RU2809402C1 - Electric filter - Google Patents

Abstract

FIELD: purification of gases.

SUBSTANCE: invention relates to the purification of gases from dust. The device includes a cylindrical housing with a swirler, gas inlet and outlet pipes, dust concentrate outlet pipes, corona and precipitation electrodes, a hopper and a high-voltage power supply. The swirler is made in the form of an even number of electrically conductive blades-plates installed inside the housing in its upper part parallel to the cylinder axis and oriented in spiral directions. The blade-plates are electrodes, and the corona surfaces are the sharpened edges of the plates facing the axis of the spiral - the axis of the body. The collecting electrodes are the side surfaces of the plates facing the adjacent discharge electrodes. The inlet pipes are located between the electrode plates and are tangentially cut into the body. The power supply is made in the form of two transformers with rectifiers for galvanic isolation of positive and negative corona discharges or in the form of a multi-winding transformer with a primary winding and a number of secondary windings and rectifiers connected at the output of the secondary windings. The first secondary winding with its rectifier is connected to the clamps of the electrode plates in pairs and parallel. The remaining windings with their rectifiers are connected to electrode plates individually for each unipolar discharge gap.

EFFECT: increased cleaning efficiency and reliability of the device.

2 cl, 4 dwg

Description

The invention relates to the sanitary purification of air from dust and microorganisms, the purification of process and ventilation gases and can be used in the energy sector, in medical institutions, as well as in other sectors of the national economy where it is necessary to purify gases from dust.

A known installation for purifying gases from dust (see US patent No. 4072477 M.Kl. V03S 3/01,1978), including a housing, a system of charging electrodes for purified gas, a system of charging electrodes for filter material, a cyclone for separating heavy particles and a hose filter for cleaning from small dust fractions. Dust separation in the installation is carried out due to the fact that floating charged particles of filter material and dust, charged in opposite ways, are attracted to each other by electrostatic forces.

The disadvantage of this installation is that the gas flow must be cleaned in a cyclone, where coarse dust is captured, and then in a bag filter to remove small dust fractions, while dust particles coagulated on the particles of the filter material can be separated from the latter due to the insignificant adhesion force .

An inertial-electrostatic dust concentrator is also known (A.S. USSR No. 559726, M.Kl. V03S 3/14, Inertial-electrostatic dust concentrator / Yu.A. Dolbnya, M.Ya. Protsaylo. Application. 03.12.1975; Publ. 30.05 .1977, Bulletin No. 20), including a housing with a swirler located in it with dividers, blades and pipes for inlet of the purified gas, outlet of the purified gas and outlet of the concentrate, and the housing is equipped with additional blades located between the blades of the swirler. The swirler is connected to one of the poles of the high-voltage current source and is a discharge electrode, and the body with blades is connected to the other and is a collecting electrode. In addition, the additional blades are made in the form of a wedge, and the gap between the top of the wedge and the swirl dividers is equal to the interelectrode distance.

The purified gas, passing through the channels between the blades, swirls, and large dust particles, due to inertial forces, are thrown towards the walls of the housing, at the same time all dust particles pass through the channels between the electrode blades, are charged in the electric field of the corona discharge and, under the influence of electrostatic force, also rush towards body. The use of the described device makes it possible to increase the efficiency of gas purification when operating as an upstream stage in front of an electric precipitator, but requires the installation of an additional blower fan to create the required gas flow rate and greater labor costs for cleaning the collecting electrodes.

An electric precipitator for purifying gases from dust is also known (RF Patent No. 163132 M.Kl. V03S 3/14. Electric precipitator / Porsev E.G., Konovalenko A.I. - Inventions and utility models of the Russian Federation: application 12/09/2015, publ. 07/10/2016, Bull. 19), which is a prototype of the claimed technical solution, containing a cylindrical body with a swirler, pipes for gas inlet and outlet, pipes for inlet and outlet of dust concentrate, corona and precipitation electrodes, a hopper and a high-voltage power supply, and the body is made vertical with a lower conical part, the swirler is made in the form of an even number of electrically conductive blades-plates installed inside the housing in its upper part parallel to the axis and oriented in spiral directions, and the blades-plates are electrodes - the corona surfaces are sharpened ribs of the plates facing the central axis spirals are the axes of the housing, the inlet pipes are placed between the electrode plates and are cut tangentially into the housing, the electrodes are connected to the poles of the power source in pairs and parallel. In addition, an outlet pipe for dust is located coaxially with the housing in its conical part, coupled with the hopper, and in the upper part of the body there is an outlet pipe for purified gas, and the outlet pipe is lowered into the housing to the level where the conical part of the body meets the cylindrical one.

The electric precipitator allows for deep cleaning of dusty gas from large and small dust particles, but due to the fact that the intensity of the corona discharge on the corona electrodes is different with different polarities of the corona electrodes, the flows of charged air through adjacent gaps-cavities will not be consistent in speed and cleaning efficiency will decrease.

In addition, due to the lack of speed matching, turbulent gas flow and deterioration of the adhesion of positively and negatively charged particles are possible, which will reduce the reliability of the electrostatic precipitator.

The objective of the present invention is to increase the efficiency of gas purification from dust particles and increase the reliability of the electrostatic precipitator.

The use of the proposed design makes it possible to increase the efficiency of gas purification from dust particles, spores of pathogenic fungi and viruses, and also increases the reliability of the operation of electrostatic precipitators-cyclones in that the electrostatic precipitator contains a power source made in the form of a multi-winding transformer with a primary winding and a number of secondary windings, and rectifiers, switched on at the output of the secondary windings, the first secondary winding with its rectifier being connected to the clamps of the electrode plates in pairs in parallel, and the remaining secondary windings with their rectifiers being connected to the electrode plates individually for each unipolar discharge gap, for example positive. The specified design is new in the declared set of features.

Constructing a power source in the form of a multi-winding transformer with a primary winding and a number of secondary windings and rectifiers connected at the output of the secondary windings, wherein the first secondary winding with its rectifier is connected to the clamps of the electrode plates in pairs-parallel, and the remaining secondary windings with their rectifiers are connected to the plates - electrodes individually for each unipolar discharge gap, for example, positive. The dependence of the speed of the “ionic wind” on the electric field strength and current density is known in science and technology [1], and it is also known that the corona discharge current density depends on the polarity of the discharge [2]. For this reason, when multi-polar corona discharges operate in the same volume inside the cyclone-electric precipitator, flows of charged gas that are inconsistent in speed appear, which cause turbulent gas flow and, as a consequence, deterioration in the adhesion of charged particles, a decrease in the efficiency of gas purification from dust, and a decrease in the reliability of the electrostatic precipitator. . The implementation of a power source in the form of a power transformer and a rectifier is known in technology, but in this totality, the listed features exhibit new properties consisting of:

a) in equalizing the velocities of gas movement in multi-polar corona discharges, which gives a turbulent flow of gases;

b) in the addition of electric field strength vectors of various galvanically independent sources of electricity, which equalizes the current densities in the region of the positive and negative corona.

Thus, the technical result expected from the use of the invention is to increase the efficiency of gas purification from suspended particles and increase the reliability of the electrostatic precipitator.

This result is achieved by the fact that the claimed technical solution has properties that are not equal to the sum of the known properties:

a) increasing the efficiency of gas purification is achieved by turbulent mixing of oppositely charged gas flows, and, as a consequence, more effective adhesion of oppositely charged dust particles;

b) increasing the reliability of the electrostatic precipitator is achieved by accurately adjusting the speeds of the “ionic wind” in multi-polar charging cavities.

In fig. Figure 1 shows the empirical dependence of the speed of the “ionic wind” on the electric field strength; in fig. Figure 2 shows the empirical dependence of the corona discharge current density on the electric field strength; in fig. Figure 3 shows a schematic diagram of the electrical superposition of electric fields in the discharge gaps; in fig. Figure 4 shows a schematic diagram of the electrical superposition of electric fields with precise adjustment of the speed of the “ionic wind”.

The electrostatic precipitator includes a cylindrical housing 1 with a swirler, pipes for gas inlet 6 and gas outlet 14, pipes for the discharge of dust concentrate, a system of charging electrodes made of blades-plates 2, having a precipitating smooth surface 3 and a corona pointed surface 4 connected to the poles of the power source 5 , and the body 1 is made vertical cylindrical with a lower conical part, the swirler is made in the form of an even number of electrically conductive blades-plates, the electrode plates 2 are installed inside the body 1 parallel to the cylinder axis and oriented in spiral directions, the corona surfaces are the sharpened ribs of the 4 electrode plates facing spiral axis, inlet pipes 6 for dusty gas are located in the housing 1 and are cut tangentially into the housing cylinder between the plates of the electrodes 2, the terminals of the electrodes 7 are connected to the power supply 5 via wires 8, and the power supply 5 is made in the form of two transformers with rectifiers for galvanic isolation positive and negative corona discharges or in the form of a multi-winding transformer on a single core 9 with a primary winding 10 and a number of secondary windings 11 and rectifiers 12 connected at the output of the secondary windings 11, and the first secondary winding with its rectifier 12 is connected to the terminals of the electrode plates in pairs-parallel , and the remaining windings with their rectifiers are connected to the electrode plates individually for each unipolar discharge gap, for example, positive; in addition, the power supply 5 may contain an output voltage control element 13 in the form of an autotransformer for positive corona discharge circuits.

The electrostatic precipitator works as follows. The power supply 5 is turned on, while a high electrical voltage is supplied to the electrodes 2 via wires 8, and in the gaps between the corona discharges 4 and the precipitating discharges 3, corona discharges occur, which generate an “ionic wind”. Due to the fact that the blade-plates are located in spiral directions, the flows of charged gas in various discharge gaps are forced closer to the axis of the cylindrical body 1, add up and form an annular air flow. Then, through the outlet pipes 6, dusty gas is fed into the discharge gaps, while dust particles, spores of pathogenic fungi, viruses are charged in each gap with an electric charge of their sign (“+” or “-”), and then getting into the annular flow, they stick together, form larger particles and settle in the lower part of the cylinder, the dust outlet and the dust collector hopper, from where they are discharged outside. Due to the fact that the speed of gas movement depends on the electric field strength, the density of the electric current of the corona discharge (see Fig. 1, 2), as well as on the mass of the electric charge carrier (electron, or α-particle or positive ion), the speed the movements of gases in the cavities between the electrode plates will be different and, accordingly, turbulization of the total gas flow is possible, worsening the characteristics of the electrostatic precipitator. The difference in gas flow rates is compensated by the operation of the power source 5, which creates a higher electric field strength in the discharge gaps with a lower gas velocity using “individual” windings 11 with their rectifiers 12.

A specific embodiment of the device is an electric precipitator for disinfecting the atmosphere of medical institutions. The electrostatic precipitator body is made of SOL-10 plexiglass, the outer diameter of the cylindrical part is 300 mm, the height of the cylinder is 400 mm, the number of inlet pipes is 6. The air capacity is 300 m ³ /hour at a voltage at the electrodes of 35 kV.

The use of the proposed electrostatic precipitator will improve the efficiency of gas purification from dust, spores of pathogenic fungi and viruses due to the fact that turbulence of gas flows passing through the cavities of positive and negative charges is eliminated due to equalization of the speeds of the “ionic wind” and increase the reliability of the electrostatic precipitator due to the possibility of precise adjustment speeds of the “ionic wind” in multipolar discharge cavities.

Claims (2)

1. An electric precipitator for purifying gases from dust, including a cylindrical housing with a swirler, pipes for gas inlet and outlet, pipes for discharging dust concentrate, corona and precipitation electrodes, a hopper and a high-voltage power supply, wherein the body is made vertical with a lower conical part, the swirler is made in the form of an even number of electrically conductive blades-plates installed inside the housing in its upper part parallel to the cylinder axis and oriented in spiral directions, and the blades-plates are electrodes, and the corona surfaces are sharpened ribs of the plates facing the axis of the spiral - the axis of the body, collecting electrodes The side surfaces of the plates are facing the adjacent corona electrodes, the inlet pipes are placed between the electrode plates and are embedded tangentially into the housing, the electrodes are connected to the poles of the power supply by wires, characterized in that the power supply is made in the form of two transformers with rectifiers for galvanic isolation of positive and negative corona discharges or in the form of a multi-winding transformer with a primary winding and a number of secondary windings and rectifiers connected at the output of the secondary windings, and the first secondary winding with its rectifier is connected to the clamps of the electrode plates in pairs-parallel, and the remaining windings with their rectifiers are connected to the plates- electrodes individually for each unipolar discharge gap. 2. The electric precipitator according to claim 1, characterized in that the power supply contains an element for regulating the output voltage in the form of an autotransformer.