JP2017193600A - Slag exhaust system, gasification furnace provided therewith and method for operating slag exhaust system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress or dissolve the clogging of a slag suction port sucking out slag from the bottom part of a gasification furnace.SOLUTION: There is provided a slag exhaust system 1A comprising: a slag hopper 5 provided at the bottom part of a gasification furnace 2, receiving slag S and further stored with slag cooling water W; a slag suction port 7p sucking out the slag S deposited on the bottom part 5a of the slag hopper 5 and the slag cooling water W; a slag cooling water feed line 7A feeding the slag S and the slag cooling water W sucked out from the slag suction port 7p to a slag separation apparatus 10 to separate the slag S; a slag delivery line 24 elongating from the vicinity of the bottom part 5a of the slag hopper 5 and conducting to the outside of the gasification furnace 2; and a slag delivery valve 26 provided at the slag delivery line 24.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a slag discharge system for a gasification furnace that thermally decomposes and gasifies a carbon-containing solid fuel such as coal, a gasification furnace including the same, and a method for operating the slag discharge system.

  In gasification furnaces that produce flammable gases by pyrolyzing carbon-containing solid fuels such as biomass fuel such as coal and wood pellets, pet coke, etc., the ash content of the carbon-containing solid fuel melts and forms slag in the gasifier. It accumulates in the slag hopper provided in the bottom. Slag cooling water is stored in the slag hopper, and the slag is solidified by being dropped into the slag cooling water and rapidly cooled.

  The slag thus solidified and crushed and collected in the slag hopper is discharged out of the gasification furnace through a lock hopper provided outside the gasification furnace. Since the slag has a higher density than the slag cooling water, conventionally, when the slag is moved from the slag hopper to the lock hopper, it is naturally dropped by gravity. For example, Patent Document 1 discloses a slag discharge system in which a lock hopper is disposed below a gasification furnace.

  However, according to the above-described slag discharge system, since the lock hopper is provided below the gasification furnace, the arrangement position of the gasification furnace becomes high. Therefore, the height from the plant installation surface to the upper part of the gasifier increases. By increasing the arrangement position of the gasification furnace, the arrangement positions of the support frame and the operation frame that support the gasification furnace are increased.

  Therefore, a slag discharge system as disclosed in Patent Document 2 has been proposed. In this slag discharge system, a lock hopper is arranged on the side of the gasification furnace, and a slag discharge line (slag cooling water circulation line) that communicates from the slag hopper at the bottom of the gasification furnace to the lock hopper is provided. A water flow from the slag hopper to the lock hopper is formed inside, and the slag in the slag hopper is discharged to the lock hopper by this water flow.

  In this way, the slag can be transported from the slag hopper to the lock hopper on the slag cooling water flow, so that the lock hopper can be disposed on the side of the gasification furnace, and the gas can be removed from the plant installation surface. The height to the upper part of the conversion furnace can be kept low.

JP 2011-74274 A Japanese Patent No. 574393

  As described above, in the conventional slag discharge system disclosed in Patent Document 2, the slag that has dropped onto the slag hopper at the bottom of the gasification furnace is sucked out together with the slag cooling water stored in the slag hopper through the slag discharge line. The suction port of the slag discharge line that sucks out the slag from the slag hopper opens vertically toward the bottom surface of the slag hopper.

  During normal operation of the gasification furnace, slag that falls into the slag hopper is sequentially sucked and discharged from the suction port of the slag discharge line, so that no slag accumulates at the suction port. However, slag may accumulate on the suction port when the gasifier is started or after a temporary shutdown. When slag suction from the slag discharge line is resumed in this state, there is a concern that the density of the slag is too high and the slag discharge line is clogged and blocked. As described above, the event of closing the slag discharge line is likely to occur mainly at the time of starting the slag discharge system, which causes an obstacle to the operation of the gasifier.

  The present invention has been made in order to solve the above-described problems, and suppresses or eliminates the blockage of the slag suction port that sucks out the slag from the bottom of the gasification furnace with the slag, thereby starting and operating the gasification furnace. It is an object of the present invention to provide a slag discharge system that can be performed smoothly, a gasification furnace equipped with the slag discharge system, and a method for operating the slag discharge system.

In order to solve the above problems, the present invention employs the following means.
That is, the slag discharge system according to the first aspect of the present invention is provided at the bottom of a gasification furnace that gasifies the carbon-containing solid fuel, receives slag generated from the carbon-containing solid fuel, and rapidly cools the slag. A slag hopper in which slag cooling water is stored, a slag suction port for sucking out the slag and slag cooling water accumulated at the bottom of the slag hopper, the slag sucked out from the slag suction port, and the slag cooling water, A slag cooling water supply line that separates the slag by the slag separator, a slag discharge line that extends from near the bottom of the slag hopper and communicates with the outside of the gasification furnace, and the slag discharge And a slag discharge valve provided in the line.

  According to the slag discharge system having the above-described configuration, the internal pressure of the gasifier and the internal pressure of the slag discharge line (for example, large pressure) are set by opening the slag discharge valve for a predetermined time (for example, several seconds) at the time of starting or operating the gasification furnace. The pressure difference from the atmospheric pressure) forms a flow that flows from the slag hopper into the slag discharge line. For this reason, at least a part of the slag accumulated in the slag hopper is discharged into the slag discharge line.

  Therefore, even if the slag suction port is buried in the accumulated slag or the slag density around the slag suction port is high, by discharging at least a part of the slag as described above, The density of slag can be reduced, and the mixture of slag and slag cooling water can be easily sucked from the slag suction port. Thereby, it can suppress or eliminate that a slag suction port is obstruct | occluded by slag, and can start and operate | move a gasifier smoothly.

  Instead of directly transferring the slag from the slag discharge line to a slag storage tank or the like, a predetermined length may be given to the slag discharge line, and the slag may be temporarily stored therein. In this way, the pressure difference between the internal pressure of the gasifier and the internal pressure (atmospheric pressure) of the slag storage tank is alleviated, the momentum of the slag that flows later is buffered, and the valves provided in the slag discharge line, Dispensing equipment such as a storage tank can be protected from damage.

  In addition, when temporarily storing slag in the slag discharge line in this way, a predetermined capacity can be secured in the slag discharge line by providing a slag outlet valve on the outlet side of the slag discharge line. A desired amount of slag can be discharged simply by opening the valve.

  The slag discharge system having the above-described configuration may further include a fluid supply line that is connected to the slag discharge line at a downstream side of the slag discharge valve and supplies a fluid to the inside of the slag discharge line.

  When the slag discharge valve is opened at the time of start-up and operation of the gasification furnace, the slag accumulated in the slag hopper as described above is transferred into the slag discharge line due to the pressure difference. Thereafter, the slag discharge valve is closed and the fluid is fed from the fluid supply line into the slag discharge line, so that the slag in the slag discharge line is discharged to the outside by the fluid. Therefore, the flow of the slag transferred into the slag discharge line can be promoted and reliably discharged to the outside.

  The slag discharge system having the above-described configuration may further include a slag outlet valve provided in the slag discharge line on the downstream side of the fluid supply line.

  When the slag discharge valve is opened during operation of the gasification furnace, the slag in the slag hopper is vigorously discharged to the slag discharge line due to the pressure difference between the internal pressure of the gasification furnace and the external pressure (atmospheric pressure). If this momentum is too strong, there is a risk of damage to the payout equipment such as the slag storage tank connected to the downstream side of the slag payout line.

  Therefore, by providing a slag outlet valve on the downstream side of the fluid supply line connection in the slag discharge line, and closing this slag outlet valve, the pressure difference between the gasifier and the slag discharge line is reduced, and gasification is performed. A buffer function for buffering the momentum of the slag transferred from the furnace to the slag discharge line can be achieved, and damage to the discharge equipment can be prevented.

  In the slag discharge system having the above configuration, it is preferable that a distance between the slag discharge valve and the slag outlet valve is equal to or longer than a predetermined length. As a result, when the slag discharge valve is opened, the amount of slag that flows into the slag discharge line is equal to or more than the amount of slag that closes the slag intake port, and the slag that closes the slag intake port Thus, the entire amount of the slag can be discharged to the slag discharge line, and the blockage of the slag suction port can be reliably suppressed or eliminated.

  In the slag discharge system having the above configuration, the fluid is a gas, and the fluid is supplied in advance from the fluid supply line to the slag discharge line before the slag discharge valve is opened. The internal pressure of the line may be set to a pressure between the internal pressure of the gasifier and the atmospheric pressure.

  In this way, by supplying a gaseous fluid such as air or nitrogen gas in advance to the inside of the slag discharge line to increase the internal pressure of the slag discharge line above atmospheric pressure, the pressure difference inside and outside the gasifier is reduced. Thus, the slag discharge speed when the slag discharge valve is opened can be reduced to prevent the discharge equipment from being damaged.

  In the slag discharge system configured as described above, the fluid is a liquid, and the fluid is supplied from the fluid supply line into the slag discharge line in advance before the slag discharge valve is opened. At least a part of the internal space may be filled.

  In this way, if the liquid discharge fluid is supplied into the slag discharge line in advance, the slag discharge speed released into the slag discharge line simultaneously with the opening of the slag discharge valve will cause the liquid discharge fluid to Damped by viscosity. For this reason, it is possible to prevent damage to the payout equipment as described above.

  In the slag discharge system having the above-described configuration, the slag discharge line may be provided with an enlarged diameter portion in which the inner diameter of the pipeline is partially enlarged.

  By providing such a diameter-expanded portion in the slag discharge line, the discharge speed (flow velocity) of the slag discharged into the slag discharge line when the slag discharge valve is opened is attenuated at the diameter-expanded portion. For this reason, it is possible to prevent damage to the payout equipment as described above. Moreover, since the internal volume per pipe length of the slag discharge line increases, the amount of slag that can be stored in the slag discharge line can be increased to enhance the buffer function. Alternatively, the slag discharge system can be made compact by reducing the pipe length of the slag discharge line without reducing the amount of slag stored.

  In the slag discharge system having the above configuration, the slag cooling water circulation is connected to the slag cooling water supply line via the slag separation device, and the slag cooling water separated from the slag by the slag separation device is circulated to the slag hopper. Line, a circulation pump connected to the slag cooling water circulation line, a pressure gauge for measuring the pressure on the suction side of the circulation pump, and pressure data measured by the pressure gauge, and the pressure data is predetermined. And a control unit that performs opening / closing control of the slag discharge valve when the threshold value is reached.

  The slag cooling water circulation line that leads to the slag cooling water supply line when the slag suction port is buried in the accumulated slag or the slag density around the slag suction port becomes high when the gasifier is started up or in operation The pressure on the suction side of the circulation pump connected to is reduced.

  The pressure data is measured by the pressure gauge and input to the control unit. When the pressure data exceeds a predetermined threshold, the control unit opens the slag discharge valve for a predetermined time. Thereby, a part of the slag of the slag hopper is discharged to the slag discharge line, and the blockage of the slag suction port is eliminated or prevented.

  In this way, the slag suction is provided by a simple configuration in which a pressure gauge is provided on the suction side of the circulation pump connected to the slag cooling water circulation line, the pressure data is input to the control unit, and the control unit opens and closes the slag discharge valve. The outlet blockage can be automatically suppressed or eliminated.

  Since the gasification furnace which concerns on the 2nd aspect of this invention is equipped with one of the above-mentioned slag discharge systems, it suppresses or eliminates clogging of the slag suction port which sucks out slag from the bottom part of a gasification furnace. The gasification furnace can be started and operated smoothly.

  The operation method of the slag discharge system according to the third aspect of the present invention is to suck out slag that has fallen into the slag hopper at the bottom of the gasification furnace that gasifies the carbon-containing solid fuel from the slag suction port together with the slag cooling water, A method of operating a slag discharge system that is sent to a slag separator through a line, when the slag suction port is blocked by the slag, or when there is a sign of blockage, from a slag discharge line that is extended to the outside from the slag hopper A slag dispensing process for dispensing the slag is provided.

  According to the operation method of the slag discharge system, the slag discharge step of discharging the slag from the slag discharge line extended outside from the slag hopper when the slag suction port is blocked by the slag or when there is a sign of the blockage. By performing, at least a part of the slag accumulated in the slag hopper is discharged to the outside due to a pressure difference between the internal pressure of the gasifier and the external pressure.

  Therefore, even if the slag suction port is buried in the accumulated slag or the slag density around the slag suction port is high, at least a part of the slag is discharged from the slag discharge line as described above. The density of the slag near the suction port can be reduced, and the mixture of slag and slag cooling water can be easily sucked from the slag suction port. Thereby, it can suppress or eliminate that a slag suction port is obstruct | occluded by slag, and can start and operate | move a gasifier smoothly.

  The above operation method may further include a fluid supply step of supplying a fluid to the slag discharge line. Thus, by supplying a fluid to the slag discharge line, the internal pressure of the slag discharge line can be adjusted to a pressure suitable for discharging the slag, or the slag passage through the slag discharge line can be improved.

  In the above operation method, the fluid supply step may be executed after the slag discharging step. Thereby, the slag transferred from the slag hopper to the slag discharge line can be reliably discharged to the outside by the fluid.

In the above operation method, a step of closing a slag outlet valve provided at a predetermined distance downstream of a slag discharge valve provided in an upstream portion of the slag discharge line is executed when the fluid supply step is executed. You may do it.
As a result, slag is discharged from the slag hopper into the slag discharge line with the slag outlet valve being the outlet of the slag discharge line having a predetermined internal volume closed, so the pressure between the gasifier and the slag discharge line The difference can be reduced, and a buffer function for buffering the momentum of the slag transferred from the gasification furnace to the slag discharge line can be provided to prevent the discharge equipment from being damaged.

  In the above operation method, when the slag discharge step is executed, the fluid supply step may be executed after the slag discharge valve is opened and closed for a predetermined time. Thereby, the amount of slag to be paid out can be controlled.

  The slag further includes a slag cooling water circulation line that is connected to the slag cooling water supply line via the slag separation device and circulates the slag cooling water separated from the slag by the slag separation device to the slag hopper. In the operation method of the discharge system, a pressure measurement step of measuring the pressure of the slag cooling water circulation line, a blockage determination step of determining a blockage state of the slag suction port based on the pressure data measured by the pressure measurement step, The slag discharge step may be executed when it is determined in the blockage determination step that the slag suction port is blocked, or when it is determined that there is a sign of blockage.

  If the slag inlet of the slag cooling water supply line is buried in the accumulated slag or the slag density around the slag outlet becomes high when the gasifier is started up or in operation, the slag cooling water supply line The pressure of the slag cooling water circulation line leading to

  Therefore, by executing the pressure measurement process for measuring the pressure, it can be determined in the blockage determination process that the slag suction port is closed or is closing. For example, when the pressure of the slag cooling water circulation line decreases to a predetermined threshold value, it is determined that the slag intake port is blocked in the blockage determination step, and the slag discharge step is executed. According to this operation method, the blockage of the slag suction port can be automatically suppressed or eliminated with a simple configuration.

  In the above operation method, when the slag discharging step is performed, the slag suction by the slag suction port and the slag cooling water supply line may be stopped.

  In this way, even if there is slag that was adsorbed by the slag suction port but was not put inside the slag suction port, this slag will stop sucking out by the slag cooling water supply line. The slag discharge process leaves the slag discharge port and is sucked into the slag discharge line. For this reason, obstruction | occlusion of a slag suction port can be eliminated reliably.

  In the above operation method, the fluid may be a gas, and the filling pressure of the gas may be set to a pressure between the internal pressure of the gasification furnace and the atmospheric pressure. In this way, the pressure difference between the inside and outside of the gasification furnace can be reduced, the slag discharge speed when the slag discharge valve is opened can be reduced, and damage to the discharge equipment can be prevented.

  In the above operation method, the fluid may be a liquid. By supplying the liquid fluid to the slag discharge line, the discharge speed of the slag discharged into the slag discharge line when the slag discharge is performed is attenuated by the viscosity of the liquid discharge fluid. For this reason, it is possible to prevent damage to the payout equipment as described above.

  As described above, according to the slag discharge system according to the present invention, the gasification furnace including the slag discharge system, and the operation method of the slag discharge system, the slag suction port for sucking out the slag from the bottom of the gasification furnace is blocked by the slag. Can be suppressed or eliminated, and start-up and operation of the gasifier can be performed smoothly.

It is a schematic block diagram of the gasification furnace and slag discharge system which show 1st Embodiment of this invention. It is a flowchart which shows the flow of operation control of the slag discharge system which concerns on this invention. It is a schematic block diagram of the gasification furnace and slag discharge system which show 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a schematic configuration diagram of a gasification furnace and a slag discharge system showing a first embodiment of the present invention. This slag discharge system 1A is used in, for example, an integrated coal gasification combined cycle (IGCC), pulverized coal obtained by pulverizing coal (carbon-containing solid fuel) with a mill or the like together with a gasifying agent such as air or oxygen. It is provided in a gasification furnace 2 (gasification furnace) that is put into the furnace and pyrolyzed and gasified. In addition to coal gasification furnaces, for example, replacement with gasification furnaces that gasify other carbon-containing solid fuels such as thinned wood, waste wood, driftwood, grass, waste, sludge, biomass fuel such as old tires, etc. May be. Moreover, this slag discharge system 1A can be applied not only to a power plant but also to, for example, a gasifier in a chemical plant.

  The gasification furnace 2 is, for example, a pressurized spouted bed type gasification furnace, and includes an inner container 2a and an outer container 2b surrounding the inner container 2a. In the inner container 2a, a combustor 2c for burning a part of pulverized coal to obtain a heat quantity necessary for a gasification reaction and a reductor 2d for obtaining a heat quantity from the combustor 2c and gasifying the pulverized coal in two stages. Has been placed.

  A slag hopper 5 is provided at the bottom of the gasification furnace 2, and slag cooling water W is stored therein. The ash content in the pulverized coal charged into the gasification furnace 2 is melted by the combustor 2c, and then falls into the slag cooling water W of the slag hopper 5 by gravity from a slag hole (not shown) below the combustor 2c as liquid molten slag. By being rapidly cooled, it solidifies and is crushed, resulting in a rough particulate solid slag S. This slag S is discharged out of the gasification furnace 2 by the slag discharge system 1A. The slag discharge system 1A is configured as follows.

  A slag line 7 is connected to the slag hopper 5. This slag line 7 is connected to the slag cooling water water supply line 7A for discharging the crushed slag S from the bottom 5a of the slag hopper 5, and one end connected to the slag cooling water water supply line 7A via the slag separator 10 and the other end. Is provided with a slag cooling water circulation line 7 </ b> B connected so as to return to the slag hopper 5.

  The upstream end of the slag cooling water supply line 7A is a slag suction port 7p, which is spaced upward from the bottom 5a of the slag hopper 5 and opens vertically downward. The slag slurry which is a mixture of the slag S and the slag cooling water W in the slag hopper 5 is sucked out from the slag suction port 7p. A pressure equivalent to the operating pressure of the gasification furnace 2 acts inside the slag cooling water feed line 7A.

  The slag separation device 10 connected in the middle of the slag line 7 separates the slag S from the slag slurry. For example, a centrifugal separation device (liquid cyclone or the like) is preferable, but a filtration type such as a strainer or a filter is used. The separation means may be used. The slag slurry sucked out from the slag suction port 7p is transferred to the slag separation device 10 by the water flow flowing through the slag cooling water supply line 7A.

  A lock hopper 12 and a discharge valve 14 are connected to the lower part of the slag separation device 10. The lock hopper 12 is a hopper that stores a predetermined amount of the slag S separated from the slag cooling water W by the slag separator 10, and the discharge valve 14 is periodically opened to discharge the slag. The discharged slag S is carried out of the gasification furnace 2 by a transport vehicle (not shown).

  In the slag cooling water circulation line 7B, a pressure gauge 16, a circulation pump 18, and a cooler 20 are connected in this order on the downstream side of the slag separation device 10. The downstream end of the slag cooling water circulation line 7 </ b> B is connected to a height corresponding to the shallow portion of the slag cooling water W in the slag hopper 5. That is, the slag line 7 is configured as a loop-shaped pipe line extending from the slag hopper 5 and connected to the recirculation portion 5b of the slag hopper 5 again.

  From the vicinity of the bottom 5a of the slag hopper 5, a slag discharge line 24 leading to the outside of the gasification furnace 2 extends over a predetermined length. A slag discharge valve 26 is provided at a position closest to the gasification furnace 2 of the slag discharge line 24, and a slag outlet valve 28 is provided at a position having a predetermined length L downstream from the slag discharge valve 26. ing. As described above, the length L is a length that gives an internal volume capable of recovering the slag S closing the slag suction port 7p to the slag discharge line 24 between the valves 26 and 28 as will be described later. The position of the open end of the slag discharge line 24 inside the slag hopper 5 is preferably in the vicinity of the slag suction port 7p. The downstream end of the slag discharge line 24 is connected to a slag storage tank (not shown), for example.

  Further, a fluid supply line 30 is connected to the slag discharge line 24 in the vicinity of a portion immediately downstream of the slag discharge valve 26, and a flow rate adjusting valve 32 is provided in the fluid supply line 30. The fluid supply line 30 is a pipe line that supplies the fluid SF into the slag discharge line 24. As the fluid SF, it is conceivable to use a gas such as air or nitrogen gas, or a liquid such as water.

  Although the slag discharge valve 26, the slag outlet valve 28, and the flow rate adjustment valve 32 may be manually opened and closed, in the present embodiment, the opening and closing is electrically controlled by the control unit 35. Furthermore, the circulation pump 18 is also controlled and operated by the control unit 35.

The slag discharge system 1A configured as described above has two operation modes, a normal operation mode and a slag discharge operation mode. Both operation modes are executed when the gasification furnace 2 is started up and operated. The slag discharge operation mode is an operation mode that is executed when the slag cooling water supply line 7A is blocked by the slag S during start-up and operation, or when there is a sign of blockage.
As will be described later, when the slag discharge system 1A is activated and operated, four steps of a pressure measurement step, a blockage determination step, a slag discharge step, and a fluid supply step shown in FIG. 2 are executed.

  In the normal operation mode, the control unit 35 closes the slag discharge valve 26, the slag outlet valve 28, and the flow rate adjustment valve 32 to operate the circulation pump 18. As a result, a water flow from the slag suction port 7p to the slag separation device 10 is formed in the slag cooling water supply line 7A, and the slag slurry deposited on the bottom portion 5a of the slag hopper 5 is transferred to the slag cooling water supply line 7A. And is supplied to the slag separation device 10 through the slag cooling water supply line 7A.

  In the slag separator 10, the slag S in the slag slurry is separated from the slag cooling water W, stored in the lock hopper 12, periodically discharged from the discharge valve 14, and carried out of the gasification furnace 2. Then, only the slag cooling water W from which the slag S has been removed flows into the slag cooling water circulation line 7B, and is sucked and discharged into the circulation pump 18, and further cooled to a predetermined temperature by the cooler 20, and then passed through the recirculation unit 5b and the slag hopper. Reflux to 5. The recirculated slag cooling water W is mixed again with the slag S deposited on the bottom portion 5a of the slag hopper 5 to become slag slurry, and is sucked out from the slag outlet 7p of the slag cooling water supply line 7A and sent to the slag separator 10. The

  In the slag discharge operation mode, the control unit 35 opens and closes the slag discharge valve 26 for a predetermined time (for example, several seconds) (slag discharge process), and then opens the slag outlet valve 28 and the flow rate adjustment valve 32 to supply fluid. The fluid SF is supplied from the line 30 into the slag discharge line 24 (fluid supply step). At this time, the circulation pump 18 may be stopped to stop the water flow of the slag line 7 (7A, 7B).

  When the slag discharge valve 26 is opened during the operation of the gasification furnace 2, the slag discharge line 24 from the slag hopper 5 is caused by the pressure difference between the internal pressure of the gasification furnace 2 and the internal pressure of the slag discharge line 24 (for example, atmospheric pressure). A flow is formed that flows into the interior. For this reason, at least a part of the slag S accumulated in the slag hopper 5 is discharged into the slag discharge line 24.

  Therefore, for example, even when the slag suction port 7p is blocked by the slag S or is slightly closed during start-up and operation, at least a part of the slag S is discharged to the slag discharge line 24 as described above. The density of the slag S in the vicinity of the slag suction port 7p can be reduced, and the slag slurry can be easily sucked from the slag suction port 7p. Thereby, obstruction | occlusion of the slag suction port 7p by the slag S can be suppressed or eliminated, and the gasification furnace 2 can be started and operated smoothly.

  Thereafter, the slag discharge valve 26 is closed, the slag outlet valve 28 is opened, and the fluid SF is fed from the fluid supply line 30 into the slag discharge line 24, whereby the slag S in the slag discharge line 24 is converted into the fluid SF. Then, it is poured out and conveyed to a slag storage tank (not shown). Therefore, the slag S transferred into the slag discharge line 24 can be reliably discharged to the outside. Further, by supplying the discharge fluid SF into the slag discharge line 24, the internal pressure of the slag discharge line 24 can be set to a pressure suitable for discharging the slag S.

  In the present embodiment, the slag S is not directly transferred from the slag discharge line 24 to the slag storage tank or the like, but a predetermined length L is given to the slag discharge line 24 and the slag S is temporarily stored therein. I have to. By doing so, the pressure difference between the internal pressure of the gasification furnace 2 and the internal pressure (atmospheric pressure) of the slag storage tank is relaxed, and the momentum of the slag S that flows later is buffered, and the valve provided in the slag discharge line 24 26, 28, and slag storage tanks can be protected from damage.

  Further, in order to temporarily store the slag S in the slag discharge line 24 as described above, a predetermined length L is given to the slag discharge line 24 and a slag outlet valve 28 is provided on the outlet side thereof. As a result, the slag discharge line 24 can secure a capacity capable of accommodating the entire amount of the slag S blocking the slag suction port 7p, and the desired amount of slag can be obtained simply by opening the slag discharge valve 26. S can be paid out, and the blockage of the slag suction port 7p can be reliably suppressed or eliminated.

  A slag outlet valve 28 is provided on the downstream side of the connecting portion of the fluid supply line 30 in the slag discharge line 24, and the pressure difference between the gasification furnace 2 and the fluid supply line 30 is reduced by closing the slag outlet valve 28. In addition, a buffer function for buffering the momentum of the slag S transferred from the gasification furnace 2 to the slag discharge line 24 can be exerted, and damage to the discharge facility can be prevented.

  A predetermined distance L is provided between the slag discharge valve 26 and the slag outlet valve 28, and this distance L is used as an internal volume capable of recovering the slag S closing the slag suction port 7 p. Since the length is given to the payout line 24, the buffer function for buffering the momentum of the slag S flowing into the slag payout line 24 when the slag discharge valve 26 is opened can be increased.

  Switching between the normal operation mode and the slag discharge operation mode may be performed manually by the operator operating the control unit 35 while monitoring the state of the slag suction port 7p, but the pressure on the suction side of the circulation pump 18 is changed. It is also possible to cause the control unit 35 to automatically perform based on the data of the pressure gauge 16 to be measured.

  In other words, when the gasification furnace 2 is started up and in operation, the slag suction port 7p is blocked or blocked when the slag suction port 7p is buried in the slag S or the slag density around the slag suction port 7p is high. The pressure on the suction side of the circulation pump 18 connected to the upstream side of the slag suction port 7p (pressure on the slag cooling water circulation line 7B) becomes low.

  The pressure data is measured by the pressure gauge 16 and input to the control unit 35 (pressure measurement step), and the control unit 35 determines the closed state of the slag suction port 7p based on the pressure data (blocking determination step). When the pressure data reaches a predetermined threshold value, the control unit 35 switches from the normal operation mode to the slag discharge operation mode and partially discharges the slag S in the slag hopper 5 as described above (slag discharge process). The blockage of the suction port 7p is suppressed or eliminated.

  In this way, the pressure gauge 16 is provided on the suction side of the circulation pump 18 in the slag cooling water circulation line 7B, and the pressure data is input to the control unit 35 so that the control unit 35 opens and closes the slag discharge valve 26. The blockage of the slag suction port 7p can be automatically suppressed or eliminated.

  In the slag discharge operation mode, when a gas such as air or nitrogen gas is supplied as the fluid SF from the fluid supply line 30 into the slag discharge line 24, the slag discharge valve 26 and the slag outlet valve 28 are opened in advance. The fluid SF is filled into the slag discharge line 24 from the fluid supply line 30 (fluid supply step), and the internal pressure of the slag discharge line 24 is set to a pressure between the internal pressure of the gasification furnace 2 and the atmospheric pressure. It is preferable to keep it.

  When the slag discharge valve 26 is opened at the time of start-up and operation of the gasification furnace 2, the slag discharge line in the slag hopper 5 is vigorously driven by the pressure difference between the internal pressure of the gasification furnace 2 and the external pressure (atmospheric pressure). To 24. If this momentum is too strong, there is a risk that the slag outlet valve 28 provided at the other end of the slag payout line 24 and the payout equipment such as the slag storage tank may be damaged.

  As described above, the gaseous fluid SF is filled in the slag discharge line 24 in advance, and the internal pressure of the slag discharge line 24 is set to a pressure between the internal pressure of the gasification furnace 2 and the atmospheric pressure. Accordingly, the pressure difference between the inside and outside of the gasification furnace 2 can be reduced, the slag discharge speed when the slag discharge valve 26 is opened can be reduced, and damage to the discharge equipment can be prevented. However, if the pressure difference between the inside and outside is made too small, the momentum for releasing the slag S will decrease, so this inside / outside pressure difference (filling pressure of the fluid SF) needs to be set appropriately.

  Alternatively, the fluid SF is a liquid such as water, and this liquid fluid SF is supplied from the fluid supply line 30 into the slag discharge line 24 in advance before the slag discharge valve 26 and the slag outlet valve 28 are opened in the slag discharge operation mode. You may keep it. The supply amount does not necessarily need to be an amount that fills the inside of the slag discharge line 24, as long as the liquid level is formed inside the slag discharge line 24.

  In this way, if the liquid fluid SF is supplied into the slag discharge line 24 in advance, the release rate of the slag S discharged into the slag discharge line 24 simultaneously with the opening of the slag discharge valve 26 is the liquid state. It is attenuated by the viscosity of the fluid SF. For this reason, it is possible to prevent damage to the dispensing equipment due to the excessive release rate of the slag S.

  Incidentally, in the slag discharge operation mode, it is preferable to stop the suction of the slag S by the slag cooling water supply line 7A. Specifically, when the slag discharge valve 26 is opened, the circulation pump 18 provided in the slag cooling water circulation line 7B is stopped.

  In this way, even if there is slag S adsorbed by the slag suction port 7p and staying in the slag suction port 7p, the slag S stops being sucked out by the slag cooling water supply line 7A. Therefore, when the slag discharge operation is executed, the slag discharge port 7p is separated from the slag discharge port 7p and is sucked into the slag discharge line 24. For this reason, obstruction | occlusion of the slag suction outlet 7p can be suppressed or eliminated reliably. This effect becomes remarkable when the position of the opening end portion of the slag discharge line 24 in the slag hopper 5 is set in the vicinity of the slag suction port 7p.

  FIG. 2 is a flowchart showing a flow of operation control of the slag discharge system 1A. Explaining this flow, a pressure measurement process is performed in which the pressure on the suction side of the circulation pump 18 is measured by the pressure gauge 16 and input to the control unit 35 when the gasification furnace 2 is started up and after the operation is started (step). S1). Next, the control unit 35 executes a blockage determination step for determining the blockage state of the slag intake port 7p based on the input pressure data (step S2).

  When it is determined that the slag suction port 7p is not blocked in the blockage determination step S2, that is, when the pressure on the suction side of the circulation pump 18 has not reached a predetermined threshold value, the control returns to the original, and the pressure measurement step S1 and blockage determination step S2 are repeated. Further, when it is determined in the blockage determination step S2 that the slag suction port 7p is blocked or there is a sign of blockage, that is, when the pressure on the suction side of the circulation pump 18 reaches a predetermined threshold value, the slag A payout process is executed (step S3), and a fluid supply process is executed (step S4).

By executing the slag discharge step S3, as described above, the slag S in the vicinity of the periphery of the slag suction port 7p is discharged from the slag discharge line 24, and the blockage of the slag suction port 7p by the slag S is avoided or eliminated. The
The front-rear relationship between the slag discharge step S3 and the fluid supply step S4 is not limited to that shown in this flowchart, and may be reversed or performed simultaneously. Thereafter, the control returns to the original, and steps S1 to S4 are repeated during operation.

  Thus, the pressure measurement step S1 for measuring the pressure of the slag cooling water circulation line 7B, the blockage determination step S2 for determining the blockage state of the slag suction port 7p based on the pressure data measured in the pressure measurement step S1, The slag discharge step S3 is executed when it is determined in the blocking determination step S2 that the slag suction port 7p is blocked or when it is determined that there is a sign of blocking.

  According to this operation method, when the gasification furnace 2 is started or during operation, when the slag suction port 7p is buried in the slag S or when the slag density around the slag suction port 7p becomes high, the slag cooling water Although the pressure of the slag cooling water circulation line 7B leading to the water supply line 7A decreases, it is blocked that the slag suction port 7p is closed or is closed by executing the pressure measurement step S1 for measuring this pressure. It can be determined in the determination step S2. Therefore, the blockage of the slag suction port 7p can be automatically suppressed or eliminated with a simple configuration.

  By the way, by performing the fluid supply step S4 after the slag discharge step S3, the slag S transferred from the slag hopper 5 to the slag discharge line 24 can be reliably discharged to the outside by the fluid SF.

  Further, when the fluid supply step S4 is performed, the slag outlet valve 28 provided at a predetermined distance L on the downstream side of the slag discharge valve 26 may be closed. As a result, the slag S is discharged from the slag hopper 5 into the slag discharge line 24 in a state in which the slag outlet valve 28 that is the outlet of the slag discharge line 24 having a predetermined internal volume is closed. The pressure difference with the slag discharge line 24 can be reduced, and the buffer function for buffering the momentum of the slag S transferred from the gasifier 2 to the slag discharge line 24 can be provided to prevent the discharge equipment from being damaged. it can.

  Furthermore, when the slag discharge step S3 is executed, the fluid supply step S4 may be executed after the slag discharge valve 26 is opened and closed for a predetermined time. Thereby, the amount of the slag S to be paid out can be controlled.

[Second Embodiment]
FIG. 3 is a schematic configuration diagram of the gasification furnace 2 and the slag discharge system 1B showing the second embodiment of the present invention. This slag discharge system 1B is different from the slag discharge system 1A of the first embodiment in that the slag discharge line 24 is provided with an enlarged diameter portion 24a, and is the same in other points. Accordingly, the same reference numerals are given to the components having the same configuration, and redundant description is omitted.

  The enlarged diameter portion 24 a is obtained by partially enlarging the inner diameter of the pipe line at the intermediate portion of the slag discharge line 24. It is desirable to provide the enlarged diameter portion 24a as close to the gasification furnace 2 as possible.

  By providing such an enlarged diameter portion 24a in the slag delivery line 24, the discharge speed (flow velocity) of the slag S released into the slag delivery line 24 when the slag delivery valve 26 is opened is a part of the enlarged diameter portion 24a. Decrease. For this reason, it is possible to prevent damage to the payout equipment as described above. Moreover, since the internal volume per pipe length of the slag discharge line 24 increases, the pipe length can be shortened and the slag discharge system 1B can be made compact. In addition, it can prevent that the inside of the slag discharge line 24 is obstruct | occluded by the slag S by providing the enlarged diameter part 24a in the vicinity of the gasification furnace 2. FIG.

  As described above, according to the slag discharge systems 1A and 1B and the gasification furnace 2 including the slag discharge systems 1A and 1B according to the first and second embodiments, the slag S is formed from the bottom of the gasification furnace 2 with a simple configuration. The slag suction port 7p and the slag cooling water supply line 7A that suck out the slag are suppressed or eliminated from being blocked by the slag S, and the gasification furnace 2 can be started and operated smoothly.

  It should be noted that the present invention is not limited to the configuration of the above-described embodiment, and can be appropriately changed or improved. Embodiments with such changes and improvements are also included in the scope of the right of the present invention. And For example, it is conceivable to change the connection order, installation position, and the like of the constituent members in the above embodiments as appropriate.

  For example, in the above-described embodiment, an example in which one slag suction port 7p and one slag discharge line 24 are provided inside the slag hopper 5 has been described, but a plurality of slag suction ports 7p and slag discharge lines 24 may be provided. Good.

1A, 1B Slag discharge system 2 Gasification furnace 5 Slag hopper 5a Slag hopper bottom 7A Slag cooling water feed line 7B Slag cooling water circulation line 7p Slag inlet 10 Slag separator 16 Pressure gauge 18 Circulation pump 24 Slag discharge line 24a Expanding part 26 Slag discharge valve 28 Slag outlet valve 30 Fluid supply line 35 Control unit S Slag SF Fluid S1 Pressure measurement step S2 Blocking determination step S3 Slag discharge step S4 Fluid supply step W Slag cooling water

Claims (18)

A slag hopper provided at the bottom of a gasification furnace for gasifying the carbon-containing solid fuel, receiving slag generated from the carbon-containing solid fuel, and storing slag cooling water for rapidly cooling the slag;
A slag suction port for sucking out the slag and the slag cooling water accumulated at the bottom of the slag hopper;
A slag cooling water feed line that sends the slag sucked out from the slag suction port and the slag cooling water to a slag separator, and separates the slag by the slag separator;
A slag discharge line extending from near the bottom of the slag hopper and leading to the outside of the gasification furnace;
A slag discharge valve provided in the slag discharge line;
A slag discharge system comprising:   The slag discharge system according to claim 1, further comprising a fluid supply line that is connected to the slag discharge line at a downstream side of the slag discharge valve and supplies a fluid to the inside of the slag discharge line.   The slag discharge system according to claim 2, further comprising a slag outlet valve provided in the slag discharge line at a downstream side of the fluid supply line.   The slag discharge system according to claim 3, wherein a distance between the slag discharge valve and the slag outlet valve is a predetermined length or more.   The fluid is a gas, and the fluid is supplied in advance from the fluid supply line into the slag discharge line before the slag discharge valve is opened, and the internal pressure of the slag discharge line is changed to the gasification by the supply of the fluid. The slag discharge system according to claim 3, which is set to a pressure between the internal pressure of the furnace and the atmospheric pressure.   The fluid is a liquid, and the fluid is supplied in advance from the fluid supply line into the slag discharge line before the slag discharge valve is opened, and at least a part of the internal space of the slag discharge line is filled with the fluid. The slag discharge system according to claim 3.   The slag discharge system according to claim 1, wherein the slag discharge line is provided with an enlarged diameter part in which a pipe inner diameter is partially enlarged. A slag cooling water circulation line that is connected to the slag cooling water feed line via the slag separation device and circulates the slag cooling water separated from the slag by the slag separation device to the slag hopper;
A circulation pump connected to the slag cooling water circulation line;
A pressure gauge for measuring the pressure on the suction side of the circulation pump;
The slag discharge according to claim 1, further comprising: a control unit that receives pressure data measured by the pressure gauge and performs opening / closing control of the slag discharge valve when the pressure data reaches a predetermined threshold value. system.   A gasification furnace comprising the slag discharge system according to any one of claims 1 to 8. A method for operating a slag discharge system that sucks slag that has fallen into a slag hopper at the bottom of a gasification furnace that gasifies carbon-containing solid fuel together with slag cooling water from a slag suction port and sends the slag to a slag separator through a slag cooling water feed line ,
An operation method of a slag discharge system comprising a slag discharge step of discharging the slag from a slag discharge line extended to the outside from the slag hopper when the slag suction port is blocked by the slag or when there is a sign of blockage.   The operation method of the slag discharge system according to claim 10, further comprising a fluid supply step of supplying a fluid to the slag discharge line.   The operation method of the slag discharge system according to claim 11, wherein the fluid supply step is executed after the slag discharge step.   12. The step of closing a slag outlet valve provided at a predetermined distance downstream of a slag discharge valve provided in an upstream portion of the slag discharge line when executing the fluid supply step. How to operate the slag discharge system.   The operation method of the slag discharge system according to claim 12, wherein the fluid supply step is executed after the slag discharge valve is opened and closed for a predetermined time when the slag discharge step is executed. A slag discharge system further comprising a slag cooling water circulation line that is connected to the slag cooling water supply line via the slag separation device and circulates the slag cooling water separated from the slag by the slag separation device to the slag hopper. In the driving method of
A pressure measuring step of measuring the pressure of the slag cooling water circulation line;
A blockage determination step of determining a blockage state of the slag suction port based on the pressure data measured by the pressure measurement step,
The operation of the slag discharge system according to claim 10, wherein the slag discharge system is executed when it is determined that the slag intake port is blocked in the blockage determination step or when there is a sign of blockage. Method.   The operation method of the slag discharge system according to claim 15, wherein when the slag discharge step is performed, the slag suction through the slag suction port and the slag cooling water supply line is stopped.   The operation method of the slag discharge system according to claim 13, wherein the fluid is a gas, and the filling pressure of the gas is set to a pressure between an internal pressure of the gasification furnace and an atmospheric pressure.   The method of operating a slag discharge system according to claim 11, wherein the fluid is a liquid.

Images