CN211133556U

CN211133556U - Prevent stifled device is prevented to fender ash that SCR deNOx systems deposition and catalyst wearing and tearing

Info

Publication number: CN211133556U
Application number: CN201921295787.3U
Authority: CN
Inventors: 冯前伟; 朱跃; 张杨; 杜振; 江建平; 裴煜坤
Original assignee: Huadian Electric Power Research Institute Co Ltd
Current assignee: Huadian Electric Power Research Institute Co Ltd
Priority date: 2019-08-12
Filing date: 2019-08-12
Publication date: 2020-07-31
Anticipated expiration: 2029-08-12

Abstract

The utility model discloses a prevent stifled device is prevented to fender ash of SCR deNOx systems deposition and catalyst wearing and tearing, including the flue, denitrification facility entry ash bucket, the ash blocking screen cloth, spout the ammonia grid, soot blower, the rectifier, catalyst layer and air compressor machine, the ash blocking screen cloth with spout the setting of ammonia grid in the uptake, and the ash blocking screen cloth sets up in the below of spouting the ammonia grid, denitrification facility entry ash bucket sets up the entrance at the uptake, and denitrification facility entry ash bucket is located the below of ash blocking screen cloth and spouting the ammonia grid, soot blower, rectifier and catalyst layer all set up in the decline flue, and soot blower, rectifier and catalyst layer from the top down arrange in proper order. The utility model discloses system flow is simple, and the energy consumption is few, and is with low costs, and maneuverability is strong, all has the suitability to newly-built denitrification facility or active service denitrification facility transformation, has created good condition for boiler and denitrification facility safety and stability operation, has good environmental protection effect and economic benefits, and application prospect is extensive.

Description

Prevent stifled device is prevented to fender ash that SCR deNOx systems deposition and catalyst wearing and tearing

Technical Field

The utility model relates to a prevent stifled device is prevented to fender ash that SCR deNOx systems deposition and catalyst wearing and tearing.

Background

The SCR flue gas denitration technology is adopted by most denitration projects of coal-fired power plants due to the advantages of stability, high efficiency and the like, and an SCR denitration system is usually arranged behind a boiler economizer and in front of an air preheater because the active temperature of a catalyst is usually 300-420 ℃. The flue gas in the region has higher dust concentration content, is a so-called high-ash region, is also called as a high-ash SCR process and is a mainstream arrangement mode for flue gas denitration of the coal-fired power plant at present. After the flue gas comes out of the boiler, the flue gas firstly enters the economizer, and then enters the SCR denitration reactor along the horizontal flue and the vertical flue, the catalyst in the denitration reactor is generally arranged in a three-layer or four-layer design, and a rectifier is usually arranged above the uppermost layer of catalyst and used for leveling the flue gas before entering the catalyst.

The flue design and the arrangement of current SCR denitration reactor entry horizontal flue to catalyst entrance are generally compacter and sharp bend many, and a large amount of deposition phenomenon often can appear in the flue gas in the corner through horizontal flue and vertical flue, and this place is mainly because the flue gas that carries the ash content leads to the ash content to drop the gathering in a large number for vertical flow direction and perpendicular striking at vertical flue wall for the turn change through 90 by the horizontal flow direction, and the rectifier is though can carry out the leveling to the flue gas flow field to a certain extent, but its and denitration reactor casing contact department do not reach the leveling, and the ash content in the flue gas is often just accumulated here. At present, the soot blower of the denitration device is mainly arranged on a catalyst layer, the soot blower is not arranged above a rectifier, and the contact position of the rectifier and a reactor shell belongs to a soot cleaning dead angle position, so that the soot blocking phenomenon is easy to occur, and in fact, the great reason of the uneven problem of the flow field generally existing in the denitration reactor is caused by the soot deposited on the upper part of the rectifier, so that the catalyst is abraded due to the fact that the flow velocity of the flue gas in the partial region of the catalyst is too fast, and the stable standard emission of the denitration system is influenced.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome the above-mentioned not enough that exists among the prior art, and provide a structural design is reasonable, solves current SCR deNOx systems deposition and blocks up and catalyst wearing and tearing problem, guarantees that the ash blocking that prevents SCR deNOx systems deposition and catalyst wearing and tearing of SCR deNOx systems normal operating prevents stifled device.

The utility model provides a technical scheme that above-mentioned problem adopted is: the dust blocking and preventing device comprises a flue, wherein the flue comprises a horizontal flue, an ascending flue and a descending flue, an outlet of the ascending flue is connected with an inlet of the horizontal flue, an outlet of the horizontal flue is connected with an inlet of the descending flue, the ascending flue and the descending flue are both vertically arranged, the horizontal flue is horizontally arranged, and the ascending flue, the horizontal flue and the descending flue form an inverted U-shaped structure; the method is characterized in that: still include denitrification facility entry ash bucket, keep off grey screen cloth, spout ammonia grid, soot blower, rectifier, catalyst layer and air compressor machine, keep off grey screen cloth and spout the setting of ammonia grid in the uptake, and keep off the setting of grey screen cloth in the below of spouting the ammonia grid, denitrification facility entry ash bucket sets up the entrance at the uptake, and denitrification facility entry ash bucket is located the below that keeps off grey screen cloth and spout the ammonia grid, soot blower, rectifier and catalyst layer all set up in the decline flue, and soot blower, rectifier and catalyst layer from the top down arrange in proper order.

Further, the soot blower is provided in plurality, and the catalyst layer is provided with a plurality of layers.

Furthermore, the material of the ash blocking screen is 316L or 2250 stainless steel, the aperture is 100-300 μm, and the distance between the ash blocking screen and the ammonia spraying grid is 300-500 mm.

Further, the soot blower comprises a soot blowing shell, a soot blowing connecting steel pipe and a soot blowing connecting hose; the soot blowing shell is arranged above the rectifier and is positioned on the inner side of the descending flue; the soot blowing connecting steel pipe is communicated with the soot blowing shell and penetrates through the side wall of the descending flue; the soot blowing connecting hose is communicated with the soot blowing connecting steel pipe and an air compressor for providing a compressed air source, and the soot blowing connecting hose is arranged on the outer side of the descending flue.

Furthermore, the soot blowing shell is of a porous spherical structure and is made of 316L or 2250 stainless steel, the aperture is 20-60 mm, the soot blowing connecting steel pipe is made of 316L or 2250 stainless steel, the pipe diameter is 20-100 mm, the length is 100-500 mm, and the quality requirement of compressed air passing through the soot blowing connecting hose is not lower than 0.6 MPa.

The working method comprises the following steps: the dust-containing flue gas firstly passes through the dust blocking screen, then sequentially passes through the ammonia spraying grid, the soot blowing device and the rectifier and then reaches the surface of the catalyst layer, and large particle ash in the flue gas is directly intercepted when passing through the dust blocking screen, so that the problem that the large particle ash enters and gathers on the surface of the rectifier and the catalyst layer along with the flue gas is avoided and alleviated, and the problem of dust deposition and blockage of an SCR (selective catalytic reduction) denitration system is solved; ammonia or contain ammonia air and spout into along the flue gas flow direction through spouting the ammonia grid, mix with the dusty flue gas that passes through the ash blocking screen cloth and then loop through soot blower and rectifier along the uptake flue, later get into the catalyst layer, carry out the denitration reaction under the effect of catalyst layer, dusty flue gas leads to the granule ash to gather to drop to the dead angle department of rectifier because gravity and kinetic energy loss at the corner that horizontal flue and decline flue are connected, combine the compressed air that soot blower utilized the air compressor machine to provide, regularly or irregularly sweep, the floated grits are carried by the flue gas and get into the denitration reactor after sweeping, thereby further prevent that SCR deNOx systems deposition and catalyst layer wearing and tearing condition from taking place.

Compared with the prior art, the utility model, have following advantage and effect: the utility model discloses system flow is simple, and the energy consumption is few, and is with low costs, and maneuverability is strong, all has the suitability to newly-built denitrification facility or active service denitrification facility transformation, has created good condition for boiler and denitrification facility safety and stability operation, has good environmental protection effect and economic benefits, and application prospect is extensive.

Drawings

Fig. 1 is a schematic front view structure diagram of an embodiment of the present invention.

Fig. 2 is a schematic structural view of the ash blocking screen in the embodiment of the present invention.

Fig. 3 is a schematic front view of a soot blower according to an embodiment of the present invention.

Fig. 4 is a schematic diagram of a position structure of a soot blower and a rectifier according to an embodiment of the present invention.

In the figure: the denitration device comprises a denitration device inlet ash bucket 1, an ash blocking screen 2, an ammonia spraying grid 3, a rectifier 4, a catalyst layer 5, a soot blowing device 6, an air compressor 7, a soot blowing shell 61, a soot blowing connecting steel pipe 62 and a soot blowing connecting hose 63.

Detailed Description

The present invention will be described in further detail by way of examples with reference to the accompanying drawings, which are illustrative of the present invention and are not intended to limit the present invention.

Referring to fig. 1 to 4, the ash blocking and preventing device for preventing the deposition of ash and the abrasion of a catalyst in an SCR denitration system in the present embodiment includes a flue, a denitration device inlet ash hopper 1, an ash blocking screen 2, an ammonia injection grid 3, a soot blower 6, a rectifier 4, a catalyst layer 5, and an air compressor 7.

The flue comprises a horizontal flue, an ascending flue and a descending flue, wherein an outlet of the ascending flue is connected with an inlet of the horizontal flue, an outlet of the horizontal flue is connected with an inlet of the descending flue, the ascending flue and the descending flue are both vertically arranged, the horizontal flue is horizontally arranged, and the ascending flue, the horizontal flue and the descending flue form an inverted U-shaped structure; keep off grey screen cloth 2 and spout ammonia grid 3 and set up in the uptake, and keep off grey screen cloth 2 and set up in the below of spouting ammonia grid 3, denitrification facility entry ash bucket 1 sets up the entrance at the uptake, and denitrification facility entry ash bucket 1 is located the below that keeps off grey screen cloth 2 and spout ammonia grid 3, soot blower 6, rectifier 4 and catalyst layer 5 all set up in the uptake, and soot blower 6, rectifier 4 and catalyst layer 5 from the top down arrange in proper order.

Preferably, the soot blower 6 is provided in plurality, and the catalyst layer 5 is provided in a plurality of layers.

Preferably, the material of the ash blocking screen 2 is 316L or 2250 stainless steel, the aperture ø 1 of the ash blocking screen 2 is 100 to 300 μm, and the distance H between the ash blocking screen 2 and the ammonia injection grid 3 is 300 to 500 mm.

Preferably, the soot blower 6 comprises a soot blowing shell 61, a soot blowing connecting steel pipe 62 and a soot blowing connecting hose 63; the soot blowing shell 61 is arranged above the rectifier 4, and the soot blowing shell 61 is positioned at the inner side of the descending flue; the soot blowing connecting steel pipe 62 is communicated with the soot blowing shell 61, and the soot blowing connecting steel pipe 62 penetrates through the side wall of the descending flue; the soot blowing connecting hose 63 is communicated with the soot blowing connecting steel pipe 62 and the air compressor 7 for providing a compressed air source, and the soot blowing connecting hose 63 is arranged outside the descending flue.

Preferably, the soot blowing shell 61 is of a porous spherical structure and is made of 316L or 2250 stainless steel, the diameter of a circular hole ø 2 of the soot blowing shell 61 is 20-60 mm, the soot blowing connecting steel pipe 62 is made of 316L or 2250 stainless steel, the pipe diameter d of the soot blowing connecting steel pipe 62 is 20-100 mm, the length L of the soot blowing connecting steel pipe 62 is 100-500 mm, and the quality requirement of compressed air passing through the soot blowing connecting hose 63 is not lower than 0.6 MPa.

The working method comprises the following steps: the flue gas that contains dirt is at first through keeping off grey screen cloth 2, then passes through in proper order and spouts behind ammonia grid 3, soot blower 6 and the rectifier 4, reaches the surface of catalyst layer 5, and large granule ash is directly intercepted when keeping off grey screen cloth 2 in the flue gas, has avoided and has alleviateed large granule ash and has got into the surface of gathering at rectifier 4 and catalyst layer 5 along with the flue gas to alleviate the problem that SCR deNOx systems deposition blockked up.

Ammonia gas or air containing ammonia are sprayed in along the flue gas flow direction through the ammonia spraying grid 3, the mixed gas and the dust-containing flue gas passing through the dust blocking screen 2 sequentially pass through the soot blowing device 6 and the rectifier 4 along an ascending flue, then the mixed gas enters the catalyst layer 5, the denitration reaction is carried out under the action of the catalyst layer 5, the dust-containing flue gas causes small particle ash accumulation to fall to the contact part of the rectifier 4 and the reactor shell due to the dead weight and kinetic energy loss at the corner where the horizontal flue and the descending flue are connected, the compressed air provided by the air compressor 7 is utilized by the soot blowing device 6, the regular or irregular blowing is carried out, the floated ash particles are carried by the flue gas to enter the denitration reactor after the blowing, and therefore the dust accumulation of an SCR denitration system and the abrasion condition of the catalyst.

Through the system, the problems of dust deposition and catalyst abrasion of the SCR denitration system can be effectively solved, and the system has good environmental protection benefits and economic benefits. Can directly control through ash blocking screen 2 through this embodiment on the one hand and avoid large granule ash content to gather in a large number on the surface of rectifier 4 and catalyst layer 5, on the other hand still can solve little granule ash and lead to little granule ash to gather because gravity and kinetic energy loss and drop to SCR deNOx systems deposition that rectifier 4 and reactor shell contact department lead to and block up and catalyst layer 5 wearing and tearing problem at the corner that horizontal flue and decline flue are connected through soot blower 6 to improve SCR deNOx systems reliability and stability of operation, have important meaning to the environmental protection.

Although the present invention has been described with reference to the above embodiments, it should not be construed as being limited to the scope of the present invention, and any modifications made by those skilled in the art without departing from the spirit and scope of the present invention should be construed as being included in the following claims.

Claims

1. The dust blocking and preventing device comprises a flue, wherein the flue comprises a horizontal flue, an ascending flue and a descending flue, an outlet of the ascending flue is connected with an inlet of the horizontal flue, an outlet of the horizontal flue is connected with an inlet of the descending flue, the ascending flue and the descending flue are both vertically arranged, the horizontal flue is horizontally arranged, and the ascending flue, the horizontal flue and the descending flue form an inverted U-shaped structure; the method is characterized in that: still include denitrification facility entry ash bucket (1), keep off grey screen cloth (2), spout ammonia grid (3), soot blower (6), rectifier (4), catalyst layer (5) and air compressor machine (7), ash blocking screen cloth (2) and spout ammonia grid (3) and set up in the uptake, and keep off grey screen cloth (2) and set up in the below of spouting ammonia grid (3), denitrification facility entry ash bucket (1) sets up in the entrance of uptake, and denitrification facility entry ash bucket (1) is located ash blocking screen cloth (2) and spouts the below of ammonia grid (3), soot blower (6), rectifier (4) and catalyst layer (5) all set up in the uptake, and soot blower (6), rectifier (4) and catalyst layer (5) from the top down arrange in proper order.

2. The ash blocking and preventing device for preventing the deposition of ash and the abrasion of a catalyst in an SCR denitration system according to claim 1, wherein: the soot blower (6) is provided with a plurality of soot blowers, and the catalyst layer (5) is provided with a plurality of layers.

3. The ash blocking and preventing device for preventing the ash deposition and the catalyst abrasion of the SCR denitration system according to claim 1, wherein the ash blocking screen (2) is made of 316L or 2250 stainless steel, the aperture is 100-300 μm, and the distance between the ash blocking screen (2) and the ammonia injection grid (3) is 300-500 mm.

4. The ash blocking and preventing device for preventing the deposition of ash and the abrasion of a catalyst in an SCR denitration system according to claim 1, wherein: the soot blower (6) comprises a soot blowing shell (61), a soot blowing connecting steel pipe (62) and a soot blowing connecting hose (63); the soot blowing shell (61) is arranged above the rectifier (4), and the soot blowing shell (61) is positioned on the inner side of the descending flue; the soot blowing connecting steel pipe (62) is communicated with the soot blowing shell (61), and the soot blowing connecting steel pipe (62) penetrates through the side wall of the descending flue; the soot blowing connecting hose (63) is communicated with the soot blowing connecting steel pipe (62) and an air compressor (7) for providing a compressed air source, and the soot blowing connecting hose (63) is arranged on the outer side of the descending flue.

5. The ash blocking and preventing device for preventing the ash deposition and the catalyst abrasion of the SCR denitration system according to claim 4, wherein the ash blowing shell (61) is of a porous spherical structure and is made of 316L or 2250 stainless steel, the pore diameter is 20-60 mm, the ash blowing connecting steel pipe (62) is made of 316L or 2250 stainless steel, the pipe diameter is 20-100 mm, and the length is 100-500 mm.