A uniform distribution plate, a wet electric precipitator and a smoke exhaust device

Abstract

The present invention provides a uniform distribution plate, a wet electrostatic precipitator and a flue gas discharge device, comprising a first area and a second area. The first area is circular, and a plurality of first holes are evenly opened on the first area; the second area is annular and arranged outside the first area; at least one circle of second holes is opened on the second area, and the area of ​​a single second hole is larger than the area of ​​a single first hole. The uniform distribution plate is arranged at the variable diameter section at the entrance of the wet electrostatic precipitator, and the variable diameter section is arranged at the top of the desulfurization tower. When working, the flue gas enters the variable diameter section from the desulfurization tower below. The opening of the second area is larger than the opening of the first area, and the airflow resistance decreases from the first area to the second area, so as to guide part of the airflow in the middle to pass through the uniform distribution plate through the second area, and part of the airflow passes through the uniform distribution plate through the first area, so that the flue gas is evenly distributed in the first area and the second area, so that the airflow evenly enters the upper dust collector body, the flow field in the dust collector is evenly distributed, the dust in the electric field is evenly charged, and the dust removal efficiency is high.

Description

Technical Field

[0001] The invention relates to the technical field of flue gas treatment, and in particular to a uniform distribution plate, a wet electric precipitator and a flue gas emission device. Background Art

[0002] At present, all newly built units in thermal power plants are required to meet ultra-low emission standards. Therefore, a wet electrostatic precipitator must be added on the top of the desulfurization tower. After passing through the desulfurization tower, the flue gas directly enters the wet electrostatic precipitator on the top of the desulfurization tower. Since the wet electrostatic precipitator is usually larger than the diameter of the desulfurization tower, the wet electrostatic precipitator includes a reducer and a precipitator body. The desulfurization tower and the precipitator body are connected by a reducer. The reducer is generally 60 degrees inclination and is an inverted cone with a small bottom and a large top. The flue gas enters the reducer from the straight section of the desulfurization tower, and then enters the upper precipitator body through the reducer. Due to the setting of the reducer, the flue gas cannot enter the upper precipitator body evenly through the reducer.

[0003] The flow field distribution in a vertical flow wet electrostatic precipitator is one of the important factors affecting the dust removal efficiency of the electrostatic precipitator. If the flow field distribution in the electric field is uneven, it will lead to uneven charging of the dust in the electric field, thus affecting the dust removal efficiency. Therefore, a uniform distribution plate needs to be set at the variable diameter section at the entrance of the wet electrostatic precipitator.

[0004] The circular uniform distribution plate in the prior art generally has circular holes on the plate surface, and the opening rate on the plate surface is the same from the center of the circle to the edge of the plate surface. The resistance encountered by the airflow when passing through the uniform distribution plate is the same along the radial direction of the uniform distribution plate. If the uniform distribution plate of this structure is set in the variable diameter section, it will result in more airflow passing through the middle part of the variable diameter section and less airflow passing through the edge, and the flue gas cannot evenly enter the upper dust collector body. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect in the prior art that the flue gas cannot evenly enter the upper wet electrostatic precipitator from the variable diameter section.

[0006] To this end, the present invention provides a uniform distribution plate, comprising

[0007] The first region is circular, and the diameter of the first region is the same as the inner diameter of the desulfurization tower; a plurality of first holes of the same shape and size are evenly opened on the first region;

[0008] The second area is in a circular shape and is arranged outside the first area. The second area is provided with at least one circle of second holes, and the area of ​​a single second hole is greater than the area of ​​a single first hole.

[0009] Optionally, in the above-mentioned uniformly distributed plate, the second holes have at least two circles, and the area of ​​a single second hole located in the outer circle is larger than the area of ​​a single second hole located in the inner circle.

[0010] Optionally, in the above-mentioned uniformly distributed plate, the second holes have at least three circles, and the area of ​​a single second hole gradually increases from the inside to the outside.

[0011] Optionally, in the uniformly distributed plate, the second holes located on the same circle have the same area.

[0012] Optionally, in the above-mentioned uniformly distributed plate, the cross-section of the second hole is elliptical.

[0013] Optionally, in the above-mentioned uniformly distributed plate, the cross-section of the second hole is circular.

[0014] Optionally, in the above-mentioned uniformly distributed plate, the second holes are distributed radially on the second area.

[0015] Optionally, in the above-mentioned uniform distribution plate, the first hole is a circular hole.

[0016] The present invention provides a wet electrostatic precipitator, comprising a precipitator body, a diameter-changing section connected below the precipitator body, and at least one uniform distribution plate described above, wherein the uniform distribution plate is arranged in the diameter-changing section.

[0017] The present invention provides a flue gas emission device, comprising the above-mentioned wet electrostatic precipitator and a desulfurization tower, wherein the diameter-changing section is arranged at the top of the desulfurization tower.

[0018] The technical solution of the present invention has the following advantages:

[0019] 1. The uniform distribution plate provided by the present invention comprises a first area and a second area. The first area is circular, the diameter of the first area is the same as the inner diameter of the desulfurization tower, and a plurality of first holes of the same shape and size are uniformly opened on the first area; the second area is annular and is arranged outside the first area; at least one circle of second holes is opened on the second area, and the area of ​​a single second hole is larger than the area of ​​a single first hole.

[0020] The uniform distribution plate of this structure is arranged on the variable diameter section at the entrance of the wet electrostatic precipitator, and the variable diameter section is arranged on the top of the desulfurization tower. When working, the flue gas enters the variable diameter section from the desulfurization tower below. The diameter of the first area is the same as the inner diameter of the desulfurization tower, and the first holes thereon have the same shape and size and are evenly distributed, so that the airflow can be evenly distributed in the first area; the second area is located outside the projection of the inner diameter of the desulfurization tower, and multiple second holes are arranged outside the first area. The area of ​​a single second hole is larger than the area of ​​a single first hole, and the opening of the second area is larger than the opening of the first area. The larger the opening, the smaller the airflow resistance, and the airflow resistance decreases from the first area to the second area, so as to guide part of the airflow in the middle to pass through the second area through the uniform distribution plate, and part of the airflow passes through the first area through the uniform distribution plate, so that the flue gas is evenly distributed in the first and second areas, and the airflow evenly enters the upper dust collector body, the flow field in the dust collector is evenly distributed, the dust in the electric field is evenly charged, and the dust removal efficiency is high.

[0021] 2. When the flue gas emission device provided by the present invention is working, the flue gas enters the variable diameter section from the desulfurization tower below, and the diameter of the first area of ​​the uniform distribution plate is the same as the inner diameter of the desulfurization tower; the second area is located outside the projection of the inner diameter of the desulfurization tower, the opening of the second area is larger than the opening of the first area, and the area of ​​the second hole gradually increases from the inside to the outside and is radial, the airflow guiding effect is good, the airflow resistance decreases from the first area to the second area, so that the airflow is evenly distributed in the first area and the second area; and the airflow resistance gradually decreases from the inside to the outside in the second area, so that the airflow is evenly distributed in the second area, so that the flue gas enters the upper dust collector body evenly along the entire plate surface of the uniform distribution plate, the flow field in the dust collector is evenly distributed, the dust in the electric field is evenly charged, and the dust removal efficiency is high. The upper and lower uniform distribution plates are set up, the airflow guiding effect is better, and the airflow distribution is more uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 This is a schematic diagram of the uniform distribution plate provided in Example 1 of the present invention;

[0024] Figure 2 A schematic diagram of the smoke exhaust device provided in Example 2;

[0025] Figure 3 It is a top view of a wet electrostatic precipitator;

[0026] Description of reference numerals:

[0027] 1-uniform distribution plate; 11-first area; 111-first hole; 12-second area; 121-second hole; 21-dust collector body; 22-diameter reducing section; 23-insulating box; 24-first connecting section; 3-desulfurization tower. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] Example 1

[0033] This embodiment provides a uniform distribution plate, such as Figure 1 As shown, it includes a first area 11 and a second area 12 .

[0034] The first area 11 is circular, and the diameter of the first area 11 is the same as the inner diameter of the desulfurization tower 3. A plurality of first holes 111 of the same shape and size are evenly opened on the first area 11; for example, the second hole 121 is a circular hole.

[0035] The second area 12 is annular and is arranged outside the first area 11; three circles of second holes 121 are opened on the second area 12, and the second holes 121 are also circular holes. The area of ​​a single second hole 121 is larger than the area of ​​a single first hole 111. The areas of the second holes 121 on the same circle are the same, and the area of ​​a single second hole 121 gradually increases from the inside to the outside. The multiple second holes 121 on any circle are located on the same circumference and are evenly distributed on the circumference to evenly guide the airflow into the second area 12. The first hole 111 and the second hole 121 are both circular holes, which are convenient for opening holes.

[0036] In the second region 12, the area of ​​the second holes 121 gradually increases from the inside to the outside in the radial direction, and the second holes 121 are radially distributed in the second region 12. The area of ​​the second holes 121 gradually increases from the inside to the outside and is radial, which has a good airflow guiding effect, can make the airflow more evenly distributed in the second region 12, and make the airflow more evenly enter the upper dust collector body 21, further improving the dust removal effect.

[0037] The uniform distribution plate 1 of this structure is arranged at the variable diameter section 22 at the entrance of the wet electrostatic precipitator, and the variable diameter section 22 is arranged at the top of the desulfurization tower 3. When working, the flue gas enters the variable diameter section 22 from the desulfurization tower 3 below. The diameter of the first area 11 is the same as the inner diameter of the desulfurization tower 3, and the first holes 111 thereon have the same shape and size and are evenly distributed, so that the airflow can be evenly distributed in the first area 11; the second area 12 is located outside the projection of the inner diameter of the desulfurization tower 3, and a plurality of second holes 121 are arranged outside the first area 11, and a single second hole 121 The area of ​​the second area 12 is larger than the area of ​​the single first hole 111, the opening of the second area 12 is larger than the opening of the first area 11, and the airflow resistance decreases from the first area 11 to the second area 12, so as to guide part of the airflow in the middle to pass through the second area 12 through the uniform distribution plate 1, and part of the airflow passes through the first area 11 through the uniform distribution plate 1, so that the flue gas is evenly distributed in the first area 11 and the second area 12, and the airflow evenly enters the upper dust collector body 21, the flow field in the dust collector is evenly distributed, the dust in the electric field is evenly charged, and the dust removal efficiency is high.

[0038] As a first alternative implementation manner of the embodiment, the cross-section of the second hole 121 can also be an ellipse, a triangle, a quadrilateral, a pentagon, a hexagon, etc.; or when the cross-section of the second hole 121 can also be any closed figure surrounded by arc segments and straight line segments, as long as the area of ​​the second hole 121 is larger than that of the first hole 111, the airflow resistance in the second area 12 is smaller than that in the first area 11, part of the airflow can be guided into the second area 12, and the airflow is evenly distributed in the first area 11 and the second area 12.

[0039] As a second alternative implementation of the embodiment, the second hole 121 can also be set with one circle, two circles, four circles, five circles, etc., and the specific number of circles can be set according to the difference between the inner diameter of the actual desulfurization tower 3 and the inner diameter of the variable diameter section 22.

[0040] As a variation, the cross-section of the first hole 111 can also be any other shape, such as a triangle, a quadrilateral, a pentagon, a hexagon, etc. There is no specific limitation on its shape, as long as the shape and size of the first holes 111 in the first area 11 are the same, the airflow can be evenly distributed in the first area 11.

[0041] Example 2

[0042] This embodiment provides a smoke exhaust device, such as Figure 2As shown, it includes a wet electrostatic precipitator and a desulfurization tower 3.

[0043] The wet electrostatic precipitator includes two uniformly distributed plates 1 in Embodiment 1, a precipitator body 21, and a diameter-reducing section 22 disposed below the precipitator body 21. The two uniformly distributed plates 1 are disposed in the diameter-reducing section 22 at intervals from top to bottom. The outer diameter of the precipitator body 21 is larger than the outer diameter of the desulfurization tower 3, and the diameter-reducing section 22 is an inverted truncated cone, whose outer diameter gradually decreases from top to bottom, and the diameter-reducing section 22 is disposed at the top of the desulfurization tower 3 to connect the desulfurization tower 3 and the precipitator body 21.

[0044] During operation, the flue gas enters the variable diameter section 22 from the desulfurization tower 3 below, and the diameter of the first area 11 of the uniform plate 1 is the same as the inner diameter of the desulfurization tower 3; the second area 12 is located outside the projection of the inner diameter of the desulfurization tower 3, the opening of the second area 12 is larger than the opening of the first area 11, and the area of ​​the second hole 121 gradually increases from the inside to the outside and is radial, the airflow guiding effect is good, the airflow resistance decreases from the first area 11 to the second area 12, so that the airflow is evenly distributed in the first area 11 and the second area 12; and the airflow resistance gradually decreases from the inside to the outside in the second area 12, so that the airflow is evenly distributed in the second area 12, so that the flue gas enters the upper dust collector body 21 evenly along the entire plate surface of the uniform plate 1, the flow field in the dust collector is evenly distributed, the dust in the electric field is evenly charged, and the dust removal efficiency is high. The upper and lower uniform plates 1 are set up to achieve a better airflow guiding effect and a more uniform airflow distribution.

[0045] See also Figure 2 and Figure 3 The wet electrostatic precipitator further includes a first connecting section 24 and an insulating box 23 ( Figure 2 The insulating box 23 is not shown in the figure). The top of the dust collector body 21 has a bearing surface, on which a truss is arranged, and the first connecting section 24 is welded and fixed to the truss on the bearing surface, and a first gap exists between the bottom outer edge of the first connecting section 24 and the outer edge of the bearing surface.

[0046] The outer contour of the bottom end of the first connecting section 24 is a regular octagon, and the top bearing surface of the dust collector body 21 is a circle. Figure 3 Due to the setting of the first gap, an annular bearing surface is formed between the outer edge of the bottom of the first connecting section 24 and the outer edge of the bearing surface, and a plurality of insulating boxes 23 are arranged on the annular bearing surface.

[0047] The wet electrostatic precipitator uses a power supply to create a high-voltage electrostatic field inside the device, charges the dust in the flue gas through the electrostatic effect between the cathode and cathode, and releases the charge at the anode to capture the dust. A cathode plate and an anode plate are provided inside the precipitator body 21. A high-voltage power supply is provided on the top of the wet electrostatic precipitator, and the current is introduced into the cathode plate and the anode plate inside the precipitator body 21 through the suspension rod through the insulating box 23.

[0048] The cross-sectional area of ​​the bottom end of the first connecting section 24 in the prior art is the same as the area of ​​the top bearing surface of the dust collector body 21, and the bottom end of the first connecting section 24 is completely covered on the bearing surface. In this structure, since there is a first gap between the bottom outer edge of the first connecting section 24 and the outer edge of the bearing surface, the bearing surface in the first gap provides a platform for bearing the insulating box 23. The insulating box 23 is directly arranged on the bearing surface in the first gap. Compared with supporting the insulating box 23 by arranging a bracket on the circumferential outer side of the dust collector body 21, the bearing surface directly supports the insulating box 23 stably and the device structure is more compact. When the insulating box 23 needs to be repaired, the personnel climb onto the bearing surface on the top of the dust collector body 21 to work, which is safer than working on the bracket arranged on the outside of the dust collector body 21.

[0049] The truss is a steel truss with a plurality of straight rods at the top of the truss. The cross-sectional area of ​​the first connecting section 24 increases gradually from top to bottom. Figure 3 The outer contour of the bottom end of the first connecting section 24 is a regular octagon, and the outer contour of the top end of the first connecting section 24 is a circle. The bottom end of the first connecting section 24 is welded to the top end of the truss, and the chimney is welded to the first connecting section 24.

[0050] Since the top of the steel truss is a plurality of straight rods, the outer contour of the bottom of the first connecting section 24 is a regular octagon, and each side of the bottom of the first connecting section 24 is a straight side. Compared with the circular structure of the bottom of the first connecting section 24,

[0051] The straight edge is easy to dock and position with the straight rod at the top of the truss, which makes it convenient to weld the straight edge to the connecting frame, saving costs; and after welding, it is also convenient to set a reinforcement beam along the straight edge of the first connecting part to increase the strength of the connecting frame and the first connecting section 24, thereby improving the stability of the device.

[0052] The chimney, wet electrostatic precipitator and desulfurization tower 3 are coaxially arranged. The outer diameter of the precipitator body 21 is larger than the outer diameter of the chimney. The chimney has a small diameter and is light in weight, which is conducive to ensuring the rigidity and stability of the device as a whole. The chimney is welded on the first connecting section 24. The chimney and the precipitator body 21 are connected by the first connecting section 24. The first connecting section 24 is truncated cone-shaped, and its cross-sectional area gradually increases from top to bottom, and has good stability. When the flue gas discharge device is working, the flue gas flows unidirectionally from bottom to top, and the diameter of the precipitator body 21 is larger than that of the chimney. The first connecting section 24, which gradually shrinks from bottom to top, gradually gathers the flue gas to the middle and enters the chimney for discharge.

[0053] The chimney, wet electrostatic precipitator and desulfurization tower 3 are coaxially arranged, the flue gas flow field is optimal, the overall resistance of the device is small, which is conducive to the unidirectional flow of flue gas from bottom to top, and the desulfurization and dust removal efficiency is high. The chimney, wet electrostatic precipitator and desulfurization tower 3 are vertically integrated and stacked to save land resources.

[0054] As a modified implementation, the number of the uniformly distributed plates 1 provided in the diameter-changing section 22 may also be one, three, four, five, and so on.

[0055] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A smoke exhaust device, characterized in that: The invention comprises a wet electrostatic precipitator and a desulfurization tower (3), wherein the wet electrostatic precipitator comprises a precipitator body (21), a diameter-changing section (22) connected below the precipitator body (21), and at least one uniform distribution plate (1), wherein the uniform distribution plate (1) is arranged in the diameter-changing section (22), and the diameter-changing section (22) is arranged at the top of the desulfurization tower (3); the uniform distribution plate (1) comprises: The first region (11) is circular, and the diameter of the first region (11) is the same as the inner diameter of the desulfurization tower (3); a plurality of first holes (111) of the same shape and size are evenly opened on the first region (11); a second area (12) which is annular and arranged outside the first area (11); the second area (12) is provided with at least one circle of second holes (121), and the area of ​​a single second hole (121) is greater than the area of ​​a single first hole (111); The wet electrostatic precipitator further comprises a first connecting section (24) and an insulating box (23); the top of the precipitator body (21) comprises a bearing surface; a first gap exists between the bottom outer edge of the first connecting section (24) and the outer edge of the bearing surface; an annular bearing surface is formed between the bottom outer edge of the first connecting section (24) and the outer edge of the bearing surface; a plurality of insulating boxes (23) are arranged on the annular bearing surface.

2. The smoke exhaust device according to claim 1, characterized in that: The second holes (121) have at least two circles, and the area of ​​a single second hole (121) located in the outer circle is larger than the area of ​​a single second hole (121) located in the inner circle.

3. The smoke exhaust device according to claim 2, characterized in that: The second hole (121) has at least three circles, and the area of ​​a single second hole (121) gradually increases from the inside to the outside.

4. The smoke exhaust device according to any one of claims 1 to 3, characterized in that: The areas of the second holes (121) located on the same circle are the same.

5. The smoke exhaust device according to any one of claims 1 to 3, characterized in that: The second hole (121) has an elliptical cross section.

6. The smoke exhaust device according to any one of claims 1 to 3, characterized in that: The second hole (121) has a circular cross section.

7. The smoke exhaust device according to any one of claims 1 to 3, characterized in that: The second holes (121) are distributed radially on the second area (12).

8. The smoke exhaust device according to any one of claims 1 to 3, characterized in that: The first hole (111) is a circular hole.

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