Energy-saving cement kiln SCR (Selective Catalytic Reduction) denitration catalyst ash removal device

Abstract

The invention discloses an energy-saving cement kiln SCR denitration catalyst deashing device which comprises an inlet flue, an SCR reactor and an outlet flue which are sequentially arranged in the flue gas flowing direction, an inlet air valve is arranged on the inlet flue, and an outlet air valve is arranged on the outlet flue; an SCR catalyst and a soot blower are arranged in the SCR reactor, an air taking valve, a dust remover and a booster fan are sequentially arranged in the flowing direction of a soot blowing medium, the output end of the booster fan is communicated with the soot blower, and the air taking valve is arranged on the upstream of an outlet air valve. The operation cost is saved, and meanwhile, the one-time investment is also reduced.

Description

Technical Field

[0001] The invention relates to the technical field of air pollution control, in particular to an energy-saving cement kiln SCR denitration catalyst cleaning device. Background Art

[0002] With the continuous improvement of environmental protection requirements, the SNCR denitrification process can no longer meet the emission requirements of the existing cement industry. The flue gas at the tail of the cement kiln must be transformed into SCR denitrification. The main processes for denitrification transformation include high-temperature and high-dust SCR, high-temperature and low-dust SCR, and medium-temperature and medium-dust SCR. At present, high-temperature and high-dust SCR denitrification is the mainstream process for denitrification transformation of flue gas at the tail of cement kilns.

[0003] Due to the particularity of the process, the dust concentration in the flue gas at the tail of cement kiln is very high, generally between 80-120g / m3, and the dust particle size is small, the particle density is low, and the adhesion is strong. It is very easy to adhere to the surface of the catalyst. The sonic soot blower alone cannot effectively remove the ash accumulation, and a rake soot blower must be used for cleaning. The SCR denitrification of cement kiln generally uses a compressed air rake soot blower, and the pressure is generally around 0.8MPa. In order to improve the injection effect and prevent the influence of cold air on the catalyst, the soot blowing medium must be heated, and the temperature is generally required to be above 200℃. Generally, electric heating or flue gas heat exchange is used, especially when the denitrification system is put into use and stopped, the electric heating must be turned on. In addition, due to the large flow and pressure of the injection medium, an air compressor needs to be configured separately. Generally speaking, for a 4500t / d cement production line, the energy consumption of the air compressor is between 250kW-300kW, and the power of the electric heating is generally above 120kW. Therefore, in general, the traditional cleaning device has high energy consumption and the light blowing effect is average.

[0004] In order to further improve the soot blowing effect, enhance the stable operation of SCR denitrification of flue gas at the kiln tail of cement industry and reduce energy consumption, an energy-saving cement kiln SCR denitrification catalyst cleaning device is proposed. Summary of the invention

[0005] The purpose of the present invention is to solve the problems in the prior art and to provide an energy-saving cement furnace SCR denitration catalyst cleaning device that can solve at least one of the above problems.

[0006] To achieve the above-mentioned purpose, the present invention proposes an energy-saving cement furnace SCR denitrification catalyst cleaning device, comprising an inlet flue, an SCR reactor and an outlet flue arranged in sequence according to the flow direction of the flue gas, an inlet air valve is arranged on the inlet flue, and an outlet air valve is arranged on the outlet flue; an SCR catalyst and a soot blower are arranged in the SCR reactor, and an air intake valve, a dust collector and a booster fan are arranged in sequence according to the flow direction of the soot blowing medium, the output end of the booster fan is connected to the soot blower, and the air intake valve is arranged upstream of the outlet air valve.

[0007] Preferably, a first ash discharge device is provided at the bottom of the SCR reactor, and a second ash discharge device is provided at the bottom of the dust collector.

[0008] Preferably, the dust collector is a high-temperature bag dust collector, which can use ceramic filter bags or metal filter bags.

[0009] Preferably, the sootblower comprises a blowing main pipe and a plurality of blowing assemblies, the blowing main pipe is connected with the blowing assemblies, the blowing assemblies comprise a plurality of connecting mechanisms, two blowing branches and a plurality of nozzles, the blowing branches are each provided with a connecting mechanism connected thereto, the lower ends of the blowing branches are each provided with nozzles arranged in a row, and the nozzles on the two blowing branches are staggered.

[0010] Preferably, the injection main pipe includes a main pipe I and a main pipe II, the connecting mechanism on the front injection branch pipe is connected to the main pipe I through a connecting pipe, and the connecting mechanism on the rear injection branch pipe is connected to the main pipe II through a connecting pipe. The output end of the booster fan is provided with an electric three-way valve, and the two output ends of the electric three-way valve are respectively connected to the main pipe I and the main pipe II through a hose.

[0011] Preferably, the spray assembly also includes a shell, a connecting mechanism is provided at the upper end of the shell, the spray branch pipe is located in the shell, the lower end of the shell is provided with through holes corresponding to and cooperating with the nozzles, and two closing mechanisms are provided in the shell for closing the front and rear rows of through holes respectively.

[0012] Preferably, the closing mechanism comprises a plurality of seat bodies, a plurality of sliding rods, a plurality of springs III, a plurality of connecting rods and an L-shaped closing plate, the seat bodies are each provided with sliding rods, an L-shaped closing plate is provided at the rear end of the sliding rods, springs III are sleeved on the sliding rods between the L-shaped closing plate and the seat bodies, and the L-shaped closing plate is hingedly connected to the corresponding blowing branch pipe through a connecting rod.

[0013] Preferably, the connecting mechanism includes a piston sleeve, a piston, a shaft tube, an upper support, a spring I, a sealing head, a limit head, a lower support and a spring II. The piston sleeve is provided with an upper support and a lower support. A sliding shaft is passed through the upper support. A sealing head for closing the upper end of the shaft tube is provided at the lower end of the sliding shaft. A limit head is provided at the upper end of the sliding shaft. A spring I is sleeved on the sliding shaft between the sealing head and the upper support. A shaft tube is passed through the lower support. A piston matching the piston sleeve is provided at the upper end of the shaft tube. A spring II is sleeved on the shaft tube between the piston and the lower support.

[0014] The beneficial effects of the present invention are as follows: 1. Due to the large air volume of soot blowing, the cleaning effect of the catalyst surface can be greatly enhanced, ensuring the service life of the catalyst and the stable operation of the system; 2. The hot flue gas at the denitrification outlet is used as the soot blowing medium without additional heating, which can greatly reduce energy consumption and reduce one-time investment; 3. When the furnace is shut down, the inlet air valve and the outlet air valve can be closed to blow soot inside the SCR reactor, so that the catalyst surface can be thoroughly cleaned.

[0015] The features and advantages of the present invention will be described in detail through embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of an energy-saving cement furnace SCR denitration catalyst cleaning device of the present invention; Figure 2 is a top view of the sootblower; Figure 3 It is a partial side view of the sootblower.

[0017] In the figure: 1-soot blower, 2-inlet flue, 3-SCR reactor, 4-SCR catalyst, 5-ash discharging device 1, 6-outlet flue, 7-outlet air valve, 8-air intake valve 1, 9-dust collector, 10-ash discharging device 2, 13-boosting fan, 14-inlet air valve, 15-feeding device, 16-linear guide slide, 11-injection main pipe, 12-injection assembly, 111-main pipeline I, 112-main pipeline II, 113-connecting pipe, 114-electric three-way valve, 115-hose, 120-seal Closing mechanism, 121-shell, 122-connecting mechanism, 123-blowing branch pipe, 124-nozzle, 125-through hole, 1201-seat body, 1202-sliding rod, 1203-spring III, 1204-connecting rod, 1205-L-shaped closing plate, 1220-sliding shaft, 1221-piston sleeve, 1222-piston, 1223-shaft tube, 1224-upper support, 1225-spring I, 1226-sealing head, 1227-limiting head, 1228-lower support, 1229-spring II. DETAILED DESCRIPTION

[0018] See also Figure 1 , Figure 2 and Figure 3 The present invention discloses an energy-saving cement furnace SCR denitration catalyst cleaning device, comprising an inlet flue 2, an SCR reactor 3 and an outlet flue 6 which are sequentially arranged in the direction of flue gas flow, an inlet air valve 14 is arranged on the inlet flue 2, and an outlet air valve 7 is arranged on the outlet flue 6; an SCR catalyst 4 and a soot blower 1 are arranged in the SCR reactor 3, an air intake valve 8, a dust collector 9 and a booster fan 13 are sequentially arranged in the direction of soot blowing medium flow, the output end of the booster fan 13 is connected to the soot blower 1, and the air intake valve 8 is arranged upstream of the outlet air valve 7.

[0019] An ash discharge device 1 5 is provided at the bottom of the SCR reactor 3 , and an ash discharge device 2 10 is provided at the bottom of the dust collector 9 .

[0020] The dust collector 9 is a high-temperature bag dust collector, which can use a ceramic filter bag or a metal filter bag.

[0021] The sootblower 1 includes a blowing main pipe 11 and a plurality of blowing assemblies 12, the blowing main pipe 11 is connected with the blowing assemblies 12, the blowing assemblies 12 include a plurality of connecting mechanisms 122, two blowing branches 123 and a plurality of nozzles 124, the blowing branches 123 are each provided with a connecting mechanism 122 connected thereto, the lower ends of the blowing branches 123 are each provided with nozzles 124 arranged in a row, and the nozzles 124 on the two blowing branches 123 are staggered.

[0022] The injection main pipe 11 includes a main pipeline I111 and a main pipeline II112. The connecting mechanism 122 on the front injection branch pipe 123 is connected to the main pipeline I111 through the connecting pipe 113, and the connecting mechanism 122 on the rear injection branch pipe 123 is connected to the main pipeline II112 through the connecting pipe 113. The output end of the booster fan 13 is provided with an electric three-way valve 114, and the two output ends of the electric three-way valve 114 are respectively connected to the main pipeline I111 and the main pipeline II112 through a hose 115.

[0023] The spray assembly 12 also includes a shell 121, a connecting mechanism 122 is provided at the upper end of the shell 121, the spray branch pipe 123 is located in the shell 121, and a through hole 125 corresponding to and cooperating with the nozzle 124 is provided at the lower end of the shell 121. Two closing mechanisms 120 are provided in the shell 121, which are respectively used to close the front and rear rows of through holes 125.

[0024] The closing mechanism 120 includes a plurality of seat bodies 1201, a plurality of sliding rods 1202, a plurality of springs III1203, a plurality of connecting rods 1204 and an L-shaped closing plate 1205. The seat bodies 1201 are each provided with sliding rods 1202. An L-shaped closing plate 1205 is provided at the rear end of the sliding rod 1202. Springs III1203 are sleeved on the sliding rod 1202 between the L-shaped closing plate 1205 and the seat bodies 1201. The L-shaped closing plate 1205 is hingedly connected to the corresponding blowing branch pipe 123 through the connecting rod 1204.

[0025] The connecting mechanism 122 includes a piston sleeve 1221, a piston 1222, a shaft tube 1223, an upper support 1224, a spring I1225, a sealing head 1226, a limit head 1227, a lower support 1228 and a spring II1229. The piston sleeve 1221 is provided with an upper support 1224 and a lower support 1228. A sliding shaft 1220 is passed through the upper support 1224. The lower end of the sliding shaft 1220 is provided with a sealing seal on the upper end of the shaft tube 1223. Head 1226, a limit head 1227 is provided at the upper end of the sliding shaft 1220, a spring I1225 is sleeved on the sliding shaft 1220 between the sealing head 1226 and the upper support 1224, a shaft tube 1223 is passed through the lower support 1228, a piston 1222 matched with the piston sleeve 1221 is sleeved on the upper end of the shaft tube 1223, and a spring II1229 is sleeved on the shaft tube 1223 between the piston 1222 and the lower support 1228.

[0026] Working process of the present invention: In the working process of the energy-saving cement furnace SCR denitration catalyst cleaning device of the present invention, first, the flue gas at the kiln tail enters the SCR reactor 3 from the inlet flue 2, and the inlet flue 2 is provided with an inlet air valve 14. Under the action of the SCR catalyst 4, the NOx in the flue gas is reduced to N2 and water in the SCR reactor 3, thereby achieving the purpose of removing pollutants. The flue gas after denitration enters the bottom of the SCR reactor 3 and is finally discharged from the outlet flue 6. The ash that partially settles freely is transported to a designated location by an ash lowering device 5, and an outlet air valve 7 is provided on the outlet flue 6.

[0027] A soot blower 1 is arranged on the surface of the SCR catalyst 4, which is used to remove the accumulated dust on the surface of the SCR catalyst 4 to prevent the SCR catalyst 4 from being blocked and corroded. The soot blower 1 performs a reciprocating feeding motion through a feeding device 15. The feeding device 15 adopts the existing technology and is not described in detail here. The soot blower medium adopts hot flue gas, which is taken out from the upstream of the outlet air valve 7 arranged on the outlet flue 6, and an air intake valve 8 is arranged. In order to achieve a better cleaning effect, the drawn hot flue gas enters the dust collector 9 for dust removal to remove the dust particles in the flue gas. The removed ash is transported to the designated position through the ash discharge device 10. The clean hot flue gas after dust removal is pressurized by the booster fan 13 to meet the pressure requirement of the soot blower, and then enters the soot blower 1 to clean the SCR catalyst 4.

[0028] Since the sootblowing medium is hot flue gas, the temperature is consistent with the hot flue gas temperature in the catalyst, so no additional heating treatment is required. At the same time, when the kiln is stopped or bypassed for maintenance, the inlet air valve 14 and the outlet air valve 7 can be closed, and then the sootblower system can be turned on. At this time, since the internal flue gas is recycled, the dust particles in the reactor are continuously removed by the dust collector 9, and the surface of the SCR catalyst 4 can be thoroughly cleaned. At the same time, since the cleaning medium is recycled flue gas, there is no problem of water condensation and corrosion of the catalyst.

[0029] The flue gas output by the booster fan 13 passes through the electric three-way valve 114, the main pipeline I111 and the corresponding connecting pipe 113, the connecting mechanism 122, the blowing branch pipe 123 and the nozzle 124 in sequence, and then blows to the SCR catalyst 4. After the soot blower 1 has made a round trip, the compressed air passes through the electric three-way valve 114, the main pipeline II112 and the corresponding connecting pipe 113, the connecting mechanism 122, the blowing branch pipe 123 and the nozzle 124 in sequence through the adjustment of the electric three-way valve 114, and then blows to the SCR catalyst 4.

[0030] When the flue gas connecting mechanism 122 is pressurized, the piston 1222 drives the shaft tube 1223 to move downward under the action of compressed air and compresses the spring II1229. The shaft tube 1223 drives the corresponding blowing branch pipe 123 to move downward. The blowing branch pipe 123 pushes the L-shaped closing plate 1205 through the corresponding connecting rod 1204 to release the obstruction of the corresponding through hole 125. The blowing branch pipe 123 moves downward and drives the nozzle 124 thereon to move downward and extend out of the through hole 125. During the downward movement of the piston 1222, the sealing head 1226 descends together with it under the action of the spring I1225. When the limit head 1227 is blocked by the upper support 1224, the sealing head 1226 cannot continue to move downward. At this time, the downward moving shaft tube 1223 is disengaged from the sealing head 1226, and compressed air enters the shaft tube 1223.

[0031] When the soot blowing is completed, the booster fan 13 stops, and the piston 1222 moves upward under the action of the spring II1229. The piston 1222 drives the corresponding blowing branch pipe 123 to move upward through the shaft tube 1223, and the blowing branch pipe 123 drives the nozzle 124 thereon to retract into the shell 121. When the shaft tube 1223 moves upward and presses on the sealing head 1226, the shaft tube 1223 pushes the sealing head 1226 to move upward and compresses the spring I1225. While the blowing branch pipe 123 pulls the connecting rod 1204 upward, the L-shaped closing plate 1205 moves toward the top of the corresponding through hole 125 under the action of the spring III1203 to block the through hole 125. In this way, the nozzle 124 is in a closed space, avoiding the sealing failure caused by the nozzle 124 always being in the flue gas.

[0032] The above embodiments are intended to illustrate the present invention, not to limit the present invention. Any solution that is a simple transformation of the present invention belongs to the protection scope of the present invention.

Claims

1. An energy-saving cement kiln SCR denitration catalyst cleaning device, characterized by: The invention comprises an inlet flue (2), an SCR reactor (3) and an outlet flue (6) which are arranged in sequence according to the flow direction of flue gas, an inlet air valve (14) being arranged on the inlet flue (2), and an outlet air valve (7) being arranged on the outlet flue (6); an SCR catalyst (4) and a soot blower (1) being arranged in the SCR reactor (3), and an air intake valve (8), a dust collector (9) and a booster fan (13) being arranged in sequence according to the flow direction of the soot blowing medium, the output end of the booster fan (13) being connected to the soot blower (1), and the air intake valve (8) being arranged upstream of the outlet air valve (7).

2. The energy-saving cement kiln SCR denitration catalyst cleaning device according to claim 1, characterized in that: A first ash removal device (5) is provided at the bottom of the SCR reactor (3), and a second ash removal device (10) is provided at the bottom of the dust collector (9).

3. The energy-saving cement kiln SCR denitration catalyst cleaning device according to claim 1, characterized in that: The dust collector (9) is a high-temperature bag dust collector, which may use a ceramic filter bag or a metal filter bag.

4. The energy-saving cement kiln SCR denitration catalyst cleaning device according to claim 1, characterized in that: The soot blower (1) comprises a blowing main pipe (11) and a plurality of blowing assemblies (12); the blowing main pipe (11) is connected to the blowing assemblies (12); the blowing assemblies (12) comprise a plurality of connecting mechanisms (122), two blowing branch pipes (123) and a plurality of nozzles (124); the blowing branch pipes (123) are each provided with a connecting mechanism (122) connected thereto; the lower ends of the blowing branch pipes (123) are each provided with nozzles (124) arranged in a row; the nozzles (124) on the two blowing branch pipes (123) are arranged in a staggered manner.

5. An energy-saving cement kiln SCR denitration catalyst cleaning device as claimed in claim 4, characterized in that: The injection main pipe (11) comprises a main pipe I (111) and a main pipe II (112); a connecting mechanism (122) on the front injection branch pipe (123) is connected to the main pipe I (111) via the connecting pipe (113); a connecting mechanism (122) on the rear injection branch pipe (123) is connected to the main pipe II (112) via the connecting pipe (113); an electric three-way valve (114) is provided at the output end of the booster fan (13); and both output ends of the electric three-way valve (114) are respectively connected to the main pipe I (111) and the main pipe II (112) via a hose (115).

6. An energy-saving cement kiln SCR denitration catalyst cleaning device as claimed in claim 4, characterized in that: The spray assembly (12) further comprises a shell (121), the upper end of the shell (121) being provided with a connecting mechanism (122), the spray branch pipe (123) being located inside the shell (121), the lower end of the shell (121) being provided with through holes (125) corresponding one-to-one with and cooperating with the spray heads (124), and two closing mechanisms (120) being provided inside the shell (121) for closing two rows of through holes (125) respectively.

7. An energy-saving cement kiln SCR denitration catalyst cleaning device as claimed in claim 4, characterized in that: The closing mechanism (120) comprises a plurality of seat bodies (1201), a plurality of sliding rods (1202), a plurality of springs III (1203), a plurality of connecting rods (1204) and an L-shaped closing plate (1205). The seat bodies (1201) are each provided with a sliding rod (1202). The rear end of the sliding rod (1202) is provided with an L-shaped closing plate (1205). The sliding rod (1202) between the L-shaped closing plate (1205) and the seat body (1201) is each provided with a spring III (1203). The L-shaped closing plate (1205) is hingedly connected to a corresponding blowing branch pipe (123) via a connecting rod (1204).

8. An energy-saving cement kiln SCR denitration catalyst cleaning device as claimed in claim 4, characterized in that: The communication mechanism (122) comprises a piston sleeve (1221), a piston (1222), a shaft tube (1223), an upper support (1224), a spring I (1225), a sealing head (1226), a limiting head (1227), a lower support (1228) and a spring II (1229). An upper support (1224) and a lower support (1228) are provided in the piston sleeve (1221). A sliding shaft (1220) is passed through the upper support (1224). A sealing member is provided at the lower end of the sliding shaft (1220) to seal the upper end of the shaft tube (1223). A sealing head (1226), a limit head (1227) is provided at the upper end of the sliding shaft (1220), a spring I (1225) is sleeved on the sliding shaft (1220) between the sealing head (1226) and the upper support (1224), a shaft tube (1223) is passed through the lower support (1228), a piston (1222) matching with the piston sleeve (1221) is sleeved on the upper end of the shaft tube (1223), and a spring II (1229) is sleeved on the shaft tube (1223) between the piston (1222) and the lower support (1228).

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