CN115888382A - A SNCR and SCR coupled flue gas denitrification system and its application method - Google Patents

Abstract

The application relates to an SNCR and SCR coupled flue gas denitration system and a using method thereof, wherein the SNCR and SCR coupled flue gas denitration system comprises an ammonia water tank, an ammonia pump, a main spray gun, an air compressor, a tail flue, a flue gas heater and an SCR reactor, wherein the tail flue is provided with a smoke inlet pipe which comprises a pipe body I, a pipe body II, a filter plate, a sleeve and a scraper; the using method comprises the following steps: a. introducing ammonia water; SNCR reaction; c, SCR reaction; d. and cleaning the filter plate. Filter the flue gas through the filter plate, reduce impurity and get into in the afterbody flue and then the inside condition of pollution equipment, thereby reduce the frequency that the staff cleared up the afterbody flue, and clear up convenient and fast more, be favorable to improving denitration efficiency, when impurity is more when on the filter plate, the filter plate rotates, scrape down accumulational impurity on with the filter screen through the scraper blade, can realize the clearance of filter plate, collect the clearance and filter as an organic whole, need not to clear up the filter plate with the help of the clearance instrument in addition, make the clearance filter plate more convenient.

Description

A SNCR and SCR coupled flue gas denitrification system and its application method

technical field

The present application relates to the field of flue gas denitrification, in particular to a flue gas denitrification system coupled with SNCR and SCR and its use method.

Background technique

Flue gas denitrification refers to the reduction of _NOx in flue gas to N ₂ , thereby removing _NOx in flue gas. In related technologies, flue gas denitrification mainly includes low-nitrogen combustion in boiler furnaces and SCR (Selective Catalytic Reduction) ) denitrification technology, SNCR (selective non-catalytic reduction) denitrification technology.

For example, the utility model patent with the patent announcement number CN212492409U discloses a flue gas denitrification system coupled with SNCR and low-temperature SCR, including a tail flue, a flue gas heater, a low-temperature SCR reactor, a main spray gun and an ammonia water tank, wherein the main spray gun The ammonia water pump is connected to the outlet of the ammonia water tank. The main spray gun is set in the front flue of the tail flue. The main spray gun is used to spray ammonia water into the front flue for SNCR reaction. The flue gas outlet of the tail flue is connected to the flue gas heater. The flue gas inlet is connected, and the flue gas outlet of the flue gas heater is connected with the flue gas inlet of the low-temperature SCR reactor. Coupling denitrification with lower SNCR and low-temperature SCR processes can save the cost of denitrification.

Using the above-mentioned SNCR and SCR coupled flue gas denitrification system, the flue gas may carry solid particle impurities such as dust. When the flue gas enters the tail flue, the impurities in the flue gas are easy to adhere to the tail flue and pollute the equipment, which requires work. It is cumbersome for personnel to clean up the equipment frequently and needs to be improved.

Contents of the invention

In order to improve the problem that the impurities in the flue gas will pollute the equipment, and it is troublesome for staff to frequently clean the equipment, this application provides a flue gas denitrification system coupled with SNCR and SCR and its use method.

In the first aspect, this application provides a flue gas denitrification system coupled with SNCR and SCR, which adopts the following technical solution:

A kind of SNCR and SCR coupling flue gas denitrification system, comprises ammonia water tank, ammonia water pump, main spray gun, air compressor, tail flue, flue gas heater and SCR reactor, and described ammonia water pump is used for described ammonia water tank The ammonia water is transported to the main spray gun, the main spray gun extends into the inside of the tail flue, the air outlet of the air compressor communicates with the air inlet of the main spray chamber, and the tail flue is provided with an inlet A smoke pipe and a smoke outlet, the flue gas heater is provided with a flue gas inlet 1 and a flue gas outlet 1, the smoke outlet is connected with the flue gas inlet 1, and the SCR reactor is provided with a flue gas Inlet 2 and flue gas outlet 2, the flue gas outlet 1 communicates with the flue gas inlet 2;

The smoke inlet pipe includes a pipe body 1 and a pipe body 2 arranged on the tail flue, a filter plate rotatably connected to the pipe body 1, a casing sleeved on the pipe body 2 and a The scraper on the second pipe body, the second pipe body is provided with a smoke inlet, the filter plate is located between the first pipe body and the second pipe body, and the scraper abuts against the The filter plate is far away from the side of the pipe body 1, and the bottom inner wall of the pipe body 2 is provided with a discharge hole, the discharge hole is located below the scraper, and the scraper is provided with a through hole. The sleeve is slidably connected to the second pipe body, and the sleeve is slid to open or cover the discharge hole.

By adopting the above technical scheme, the flue gas entering the tail flue is filtered through the filter plate, reducing the situation that solid particles such as dust enter the tail flue and pollute the inside of the equipment, thereby reducing the frequency of staff cleaning the tail flue, and only It only needs to clean the filter plate. Compared with cleaning the tail flue, the cleaning is more convenient and quicker, which can reduce the time required for cleaning, thereby reducing the occupation of the operating time of the denitrification system, and is conducive to improving the denitrification efficiency.

When there are many impurities on the filter plate, turn the filter plate and scrape off the accumulated impurities on the filter screen through the scraper. Under the action, it falls into the discharge hole for collection, reducing the situation of impurities falling to the ground and polluting the surrounding environment, and the cleaning of the filter plate can be realized. It integrates cleaning and filtration, and does not need to use additional cleaning tools to clean the filter plate, making the cleaning of the filter plate easier. The plate is more convenient. When there is a lot of impurities in the discharge hole, move the casing to open the discharge hole, so that the impurities in the discharge hole fall out, and the impurities that fall out can be treated.

Preferably, the tube body 2 is provided with a protrusion, and the sleeve is provided with an elastic member 1, and the elastic member 1 presses against the protrusion, so that the sleeve has a function to cover the discharge hole. the trend of.

By adopting the above technical scheme, the protrusion and the elastic part 1 are set. After the casing is moved to open the discharge hole, the sleeve is released, and the sleeve can be reset under the action of the elastic part 1, and then the discharge hole is re-covered to The scraped impurities are collected, and at the same time, the elastic force of the elastic part 1 can limit the casing to a certain extent, which reduces the movement of the casing under sudden factors such as vibration.

Preferably, a chute is provided on the inner wall of the sleeve, and the protrusion is slidably connected in the chute, and a channel is opened on the inner wall of the chute, and the channel is located at a position where the protrusion is far away from the chute. One side of the tail flue, the end of the passage far away from the chute is set toward the scraper and communicates with the inside of the pipe body two, and an elastic layer is provided on the protrusion, and the elastic layer Press against the inner wall of the chute.

By adopting the above technical scheme, the chute, the channel and the elastic layer are set. When the moving sleeve opens the discharge hole, the protrusion moves and pushes the gas in the chute to be discharged through the channel, and then blows onto the scraper, so that the gas on the scraper The adhered impurities are blown off, reducing the impurities adhering to the scraper, making the cleaning effect of impurities better.

Preferably, the scraper is arranged inclined downward in the horizontal direction, the through hole is located at the lower end of the scraper, and the end of the channel away from the chute is located at a side of the scraper away from the through hole. side.

By adopting the above technical scheme, when the scraper scrapes off the impurities on the filter plate, more impurities can slide down along the inclined direction of the scraper and fall out from the through hole, and the gas discharged in the channel is blown to the scraper. When it is on the scraper, it is easy to push more impurities adhered to the scraper to slide off, further improving the cleaning effect on impurities.

Preferably, the pipe body 1 is hinged with a knocking rod, and the hinge shaft of the knocking rod is provided with an elastic member 2, and the elastic member 2 is pressed against the pipe body 1, so that the knocking rod is pressed against the The filter plate is provided with a transmission assembly on the first tube body. When the filter plate rotates, the filter plate drives the knocking rod through the transmission assembly to strike the filter plate back and forth.

By adopting the above technical scheme, when the filter plate is rotated, the scraper scrapes off the impurities accumulated on the filter plate, and some impurities may accumulate at the corners of the filter plate. The vibration shakes off the remaining impurities on the filter plate, reducing the residue of impurities on the filter plate and making the cleaning effect of the filter plate better.

Preferably, the transmission assembly includes bevel gear 1 arranged on the filter plate, bevel gear 2 rotatably connected to the pipe body 1, and a cam coaxially arranged on the bevel gear 2, the bevel gear The first gear is arranged coaxially with the pipe body, the second bevel gear meshes with the first bevel gear, and the cam is pressed against the knocking rod.

By adopting the above technical scheme, when the filter plate is rotated, the bevel gear 1 and the bevel gear 2 are meshed to drive the bevel gear 2 and the cam to rotate, and the cam is pressed against the knocking rod, thereby driving the knocking rod to turn back and forth, and then repeatedly knocking on the filter plate To shake off the impurities on the filter plate.

Preferably, one end of the filter plate extends into the casing.

By adopting the above technical scheme, the gap between the second tube body and the filter plate is covered by the sleeve to reduce impurities falling into the gap between the second tube body and the filter plate, thereby reducing the filter plate and tube when rotating the filter plate. The friction between the two bodies becomes larger or stuck, making it more convenient to rotate the filter plate.

In the second aspect, this application provides a method for using a SNCR and SCR coupled flue gas denitrification system, which adopts the following technical solution:

A method for using the above-mentioned SNCR and SCR coupled flue gas denitrification system, comprising the following steps:

a. Through the ammonia water: turn on the ammonia water pump and the air compressor, so that the ammonia water in the ammonia water tank enters the main spray gun through the ammonia water pump, and the air is compressed by the air compressor and then passes into the main spray gun. After the ammonia water is atomized, it is sprayed into the tail smoke from the main spray gun inside the road;

b. SNCR reaction: pass the flue gas into the smoke inlet, filter the flue gas through the filter plate, and perform SNCR reaction on the atomized ammonia water and the flue gas in the tail flue;

c. SCR reaction: after the SNCR reaction in the tail flue, the flue gas enters the flue gas heater for heating, and the heated flue gas enters the SCR reactor for SCR reaction, and the SCR reactor is used in the tail flue The escaped ammonia escaped in the SNCR reaction carried out is used as a denitrification reducing agent to carry out the SCR reaction, and the reduced _N2 is discharged through the second flue gas outlet;

d. Clean the filter plate: Turn the filter plate, scrape off the impurities on the filter plate through the scraper, then move the sleeve to open the discharge hole, until the impurities in the discharge hole fall out, cover the discharge hole again with the sleeve .

In summary, the present application includes at least one of the following beneficial technical effects:

1. Filter the flue gas entering the tail flue through the filter plate to reduce the solid particle impurities such as dust entering the tail flue and polluting the inside of the equipment, thereby reducing the frequency of staff cleaning the tail flue, and cleaning is more convenient and quick. It is beneficial to improve the denitrification efficiency. When there are many impurities on the filter plate, turn the filter plate to scrape off the accumulated impurities on the filter plate through the scraper, and the scraped impurities fall into the discharge hole for collection, and the filter plate can be cleaned. , Integrate cleaning and filtering into one, no need to use additional cleaning tools to clean the filter plate, making cleaning the filter plate more convenient;

2. By setting the protrusion, elastic part 1, chute, channel and elastic layer, when the casing is moved to open the discharge hole, the protrusion moves to push the gas in the chute to be discharged through the channel, and then blows to the scraper. In this way, the impurities adhered to the scraper are blown off, so that the cleaning effect of impurities is better;

3. By setting the transmission component and the knocking rod, when the filter plate is rotated, the scraper scrapes off the impurities accumulated on the filter plate, and at the same time, the transmission component drives the knocking rod to beat the filter plate back and forth, and the vibration generated by the beating vibrates the remaining impurities on the filter plate. It can reduce the residue of impurities on the filter plate and make the cleaning effect of the filter plate better.

Description of drawings

Fig. 1 is the overall schematic diagram of the SNCR and SCR coupling flue gas denitrification system of the embodiment of the present application;

Figure 2 is a partial structural schematic diagram of the SNCR and SCR coupled flue gas denitrification system of the embodiment of the present application, mainly showing the structure of the smoke inlet pipe;

Figure 3 is a partial structural diagram of the SNCR and SCR coupled flue gas denitrification system in the embodiment of the present application cut at the smoke inlet pipe, mainly showing the structure of the smoke inlet pipe;

Figure 4 is an enlarged view of part A in Figure 3, mainly showing the structure of the filter plate and the transmission assembly;

Figure 5 is a partial structural schematic diagram of the SNCR and SCR coupled flue gas denitrification system of the embodiment of the present application, mainly showing the structure of the scraper;

Fig. 6 is a partial structural view of the SNCR and SCR coupled flue gas denitrification system in the embodiment of the present application cut away at the bushing, mainly showing the structure of the channel.

Explanation of reference signs: 1. Ammonia water tank; 2. Ammonia water pump; 3. Main spray gun; 4. Air compressor; 5. Tail flue; 51. Smoke outlet; 6. Flue gas heater; 61. Flue gas inlet 1; 62, flue gas outlet 1; 7, SCR reactor; 71, flue gas inlet 2; 72, flue gas outlet 2; 8, smoke inlet pipe; 81, pipe body 1; 82, pipe body 2; 821, inlet Smoke port; 83, filter plate; 831, plate body; 8311, filter hole; 832, collar; 84, scraper; 841, through hole; 85, casing; 9, discharge hole; 10, bump; 101 , elastic layer; 11, chute; 111, channel; 12, elastic piece one; 13, knocking rod; 14, elastic piece two; 15, transmission assembly; 151, bevel gear one; 152, bevel gear two; 153, cam .

Detailed ways

The present application will be described in further detail below in conjunction with accompanying drawings 1-6.

The embodiment of the present application discloses a flue gas denitrification system coupled with SNCR and SCR. Referring to Figure 1, the SNCR and SCR coupled flue gas denitrification system includes ammonia water tank 1, ammonia water pump 2, main spray gun 3, air compressor 4, tail flue 5, flue gas heater 6 and SCR reactor 7, and main spray gun 3 passes through The ammonia water pump 2 is connected with the ammonia water tank 1, the ammonia water pump 2 is used to transport the ammonia water in the ammonia water tank 1 to the main spray gun 3, the main spray gun 3 is installed in the tail flue 5 and extends into the tail flue 5, and the main spray gun 3 It is fixedly connected with the tail flue 5, and the air outlet of the air compressor 4 communicates with the air inlet of the main spray gun 3.

Referring to Fig. 1, a smoke outlet 51 is provided on the outer wall of the tail flue 5, and the smoke outlet 51 communicates with the interior of the tail flue 5, and the flue gas heater 6 is provided with a flue gas inlet 61 and a flue gas outlet 1 62. The smoke outlet 51 communicates with the flue gas inlet 1 61. The SCR reactor 7 is provided with a flue gas inlet 2 71 and a flue gas outlet 2 72. The flue gas outlet 1 62 communicates with the flue gas inlet 2 71.

Referring to Fig. 2 and Fig. 3, a smoke inlet pipe 8 is also fixed on the outer wall of the tail flue 5, and the smoke inlet pipe 8 includes a pipe body 1 81, a pipe body 2 82, a filter plate 83, a scraper 84 and a casing 85, Pipe body 1 81 is fixed on the outer wall of tail flue 5 and communicates with the inside of tail flue 5 , pipe body 2 82 is located on the side of pipe body 1 81 away from tail flue 5 and is fixed on tail flue 5 , The end of the second pipe body 82 away from the first pipe body 81 is provided with a smoke inlet 821 .

Referring to Fig. 3 and Fig. 4, the filter plate 83 includes a plate body 831 and a collar 832, the plate body 831 is located between the first pipe body 81 and the second pipe body 82 and abuts against the first pipe body 81, the plate body 831 is provided with several The filter hole 8311, the collar 832 is located on the side of the plate body 831 close to the tube body 81 and is arranged around the outer circumference of the tube body 81, and the collar 832 and the plate body 831 are fixedly connected, and the collar 832 rotates coaxially on the tube body 1 81 on.

3 and 5, the scraper 84 is located in the second tube 82 and fixedly connected to the inner wall of the second tube 82, and the scraper 84 abuts against the side of the plate 831 away from the first tube 81, and the scraper 84 moves along the The horizontal direction is inclined downward. The upper end surface of the scraper 84 is provided with a through hole 841. The through hole 841 is located at the lower end of the scraper 84 and vertically runs through the scraper 84. The bottom inner wall of the pipe body 2 82 is provided with a discharge hole 9 , The discharge hole 9 is located directly below the scraper 84 .

Referring to Fig. 3 and Fig. 4, the sleeve 85 is sleeved on the outside of the pipe body 2 82 and the plate body 831, the sleeve 85 is slidingly connected to the pipe body 2 82, and the sleeve 85 is slid close to or away from the tail flue 5 ( See FIG. 2 ), and the sleeve 85 slides to open or cover the discharge hole 9 .

Referring to Fig. 4, the outer wall of the pipe body 2 82 is fixed with a bump 10, and the inner wall of the casing 85 is provided with a chute 11, and the length direction of the chute 11 is parallel to the axis of the pipe body 2 82, and the bump 10 Located in the chute 11, when the sleeve 85 moves, the protrusion 10 is slidably connected to the chute 11 relative to the sleeve 85, and the outer wall of the protrusion 10 parallel to its sliding direction is covered with an elastic layer 101 , the elastic layer 101 is pressed against the inner wall of the chute 11, and in this embodiment, the material of the elastic layer 101 is silica gel.

Referring to Fig. 3 and Fig. 6, a channel 111 is opened on the inner wall of the chute 11 away from the pipe body 2 82, the channel 111 is located on the side of the projection 10 away from the tail flue 5, and the end of the channel 111 away from the chute 11 is located on the scraper 84 is away from the side of the through hole 841 and is located above the scraper 84 , and the channel 111 communicates with the inside of the second tube 82 and is arranged toward the scraper 84 .

2 and 4, the sleeve 85 is fixed with an elastic piece 12, the elastic piece 12 is located in the chute 11 and on the side of the projection 10 away from the tail flue 5, and the opposite ends of the elastic piece 12 are They are respectively fixedly connected to the inner wall of the chute 11 and the projection 10, and the opposite ends of the elastic member 12 are pressed against the inner wall of the chute 11 and the projection 10 respectively, so that the sleeve 85 has the ability to slide away from the tail flue 5 to cover and close it. The trend of material hole 9. In this embodiment, the first elastic member 12 is a spring. It should be pointed out that the elastic force of the first elastic member 12 is greater than the frictional force between the elastic layer 101 and the inner wall of the chute 11 .

Referring to Fig. 2 and Fig. 4, the pipe body one 81 is hinged with a knocking rod 13, which is located on the side of the plate body 831 close to the tail flue 5, and the hinge axis of the knocking rod 13 is set perpendicular to the axis of the pipe body one 81 , The second elastic member 14 is fixed on the hinge shaft of the knocking rod 13, and the second elastic member 14 is pressed against the first pipe body 81, so that the knocking rod 13 is pressed against the end surface of the plate body 831 near the tail flue 5. In this embodiment, the second elastic member 14 is a torsion spring.

Referring to Fig. 2 and Fig. 4, a transmission assembly 15 is also provided on the pipe body 1 81. The transmission assembly 15 includes a bevel gear 151, a bevel gear 2 152 and a cam 153. One side is fixedly connected with the collar 832, and the bevel gear one 151 surrounds the outer circumference of the pipe body one 81 and is coaxially arranged with the pipe body one 81, and the bevel gear two 152 is located on the side of the bevel gear one 151 near the tail flue 5 and It is located on the outside of the first pipe body 81, and the bevel gear two 152 is rotatably connected to the first pipe body 81 and meshed with the bevel gear one 151. The rotation axis of the bevel gear two 152 is perpendicular to the axis of the first pipe body 81, and the cam 153 is located on the knock rod. 13 is close to the side of the tail flue 5 and is against the knock rod 13, and the end of the knock rod 13 abutting the plate body 831 and the cam 153 are respectively located on the opposite sides of the hinge shaft of the knock rod 13, the cam 153 and the bevel gear two 152 coaxial fixed.

In actual use, when the filter plate 83 is rotated, the filter plate 83 drives the first bevel gear 151 to rotate, and the first bevel gear 151 drives the second bevel gear 152 and the cam 153 to rotate through the meshing cooperation with the second bevel gear 152, and the cam 153 is pressed against the Knock the rod 13, thereby driving the knock rod 13 to turn back and forth, and then knock the filter plate 83 back and forth to shake off the impurities on the filter plate 83.

The implementation principle of an SNCR and SCR coupled flue gas denitrification system in the embodiment of this application is as follows:

When the flue gas enters the tail flue 5 from the smoke outlet 51, the flue gas entering the tail flue 5 is filtered through the filter plate 83 to reduce the solid particle impurities such as dust entering the tail flue 5 and polluting the inside of the equipment. Thereby reducing the frequency of staff cleaning the tail flue 5, and only need to clean the filter plate 83, compared with cleaning the tail flue 5, cleaning is more convenient and quick, can reduce the time required for cleaning, and then reduce the need for denitrification system operation. Occupation of time is conducive to improving the denitrification efficiency.

When there are many impurities on the filter plate 83, the filter plate 83 is rotated, and the impurities accumulated on the filter screen are scraped off by the scraper 84. The vibrated impurities slide down along the scraper 84, and fall from the through hole 841 to the inner wall of the pipe body 2 82, and then fall into the discharge hole 9 under the action of gravity for collection, so that the filter plate 83 can be cleaned and collected. It is integrated with filtration, and there is no need to clean the filter plate 83 with additional cleaning tools, which makes cleaning the filter plate 83 more convenient.

When the impurities in the discharge hole 9 accumulate more, move the casing 85 toward the direction close to the tail flue 5 to open the discharge hole 9, so that the impurities in the discharge hole 9 fall out, and at the same time, the protrusion 10 is relatively 85 moves and pushes the gas in the chute 11 to be discharged through the channel 111, and then blows onto the scraper 84, thereby blowing off the impurities adhered to the scraper 84, so that more impurities fall out from the discharge hole 9, and then Unclamp the sleeve pipe 85, and the sleeve pipe 85 resets and covers the discharge hole 9 again under the action of the elastic part one 12, so that the impurities continue to fall into the discharge hole 9 for collection.

The embodiment of the present application also discloses a method for using a SNCR and SCR coupled flue gas denitrification system, including the following steps:

a. Through the ammonia water: turn on the ammonia water pump 2 and the air compressor 4, so that the ammonia water in the ammonia water tank 1 enters the main spray gun 3 through the ammonia water pump 2, and the air is compressed by the air compressor 4 and then passed into the main spray gun 3, and the ammonia water is atomized Spray into the tail flue 5 from the main spray gun 3;

b. SNCR reaction: pass the flue gas into the smoke inlet 821, filter the flue gas through the filter plate 83, and perform SNCR reaction on the atomized ammonia water and the flue gas in the tail flue 5;

c. SCR reaction: the flue gas after the SNCR reaction in the tail flue 5 enters the flue gas heater 6 for heating, and the heated flue gas enters the SCR reactor 7 for the SCR reaction. The SCR reactor 7. Use the escaped ammonia escaped from the SNCR reaction carried out in the tail flue 5 as a denitrification reducing agent to carry out the SCR reaction, and discharge the reduced N2 through the flue gas outlet 2 72;

d. Clean the filter plate 83: Rotate the filter plate 83, scrape off the impurities on the filter plate 83 by the scraper 84, and then move the casing 85 in the direction close to the tail flue 5 until the discharge hole 9 is opened, so that the discharge Impurities in the hole 9 fall out, and then the sleeve pipe 85 is loosened to make the sleeve pipe 85 cover the discharge hole 9 again.

All of the above are preferred embodiments of the application, and are not intended to limit the protection scope of the application. Therefore, all equivalent changes made according to the structure, shape, and principle of the application should be covered by the protection scope of the application. Inside.

Claims (8)

1. An SNCR and SCR coupled flue gas denitration system comprises an ammonia water tank (1), an ammonia water pump (2), a main spray gun (3), an air compressor (4), a tail flue (5), a flue gas heater (6) and an SCR reactor (7), wherein the ammonia water pump (2) is used for conveying ammonia water in the ammonia water tank (1) to a main spray gun (3), the main spray gun (3) extends into the tail flue (5), an air outlet of the air compressor (4) is communicated with an air inlet of a main spray cavity, a flue gas inlet pipe (8) and a flue gas outlet (51) are arranged on the tail flue (5), a first flue gas inlet (61) and a first flue gas outlet (62) are arranged on the flue gas heater (6), the flue gas outlet (51) is communicated with the first flue gas inlet (61), a second flue gas inlet (71) and a second flue gas outlet (72) are arranged on the SCR reactor (7), and the first flue gas outlet (62) is communicated with the second flue gas inlet (71);

the method is characterized in that: advance tobacco pipe (8) including locating body one (81) and body two (82) on afterbody flue (5), rotate connect in filter plate (83) on body one (81), the cover is located sleeve pipe (85) on body two (82) and is located scraper blade (84) on body two (82), be equipped with into mouth (821) on body two (82), filter plate (83) are located body one (81) with between body two (82), scraper blade (84) butt in filter plate (83) are kept away from one side of body one (81), discharge opening (9) have been seted up on the bottom inner wall of body two (82), discharge opening (9) are located the below of scraper blade (84), through-hole (841) have been seted up on scraper blade (84), sleeve pipe (85) slide connect in on body two (82), just sleeve pipe (85) slide to open or cover discharge opening (9).

2. The SNCR and SCR coupled flue gas denitration system of claim 1, wherein: the pipe body II (82) is provided with a convex block (10), the sleeve (85) is provided with a first elastic part (12), and the first elastic part (12) abuts against the convex block (10), so that the sleeve (85) has the tendency of covering the discharge hole (9).

3. The SNCR and SCR coupled flue gas denitration system of claim 2, wherein: the improved smoke exhaust ventilator is characterized in that a sliding groove (11) is formed in the inner wall of the sleeve (85), the protruding block (10) is connected in the sliding groove (11) in a sliding mode, a channel (111) is formed in the inner wall of the sliding groove (11), the channel (111) is located on one side, away from the tail flue (5), of the protruding block (10), the end portion, away from the sliding groove (11), faces towards the scraper blade (84) and is communicated with the inside of the second pipe body (82), an elastic layer (101) is arranged on the protruding block (10), and the elastic layer (101) abuts against the inner wall of the sliding groove (11).

4. The SNCR and SCR coupled flue gas denitration system of claim 3, wherein: the scraper blade (84) sets up along the horizontal direction downward sloping, through-hole (841) are located the lower extreme of scraper blade (84), the tip that spout (11) were kept away from in passageway (111) is located scraper blade (84) is kept away from one side of through-hole (841).

5. The SNCR and SCR coupled flue gas denitration system of claim 1, wherein: articulated have rapping bar (13) on body one (81), be equipped with elastic component two (14) on the articulated shaft of rapping bar (13), elastic component two (14) support tightly in body one (81), make rapping bar (13) support tightly in filter plate (83), still be equipped with drive assembly (15) on body one (81), work as when filter plate (83) rotate, filter plate (83) pass through drive assembly (15) drive rapping bar (13) are reciprocal to be beaten filter plate (83).

6. The SNCR and SCR coupled flue gas denitration system of claim 5, wherein: the transmission assembly (15) comprises a first bevel gear (151) arranged on the filter plate (83), a second bevel gear (152) rotationally connected to the first pipe body (81) and a cam (153) coaxially arranged on the second bevel gear (152), the first bevel gear (151) and the first pipe body (81) are coaxially arranged, the second bevel gear (152) is meshed with the first bevel gear (151), and the cam (153) abuts against the knock rod (13).

7. The SNCR and SCR coupled flue gas denitration system of claim 1, wherein: one end of the filter plate (83) extends into the sleeve (85).

8. Use of the SNCR and SCR coupled flue gas denitration system according to any one of claims 1 to 7, comprising the steps of:

a. introducing ammonia water: an ammonia water pump (2) and an air compressor (4) are started, so that ammonia water in an ammonia water tank (1) enters a main spray gun (3) through the ammonia water pump (2), air is compressed by the air compressor (4) and then is introduced into the main spray gun (3), and the ammonia water is atomized and then is sprayed into a tail flue (5) from the main spray gun (3);

SNCR reaction: introducing the flue gas into a flue gas inlet (821), filtering the flue gas through a filter plate (83), and carrying out SNCR reaction on the atomized ammonia water and the flue gas in the tail flue (5);

c, SCR reaction: flue gas subjected to SNCR reaction in the tail flue (5) enters a flue gas heater (6) from the tail flue (5) to be heated, the heated flue gas enters an SCR reactor (7) to be subjected to SCR reaction, the SCR reactor (7) performs SCR reaction by using escaped ammonia escaping from the SNCR reaction in the tail flue (5) as a denitration reducing agent, and reduced N ₂ Is discharged through a second smoke outlet (72);

d. cleaning the filter plate (83): the filter plate (83) is rotated, impurities on the filter plate (83) are scraped through the scraper (84), then the sleeve (85) is moved to open the discharge hole (9), the impurities in the discharge hole (9) fall out, and the sleeve (85) covers the discharge hole (9) again.

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