

FIG. t shows a device diagram of f-gas in zone 1 must be at least

with the help of which it was carried out -1.2 m / s (the Reynolds number is more than

This method is illustrated in FIG. 2 - vari-13000). ant device execution.

If the diameter of the precipitating elements is 0.01, the distance between them, zone 1, located near the corona-15 is also 0.01 m, then at the drift velocity {electrodes 2, the deposition zone in the electric field is 0.05 m / s,

necessary for the particles to achieve a precipitating surface, with a laminar gas flow between these elements (the Reynolds number is less than

2000) will be 0.1 s, and the gas velocity should be no more than 0.1 m / s. From here it can be determined that the length of the deposition electrode should be 25 liters 3.6 m, and the residence time of the gas in the electrostatic precipitator is 6 s, which is 2.3 times less than 13.8.sec for a known electrostatic precipitator.

The optimal range of values (the number between the corona-emitters and the 30-Reynolds OS is more than 13,000 for the conditional electrodes of 0.15 m and the charging speed of the dust particles in the turbine gas in the charging zone should not be within the band and less than 2000 for sedimentation of particles in the conditions of laminar motion) was determined as a result of experimental mastering of the method of electrical gas cleaning from the core. : The test results are presented in the table.

The device includes a turbulent

3, located near the electrodes 4. Example 1. The powdered gas stream enters the turbulent zone (the Reynolds number is more than 13,000) of the unipolar corona discharge, in which the turbulent pulsations due to turbulent pulsations increase the probability of dust particles passing through the area near the corona electrodes 2, where the increased charge of the particles is achieved due to the maximum the intensity of the electric field and the density of ions in this region.

less than 1.2 m / s. The particle charge, close to the maximum (more than 90%), is reached in a time of 0.1-0.2 s.

Then the dust and gas flow is forcibly transported to the sedimentation zone} 3, where the movement of the laminar gas (. Reynolds number is less than 2000), by means of the aerodynamic forces of the gas flow.

To create an electric field, a potential difference of about 35-50 kV is applied to the electrodes 4. At a distance of 4 0.15 m between the electrodes, the gas velocity should not exceed 0.18 m / s, and the residence time of the gas in the deposition zone should not be less than 3 s.

Thus, the residence time of the pie-gas flow in the core of the electrostatic precipitator is 3.2 s, which is 4.3 times less than in a conventional electrostatic precipitator.

Example 2. The electrostatic precipitator is equipped with corona electrodes 2 (see Fig. 2) and precipitation electrodes 45

50

55

Dyed gas from the turbulent zone 1 (the Reynolds number is more than 13000), where the particles are charged, is forcibly divided into laminar flows in the gaps 6 between the elements of the collecting electrodes 5, At a distance between the precipitating and corona- ruyuprmi electrodes 0.15 m speed

An analysis of the test results shows that when charging dust particles in the gas flow zone when the Reynolds number is more than 13,000, and when part of the dust is deposited in the zone of motion of the gas flow with the Reynolds number less than 2000, there is a sharp increase in the efficiency of cushioning in the electrostatic precipitator.

It is known that the degree of purification of gases is determined in accordance with the equation

one

- f N

(one)

where W is the drift velocity of particles, m / s,

The gas exposure time in the core of the electrostatic precipitator is

 L is the length of the core, m, V is the gas velocity, m / s, H is the distance between the corona and collecting electrodes, m.

Equation (1) is derived from the condition of uniform distribution of the particle concentration over the cross section of the interelectrode gap. In existing electric filters operating at gas velocities of about 1 m / s or more, gas movement in the core of the electrostatic precipitator is always turbulent with numerical values of the Reynolds number 2600-13000, while the concentration of particles of a pie less than 20 µm is equal in the cross-section of the gap and equation (1) is valid. 4Q

In accordance with equation (1), to achieve a degree of very good 99%. for particles with a diameter of 1 µm, when the particle drift velocity in the electric field is W 0.05 m / s and the distance between 45 corona and collecting electrodes H 0.15 m, the residence time of the gas in the core of the electrostatic precipitator is 13.8 s.

50

If the deposition of particles is carried out under laminar gas flow conditions, then the time required to reach the most remote particle of the deposition electrode will be 55

20

25

thirty

- - “- W

0, T5

3 s

those. 4.6 times less than in known electrostatic precipitators. In the turbulent zone of the electrostatic precipitator, the Reynolds number over 13000 is achieved by decreasing the cross-sectional area of the inter-electrode corona channels in the direction of gas flow, and in the laminar zone the Reynolds number less than 2000 is due to the implementation of precipitation electrodes.

bulky surfaces with large; . Coefficients of the living section, Forced transport of iBcex charged particles allows them to be mechanically transported,

 in addition to the electric, to the collecting electrodes, where the deposition occurs, the particle values in the laminar zone,

NPiJD transportation of breeders-lacTsni; The laminar zone, by means of the aerodynamic forces of the gas flow, provides not only a consistent flow direction for all suspended particles, but also allows the creation of conditions for the complex use of the same gas head, respectively, for charging and desiccation of the particles.

Forced transport of charge; enh particles is achieved by

performing the interelectrode turbulent charging zone in the form of a dispensing channel with porous bulk precipitator-Hbit iH elements, inside the cells of which. an electroplating process takes place.

35 4Q

45

50

55

 The technical and economic advantages of this method lie in the fact that it is possible to significantly increase the degree of electrical cleaning of gases from a plug at a low cost. In addition, it can be practically implemented both on already operating electrostatic precipitators with increased dust and gas flow rates (short residence time of the flow in the core) and on construction sites. reducing the size by forcing the transport of charged particles into the zone of laminar movement, due to the aerodynamic flow of the gas.

Thus, if the optimum values of the Reynolds number (more than 13000 in the turbulent zone of the electrostatic precipitator and less than 2000 for the conditions of efficient deposition of the plush particles in the laminar zone) are observed and the forced transport of the charged particles to the zone

$ 12201956

sedimentation due to aerodynamic particles with a decrease in size and a decrease in the gas flow is provided for by the residence time of the piezo-gas-effective degree of trapping of the flow in the electrostatic precipitator.

Zvytylentsh mmos gas

 BQseS stream

Claims (1)

METHOD OF ELECTRIC CLEANING OF GASES FROM DUST, including charging dust particles in a unipolar corona discharge field and depositing them in an electric field, characterized in that, in order to increase the degree of gas purification and reduce the size of the electrostatic precipitator, charging is carried out in a turbulent zone with a Reynolds number of more than 13000 and the deposition of particles is carried out in the laminar zone with a Reynolds number of less than 2000. Dusty Nomeft Zoo Yu SP> 1 1220195