CN111408270A

CN111408270A - SCR denitration system

Info

Publication number: CN111408270A
Application number: CN202010374245.6A
Authority: CN
Inventors: 陈昊; 周宇凡
Original assignee: Suzhou Dongyu Environmental Protection Technology Co ltd
Current assignee: Suzhou Dongyu Environmental Protection Technology Co ltd
Priority date: 2020-05-06
Filing date: 2020-05-06
Publication date: 2020-07-14

Abstract

The invention relates to the technical field of flue gas denitration, in particular to an SCR denitration system, which comprises a mixing tower, an ammonia spray pipe, a catalytic tower and a controller, wherein the mixing tower is arranged in the mixing tower; the bottom of the mixing tower is circumferentially provided with an annular ammonia spray pipe, and the ammonia spray pipe is provided with air pumps distributed in a surrounding manner; the air pump is controlled by the controller; because the mixing degree of the flue gas fed into the mixing tower and the pumped ammonia gas is difficult to control, the flue gas which is not completely mixed can reduce the subsequent catalytic denitration effect, and meanwhile, excessive ammonia gas pumped into the mixing tower can cause ammonia escape and pollute the environment; therefore, the air pumps are arranged on the mixing tower in a surrounding manner, the power of each air pump is adjusted to control the uniform mixing degree of the flue gas and the ammonia gas in the mixing tower after the measured parameters of the gas in the mixing tower are fed back to the controller by the induction ring, and the mixed gas flowing into the catalytic tower is reacted completely, so that the use effect of the SCR denitration system is improved.

Description

SCR denitration system

Technical Field

The invention relates to the technical field of flue gas denitration, in particular to an SCR denitration system.

Background

A Selective Catalytic Reduction (SCR) method is widely used in denitration treatment of nitrogen oxides in coal-fired power plants due to its high denitration efficiency, simple apparatus and wide application range; the SCR technical principle is that under the condition of certain temperature and the existence of a catalyst, a reducing agent (such as NH3, urea) selectively and rapidly reacts with nitrogen oxides in smoke to promote the reaction of the nitrogen oxides and ammonia to generate pollution-free nitrogen and water; for a description of SCR denitration systems, see: structural optimization of an SCR denitration device and ammonia spraying atomization simulation [ D ] in Jiangxing, Jiangsu university, 2016.

In the actual engineering design, the denitration efficiency is improved, the ammonia escape rate is reduced, and the economic benefit and the operation stability of the whole SCR denitration system are improved; the method generally starts from two aspects, namely, the residence time, the reaction temperature, the ammonia nitrogen molar ratio and the pressure drop loss caused by the flow guide device are optimized by optimizing the structural design of the SCR denitration device and by installing and adjusting the arrangement and the shape structure of the flow guide device.

Some technical schemes related to a flue gas denitration SCR system also appear in the prior art, and for example, a chinese patent with application number 201510679350X discloses a flue gas denitration SCR system, which includes a flue gas-flue gas heat exchanger, a flue gas-steam heat exchanger, a low-temperature economizer and an SCR denitration reaction tower; the flue gas-steam heat exchanger is connected with the flue gas-flue gas heat exchanger in series and then is respectively connected with the low-temperature economizer and the SCR denitration reaction tower in parallel; the outlet of the SCR denitration reaction tower is communicated with the flue gas-flue gas heat exchanger, and the inlet of the low-low temperature economizer is communicated with the flue gas-flue gas heat exchanger; the flue gas inlet is communicated with the flue gas-flue gas heat exchanger, the outlet of the low-temperature economizer and the chimney; the flue gas denitration SCR system in the technical scheme can carry out denitration treatment on catalysts with different temperature requirements and can realize various different technical effects; however, the SCR denitration system in the technical scheme does not solve the problems of balanced mixing of ammonia gas and flue gas in reaction, temperature loss in reaction and failure in catalysis, so that the use effect of the SCR denitration system is not stable enough.

In view of this, in order to overcome the above technical problems, the present inventors designed and developed an SCR denitration system, which employs a special denitration treatment structure to solve the above technical problems.

Disclosure of Invention

In order to make up for the defects of the prior art, the invention provides the SCR denitration system, wherein the air pumps are arranged on the mixing tower in a surrounding manner, the power of each air pump is adjusted to control the uniform mixing degree of the flue gas and the ammonia gas in the mixing tower after the measured parameters of the gas in the mixing tower are fed back to the controller by the induction ring, and then the mixed gas flowing into the catalytic tower is reacted completely, so that the use effect of the SCR denitration system is improved.

The SCR denitration system comprises a mixing tower, an ammonia spray pipe, a catalytic tower and a controller; a flue gas pipe is arranged in the center of the bottom of the mixing tower, a catalytic tower is arranged on one side of the mixing tower, and an air outlet pipe is arranged at the bottom of the catalytic tower; the bottom parts of the mixing tower and the catalytic tower are provided with supporting legs, a connecting pipeline is arranged between the mixing tower and the catalytic tower and used for communicating the mixing tower with the top part of the catalytic tower; the bottom of the mixing tower is circumferentially provided with an annular ammonia spray pipe, and the ammonia spray pipe is provided with air pumps distributed in a surrounding manner; the air pump is controlled by the controller, a convex spray head is arranged at the top of the air pump, and the spray head penetrates through and extends into the mixing tower; the air pump pumps the ammonia gas in the ammonia spray pipe into the mixing tower through the spray head; the outer side of the ammonia spray pipe is provided with a gas storage pipe which is arranged on a support leg of the mixing tower; two layers of induction rings are arranged in the middle of the inner wall of the mixing tower, the induction rings are installed at fixed positions in the mixing tower and are connected with a controller; the induction ring feeds back the detected parameters in the mixing tower to the controller, and then controls the operation of the air pump on the ammonia spray pipe; when the SCR denitration system operates, waste gas enters the mixing tower from the flue gas pipe, is mixed with pumped ammonia gas, and enters the catalytic tower through the connecting pipeline to react, and finally nitrate components containing nitrogen and oxygen elements in the flue gas are removed; therefore, the air pump and the spray heads which are arranged on the circumference of the mixing tower in a surrounding manner are matched with the two layers of induction rings arranged in the mixing tower, parameters between the flue gas and the ammonia gas in the mixing tower are fed back to the controller, the flow of the ammonia gas pumped into the mixing tower is adjusted by controlling the operating power of the air pump, the mixing degree of the air phases in the mixing tower is balanced, so that the nitrogen and oxygen elements in the mixed gas are completely denitrated by the catalytic tower and are finally discharged through the gas outlet pipe; according to the invention, the air pumps which are arranged on the mixing tower in a surrounding manner are utilized, the power of each air pump is adjusted after the measured parameters of the gas in the mixing tower are fed back to the controller, so that the uniform mixing degree of the flue gas and the ammonia gas in the mixing tower is controlled, the mixed gas which flows into the catalytic tower is reacted completely, and the use effect of the SCR denitration system is improved.

Preferably, the heating blanket is arranged on the outer wall of the gas storage pipe, and the heating blanket maintains the temperature of the ammonia gas in the gas storage pipe at 360-400 ℃; a heating ring is arranged on a nozzle of the air pump, and the temperature of the ammonia gas sprayed by the air pump is maintained at 390-420 ℃; the proper temperature of the catalytic reaction in the SCR system is between 320 and 400 ℃, the flue gas discharged into the mixing tower has residual temperature, the temperature can change in the mixing process of pumping ammonia gas, and the effect and the speed of the catalytic denitration reaction are influenced after the flue gas flows into the catalytic tower; through setting up the heating blanket on the gas storage pipe, the ammonia temperature before will pumping into the mixing tower improves to required within range, carries out the secondary heating to the ammonia of pumping into to the mixing tower by the heating ring on the spout again, ensures that the gaseous phase after the mixture still can be in suitable catalysis temperature in the catalytic tower after the heat through the connecting tube scatters and disappears to SCR deNOx systems's catalytic effect has been promoted.

Preferably, a guide plate is arranged at a corner of the inner wall at the top of the connecting pipeline; a drainage cover is arranged at the corner of the inner wall of the bottom of one side, close to the mixing tower, of the connecting pipeline, the drainage cover is of a fan-shaped cylindrical structure, and a driving rod is arranged on the axis of the drainage cover; the driving rod is rotatably installed on the connecting pipeline, a servo motor is arranged on the connecting pipeline at the end part of the driving rod, and the driving rod is in transmission connection with the servo motor; the corner in the connecting pipeline can interfere the gas in circulation, so that the flow rate of the gas entering the catalytic tower is influenced, the time of the gas entering the catalytic tower is prolonged, the mixing degree of the mixed gas is reduced, and the catalytic denitration effect is further influenced; through setting up the guide plate on the connecting tube, reduce the hindrance of the top corner of connecting tube to the velocity of flow when the gas circulation, set up at bottom corner pivoted drainage cover, detect the inside gas velocity of flow condition of mixing tower with the induction ring, through controller control servo motor's operation, change the rotation angle of drainage cover, and then adjust the velocity of flow of gas in getting into the connecting tube from mixing tower, stabilize the torrent degree that flue gas and ammonia mix, thereby maintain SCR deNOx systems's result of use.

Preferably, a rectification grid is arranged at a corner of the connecting pipeline close to one side of the catalytic tower, fixing plates are arranged at two ends of the rectification grid, and the rectification grid is rotatably arranged on the connecting pipeline through the fixing plates; the rotating axis of the fixed plate is vertical to the gas flow direction in the connecting pipeline; the mixed gas entering the catalytic tower needs to be subjected to complete catalytic reaction to reach the emission standard, the gas conveyed by the connecting pipeline cannot be uniformly distributed on the section of the catalytic tower, so that the quantity of the gas reacted in the catalytic process is different, and the gas flowing through the catalytic tower cannot be completely catalyzed, so that the action effect of the catalytic tower is influenced; through the rectification grid that sets up in the pipeline of catalytic tower top connecting, gas guide in with the transmission is to the direction of perpendicular to catalytic tower cross-section, and when the gas flow in the connecting tube changes, makes the rotation that the rectification grid produced the correspondence to the effect of catalytic tower reaction is ensured to the balanced gas quantity that flows into to the catalytic tower, thereby has promoted SCR deNOx systems's catalytic effect.

Preferably, three layers of convex rings are arranged at the positions of the rectifying grids corresponding to the catalytic tower, the convex rings are superposed in the axial direction of the catalytic tower, and a honeycomb box filled with catalyst is arranged in each convex ring; the honeycomb box is arranged on the catalytic tower through a convex ring; when the catalytic tower catalyzes gas, impurities mixed in the gas can interfere normal use of catalytic reaction, and the failed catalytic tower destroys the operation of a denitration system; through the bulge loop of setting up the three-layer in the catalytic tower, change the honeycomb case that has the catalyst through installing the bulge loop on the catalytic tower to packing, two-layer in the bulge loop structure of three-layer is direct as catalytic reaction and uses, and the honeycomb case in the bulge loop of third layer is as catalytic reaction's standby structure, avoids single-deck catalysis's inefficacy to influence the holistic effect of catalytic tower to SCR deNOx systems's catalytic effect has been maintained.

Preferably, a guide groove is arranged in a nest hole of the honeycomb box, and a cavity is arranged at the bottom of the box body of the honeycomb box; the bottom of the guide groove is communicated to the cavity of the honeycomb box; the gas in the catalytic tower generates moisture under the catalytic action, and the moisture accumulated gradually blocks the continuous action of the catalyst and the gas, so that the catalytic effect of the catalytic tower is reduced; through the guide slot that sets up in the nest hole, in leading the cavity in the honeycomb case with the moisture that produces in the catalytic reaction, avoided the moisture that adheres to on the catalyst to disturb the going on of catalytic reaction to SCR deNOx systems's result of use has been maintained.

The invention has the following beneficial effects:

1. the uniform mixing degree of the flue gas and the ammonia gas in the mixing tower is controlled by the air pumps which are arranged on the mixing tower and distributed in a surrounding way; the arranged heating blanket and heating ring ensure that the mixed gas can still be at the proper catalytic temperature in the catalytic tower; the guide plate and the drainage cover of setting on the connecting tube adjust the velocity of flow of gas in getting into the connecting tube from the mixing tower, stabilize the torrent degree that flue gas and ammonia mix, maintain SCR deNOx systems's result of use.

2. The invention balances the gas quantity flowing into the catalytic tower through the rectifying grating arranged in the connecting pipeline, thereby ensuring the reaction effect of the catalytic tower; the three layers of convex rings arranged in the catalytic tower avoid the failure of the single-layer catalysis effect from influencing the overall effect of the catalytic tower; the guide slot of setting in the nest hole has avoided the moisture that adheres to on the catalyst to disturb the going on of catalytic reaction, has maintained SCR deNOx systems's result of use.

Drawings

The invention is further described with reference to the following figures and embodiments.

FIG. 1 is a perspective view of an SCR denitration system according to the present invention;

FIG. 2 is a cross-sectional view of an SCR denitration system of the present invention;

FIG. 3 is a perspective view of a connecting duct member according to the present invention;

FIG. 4 is an enlarged view of a portion of FIG. 2 at A;

in the figure: mixing tower 1, flue gas pipe 11, gas outlet pipe 12, induction ring 13, ammonia spray pipe 2, air pump 21, heating ring 211, shower nozzle 22, catalysis tower 3, bulge loop 31, honeycomb case 32, guide slot 321, cavity 322, landing leg 4, connecting tube 5, guide plate 51, drainage cover 52, actuating lever 521, servo motor 522, rectification grid 53, fixed plate 531, gas storage pipe 6, heating blanket 61.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.

As shown in fig. 1 to 4, an SCR denitration system according to the present invention includes a mixing tower 1, an ammonia injection pipe 2, a catalytic tower 3, and a controller; a flue gas pipe 11 is arranged at the center of the bottom of the mixing tower 1, a catalytic tower 3 is arranged on one side of the mixing tower 1, and an air outlet pipe 12 is arranged at the bottom of the catalytic tower 3; the bottom parts of the mixing tower 1 and the catalytic tower 3 are provided with supporting legs 4, a connecting pipeline 5 is arranged between the mixing tower 1 and the catalytic tower 3, and the top parts of the mixing tower 1 and the catalytic tower 3 are communicated through the connecting pipeline 5; the bottom of the mixing tower 1 is circumferentially provided with an annular ammonia spray pipe 2, and the ammonia spray pipe 2 is provided with air pumps 21 which are distributed in a surrounding manner; the air pump 21 is controlled by the controller, a convex spray head 22 is arranged at the top of the air pump 21, and the spray head 22 penetrates and extends into the mixing tower 1; the air pump 21 pumps the ammonia gas in the ammonia nozzle 2 into the mixing tower 1 through the spray head 22; the outer side of the ammonia spray pipe 2 is provided with a gas storage pipe 6, and the gas storage pipe 6 is arranged on a support leg 4 of the mixing tower 1; two layers of induction rings 13 are arranged in the middle of the inner wall of the mixing tower 1, the induction rings 13 are installed at fixed positions inside the mixing tower 1, and the induction rings 13 are connected with a controller; the induction ring 13 feeds back the detected parameters inside the mixing tower 1 to the controller, and then controls the operation of the air pump 21 on the ammonia spray pipe 2; when the SCR denitration system operates, waste gas enters the mixing tower 1 from the flue gas pipe 11, is mixed with pumped ammonia gas, enters the catalytic tower 3 through the connecting pipeline 5, reacts, and finally removes nitrated compounds containing nitrogen and oxygen elements in the flue gas, because the mixing degree of the flue gas fed into the mixing tower 1 and the pumped ammonia gas is difficult to control, the flue gas which is not completely mixed can reduce the effect of subsequent catalytic denitration, and meanwhile, excessive ammonia gas pumped into the mixing tower 1 can cause ammonia escape, thereby polluting the environment; therefore, the air pump 21 and the spray head 22 which are arranged on the mixing tower 1 in the circumferential direction in a surrounding manner are matched with the two layers of induction rings 13 arranged in the mixing tower 1, parameters between the flue gas and the ammonia gas in the mixing tower 1 are fed back to the controller, the flow of the ammonia gas pumped into the mixing tower 1 is adjusted by controlling the operating power of the air pump 21, the mixing degree of the air phases in the mixing tower 1 is balanced, so that the nitrogen and oxygen elements in the mixed gas are completely denitrated by the catalytic tower 3 and finally discharged through the gas outlet pipe 12; according to the invention, the air pumps 21 which are arranged on the mixing tower 1 in a surrounding manner are utilized, the power of each air pump 21 is adjusted after the measured parameters of the gas in the mixing tower 1 are fed back to the controller by the induction ring 13, so that the uniform mixing degree of the flue gas and the ammonia gas in the mixing tower 1 is controlled, the mixed gas flowing into the catalytic tower 3 is completely reacted, and the use effect of the SCR denitration system is improved.

As an embodiment of the invention, a heating blanket 61 is arranged on the outer wall of the gas storage pipe 6, and the heating blanket 61 maintains the temperature of the ammonia gas in the gas storage pipe 6 at 360-400 ℃; a heating ring 211 is arranged on a nozzle of the air pump 21, and the temperature of the ammonia gas sprayed by the air pump 21 is maintained at 390-420 ℃; the proper temperature of the catalytic reaction in the SCR system is between 320 and 400 ℃, the flue gas discharged into the mixing tower 1 has residual temperature, the temperature can change in the mixing process with pumped ammonia gas, and the effect and the speed of the catalytic denitration reaction are influenced after the flue gas flows into the catalytic tower 3; through setting up heating blanket 61 on gas storage pipe 6, the ammonia temperature before will pumping into mixing tower 1 improves to required within range, carries out the secondary heating by heating ring 211 on the spout to the ammonia of pumping into mixing tower 1 again, ensures that the gaseous phase after the mixture still can be in suitable catalysis temperature in catalytic tower 3 after the heat through connecting tube 5 scatters and disappears to the catalytic effect of SCR deNOx systems has been promoted.

As an embodiment of the present invention, a flow guide plate 51 is disposed at a corner of an inner wall at the top of the connecting pipe 5; a drainage cover 52 is arranged at the corner of the inner wall of the bottom of the connecting pipeline 5 close to one side of the mixing tower 1, the drainage cover 52 is of a fan-shaped cylindrical structure, and a driving rod 521 is arranged on the axis of the drainage cover 52; the driving rod 521 is rotatably installed on the connecting pipeline 5, a servo motor 522 is arranged on the connecting pipeline 5 at the end part of the driving rod 521, and the driving rod 521 is in transmission connection with the servo motor 522; the corner in the connecting pipeline 5 can interfere with the gas in circulation, so that the flow rate of the gas entering the catalytic tower 3 is influenced, the time of the gas entering the catalytic tower 3 is prolonged, the mixing degree of the mixed gas is reduced, and the catalytic denitration effect is further influenced; through setting up guide plate 51 on connecting tube 5, reduce the hindrance of the top corner of connecting tube 5 to the velocity of flow when the gas circulation, set up in bottom corner pivoted drainage cover 52, detect the gas velocity of flow condition of mixing tower 1 inside with induction ring 13, through controller control servo motor 522's operation, change the rotation angle of drainage cover 52, and then adjust the velocity of flow that gets into gas in the connecting tube 5 from mixing tower 1, stabilize the torrent degree that flue gas and ammonia mix, thereby maintain SCR deNOx systems's result of use.

As an embodiment of the present invention, a rectifying grating 53 is disposed at a corner of the connecting pipe 5 near the catalytic tower 3, fixing plates 531 are disposed at two ends of the rectifying grating 53, and the rectifying grating 53 is rotatably mounted on the connecting pipe 5 through the fixing plates 531; the rotating axis of the fixing plate 531 is perpendicular to the flow direction of the gas in the connecting pipeline 5; the mixed gas entering the catalytic tower 3 needs to be subjected to complete catalytic reaction to reach the emission standard, the gas conveyed by the connecting pipeline 5 cannot be uniformly distributed on the section of the catalytic tower 3, so that the amount of the gas reacted in the catalytic process is different, and the gas flowing through the catalytic tower 3 cannot be completely catalyzed, so that the action effect of the catalytic tower 3 is influenced; through setting up the rectification grid 53 in the connecting tube 5 above the catalytic tower 3, the gas guide in the transmission is to the direction of perpendicular to the 3 cross-sections of catalytic tower, and when the gas flow in the connecting tube 5 changes, makes rectification grid 53 produce corresponding rotation to the balanced gas quantity that flows into in the catalytic tower 3, ensures the effect of catalytic tower 3 reaction, thereby has promoted SCR deNOx systems's catalytic effect.

As an embodiment of the present invention, three layers of convex rings 31 are disposed at positions of the rectifying grid 53 corresponding to the catalytic tower 3, the convex rings 31 are overlapped in the axial direction of the catalytic tower 3, and a honeycomb box 32 filled with catalyst is disposed in the convex rings 31; the honeycomb box 32 is installed on the catalytic tower 3 through a convex ring 31; when the catalytic tower 3 catalyzes the gas, impurities mixed in the gas can interfere the normal use of catalytic reaction, and the failed catalytic tower 3 destroys the operation of a denitration system; through the bulge loop 31 of the three-layer that sets up in catalytic tower 3, it has the honeycomb case 32 of catalyst to fill through installing the bulge loop 31 on catalytic tower 3, two-layer in the bulge loop 31 structure of three-layer is directly as catalytic reaction use, honeycomb case 32 in the bulge loop 31 of third layer is as catalytic reaction's standby structure, avoids single-deck catalytic action's inefficacy to influence the holistic effect of catalytic tower 3 to SCR deNOx systems's catalytic effect has been maintained.

As an embodiment of the present invention, a guide groove 321 is provided in a cell of the honeycomb box 32, and a cavity 322 is provided at the bottom of the box body of the honeycomb box 32; the bottom of the guide groove 321 communicates with the cavity 322 of the honeycomb case 32; the gas in the catalytic tower 3 generates moisture under the catalytic action, the moisture accumulated gradually blocks the continuous action of the catalyst and the gas, and the catalytic effect of the catalytic tower 3 is reduced; through the guide grooves 321 arranged in the honeycomb holes, moisture generated in the catalytic reaction is guided into the cavities 322 in the honeycomb box 32, so that the moisture attached to the catalyst is prevented from interfering with the catalytic reaction, and the using effect of the SCR denitration system is maintained.

During operation, the waste gas enters the mixing tower 1 from the flue gas pipe 11, is mixed with pumped ammonia gas, enters the catalytic tower 3 through the connecting pipeline 5 for reaction, and finally the nitrated compound containing nitrogen and oxygen in the flue gas is removed; through an air pump 21 and a spray head 22 which are arranged on the circumference of the mixing tower 1 and distributed in a surrounding way, and a two-layer induction ring 13 arranged in the mixing tower 1, parameters between the flue gas and the ammonia gas in the mixing tower 1 are fed back to a controller, the flow of the ammonia gas pumped into the mixing tower 1 is adjusted by controlling the running power of the air pump 21, the mixing degree of the gas phases in the mixing tower 1 is balanced, so that the nitrogen-oxygen element in the mixed gas is completely denitrated by the catalytic tower 3 and finally discharged through an air outlet pipe 12; the heating blanket 61 arranged on the gas storage pipe 6 raises the temperature of the ammonia gas before being pumped into the mixing tower 1 to a required range, and the heating ring 211 on the nozzle carries out secondary heating on the ammonia gas pumped into the mixing tower 1, so that the mixed gas phase can still be at a proper catalytic temperature in the catalytic tower 3 after the heat in the connecting pipeline 5 is dissipated; the guide plate 51 is arranged on the connecting pipeline 5, so that the obstruction of the top corner of the connecting pipeline 5 to the flow velocity of gas during flowing is reduced, the guide cover 52 which rotates at the bottom corner is arranged, the induction ring 13 detects the gas flow velocity condition in the mixing tower 1, the operation of the servo motor 522 is controlled through the controller, the turning angle of the guide cover 52 is changed, the flow velocity of gas entering the connecting pipeline 5 from the mixing tower 1 is further adjusted, and the turbulence degree of mixing of the flue gas and the ammonia gas is stabilized; the rectifying grating 53 is arranged in the connecting pipeline 5 above the catalytic tower 3, guides the gas in transmission to the direction vertical to the section of the catalytic tower 3, and when the gas flow in the connecting pipeline 5 is changed, the rectifying grating 53 generates corresponding rotation so as to balance the gas quantity flowing into the catalytic tower 3 and ensure the reaction effect of the catalytic tower 3; the three layers of convex rings 31 arranged in the catalytic tower 3 replace the honeycomb boxes 32 filled with the catalyst through the convex rings 31 arranged on the catalytic tower 3, two layers of the three layers of convex rings 31 are directly used as catalytic reaction, and the honeycomb boxes 32 in the third layer of convex rings 31 are used as standby structures of the catalytic reaction, so that the influence of the failure of the single-layer catalytic action on the whole effect of the catalytic tower 3 is avoided; the guide grooves 321 provided in the cells guide moisture generated in the catalytic reaction to the cavities 322 in the honeycomb case 32, and prevent the moisture adhering to the catalyst from interfering with the progress of the catalytic reaction.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. An SCR denitration system comprises a mixing tower (1), an ammonia spray pipe (2), a catalytic tower (3) and a controller; a flue gas pipe (11) is arranged in the center of the bottom of the mixing tower (1), a catalytic tower (3) is arranged on one side of the mixing tower (1), and an air outlet pipe (12) is arranged at the bottom of the catalytic tower (3); the bottom parts of the mixing tower (1) and the catalytic tower (3) are provided with supporting legs (4), a connecting pipeline (5) is arranged between the mixing tower (1) and the catalytic tower (3), and the top parts of the mixing tower (1) and the catalytic tower (3) are communicated through the connecting pipeline (5); the method is characterized in that: the bottom of the mixing tower (1) is circumferentially provided with an annular ammonia spray pipe (2), and the ammonia spray pipe (2) is provided with air pumps (21) which are distributed in a surrounding manner; the air pump (21) is controlled by the controller, a convex spray head (22) is arranged at the top of the air pump (21), and the spray head (22) penetrates into the mixing tower (1); the air pump (21) pumps the ammonia gas in the ammonia nozzle (2) into the mixing tower (1) through the spray head (22); the outer side of the ammonia spray pipe (2) is provided with a gas storage pipe (6), and the gas storage pipe (6) is arranged on a support leg (4) of the mixing tower (1); two layers of induction rings (13) are arranged in the middle of the inner wall of the mixing tower (1), the induction rings (13) are installed at fixed positions inside the mixing tower (1), and the induction rings (13) are connected with a controller; the induction ring (13) feeds back the detected parameters inside the mixing tower (1) to the controller, and then controls the operation of the air pump (21) on the ammonia spray pipe (2).

2. The SCR denitration system of claim 1, wherein: a heating blanket (61) is arranged on the outer wall of the gas storage pipe (6), and the heating blanket (61) maintains the temperature of the ammonia gas in the gas storage pipe (6) at 360-400 ℃; a heating ring (211) is arranged on a nozzle of the air pump (21) to maintain the temperature of the ammonia gas sprayed by the air pump (21) at 390-420 ℃.

3. The SCR denitration system of claim 1, wherein: a guide plate (51) is arranged at the corner of the inner wall at the top of the connecting pipeline (5); a drainage cover (52) is arranged at the corner of the inner wall of the bottom of one side, close to the mixing tower (1), of the connecting pipeline (5), the drainage cover (52) is of a fan-shaped cylindrical structure, and a driving rod (521) is arranged on the axis of the drainage cover (52); the driving rod (521) is installed on the connecting pipeline (5) in a rotating mode, a servo motor (522) is arranged on the connecting pipeline (5) at the end portion of the driving rod (521), and the driving rod (521) is in transmission connection with the servo motor (522).

4. The SCR denitration system of claim 3, wherein: a rectifying grating (53) is arranged at a corner of one side of the connecting pipeline (5) close to the catalytic tower (3), fixing plates (531) are arranged at two ends of the rectifying grating (53), and the rectifying grating (53) is rotatably installed on the connecting pipeline (5) through the fixing plates (531); the rotating axis of the fixed plate (531) is vertical to the flow direction of the gas in the connecting pipeline (5).

5. The SCR denitration system of claim 4, wherein: three layers of convex rings (31) are arranged at the position of the rectifying grating (53) corresponding to the catalytic tower (3), the convex rings (31) are overlapped in the axial direction of the catalytic tower (3), and a honeycomb box (32) filled with catalyst is arranged in each convex ring (31); the honeycomb box (32) is arranged on the catalytic tower (3) through a convex ring (31).

6. The SCR denitration system of claim 5, wherein: a guide groove (321) is arranged in a nest hole of the honeycomb box (32), and a cavity (322) is arranged at the bottom of the box body of the honeycomb box (32); the bottom of the guide groove (321) is communicated to the cavity (322) of the honeycomb box (32).