RU2111797C1 - Filter cell for electrostatic precipitator - Google Patents

Abstract

FIELD: cleaning air and gas from dust and dirt in living and industrial rooms. SUBSTANCE: filter cell includes corona electrodes and end panels with beads. Arranged between end panels on electrode holders in alternating order are immovable charged and earthed electrodes of precipitator made in the form of flat plates. Each corona electrode is located on one plate with charged electrode and is made in the form of equidistant teeth in plane of charged electrodes. EFFECT: effective operation at different nominal values of ionizing voltage; enhanced efficiency of cleaning air due to increased active area of precipitation. 8 cl, 9 dwg

Description

 The invention relates to devices for electrostatic gas purification, characterized by the presence of fixed electrodes with flat surfaces parallel to the gas stream, and can be used in electrostatic filters to clean air and gas from dust and dirt in both residential and industrial premises.

 Known filter cells of electrostatic filters for air purification, containing flat stationary precipitation electrodes located parallel to the gas stream: highly efficient electrostatic filtering device [1]; electrostatic precipitator [2]; dual-zone electrostatic precipitator for gas purification [3].

 All known devices have an ionization zone - an ionizer, in which dust and dirt particles contained in air are charged in an electrostatic field with a voltage of up to 12000 V, and the deposition zone is a precipitator.

 The ionizer is a corona electrode in the form of metal, for example, tungsten filaments.

 The precipitator is made in the form of grounded ones, on which dust and dirt charged in the ionizer are deposited, and charged electrodes with a flat surface, parallel to the gas or air flow. All known devices contain separately structurally located ionizer and precipitant.

Common disadvantages of these devices are:
the presence of several structural elements that ensure uniform distribution and tension of thin metal threads of the corona electrode, which leads to a decrease in the reliability of the structure;
the implementation in the form of separate structural elements of the ionizer and precipitator, which leads to the need to use several ratings of the supply voltage, which complicates the device.

 Closest to the proposed result is a filter cell used in a dual-zone electrostatic precipitator for air purification [4]. The known filter cell is made in the form of end panels with flanges and insulators having terminals, between which precipitating and corona electrodes are located on the electric holders, the last of which are mounted on suspensions, and the vertical flanging of the panels is made with slots, and the insulator terminals are made in the form of C-shaped springs mounted on the electrode holder of the corona electrodes, and the ends of the pendants have slots for installing corona electrodes.

The disadvantages of this device are:
insufficient design reliability due to an increase in the structural elements of the device due to the separate mounting of the corona electrode on the suspension and the corona electrode being made in the form of long metal threads;
low stability of the device due to the inability to ensure reliable uniform tension of the corona electrodes;
the use of several ratings of the supply voltage due to the separate design of the ionizer and precipitator;
the inability to optimize the operating mode of the device by adjusting to the nominal operating voltage, for example, by changing the gap between the precipitation electrodes.

 The purpose of the invention is the creation of a device - a filter cell for an electrostatic filter, which optimally and efficiently operates at different ratings of ionizing voltage, is reliable and structurally simple, energy-efficient, technologically advanced to manufacture, convenient to use, stable in operating conditions, and also provides an increase in the degree of cleaning air by increasing the active area of deposition.

The basis of the invention is the idea of creating a filter cell for an electrostatic filter, in which:
the ionization functions of air or gas particles and deposition are combined in one structural element, which eliminates the need to create complex attachment points of the corona electrode to the filter housing due to the supply of a high-voltage voltage to it, thereby increasing the reliability of the filter by simplifying its design and its manufacturability in the manufacture and operation;
the corona electrode is aligned with the charged electrode of the precipitator, i.e. corona and charged electrodes are a single structural element that allows you to save energy consumption and increase the stability of the filter by using only one nominal voltage, as well as increase the active area of deposition of dust and dirt contained in air or gas, without increasing the size of the filter cell ;
the size of the air gap between the electrodes is regulated depending on the nominal voltage, which allows you to optimize and increase the efficiency of the filter cell when changing the nominal voltage.

 This is achieved by the fact that the filter cell for the electrostatic filter includes two end panels with flanges. Between the end panels, perpendicular to them, electric holders are placed, which are rigidly attached to them through the holes in the end panels. Each electric holder is a hairpin with several tubular metal bushings put on it. By changing the length of the bushings, it is possible to change the air gap between the electrodes of the filter cell, the value of which is determined by the nominal value of the high-voltage voltage supplied to the electrodes. All electric holders play the role of supporting structural elements for the electrodes of the filter cell.

 Some power holders are directly attached to the end panels and connected to the grounded electrodes of the filter cell. Other electric holders are attached to the end panels through insulators and connected to the charged electrodes of the filter cell.

 To stiffen the design of the filter cell, four corners are attached parallel to the electric carriers to the corresponding flanges on opposite end panels.

 All electrodes of the filter cell are plates with flat surfaces. The plates are mounted on the electric holders so that their flat surfaces are perpendicular to the electric holders and parallel to the direction of air flow. The grounded and charged electrodes of the filter cell are placed in alternating order, and there are one more charged electrodes than the grounded ones, therefore, a charged electrode is placed next to each end panel.

 The length of the grounded electrodes on the side of the incoming air stream exceeds the length of the charged electrodes.

 The charged electrode is made in such a way that on the side of the incoming air stream, its rib has the shape of a comb, the teeth of which are equal isosceles triangles, the base of each of which is equal to the length L of the horizontal gap between the teeth and lies with it on a straight line and is 0.8 heights h.

 This technical solution made it possible to combine charged and corona elements — a comb on the edge of a charged electrode — electrodes into a single structural element, which in turn allows using only one voltage rating and increasing the active deposition area without increasing the dimensions of the filter cell.

 Due to the fact that the length of the grounded electrode is longer than the length of the charged electrode, the corona tip of the charged electrode and the grounded electrode create an ionization zone of air or gas particles.

 In FIG. 1 shows a filter cell of an electrostatic filter, a general view; in FIG. 2 - filter cell electrostatic filter, side view; in FIG. 3 is a section AA in FIG. 2; in FIG. 4 is a section BB in FIG. 2; in FIG. 5 - filter cell electrostatic filter, rear view; in FIG. 6 is a section BB in FIG. 5, zoomed in; in FIG. 7 - grounded electrode, side view; in FIG. 8 is a side view of a charged electrode combined with a corona electrode; in FIG. 9 - corona electrode, enlarged scale.

 The filter cell (Fig. 1) of the electrostatic filter contains end panels 1 (Figs. 2-5) with flanges 2, to which corners 6 are attached using screws 3 (Fig. 6), washers 4 and nuts 5.

 Through holes 7, having in the end panels 1, electrical supports 8 are inserted - studs, which are connected to the grounded electrodes 9 (Figs. 3 and 7) through the holes 10 available in them. On the electric supports 8 are placed tubular metal sleeves 11, which provide tight contact with the grounded electrodes 9. The electric holders 8 with nuts 12 and washers 13 are rigidly attached to the end panels 1.

 Through holes 14, available in the end panels 1, are inserted elektroderzhateli 15 - studs, which are connected to the infected electrodes 16 through the holes 17 available in them (Fig. 4 and 8). Tubular metal sleeves 18 and sleeves 19 are placed on the holders 15. The length of the sleeves 19 is half the length of the sleeves 18 to ensure that the distance between the end panel 1 and the corresponding corresponding charged electrode 16 is equal to the distance between the adjacent charged electrode 16 and the grounded electrode 9. Bushings 18 and 19 provide tight contact with the charged electrodes 16. The electric holders 15 with nuts 20 and washers 21 through insulators 22, ensuring the absence of electrical contact with the end panels 1, rigidly fixing to the end panels 1.

 The bushings 11 and 18 have the same dimensions; vary their length and, accordingly, the length of the bushings 19; you can change the gap between the electrodes 9 and 16, which allows you to optimize and increase the efficiency of the filter cell when changing the nominal high-voltage supply voltage from the calculation of ≈1.2 mm / 1 kV.

 In order to completely eliminate the contact between the studs 8 and the charged electrodes 16, as well as between the electrode holders 15 and the grounded electrodes 9, in the charged electrodes 16 (Fig. 8) there are holes 23 and end recesses 24, and in the grounded electrodes 9 (Fig. 7) - holes 25, the diameters of which sufficiently exceed the diameter of the bushings 11 and 18.

 Grounded electrodes 9 and charged electrodes 16 are plates ≈0.5 mm thick with flat surfaces. The plates are mounted on the holders parallel to each other, at the same distance from each other in alternating order - through one.

 The corona electrode 26 (Fig. 8) is formed by a comb located on the end of the charged electrode 17, which is a sequence of teeth 27 (Fig. 9) in the form of equal isosceles triangles lying in the plane of the charged electrode 16 and equally spaced from each other, the base of each of them is the interval L between their bases, and the height h = 1.25 L.

 The filter cell of the electrostatic filter operates as follows.

 The cleaned air or gas under the influence of forced ventilation (not shown) enters the ionization zone 28 of the filter cell. The ionization zone 28 is formed by grounded electrodes 9 and corona electrodes 26, to which a voltage of ≈6 kV is supplied from an external high-voltage power supply (not shown). Between the teeth 27 of the corona electrode 26 and the elongated ends of the grounded electrodes 9, an inhomogeneous electrostatic field is formed, under the influence of which a corona gas discharge occurs on the tip of the teeth 17. Particles contained in the cleaned air passing through the corona discharge zone — ionization zone 28 acquire a positive electric potential.

 Then, charged particles with a stream of air enter the precipitation zone 29, which is formed by grounded electrodes 9 and charged electrodes 16.

 Charged particles under the action of an electric field acting in the precipitation zone 29 are attracted and deposited on the grounded electrodes 9.

 The present invention can be easily made on the basis of existing technologies using modern materials and find wide application in electrostatic filters for cleaning air or gas from dust and dirt, both in residential and industrial premises.

Claims (8)

 1. The filter cell for an electrostatic filter, including corona electrodes, end with flanging panels, between which fixed, grounded and charged electrodes of the precipitator in the form of flat plates located perpendicular to the axes of the electrode holders are placed in alternating order on the electrode holders connected to the power source, characterized in that each corona electrode is placed on one flat plate with one charged electrode.  2. The cell according to claim 1, characterized in that on the holders between adjacent charged electrodes, between adjacent grounded electrodes and between end panels and nearby grounded electrodes, bushings of equal length are placed, and between end panels and nearby charged electrodes are bushings whose length is equal to half the length of the bushings placed between adjacent charged electrodes.  3. The cell according to claim 2, characterized in that the bushings are installed with the possibility of regulating the distance between adjacent electrodes of the precipitator and between the end panels and the adjacent electrodes of the precipitator.  4. The cell according to claim 1, characterized in that the corresponding flanging of the opposite placed end panels are connected by corners.  5. The cell according to claim 1, characterized in that the grounded electrodes have holes that exclude contact with insulated electrodes from the end panels, on which charged electrodes are placed, and the charged electrodes have openings and end recesses that exclude contact with electrodes that have grounded electrodes.  6. The cell according to claim 1, characterized in that the grounded electrodes are elongated with respect to the corona electrodes.  7. The cell according to claim 1, characterized in that each corona electrode is placed at the end of the charged electrode in the form of a sequence of teeth.  8. The cell according to claim 7, characterized in that the teeth of the corona electrode are made in the form of equal isosceles triangles lying in the plane of the charged electrode and equally spaced from each other, and the tooth height h = 1.25L, where L is the interval between the bases of adjacent teeth equal to the length of the base of the tooth.

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