JP4331710B2 - Dust collector and dust discharge method - Google Patents

Description

  The present invention is applied to industrial boilers, power plants, waste incinerators, and the like, and relates to a dust collector that collects dust from exhaust gas and conveys the dust, and a dust discharge method.

  For example, in an exhaust duct connected to a boiler of a thermal power plant, a heat exchanger that cools exhaust gas, an electric dust collector that collects and removes dust such as suspended particulate matter, a desulfurizer that removes sulfur oxide, and a treated exhaust gas Chimneys that release gas to the atmosphere are provided. Therefore, the exhaust gas discharged from the boiler is cooled to a predetermined temperature by a heat exchanger, dust is collected and removed by an electric dust collector, sulfur oxide is removed by a desulfurization device, and the treated exhaust gas is released from the chimney to the atmosphere. Is done.

  An electric dust collector applied to such an exhaust gas treatment system is provided with a plurality of dust collecting electrodes and discharge electrodes alternately in an exhaust gas passage, and generates ions by applying a high voltage between them. In this method, the dust in the charged gas is attracted to and collected by the opposing dust collecting electrode by electric force. The dust accumulated on the dust collecting electrode is removed by a hammering device every predetermined period and stored in the hopper. When the amount of dust stored in the hopper reaches a predetermined amount, the discharge port is opened and the external To be discharged.

  As such a conventional dust collector, there is one described in Patent Document 1 below. The hopper of the dust collector described in Patent Document 1 has a two-stage configuration of an upper hopper and a lower hopper, and the upper end opening of the lower hopper is formed larger than the lower end opening of the upper hopper. In addition, an enlarged diameter part is formed at the connecting part between the upper hopper and the lower hopper, the dust is prevented from being consolidated, and the dust solidification is effectively suppressed to suppress the generation of dust bridges. The discharge is made smooth.

Japanese Patent Laid-Open No. 11-104520

  In the conventional dust collector described above, the hopper is composed of the upper hopper and the lower hopper, and the upper end opening of the lower hopper is formed larger than the lower end opening of the upper hopper so that the dust becomes compact. Prevents the discharge to be smooth. However, in recent years, diversification of fuel used in boilers has caused variations in dust adhesion and curability. Therefore, even with the dust collector described above, dust may remain attached to the inner wall surface of the hopper and cannot be reliably discharged to the outside. In the conventional dust collector described above, an air nozzle is provided in the vicinity of the lower end of the lower hopper, and the compressed air is jetted to the discharge port so that the dust is smoothly discharged. However, it is difficult to reliably discharge dust adhering to the inner wall surface of the hopper even if the compressed air is simply injected toward the discharge port. In addition, some dust adhering to the inner wall surface of the hopper solidifies as time passes. As a result of repeated adhesion and solidification, the hopper may be blocked as a result.

  The present invention solves such problems, and provides a dust collecting apparatus and a dust discharging method that improve dust processing efficiency by reliably discharging dust stored in a hopper after being collected to the outside. The purpose is to provide.

The dust collector of the invention of claim 1 for achieving the above object includes a casing having a gas inlet and a gas outlet, a dust collector provided in the casing and collecting dust in the exhaust gas, A hopper that has a discharge port at the bottom and catches the dust that has left the dust collector, a gate that opens and closes the discharge port of the hopper, and a dust that is stored in the vicinity of the discharge port in the hopper . An agitator air nozzle that continuously injects air of a predetermined pressure over a predetermined number of seconds, and a pulse that injects air of a predetermined pressure one or more times in a short time of less than 1 second toward the inner wall surface of the dust storage area in the hopper comprising the air nozzle, and the agitator air nozzle and the pulse air nozzle drive controllable control means, opening the outlet by the gate After the agitator air for a predetermined time injected by the agitator air nozzles, subsequently, is characterized in that the injecting the predetermined time pulsed air by the pulse air nozzle.

In the dust collector of the invention of claim 2 , a plurality of the hoppers are provided below the dust collector along the flow direction of the exhaust gas, and dust that can be transported by pressure-feeding the dust to the discharge ports of all the hoppers A transport pipe is connected, and each discharge port of each of the hoppers and the dust transport tube are sequentially communicated so that the dust discharged from the discharge port can be transported by the dust transport tube and transported to a predetermined collection location. In addition, the dust discharge frequency of the hopper located downstream in the exhaust gas flow direction is set lower than the dust discharge frequency of the hopper located upstream in the exhaust gas flow direction.

In the dust collector of the invention of claim 3, the pulse air nozzle has a tip projecting into the hopper and injecting pulsed air along the inner surface of the hopper.

In a dust collector according to a fourth aspect of the present invention, the pulse air nozzle ejects pulse air in a fan shape along the inner surface of the hopper.

The dust collector of the invention of claim 5 is characterized in that an inclined plate that suppresses adhesion of dust is mounted above the pulse air nozzle.

According to a sixth aspect of the present invention, there is provided a dust discharge method comprising: a dust collector that collects dust in exhaust gas; a hopper that has a lower discharge port to receive dust that has separated from the dust collector; and the lower discharge port of the hopper is opened and closed in the dust collecting device with a gate which, by moving the gate of the hopper to open the lower outlet, firstly, a predetermined set in advance toward the dust stored in the vicinity of the bottom outlet of the hopper given to continue the agitator air of a predetermined pressure for a few seconds to a predetermined time-injection, then one or more times a pulsed air of a predetermined pressure in a short time of less than one second toward the inner wall surface of the storage area of the dust in the hopper The dust in the hopper is discharged from the lower discharge port by time injection.

In the dust discharge method according to the seventh aspect of the present invention, a dust transfer pipe capable of conveying dust by pressure is connected to the discharge port of the hopper, and the dust discharged from the discharge port by injection of the agitator air and the pulse air. Is transported by a dust transport pipe and transported to a predetermined collection location.

The dust discharge method according to an eighth aspect of the invention is characterized in that, after the agitator air is injected, the pulsed air is injected when the pressure in the dust transfer pipe falls below a first predetermined pressure set in advance.

In the dust discharge method according to the ninth aspect of the invention, after the agitator air is injected, the agitator air is repeatedly injected when the pressure in the dust transfer pipe does not become a predetermined first predetermined pressure or less. It is a feature.

In the dust discharging method according to the tenth aspect of the present invention, after the pulsed air is injected, the gate of the hopper is closed after a lapse of a predetermined time when the pressure in the dust transfer pipe becomes equal to or lower than a first predetermined pressure set in advance. It is characterized by that.

The dust discharge method according to claim 11 is characterized in that, after the pulse air is injected, the agitator air is repeatedly injected when the pressure in the dust transport pipe does not become equal to or lower than a preset first predetermined pressure. It is said.

In the dust discharging method according to the twelfth aspect of the present invention, after the hopper gate is opened, when the pressure in the dust transfer pipe is equal to or higher than a predetermined second predetermined pressure, the hopper gate is closed, The agitator air and the injection of the pulsed air are stopped.

According to the dust collecting apparatus of the first aspect of the present invention, the dust collector for collecting dust in the exhaust gas is provided in the casing having the gas inlet and the gas outlet, and the dust collector is separated from the dust collector by having the outlet at the lower part. An agitator air nozzle that injects agitator air toward the dust stored near the discharge port in the hopper, and a pulse air nozzle that injects pulsed air toward the inner wall surface of the dust storage area in the hopper The control means, after opening the discharge port by the gate, injects the agitator air by the agitator air nozzle for a predetermined time, and then injects the pulse air by the pulse air nozzle for a predetermined time. By agitating air toward the accumulated dust, it is stored in the hopper. Most of the dust is discharged to the outside through the discharge port, and the pulse air is injected toward the inner wall surface of the dust storage area by the pulse air nozzle, so that the dust attached to the inner wall surface of the hopper is surely dropped and is discharged from the discharge port to the outside. Thus, the dust stored in the hopper can be reliably discharged to the outside, and the dust processing efficiency can be improved. Further, by jetting agitator air for a predetermined time and then pulsed air for a predetermined time, dust stored in the hopper and dust attached to the inner wall surface of the hopper can be reliably discharged from the discharge port.

According to the dust collector of claim 2 , a dust transport pipe that is provided with a plurality of hoppers along the flow direction of the exhaust gas below the dust collector and can transport the dust by pressure feeding to the discharge ports of all the hoppers. And connecting each discharge port of each hopper and the dust transport pipe in order, so that the dust discharged from the discharge port can be transported by the dust transport pipe and transported to a predetermined collection location, and the flow of exhaust gas The dust discharge frequency of the hopper located downstream in the direction is set lower than the dust discharge frequency of the hopper located upstream in the flow direction of the exhaust gas, so the dust stored in the hopper can be properly discharged by the dust transport pipe In addition, the dust stored by a predetermined amount can be efficiently discharged.

According to the dust collector of the invention of claim 3 , since the tip of the pulse air nozzle protrudes into the hopper and jets the pulse air along the inner surface of the hopper, the pulse air nozzle is driven by the pulse air jetted along the inner surface of the hopper. The dust adhering to can be surely dropped.

According to the dust collector of the invention of claim 4 , since the pulse air nozzle injects the pulse air in a fan shape along the inner surface of the hopper, dust in a predetermined area is generated by the fan-shaped pulse air injected from one pulse air nozzle. Can be dropped, and dust can be dropped efficiently by a small number of pulse air nozzles.

According to the dust collecting device of the fifth aspect of the invention, since the inclined plate that suppresses the adhesion of dust is mounted above the pulse air nozzle, the dust separated from the dust collector is guided by the inclined plate and received in the hopper. , Dust accumulation on the pulse air nozzle can be suppressed.

According to the dust discharge method of the sixth aspect of the present invention, a dust collector that collects dust in the exhaust gas, a hopper that has a lower discharge port and receives the dust separated from the dust collector, and opens and closes the lower discharge port of the hopper In a dust collector equipped with a gate that moves , the gate of the hopper is moved to open the lower discharge port, and first, agitator air is injected toward the dust stored near the lower discharge port of the hopper, and then by injecting the pulsed air toward the inner wall surface of the storage area of the dust in the hopper, since so as to discharge the dust in the hopper from the lower discharge port, most of the dust that is stored in the hopper by the agitator air underdrain is discharged from the outlet to the outside, and dust adhering to the inner wall surface of the hopper is reliably drop will be discharged to the outside from the lower outlet by pulsed air, savings in the hopper Was dust reliably discharged to the outside, it is possible to improve the processing efficiency of dust.

According to the dust discharge method of the seventh aspect of the present invention, the dust transport pipe capable of transporting dust by pressure is connected to the discharge port of the hopper, and the dust discharged from the discharge port by the jet of agitator air and pulsed air is Since it is transported by the transport pipe and transported to a predetermined collection location, the dust stored in the hopper can be properly discharged by the dust transport pipe.

According to the dust discharge method of the eighth aspect of the invention, since the agitator air is jetted and then the pulse air is jetted when the pressure in the dust carrying pipe becomes equal to or lower than a preset first predetermined pressure. By injecting pulsed air while checking the clogging of dust by the pressure in the pipe, the dust in the hopper can be properly discharged.

According to the dust discharge method of the ninth aspect of the present invention, after the agitator air is injected, the agitator air is repeatedly injected when the pressure in the dust transfer pipe does not fall below the first predetermined pressure set in advance. Therefore, when the clogging of dust is detected by the pressure in the dust transfer pipe, the clogging of the dust can be repaired by repeatedly ejecting the agitator air.

According to the dust discharging method of the tenth aspect of the present invention, after the pulse air is injected, the hopper gate is closed after elapse of a predetermined time when the pressure in the dust transport pipe becomes equal to or lower than the first predetermined pressure set in advance. Therefore, the dust discharge operation in the hopper can be properly executed by closing the hopper gate after confirming the clogging of the dust and the discharge state of the dust by the pressure in the dust transfer pipe.

According to the dust discharge method of the eleventh aspect of the present invention, after the pulse air is injected, the agitator air is repeatedly injected when the pressure in the dust transfer pipe does not become lower than the first predetermined pressure set in advance. When the clogging of the dust is detected by the pressure in the dust transport pipe, the clogging of the dust can be repaired by repeatedly ejecting the agitator air.

According to the dust discharge method of the twelfth aspect of the present invention, after the hopper gate is opened, the hopper gate is closed and the agitator air is closed when the pressure in the dust transfer pipe exceeds a preset second predetermined pressure. In addition, when the limit of dust discharge processing amount or dust clogging is detected by the pressure in the dust transfer pipe, the hopper gate is closed to discharge the dust into the dust transfer pipe. By stopping, blockage of the dust transfer pipe can be prevented.

  Exemplary embodiments of a dust collector according to the present invention will be described below in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments.

  1 is a schematic configuration diagram of a dust collector according to one embodiment of the present invention, FIG. 2 is a front view of the dust collector of the present embodiment, FIG. 3 is a plan view of the dust collector of the present embodiment, 4 is a front view of a hopper in the dust collector of the present embodiment, FIG. 5 is a plan view of the hopper in the dust collector of the present embodiment, and FIG. 6 is an attachment of a pulse air nozzle in the dust collector of the present embodiment. State sectional drawing, FIG. 7 is a front view of a pulse air nozzle in the dust collector of the present embodiment, FIGS. 8-1 to 8-6 are schematic diagrams showing dust discharge work in the dust collector of the present embodiment, 9 to 11 are flowcharts for executing the dust discharging method in the dust collecting apparatus of the present embodiment, and FIGS. 12 to 15 are diagrams for explaining the dust discharging method in the dust collecting apparatus of the present embodiment. It is a time chart.

  In the dust collector of the present embodiment, as shown in FIGS. 2 and 3, the casing 11 has a box-shaped hollow shape and is installed at a predetermined position by a plurality of legs 12, and gas is introduced into one end. A port 13 is formed, and a gas discharge port 14 is formed at the other end. An electric dust collector 15 that collects dust in the exhaust gas is disposed in the upper portion of the casing 11. The electric dust collector 15 charges dust (ash) in the exhaust gas and collects the charged particles. That is, although not illustrated, a plurality of plate-like dust collecting electrodes are provided, and discharge electrodes are provided at predetermined intervals corresponding to the dust collecting electrodes, and the dust collecting electrodes are disposed between the dust collecting electrodes and the discharge electrodes. A high-voltage current field is generated and exhaust gas is allowed to flow there. Then, a corona discharge is generated between the two electrodes, and a number of negatively ionized gas molecules move toward the anode and collide with dust particles in the exhaust gas to be charged. The charged particles are collected on each dust collecting electrode, collected on the surface, and deposited.

  A plurality (12 in this embodiment) of hoppers 16 a to 16 d, 17 a to 17 d, and 18 a to 18 d are positioned below the electric dust collector 15 and are connected to the lower portion of the casing 11. As described above, the electrostatic precipitator 15 collects and accumulates dust in the exhaust gas on the surface of each dust collecting electrode. However, dust particles deposited on the dust collecting electrode are removed by a hammering device every predetermined period. The hoppers 16a to 16d, 17a to 17d, and 18a to 18d receive the separated dust.

  In addition, one dust transport pipe 19 is arranged in an S shape below each of the hoppers 16a to 16d, 17a to 17d, and 18a to 18d, and each hopper 16a to 16d, 17a to 17d is disposed. , 18a to 18d are connected to the dust transfer pipe 19. The dust transport pipe 19 has a preheater 20 attached to one end thereof, and the other end connected to an upper portion of the dust processing device 21. The dust treatment device 21 separates dust from air fed together with dust by a bag filter (not shown). In addition, one end of a suction pipe 22 is connected to the dust treatment device 21, and a vacuum blower 23 is attached to the other end of the suction pipe 22.

  Therefore, when the vacuum blower 23 is driven, the suction pipe 22, the dust processing device 21, and the dust transport pipe 19 are sucked, and air heated by the preheater 20 is introduced from the end of the dust transport pipe 19. In this state, when the hoppers 16a to 16d, 17a to 17d, 18a to 18d and the dust transport pipe 19 are sequentially communicated, the dust stored in the hopper falls into the dust transport pipe 19 and is sucked by the suction force of the vacuum blower 23. The dust is sent to the dust treatment device 21 where the dust is separated from the compressed air by the bag filter. The dust is stored here and transported to the outside, while the separated gas is returned to the flue of the electric dust collector 15. It is.

  Here, the hoppers 16a to 16d, 17a to 17d, and 18a to 18d in the dust collector of the above-described embodiment will be described in detail. However, since the configurations of the hoppers 16a to 16d, 17a to 17d, and 18a to 18d are substantially the same, only the hopper 16a will be described.

  As shown in FIGS. 1, 4, and 5, the hopper 16 a includes an upper cone portion 31, a square tube portion 32, and a lower cone portion 33, and an upper end portion of the upper cone portion 31 is fixed to the casing 11. On the other hand, a discharge port 34 is formed at the lower end portion of the lower cone portion 33, and a gate 35 that is connected to the dust transfer pipe 19 and can be opened and closed is mounted.

  Upper agitator air nozzles 36 are provided at equal intervals along the circumferential direction at the upper end of the rectangular cylinder portion 32 in the hopper 16a. The upper agitator air nozzles 36 inject agitator air toward the inner wall surface of the hopper 16a. can do. The lower cone portion 33 of the hopper 16a is provided with lower agitator air nozzles 37 at equal intervals along the circumferential direction, and throat agitator air nozzles 38. The agitator air nozzles 37, 38 are each provided with a hopper. Agitator air can be injected toward the discharge port 34 of 16a. The first air supply pipe 40 branched from the air pipe 39 is connected to the upper agitator air nozzle 36, and the second air supply pipe 41 branched from the first air supply pipe 40 is connected to the lower agitator air nozzle 37 and the throat agitator air nozzle. 38. The air supply pipes 40 and 41 are equipped with air supply electromagnetic valves 42 and 43 and inspection opening and closing valves 44 and 45, respectively.

  Moreover, the top agitator air nozzle 46 is provided in the upper end part of the upper cone part 31 in the hopper 16a at equal intervals along the circumferential direction, and this top agitator air nozzle 46 is directed downward and horizontally in the hopper 16a. Agitator air can be injected. A third air supply pipe 47 branched from the first air supply pipe 40 is connected to the top agitator air nozzle 46. The third air supply pipe 47 includes an electromagnetic valve 48 for supplying air and an opening and closing for inspection. A valve 49 is mounted. A drain pipe 51 having an opening / closing valve 50 is connected to the third air supply pipe 47.

  The agitator air ejected from each agitator air nozzle 36, 37, 38, 46 is the dust accumulated in the hopper 16a by continuously ejecting air at a predetermined pressure for a predetermined predetermined seconds. It contains a large amount of air, and improves the fluidity of the dust to facilitate discharge.

  Furthermore, upper pulse air nozzles 52 are provided at equal intervals along the circumferential direction at the lower end portion of the rectangular cylinder portion 32 in the hopper 16a, and middle pulse air nozzles at equal intervals along the circumferential direction at the upper end portion of the lower cone portion 33. 53, and lower pulse air nozzles 54 are provided below the lower conical portion 33 at equal intervals along the circumferential direction. Each of the pulse air nozzles 52, 53, 54 can inject pulse air toward the inner wall surface of the dust storage region S in the hopper 16a. An upper ring tube 55 is disposed on the outer peripheral portion of the rectangular tube portion 32 in the hopper 16a, and a lower ring tube 56 is disposed on the outer peripheral portion of the lower conical portion 33. The upper ring tube 55 and each upper stage The pulse air nozzle 52 is connected by a flexible tube 57, and the lower ring pipe 56, each middle pulse air nozzle 53 and the lower pulse air nozzle 54 are connected by flexible tubes 58 and 59.

  The pulsed air ejected from each of the pulsed air nozzles 52, 53, 54 is dust that adheres to the wall surface of the hopper 16a with a small amount of air by ejecting air at a predetermined pressure once or more in a short time of less than 1 second. It is intended to sweep away the dust and prevent dust from remaining.

  Further, a header pipe 60 is provided in the vicinity of each ring pipe 55, 56, and a fourth air supply pipe 61 branched from the first air supply pipe 40 is connected to the header pipe 60. A pressure sensor 62 is connected. The header pipe 60 and the upper ring pipe 55 are connected by a fifth air supply pipe 63, and the header pipe 60 and the lower ring pipe 56 are connected by a sixth air supply pipe 64. The air supply pipes 63 and 64 are provided with air supply pulse valves 65 and 66 and inspection opening and closing valves 67 and 68, and bypass pipes 69 and 68 bypassing the air supply pipes 63 and 64, respectively. 70 is equipped with orifices 71 and 72 for preventing nozzle clogging.

  Each of the above-described open / close valves 44, 45, 49, 67, 68 is normally open, and the electromagnetic valves 42, 43, 48 and the pulse valves 65, 66 are normally closed. Further, a steam pipe 75 is provided along the dust transfer pipe 39, and the air flowing in the dust transfer pipe 39 is heated to improve the dust transfer performance.

  By the way, in each of the above-described pulse air nozzles 52, 53, 54, as shown in FIGS. 6 and 7, the tip of the nozzle body 81 penetrates through the hopper 16 and protrudes to the inside, and a cap 82 is screwed to the tip. Fixed together. The cap 82 has a slit-shaped injection port 83 formed in the lower portion, and the injection port 83 is wide at a predetermined angle θ. Therefore, each of the pulse air nozzles 52, 53, 54 can inject the pulse air in a fan shape along the inner surface of the hopper 16 from the injection port 83. Further, an inclined plate 84 having a triangular cross-sectional shape is fixed above the tip end portions of the pulse air nozzles 52, 53, and 54 to suppress the adhesion and accumulation of dust on the pulse air nozzles 52, 53, and 54. Can do.

  In the dust collecting apparatus of the present embodiment, a pressure sensor 74 is provided in the suction pipe 22 communicating with the dust transfer pipe 19, and the control device 73 detects the pressure (vacuum degree−negative pressure) of the suction pipe 22 detected by the pressure sensor 74. ), The electromagnetic valves 42, 43, 48 of the agitator air nozzles 36, 37, 38, 46 and the pulse valves 65, 66 of the pulse air nozzles 52, 53, 54 can be controlled. Here, increasing the pressure means lowering the negative pressure and lowering the degree of vacuum. The control device 73 can drive and control an opening / closing device 74 that opens and closes the gate 35 of the hopper 16a. In this embodiment, the dust is discharged in order from the hoppers 16a to 16d, 17a to 17d, and 18a to 18d using the dust transfer pipe 19, but is located downstream in the flow direction of the exhaust gas to the electrostatic precipitator 15. The dust discharge frequency of the hopper is set lower than the dust discharge frequency of the hopper located upstream in the flow direction of the exhaust gas. In the dust discharge processing in each of the hoppers 16a to 16d, 17a to 17d, and 18a to 18d, the control device 73 opens the discharge port 34 with the gate 35, and then supplies the agitator air with the agitator air nozzles 37 and 38 for a predetermined time. Then, the pulse air is ejected by the pulse air nozzles 52, 53, and 54 for a predetermined time so that the dust in the hopper is dropped onto the dust transport pipe 19.

  Here, the dust discharge processing in the hopper will be specifically described with reference to the schematic diagrams illustrating the dust discharge processing of FIGS. 8-1 to 8-6 and the flowcharts of FIGS. 9 and 10.

  As shown in FIG. 8A, when a predetermined amount of dust is stored in the hopper 16a, dust discharge processing is started in step S1, as shown in FIG. Then, when the discharge port 34 is opened by the gate 35 in step S2, as shown in FIG. 8-2, in the hopper 16a, only dust accumulated above the discharge port 34 falls into the dust transport pipe 19, The surrounding dust remains. In step S3, when agitator air is injected from the lower agitator air nozzle 37 and the throat agitator air nozzle 38 for a predetermined time, dust remaining in the hopper 16a is agitated by each agitator air as shown in FIG. As shown in FIG. 8-4, most of the dust in the hopper 16a falls into the dust transport pipe 19, and some dust adheres to the inclined surface of the lower cone portion 33 and remains.

  In step S4, whether a predetermined time, in this case, 10 seconds has elapsed since the negative pressure VC of the suction pipe 22 (dust transfer pipe 19) detected by the pressure sensor 74 has become equal to or lower than the first predetermined pressure VC-1 set in advance. Determine if. Here, if it is determined that the negative pressure VC of the suction pipe 22 has become equal to or lower than the first predetermined pressure VC-1 and 10 seconds have elapsed, the cleaning mode is started in step S5. In step S6, pulse air is ejected from the middle pulse air nozzle 53 and the lower pulse air nozzle 54 for a predetermined time, and in step S7, pulse air is ejected from the upper pulse air nozzle 52 for a predetermined time. Further, in steps S8 and S9, similarly, pulse air is ejected from the middle pulse air nozzle 53 and the lower pulse air nozzle 54 for a predetermined time, and pulse air is ejected from the upper pulse air nozzle 52 for a predetermined time.

  Then, as shown in FIG. 8-5, the dust adhering to the inclined surface of the lower cone portion 33 of the hopper 16a falls into the dust transport pipe 19 by each pulse air. In step S10, the cleaning mode is terminated, and in step S11, agitator air is injected from the upper agitator air nozzle 36. Then, as shown in FIG. 8-6, some dust remaining on the inner wall surface of the hopper 16a is finished and cleaned by the agitator air, and all falls into the dust transport pipe 19.

  Thereafter, in step S12, it is determined whether or not a predetermined time, 50 seconds, has elapsed since the negative pressure VC of the suction pipe 22 detected by the pressure sensor 74 becomes equal to or lower than the first predetermined pressure VC-1. Here, if it is determined that the negative pressure VC of the suction pipe 22 has become equal to or lower than the first predetermined pressure VC-1 and 50 seconds have elapsed, the discharge port 34 is closed by the gate 35 in step S13, and in step S14. Then, the dust discharge process of the hopper 16a is finished.

  On the other hand, when it is determined in step S4 that the negative pressure VC of the suction pipe 22 does not become the first predetermined pressure VC-1 or less, the process returns to step S3, and the agitator air is supplied from the lower agitator air nozzle 37 and the throat agitator air nozzle 38 for a predetermined time. By spraying only, the clogging of dust in the vicinity of the dust transfer pipe 19 is eliminated. Here, when the clogging of the dust in the vicinity of the dust transfer pipe 19 is resolved, the negative pressure VC of the suction pipe 22 becomes equal to or lower than the first predetermined pressure VC-1 in the determination process of step S4, and 10 seconds elapse. In step S5, the cleaning mode is started.

  In step S12, if it is determined that the negative pressure VC of the suction pipe 22 does not become the first predetermined pressure VC-1 or less, it is estimated that dust is clogged in the vicinity of the dust transfer pipe 19, and in step S15, By ejecting agitator air from the agitator air nozzle 37 and the throat agitator air nozzle 38 for a predetermined time, the clogging of dust in the vicinity of the dust transfer pipe 19 is eliminated. Here, when the clogging of the dust in the vicinity of the dust transfer pipe 19 is resolved, the negative pressure VC of the suction pipe 22 becomes equal to or lower than the first predetermined pressure VC-1 in the determination process of step S12, and 50 seconds elapse. In step S13, the discharge port 34 is closed by the gate 35, and in step S14, the dust discharge processing of the hopper 16a is completed.

  In addition, the generation of a large amount of dust is monitored in parallel with the dust discharge processing routine described in FIG. That is, as shown in FIG. 10, when the discharge port 34 is opened by the gate 35 in step S21, it is determined that the dust in the hopper 16a is thrown into the dust transport pipe 19, and in step S22, It is determined whether or not the negative pressure VC of the suction pipe 22 has become equal to or higher than the second predetermined pressure VC-2. In this case, in step S22, the process waits until the negative pressure VC of the suction pipe 22 becomes equal to or higher than the second predetermined pressure VC-2.

  On the other hand, if it is determined in step S22 that the negative pressure VC of the suction pipe 22 has become equal to or higher than the second predetermined pressure VC-2, a large amount of dust is thrown into the dust transfer pipe 19 from the hopper 16a and the transfer process is sufficiently performed. Estimate that it is not possible. In step S23, a signal for stopping injection of agitator air or pulsed air is output, and in step S24, the discharge port 34 is closed by the gate 35. Thereafter, when it is determined that the pressure is equal to or lower than the second predetermined pressure VC-2, it is presumed that the transfer processing of dust input from the hopper 16a to the dust transfer pipe 19 is completed, and the discharge port 34 is opened by the gate 35, Restart the dust discharge process.

  Further, the blockage of the hopper 16a due to dust is also monitored in parallel with the dust discharge processing routine described in FIG. That is, as shown in FIG. 11, when the discharge port 34 is opened by the gate 35 in step S31, it is determined that the dust in the hopper 16a has been put into the dust transport pipe 19, and in step S32, It is determined whether or not a predetermined time, here 10 minutes, has elapsed since the discharge port 34 was opened by the gate 35. Here, it waits for 10 minutes after the discharge port 34 is opened by the gate 35.

  On the other hand, in step S32, when 10 minutes have passed since the discharge port 34 was opened by the gate 35, the process proceeds to step S33, where an alarm is issued to notify the operator, and in step S34, the discharge port 34 is opened by the gate 35. Close. That is, in steps S3 and S4 in the flowchart of FIG. 9 described above, the agitator air is repeatedly injected from the lower agitator air nozzle 37 and the throat agitator air nozzle 38, and even if 10 minutes have elapsed since the start of the discharge process, When the clogging is not resolved, an alarm is issued to notify the operator, the discharge port 34 is closed, and the dust discharge processing of the hopper 16a is completed. Further, in steps S12 and S15 in the flowchart of FIG. 9, the agitator air is repeatedly injected from the lower agitator air nozzle 37 and the throat agitator air nozzle 38. When the clogging is not resolved, an alarm is issued to notify the operator, the discharge port 34 is closed, and the dust discharge processing of the hopper 16a is completed.

  Here, the flow of the dust discharge process of the hopper 16a described above will be specifically described. First, when the dust discharge process of the hopper 16a is normally performed, as shown in FIG. 12, when the discharge port 34 is opened by the gate 35, the agitator is discharged from the lower agitator air nozzle 37 and the throat agitator air nozzle 38 after 3 seconds. Air is sprayed for 3 seconds to promote fluidization of dust in the hopper 16a. When the negative pressure VC of the suction pipe 22 becomes equal to or lower than the first predetermined pressure VC-1 and 10 seconds have passed, the cleaning mode is started, and after 5 seconds, pulse air is injected from the middle pulse air nozzle 53 and the lower pulse air nozzle 54 for 0.3 seconds. 10 seconds later, pulse air is ejected from the upper pulse air nozzle 52 for 0.3 seconds. Similarly, pulse air is ejected from the middle pulse air nozzle 53 and the lower pulse air nozzle 54 for 0.3 seconds after 10 seconds, and pulse air is ejected from the upper pulse air nozzle 52 after 0.3 seconds for 0.3 seconds. Then, the dust adhering to the inner wall surface of the hopper 16a is cleaned and the cleaning mode is terminated, and the agitator air is sprayed from the upper agitator air nozzle 36 for 3 seconds to complete the cleaning. When 50 seconds have elapsed after the negative pressure VC of the suction pipe 22 becomes equal to or lower than the first predetermined pressure VC-1, the discharge port 34 is closed by the gate 35, the dust discharge processing of the hopper 16a is terminated, and the next hopper Migrate to

  Next, in the dust discharge processing of the hopper 16a, when dust clogging occurs before entering the cleaning mode, as shown in FIG. 13, when the discharge port 34 is opened by the gate 35, the lower agitator 3 seconds later. Agitator air is sprayed from the air nozzle 37 and the throat agitator air nozzle 38 for 3 seconds to promote fluidization of dust in the hopper 16a. Here, when the negative pressure VC of the suction pipe 22 does not become the first predetermined pressure VC-1 or less, the dust is clogged by jetting agitator air from the lower agitator air nozzle 37 and the throat agitator air nozzle 38 again after 69 seconds for 3 seconds. Is solved. If the clogging of dust is not eliminated even after repeated injection of agitator air from each agitator air nozzle 37, 38 for 10 minutes, the discharge port 34 is closed by the gate 35, and the dust discharge processing of the hopper 16a is completed. Move to the next hopper. Here, the operator eliminates the clogging of dust.

  Further, in the dust discharge processing of the hopper 16a, when clogging of dust occurs after the cleaning mode is completed, the lower agitator air nozzle 37 is opened after 3 seconds when the discharge port 34 is opened by the gate 35 as shown in FIG. And agitator air is injected from the throat agitator air nozzle 38 for 3 seconds to promote fluidization of dust in the hopper 16a. When the negative pressure VC of the suction pipe 22 becomes equal to or lower than the first predetermined pressure VC-1 and 10 seconds have passed, the cleaning mode is started, and after 5 seconds, pulse air is injected from the middle pulse air nozzle 53 and the lower pulse air nozzle 54 for 0.3 seconds. 10 seconds later, pulse air is ejected from the upper pulse air nozzle 52 for 0.3 seconds. Similarly, pulse air is ejected from the middle pulse air nozzle 53 and the lower pulse air nozzle 54 for 0.3 seconds after 10 seconds, and pulse air is ejected from the upper pulse air nozzle 52 after 0.3 seconds for 0.3 seconds. Then, the dust adhering to the inner wall surface of the hopper 16a is cleaned and the cleaning mode is terminated, and the agitator air is sprayed from the upper agitator air nozzle 36 for 3 seconds to complete the cleaning. At this time, if the negative pressure VC of the suction pipe 22 does not become the first predetermined pressure VC-1 or less, it is estimated that the dust transport pipe 19 is clogged, and the lower agitator air nozzle 37 and the throat agitator air nozzle 69 seconds later. The clogging of dust is eliminated by injecting agitator air from 38 for 3 seconds. If the clogging of dust is not eliminated even after repeated injection of agitator air from each agitator air nozzle 37, 38 for 10 minutes, the discharge port 34 is closed by the gate 35, and the dust discharge processing of the hopper 16a is completed. Move to the next hopper. Here, the worker eliminates the clogging of dust.

  When a large amount of dust is generated during the cleaning mode in the dust discharge processing of the hopper 16a, as shown in FIG. 15, when the discharge port 34 is opened by the gate 35, the lower agitator air nozzle 37 and Agitator air is sprayed from the throat agitator air nozzle 38 for 3 seconds to promote dust fluidization in the hopper 16a. When the negative pressure VC of the suction pipe 22 becomes equal to or lower than the first predetermined pressure VC-1 and 10 seconds have passed, the cleaning mode is started, and after 5 seconds, pulse air is injected from the middle pulse air nozzle 53 and the lower pulse air nozzle 54 for 0.3 seconds. To do. Here, if it is determined that the negative pressure VC of the suction pipe 22 has become equal to or higher than the second predetermined pressure VC-2, it is estimated that a large amount of dust is thrown into the dust transfer pipe 19 from the hopper 16a and the transfer process cannot be sufficiently performed. Then, the injection of the pulsed air is stopped and the discharge port 34 is closed by the gate 35. When it is determined that the pressure is equal to or lower than the second predetermined pressure VC-2, the discharge port 34 is opened by the gate 35, and the dust discharge process is resumed.

  When the dust discharge processing of the hopper 16a is completed in this way, the dust discharge processing is sequentially executed in order of the hoppers 16b, 16c, 16d, 17a. In this case, dust contained when the exhaust gas passes through the electrostatic precipitator 15 is collected, and dust is removed by the hammering device and stored in each hopper 16a to 16d, 17a to 17d, 18a to 18d. The amount of dust stored in the hoppers 18a to 18d located downstream in the exhaust gas flow direction is reduced. Therefore, in this embodiment, the dust discharge frequency of the hopper located on the downstream side in the flow direction of the exhaust gas to the electrostatic precipitator 15 is set lower than the dust discharge frequency of the hopper located on the upstream side in the flow direction of the exhaust gas. .

  That is, as shown in FIG. 3, the order of the dust discharge processing of the hoppers 16a to 16d, 17a to 17d, and 18a to 18d is hopper 18d-hopper 17a-hopper 17b-hopper 17c-hopper 17d-hopper 17 16d-hopper 16c-hopper 16b-hopper 16a, the second cycle becomes hopper 18c-hopper 17a-hopper 17b-hopper 17c-hopper 17d-hopper 16d-hopper 16c-hopper 16b-hopper 16a, and the third cycle Hopper 18b-hopper 17a-hopper 17b-hopper 17c-hopper 17d-hopper 16d-hopper 16c-hopper 16b-hopper 16a The fourth cycle is hopper 18a-hopper 17a-hopper 17b-hopper 17c-hopper 17d-hopper 16d-hopper 16c- The Tsu path 16b- hopper 16a. That is, the hoppers 16a to 16d on the most downstream side perform the dust discharge process at a rate of once every four cycles.

  When one cycle of dust discharge processing is completed, the hoppers 16a to 16d, 17a to 17d, and 18a to 18d do not perform dust discharge processing, and warm the dust transport pipe 19 with high-temperature air through the preheater 20. This suppresses the adhesion of dust to the inner wall surface.

  As described above, in the dust collector of the present embodiment, the electric dust collector 15 for collecting dust in the exhaust gas is provided in the casing 11 having the gas inlet 13 and the gas outlet 14, and the outlet is provided at the lower part. Hoppers 16a to 16d, 17a to 17d, and 18a to 18d that receive the dust separated from the electrostatic precipitator 15 are provided, and in the vicinity of the discharge port 34 in the hoppers 16a to 16d, 17a to 17d, and 18a to 18d. Agitator air nozzles 37 and 38 for injecting agitator air toward the accumulated dust, and pulse air nozzles 52 and 53 for injecting pulsed air toward the inner wall surface of the dust storage area in the hoppers 16a to 16d, 17a to 17d, and 18a to 18d. , 54 are provided.

  Accordingly, the agitator air nozzles 37 and 38 inject the agitator air toward the dust stored in the vicinity of the discharge port 34 of the hoppers 16a to 16d, 17a to 17d, and 18a to 18d, thereby the hoppers 16a to 16d and 17a to 17d. , 18a to 18d, most of the dust stored in the discharge port is discharged to the outside, and the pulse air nozzles 52, 53, and 54 inject the pulsed air toward the inner wall surface of the dust storage region, so that the hoppers 16a to 16d, The dust adhering to the inner wall surfaces of 17a to 17d and 18a to 18d is surely dropped and discharged to the outside from the discharge port 34, and the dust stored in the hoppers 16a to 16d, 17a to 17d, and 18a to 18d is surely secured. The dust can be discharged to the outside and the dust processing efficiency can be improved.

  In the dust collecting apparatus of the present embodiment, the control means 73 first opens the discharge ports 34 of the hoppers 16a to 16d, 17a to 17d, and 18a to 18d by the gate 35, and then firstly the agitator air nozzles 37 and 38 to agitator. Air is jetted for a predetermined time, and then pulse air is jetted by the pulse air nozzles 52, 53, and 54 for a predetermined time, and dust and inner wall surfaces stored in the hoppers 16a to 16d, 17a to 17d, and 18a to 18d. The dust adhering to can be reliably discharged from the discharge port 34.

  In the dust collector of the present embodiment, a plurality of hoppers 16a to 16d, 17a to 17d, and 18a to 18d are provided below the electric dust collector 15 along the flow direction of the exhaust gas, and all the hoppers 16a to 16d and 17a are provided. The dust transport pipes 19 that can transport dust by pressure are connected to the discharge ports 34 to 17d and 18a to 18d, and the dusts in the hoppers 16a to 16d, 17a to 17d, and 18a to 18d are connected by the dust transport pipe 19 The hoppers 18a to 18d located on the downstream side in the flow direction of the exhaust gas are made to discharge in order and can be conveyed to the outside, and the hoppers 16a to 16d and 17a to 17d located on the upstream side in the flow direction of the exhaust gas. Is set lower than the dust discharge frequency. Therefore, the dust stored in the hoppers 16a to 16d, 17a to 17d, and 18a to 18d can be properly discharged by the dust transport pipe 19, and the dust stored by a predetermined amount can be efficiently discharged.

  Furthermore, in the dust collector of the present embodiment, each of the pulse air nozzles 52, 53, 54 has a tip portion protruding into the hoppers 16a-16d, 17a-17d, 18a-18d, and pulsating the pulse air along the inner wall surface. I try to spray. Accordingly, the dust attached thereto can be surely dropped by the pulse air injected along the inner surfaces of the hoppers 16a to 16d, 17a to 17d, and 18a to 18d, and the fan shape injected from one pulse air nozzle is used. Thus, dust in a predetermined region can be dropped by the pulse air, and dust can be efficiently dropped by a small number of pulse air nozzles.

  Further, in the dust collector of the present embodiment, the inclined plate 84 that suppresses the adhesion of dust is mounted above the pulse air nozzles 52, 53, 54, and the dust separated from the electric dust collector 15 is guided by the inclined plate 84. Thus, it is received in the hoppers 16a to 16d, 17a to 17d, and 18a to 18d, and dust accumulation on the pulse air nozzles 52, 53, and 54 can be suppressed.

  In the dust discharging method of the present embodiment, after agitator air is injected, pulse air is injected when the negative pressure VC in the dust transport pipe 19 becomes equal to or lower than a first predetermined pressure VC-1 set in advance. When the negative pressure VC does not become equal to or lower than the first predetermined pressure VC-1, the agitator air is repeatedly injected. Accordingly, since pulsed air is injected while confirming the clogging of the dust by the pressure in the dust transfer pipe 19, the dust in the hoppers 16a to 16d, 17a to 17d, and 18a to 18d can be properly discharged, and the dust is transferred. When the clogging of the dust in the pipe 19 is detected, the clogging of the dust can be repaired by repeatedly ejecting the agitator air.

  Further, in the dust discharging method of the present embodiment, when the negative pressure VC in the dust transport pipe 19 becomes equal to or lower than the first predetermined pressure VC-1 after jetting the pulse air, the hoppers 16a to 16d, 17a to 17d, and 18a. The gate 35 of ˜18d is closed, and when the negative pressure VC does not become the first predetermined pressure VC-1 or less, the agitator air is repeatedly injected. Therefore, after confirming the clogging of the dust and the discharge state of the dust due to the pressure in the dust transfer pipe 19, the gates 35 of the hoppers 16a to 16d, 17a to 17d, and 18a to 18d are closed, so that the dust discharge operation is performed properly In addition to being able to execute, when the clogging of the dust is detected by the pressure in the dust transport pipe 19, it is possible to repair the clogging of the dust by repeatedly ejecting the agitator air.

  Further, in the dust discharging method of the present embodiment, after the gates 35 of the hoppers 16a to 16d, 17a to 17d, and 18a to 18d are opened, the negative pressure VC in the dust transfer pipe 19 is set to a second predetermined pressure set in advance. When VC-2 or higher, the gates 35 of the hoppers 16a to 16d, 17a to 17d, and 18a to 18d are closed to stop the injection of agitator air and pulsed air. Accordingly, when the limit of the amount of dust discharged or the clogging of dust is detected by the pressure in the dust transport pipe 19, the gates 35 of the hoppers 16a to 16d, 17a to 17d, and 18a to 18d are closed to close the dust transport pipe 19. By stopping the discharge of the dust, the blockage of the dust transport pipe 19 can be prevented.

  In the dust collector and the dust discharging method according to the present invention, the agitator air is sprayed toward the dust in the hopper, and then the pulse air is sprayed toward the inner wall surface of the dust storage area in the hopper. The dust is surely discharged from the discharge port, and can be applied to a dust collector installed in any place.

It is a schematic block diagram of the dust collector which concerns on one Example of this invention. It is a front view of the dust collector of a present Example. It is a top view of the dust collector of a present Example. It is a front view of the hopper in the dust collector of a present Example. It is a top view of the hopper in the dust collector of a present Example. It is sectional drawing of the attachment state of the pulse air nozzle in the dust collector of a present Example. It is a front view of the pulse air nozzle in the dust collector of a present Example. It is the schematic showing the discharge operation | work of the dust in the dust collector of a present Example. It is the schematic showing the discharge operation | work of the dust in the dust collector of a present Example. It is the schematic showing the discharge operation | work of the dust in the dust collector of a present Example. It is the schematic showing the discharge operation | work of the dust in the dust collector of a present Example. It is the schematic showing the discharge operation | work of the dust in the dust collector of a present Example. It is the schematic showing the discharge operation | work of the dust in the dust collector of a present Example. It is a flowchart for performing the discharge method of the dust in the dust collector of a present Example. It is a flowchart for performing the discharge method of the dust in the dust collector of a present Example. It is a flowchart for performing the discharge method of the dust in the dust collector of a present Example. It is a time chart for demonstrating the discharge method of the dust in the dust collector of a present Example. It is a time chart for demonstrating the discharge method of the dust in the dust collector of a present Example. It is a time chart for demonstrating the discharge method of the dust in the dust collector of a present Example. It is a time chart for demonstrating the discharge method of the dust in the dust collector of a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Casing 13 Gas inlet 14 Gas outlet 15 Electric dust collector 16a-16d, 17a-17d, 18a-18d Hopper 19 Dust conveyance pipe 21 Dust processing apparatus 22 Suction piping 23 Vacuum blower 31 Upper cone part 32 Square cylinder part 33 Lower cone Port 34 Discharge port 35 Gate 36 Upper agitator air nozzle 37 Lower agitator air nozzle 38 Throat agitator air nozzle 46 Top agitator air nozzle 52 Upper pulse air nozzle 53 Middle pulse air nozzle 54 Lower pulse air nozzle 73 Controller 74 Pressure sensor 81 Nozzle body 83 Injecting plate 84 Inclined plate 84

Claims (12)

A casing having a gas inlet and a gas outlet, a dust collector that is provided in the casing and collects dust in the exhaust gas, and a hopper that has a discharge port in the lower portion and receives the dust separated from the dust collector; A gate that opens and closes the discharge port of the hopper, an agitator air nozzle that continuously injects air of a predetermined pressure for a predetermined number of seconds set in advance to dust stored in the vicinity of the discharge port in the hopper, A pulse air nozzle that injects air at a predetermined pressure one or more times in a short time of less than 1 second toward an inner wall surface of a dust storage area in the hopper, and a control unit that can drive and control the agitator air nozzle and the pulse air nozzle. The control means opens the discharge port by the gate and then supplies agitator air by the agitator air nozzle. And time injection, followed by dust collecting apparatus characterized by a predetermined time injects pulsed air by the pulse air nozzle.   2. The dust collector according to claim 1, wherein a plurality of the hoppers are provided below the dust collector along the flow direction of the exhaust gas, and dust that can be transported by pressure-feeding dust to the discharge ports of all the hoppers. A transport pipe is connected, and each discharge port of each of the hoppers and the dust transport tube are sequentially communicated so that the dust discharged from the discharge port can be transported by the dust transport tube and transported to a predetermined collection location. In addition, the dust collector is characterized in that the dust discharge frequency of the hopper located downstream in the flow direction of the exhaust gas is set lower than the dust discharge frequency of the hopper positioned upstream in the flow direction of the exhaust gas. 3. The dust collection device according to claim 1, wherein a tip of the pulse air nozzle protrudes into the hopper and jets pulse air along an inner surface of the hopper. 4. apparatus. 4. The dust collector according to claim 3 , wherein the pulse air nozzle injects pulsed air in a fan shape along the inner surface of the hopper. In the dust collecting apparatus according to any one of claims 1 to 4, the dust collecting apparatus characterized by suppressing the inclined plate adhesion of dust above the pulse air nozzle is mounted. In a dust collector comprising: a dust collector that collects dust in exhaust gas; a hopper that has a lower discharge port and receives dust that has left the dust collector; and a gate that opens and closes the lower discharge port of the hopper. move the gate of the hopper opening the lower discharge opening, firstly, to continue agitator air of a predetermined pressure for a predetermined number of seconds set in advance toward the dust stored in the vicinity of the bottom outlet of the hopper Te predetermined time injection, then, by a predetermined time to inject one or more times a pulsed air of a predetermined pressure in a short time of less than one second toward the inner wall surface of the storage area of the dust in the hopper, the dust of the hopper A method for discharging dust, wherein the dust is discharged from the lower discharge port. The dust discharge method according to claim 6 , wherein a dust transfer pipe capable of conveying dust by pressure is connected to the discharge port of the hopper, and the dust discharged from the discharge port by injection of the agitator air and the pulse air. The dust is discharged by the dust transport pipe and transported to a predetermined collection place. 8. The dust discharging method according to claim 7 , wherein after the agitator air is injected, the pulsed air is injected when the pressure in the dust transfer pipe becomes equal to or lower than a preset first predetermined pressure. Discharge method. 9. The dust discharge method according to claim 8 , wherein after the agitator air is injected, the agitator air is repeatedly injected when the pressure in the dust transfer pipe does not become a predetermined first predetermined pressure or less. Characteristic dust discharge method. 8. The dust discharging method according to claim 7 , wherein after the pulse air is injected, the gate of the hopper is closed after a predetermined time has elapsed when the pressure in the dust transport pipe becomes equal to or lower than a preset first predetermined pressure. A dust discharge method characterized by the above. 11. The dust discharge method according to claim 10 , wherein after the pulse air is injected, the agitator air is repeatedly injected when the pressure in the dust transfer pipe does not become a preset first predetermined pressure or less. Dust discharging method. In the discharge process of dust according to claims 8 to any one of 10, If the after opening the gates of the hopper, the dust pressure of the conveying pipe becomes second predetermined pressure or more set in advance, the hopper The dust discharging method, wherein the gate of the agitator air and the pulsed air are stopped.

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