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

Abstract

The utility model discloses an energy-saving cement kiln SCR (Selective Catalytic Reduction) denitration catalyst deashing device which comprises an inlet flue, an SCR reactor and an outlet flue which are sequentially arranged along the flowing direction of 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, 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] This utility model relates to the technical field of air pollution control, and in particular to an energy-saving SCR denitrification catalyst cleaning device for cement kilns. Background Technology

[0002] With increasingly stringent environmental protection requirements, the SNCR denitrification process can no longer meet the emission requirements of the existing cement industry. The kiln tail flue gas in the cement industry must undergo SCR denitrification retrofit. The main denitrification retrofit processes include high temperature and high dust SCR, high temperature and low dust SCR, and medium temperature and medium dust SCR. Currently, high temperature and high dust SCR denitrification is the mainstream process for denitrification retrofit of cement kiln tail flue gas.

[0003] Due to the unique nature of the cement kiln's flue gas process, the dust concentration in the flue gas is extremely high, typically between 80-120 g / m³. Furthermore, the dust particles are small, low in density, and highly adhesive, easily adhering to the catalyst surface. Sonic soot blowers alone cannot effectively remove the accumulated dust; a rake soot blower is necessary. SCR denitrification in cement kilns generally uses compressed air rake soot blowers at pressures around 0.8 MPa. To improve the blowing effect and prevent the cold air from affecting the catalyst, the blowing medium must be heated, typically to above 200℃. This is usually achieved through electric heating or flue gas heat exchange, especially when the denitrification system is started and stopped. Moreover, because the flow rate and pressure of the blowing medium are relatively high, a separate air compressor is required. Generally, for a 4500 t / d cement production line, the air compressor's energy consumption is between 250 kW and 300 kW, while the electric heating power is generally above 120 kW. Therefore, overall, traditional soot blowing devices are energy-intensive and offer only moderate blowing efficiency.

[0004] To further improve the soot blowing effect, enhance the stable operation of SCR denitrification in cement kiln tail gas, and reduce energy consumption, an energy-saving cement kiln SCR denitrification catalyst cleaning device is proposed. Summary of the Invention

[0005] The purpose of this invention is to solve the problems in the prior art by proposing an energy-saving SCR denitrification catalyst cleaning device for cement kilns, which can solve at least one of the above problems.

[0006] To achieve the above objectives, this utility model proposes an energy-saving SCR denitrification catalyst cleaning device for cement kilns, comprising an inlet flue, an SCR reactor, and an outlet flue arranged sequentially in the flue gas flow direction. An inlet air valve is installed on the inlet flue, and an outlet air valve is installed on the outlet flue. An SCR catalyst and a soot blower are installed inside the SCR reactor. An air intake valve, a dust collector, and a booster fan are arranged sequentially in the soot blowing medium flow direction. The output end of the booster fan is connected to the soot blower, and the air intake valve is located upstream of the outlet air valve.

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

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

[0009] Preferably, the soot blower includes a main blowing pipe and several blowing components. The main blowing pipe and the blowing components are connected. The blowing components include several connecting mechanisms, two blowing branch pipes and several nozzles. Each blowing branch pipe is provided with a connecting mechanism connected to it. The lower end of each blowing branch pipe is provided with nozzles arranged in a row. The nozzles on the two blowing branch pipes are staggered.

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

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

[0012] Preferably, the sealing mechanism includes several seats, several slide rods, several springs III, several connecting rods and an L-shaped sealing plate. Each seat is provided with a slide rod, and the rear end of each slide rod is provided with an L-shaped sealing plate. Each slide rod between the L-shaped sealing plate and the seat is fitted with a spring III. The L-shaped sealing plate is hinged to the corresponding jetting branch pipe through a connecting rod.

[0013] Preferably, the communication mechanism includes a piston sleeve, a piston, a shaft tube, an upper support, a spring I, a sealing head, a limiting head, a lower support, and a spring II. The piston sleeve contains the upper support and the lower support. A sliding shaft passes through the upper support. The lower end of the sliding shaft is provided with a sealing head that closes the upper end of the shaft tube. The upper end of the sliding shaft is provided with a limiting head. Spring I is sleeved on the sliding shaft between the sealing head and the upper support. A shaft tube passes through the lower support. A piston that cooperates with the piston sleeve is sleeved on the upper end of the shaft tube. Spring II is sleeved on the shaft tube between the piston and the lower support.

[0014] The beneficial effects of this utility model are as follows: 1. Due to the large volume of soot blowing air, the soot removal effect on the catalyst surface can be greatly enhanced, ensuring the service life of the catalyst and the stable operation of the system; 2. Using the hot flue gas from the denitrification outlet as the soot blowing medium eliminates the need for additional heating, which can greatly reduce energy consumption and reduce initial investment; 3. When the furnace is shut down, the inside of the SCR reactor can be soot blown by closing the inlet air valve and the outlet air valve, which can thoroughly clean the catalyst surface.

[0015] The features and advantages of this utility model will be described in detail through embodiments and accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an energy-saving SCR denitrification catalyst cleaning device for cement kilns according to this utility model;

[0017] Figure 2 This is a top view of the soot blower;

[0018] Figure 3 This is a partial side view of the soot blower.

[0019] In the diagram: 1-Soot blower, 2-Inlet flue, 3-SCR reactor, 4-SCR catalyst, 5-Ash removal device one, 6-Outlet flue, 7-Outlet air valve, 8-Air intake valve one, 9-Dust collector, 10-Ash removal device two, 13-Booster fan, 14-Inlet air valve, 15-Feeding device, 16-Linear guide rail slide, 11-Pulse jet main pipe, 12-Pulse jet assembly, 111-Main pipe I, 112-Main pipe II, 113-Connecting pipe, 114-Electric three-way valve, 115-Hose, 120-Sealer Closing mechanism, 121-housing, 122-connecting mechanism, 123-puffing branch pipe, 124-nozzle, 125-through hole, 1201-seat body, 1202-slide rod, 1203-spring III, 1204-connecting rod, 1205-L-shaped sealing 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 Implementation

[0020] See Figure 1 , Figure 2 and Figure 3 This utility model discloses an energy-saving SCR denitrification catalyst cleaning device for cement kilns, comprising an inlet flue duct 2, an SCR reactor 3, and an outlet flue duct 6 arranged sequentially in the flue gas flow direction. An inlet air valve 14 is installed on the inlet flue duct 2, and an outlet air valve 7 is installed on the outlet flue duct 6. An SCR catalyst 4 and a soot blower 1 are installed inside the SCR reactor 3. An air intake valve 8, a dust collector 9, and a booster fan 13 are arranged sequentially in the soot blowing medium flow direction. The output end of the booster fan 13 is connected to the soot blower 1, and the air intake valve 8 is located upstream of the outlet air valve 7.

[0021] The bottom of the SCR reactor 3 is provided with an ash discharge device 5, and the bottom of the dust collector 9 is provided with an ash discharge device 10.

[0022] The dust collector 9 is a high-temperature bag filter, which can use ceramic filter bags or metal filter bags.

[0023] The soot blower 1 includes a main blowing pipe 11 and several blowing components 12. The main blowing pipe 11 and the blowing components 12 are all connected. The blowing components 12 include several connecting mechanisms 122, two blowing branch pipes 123 and several nozzles 124. Each blowing branch pipe 123 is provided with a connecting mechanism 122 connected to it. The lower end of each blowing branch pipe 123 is provided with a row of nozzles 124. The nozzles 124 on the two blowing branch pipes 123 are staggered.

[0024] The main jetting pipe 11 includes a main pipe I111 and a main pipe II112. The connecting mechanism 122 on the front jetting branch pipe 123 is connected to the main pipe I111 through a connecting pipe 113. The connecting mechanism 122 on the rear jetting branch pipe 123 is connected to the main pipe II112 through a connecting pipe 113. The output end of the booster fan 13 is equipped with an electric three-way valve 114. The two output ends of the electric three-way valve 114 are connected to the main pipe I111 and the main pipe II112 respectively through a hose 115.

[0025] The spray assembly 12 also includes a housing 121. The upper end of the housing 121 is provided with a connecting mechanism 122. The spray branch pipe 123 is located inside the housing 121. The lower end of the housing 121 is provided with through holes 125 that correspond one-to-one with and cooperate with the nozzles 124. The housing 121 is provided with two closing mechanisms 120 for closing the through holes 125 in the front and rear rows respectively.

[0026] The sealing mechanism 120 includes several seats 1201, several slide rods 1202, several springs III 1203, several connecting rods 1204, and an L-shaped sealing plate 1205. Each seat 1201 is provided with a slide rod 1202. The rear end of each slide rod 1202 is provided with an L-shaped sealing plate 1205. Each slide rod 1202 between the L-shaped sealing plate 1205 and the seat 1201 is fitted with a spring III 1203. The L-shaped sealing plate 1205 is hinged to the corresponding jetting branch pipe 123 through the connecting rod 1204.

[0027] The communication mechanism 122 includes 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. The piston sleeve 1221 is provided with an upper support 1224 and a lower support 1228. A sliding shaft 1220 passes through the upper support 1224. The lower end of the sliding shaft 1220 is provided with a seal that closes the upper end of the shaft tube 1223. The upper end of the sliding shaft 1220 is provided with a limiting head 1227. 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 that cooperates with the piston sleeve 1221 is sleeved on the upper end of the shaft tube 1223. A spring II1229 is sleeved on the shaft tube 1223 between the piston 1222 and the lower support 1228.

[0028] The working process of this utility model:

[0029] In the operation of this energy-saving SCR denitrification catalyst cleaning device for cement kilns, the kiln tail flue gas first enters the SCR reactor 3 through the inlet flue 2. The inlet flue 2 is equipped with an inlet air valve 14. Under the action of the SCR catalyst 4, NOx in the flue gas is reduced to N2 and water in the SCR reactor 3, thereby achieving the purpose of removing pollutants. The denitrified flue gas enters the bottom of the SCR reactor 3 and is finally discharged from the outlet flue 6. Some of the freely settled ash is transported to a designated location by the ash removal device 5. An outlet air valve 7 is installed on the outlet flue 6.

[0030] A soot blower 1 is installed on the surface of the SCR catalyst 4 to remove the accumulated ash on the surface of the SCR catalyst 4, preventing blockage and corrosion of the SCR catalyst 4. The soot blower 1 performs a reciprocating feeding motion through the feeding device 15. The feeding device 15 adopts existing technology and will not be described in detail here. The soot blower medium is hot flue gas. The hot flue gas is taken out from the upstream of the outlet air valve 7 set on the outlet flue 6, and an air intake valve 8 is set. In order to achieve a better cleaning effect, the hot flue gas is drawn into the dust collector 9 for dust removal treatment to remove dust particles in the flue gas. The removed ash is transported to a designated position by the ash discharge device 10. After dust removal, the clean hot flue gas is pressurized by the booster fan 13 to meet the pressure requirements of the soot blower, and then enters the soot blower 1 to clean the SCR catalyst 4.

[0031] Since the soot blowing medium is hot flue gas, and its temperature is the same as that of the hot flue gas in the catalyst, no additional heating treatment is required. At the same time, when the kiln is shut down or when bypassing for maintenance, the inlet air valve 14 and the outlet air valve 7 can be closed, and then the soot blowing system can be turned on again. At this time, since the internal flue gas is recycled, the dust particles in the reactor are continuously removed by the dust collector 9, which can thoroughly clean the surface of the SCR catalyst 4. At the same time, since the cleaning medium is recycled flue gas, there is no problem of water condensation corroding the catalyst.

[0032] The flue gas output by the booster fan 13 passes sequentially through the electric three-way valve 114, the main pipe I111 and the corresponding connecting pipe 113, the connecting mechanism 122, the injection branch pipe 123 and the nozzle 124, and then blows towards the SCR catalyst 4. After the soot blower 1 has made one round trip, the compressed air is adjusted by the electric three-way valve 114 to pass sequentially through the electric three-way valve 114, the main pipe II112 and the corresponding connecting pipe 113, the connecting mechanism 122, the injection branch pipe 123 and the nozzle 124, and then blown towards the SCR catalyst 4.

[0033] When the pressurized flue gas connection mechanism 122 is activated, the piston 1222, under the action of compressed air, drives the shaft tube 1223 to move downward and compresses the spring II 1229. The shaft tube 1223 drives the corresponding jetting branch pipe 123 to move downward. The jetting branch pipe 123 pushes the L-shaped sealing plate 1205 to release the obstruction of the corresponding through hole 125 through the corresponding connecting rod 1204. While the jetting branch pipe 123 moves downward, it drives the nozzle 124 on it 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 under the action of the spring I 1225. When the limiting 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 disengages from the sealing head 1226, and compressed air enters the shaft tube 1223.

[0034] After soot blowing is completed, the booster fan 13 stops, and the piston 1222 moves upward under the action of spring II 1229. The piston 1222 drives the corresponding blowing branch pipe 123 to move upward through the shaft tube 1223. The blowing branch pipe 123 drives the nozzle 124 on it to retract into the housing 121. When the shaft tube 1223 moves upward and presses against the sealing head 1226, the shaft tube 1223 pushes the sealing head 1226 upward and compresses the spring I 1225. At the same time, the blowing branch pipe 123 pulls the connecting rod 1204 upward, and the L-shaped sealing plate 1205 moves above the corresponding through hole 125 under the action of spring III 1203 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.

[0035] The above embodiments are illustrative of the present invention and are not intended to limit the present invention. Any simple modifications to the present invention are within the protection scope of the present invention.

Claims

1. An energy-saving SCR denitrification catalyst cleaning device for cement kilns, characterized in that: The system includes an inlet flue (2), an SCR reactor (3), and an outlet flue (6) arranged sequentially in the direction of flue gas flow. An inlet air valve (14) is installed on the inlet flue (2), and an outlet air valve (7) is installed on the outlet flue (6). An SCR catalyst (4) and a soot blower (1) are installed inside the SCR reactor (3). An air intake valve (8), a dust collector (9), and a booster fan (13) are arranged sequentially 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 located upstream of the outlet air valve (7).

2. The energy-saving SCR denitrification catalyst cleaning device for cement kilns as described in claim 1, characterized in that: The bottom of the SCR reactor (3) is provided with a first ash-collecting device (5), and the bottom of the dust collector (9) is provided with a second ash-collecting device (10).

3. The energy-saving SCR denitrification catalyst cleaning device for cement kilns as described in claim 1, characterized in that: The dust collector (9) is a high-temperature bag filter, which can use ceramic filter bags or metal filter bags.

4. The energy-saving SCR denitrification catalyst cleaning device for cement kilns as described in claim 1, characterized in that: The soot blower (1) includes a main blowing pipe (11) and several blowing components (12). The main blowing pipe (11) and the blowing components (12) are connected. The blowing components (12) include several connecting mechanisms (122), two blowing branch pipes (123) and several nozzles (124). Each blowing branch pipe (123) is provided with a connecting mechanism (122) connected to it. The lower end of each blowing branch pipe (123) is provided with nozzles (124) arranged in a row. The nozzles (124) on the two blowing branch pipes (123) are staggered.

5. The energy-saving SCR denitrification catalyst cleaning device for cement kilns as described in claim 4, characterized in that: The main jetting pipe (11) includes a main pipe I (111) and a main pipe II (112). The connecting mechanism (122) on the front jetting branch pipe (123) is connected to the main pipe I (111) through the connecting pipe (113). The connecting mechanism (122) on the rear jetting branch pipe (123) is connected to the main pipe II (112) through the connecting pipe (113). The output end of the booster fan (13) is equipped with an electric three-way valve (114). The two output ends of the electric three-way valve (114) are connected to the main pipe I (111) and the main pipe II (112) respectively through the hose (115).

6. The energy-saving SCR denitrification catalyst cleaning device for cement kilns as described in claim 4, characterized in that: The spray assembly (12) also includes a housing (121), the upper end of which is provided with a connecting mechanism (122), the spray branch pipe (123) is located inside the housing (121), the lower end of the housing (121) is provided with through holes (125) that correspond one-to-one with the nozzle (124) and cooperate with it, and the housing (121) is provided with two closing mechanisms (120) for closing the through holes (125) in the front and rear rows respectively.

7. The energy-saving SCR denitrification catalyst cleaning device for cement kilns as described in claim 6, characterized in that: The closing mechanism (120) includes several seats (1201), several slide rods (1202), several springs III (1203), several connecting rods (1204), and an L-shaped closing plate (1205). Each seat (1201) is provided with a slide rod (1202). The rear end of each slide rod (1202) is provided with an L-shaped closing plate (1205). Each slide rod (1202) between the L-shaped closing plate (1205) and the seat (1201) is fitted with a spring III (1203). The L-shaped closing plate (1205) is hinged to the corresponding jetting branch pipe (123) through the connecting rod (1204).

8. The energy-saving SCR denitrification catalyst cleaning device for cement kilns as described in claim 4, characterized in that: The communication mechanism (122) includes 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). The piston sleeve (1221) is provided with an upper support (1224) and a lower support (1228). A sliding shaft (1220) passes through the upper support (1224), and the lower end of the sliding shaft (1220) is provided with a sealing seal that closes the upper end of the shaft tube (1223). The sealing head (1226) has a limiting head (1227) 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) that cooperates with the piston sleeve (1221) is sleeved on the upper end of the shaft tube (1223). A spring II (1229) is sleeved on the shaft tube (1223) between the piston (1222) and the lower support (1228).

Images