JP2012107085A - Slag removal method in coal gasification apparatus, and coal gasification apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively remove slag deposits around a slag discharge port to thereby prevent clogging of the slag discharge port.SOLUTION: There is provided a method for removing slag deposits deposited around a slag discharge port 12, in a coal gasification apparatus 4 having: a reaction furnace body 11 in the interior of which the combustion reaction of coal 16, 19 is generated to thereby generate a coal gasified gas containing at least hydrogen gas and carbon monoxide gas, and a slag 25; and a discharge tank 13 which communicates with the reaction furnace body 11 through a slag discharge port 12, and into which the slag 25 is discharged through the slag discharge port 12 from the reaction furnace body 11. In the method, there is provided a leading-in step of leading the coal gasified gas into the discharge tank 13 from the reaction furnace body 11 through the slag discharge port 12.

Description

  The present invention relates to a slag removal method in a coal gasification apparatus that produces a coal gasification gas containing at least hydrogen gas and carbon monoxide gas, and a coal gasification apparatus.

  Conventionally, as this kind of coal gasifier, the combustion reaction of coal occurs inside, and the reactor main body in which the coal gasification gas and slag are generated, and the inside of the reactor main body and the slag discharge hole communicate with each other. There is known a configuration including a discharge tank in which slag is discharged from the reactor main body through a slag discharge hole.

However, in this coal gasifier, the slag discharge hole is blocked by, for example, slag deposits attached to the periphery of the slag discharge hole (such as the inner peripheral surface of the slag discharge hole or the peripheral edge of the slag discharge hole in the discharge tank). As a result, slag may not be discharged from the reactor body.
Therefore, in order to solve this problem, for example, the operation method of the gasifier described in Patent Document 1 below may be applied to a slag removal method in a coal gasifier that discharges slag from the reactor main body to the discharge tank. It is done.

In this method, an oxygen-containing gas is supplied to the discharge tank, and combustible components contained in the gas flowing into the discharge tank from the slag discharge hole are combusted. Here, the gas flowing into the discharge tank flows together with the slag discharged from the slag discharge hole to the discharge tank.
In this method, flammable components contained in the gas flowing into the discharge tank from the slag discharge hole are burned to maintain the internal temperature of the discharge tank, particularly the temperature around the slag discharge hole, and heat the slag deposits. It is intended to remove and slag discharge smoothly.

JP 2004-99760 A

However, in the conventional slag removal method in the coal gasifier, since the amount of gas flowing into the discharge tank from the slag discharge hole is very small, the temperature around the slag discharge hole is maintained at a high temperature by the combustion of the combustible component. It was difficult to do.
Therefore, in the slag removal method in the conventional coal gasifier, slag deposits may not be sufficiently removed. As a result, in the coal gasifier, the slag discharge hole is blocked by the slag deposit, and there is a possibility that the slag may not be discharged from the reactor main body.
Although it is conceivable to maintain the temperature around the slag discharge hole at a high temperature using a burner that supplies an oxygen-containing gas to the discharge tank, in this case, the amount of fuel gas supplied from the burner must be increased. This is disadvantageous because it leads to increased costs.

  This invention is made in view of the situation mentioned above, The objective is in the coal gasifier which can remove the slag deposits around a slag discharge hole effectively, and can prevent blockage of a slag discharge hole. It is to provide a slag removal method.

The inventor of the present application uses high-temperature coal gasification gas generated in the reactor main body, draws it into the discharge tank, and further burns it to heat the periphery of the slag discharge hole to prevent slag adhesion around the slag discharge hole The present inventors have found out that it is possible to achieve the present invention.
That is, in order to solve the above problems, the present invention proposes the following means.
The slag removal method in the coal gasifier according to the present invention includes a reaction furnace main body in which a coal combustion reaction occurs and a coal gasification gas containing at least hydrogen gas and carbon monoxide gas and slag are generated. And a slag removal method in a coal gasifier comprising: a slag discharge hole that communicates with the reaction furnace main body through a slag discharge hole and that discharges the slag from the reaction furnace main body through the slag discharge hole. And a drawing step of drawing the coal gasification gas into the discharge tank through the slag discharge hole from within the reaction furnace main body, and removing slag deposits attached around the slag discharge hole.
The periphery of the slag discharge hole means the inner peripheral surface of the slag discharge hole or the opening peripheral edge of the slag discharge hole in the discharge tank.

  According to this invention, since the coal gasification gas is drawn into the discharge tank from the reaction furnace main body through the slag discharge hole during the drawing process, the high-temperature coal gasification gas generated in the reaction furnace main body is put into the discharge tank. It becomes possible to flow in a large amount, and slag deposits can be heated by this coal gasification gas. Therefore, slag deposits can be effectively removed.

  The discharge tank stores a cooling liquid that cools the slag discharged from the reactor main body, and the drawing-in step is a liquid level lowering process that lowers the liquid level of the cooling liquid in the discharge tank. You may have.

In this case, since the cooling liquid is stored in the discharge tank, the slag discharged from the reactor main body to the discharge tank can be cooled by the cooling liquid.
Moreover, the inside of a discharge tank can be made into a negative pressure by dropping the liquid level of the cooling liquid in a discharge tank at the time of a liquid level fall process. Thereby, coal gasification gas can be drawn in in a discharge tank through a slag discharge hole from the inside of a reaction furnace main body.

  In addition, the drawing step includes a liquid level raising step for raising the liquid level of the cooling liquid in the discharge tank after the liquid level lowering step, and the liquid level lowering step and the liquid level rising step. It may be repeated alternately.

In this case, since the liquid level lowering step and the liquid level rising step are alternately repeated, the coal gasification gas can be repeatedly drawn into the discharge tank from the reactor main body through the slag discharge hole, and the slag deposits can be further removed. It can be effectively removed.
In addition, the liquid level lowering process and the liquid level rising process are alternately repeated instead of continuously performing the liquid level lowering process, so that the liquid level position of the cooling liquid in the discharge tank is secured within a predetermined height range. Thus, the slag discharged from the reactor main body to the discharge tank can be effectively cooled by the cooling liquid.

  Moreover, you may have the gas combustion process which burns the said coal gasification gas drawn in in the said discharge tank.

In this case, the slag deposit can be heated by burning the coal gasification gas drawn into the discharge tank during the gas combustion step. Therefore, combined with heating the slag deposit by drawing the coal gasification gas into the discharge tank through the slag discharge hole, the slag deposit can be more effectively removed.
Moreover, since the slag deposits can be heated by burning the coal gasification gas, it is not necessary to separately supply fuel gas into the discharge tank in order to heat the slag deposits. However, the amount used can be suppressed.

  The coal gasifier further includes a hole heating burner that heats an opening peripheral edge of the slag discharge hole in the discharge tank, and the gas combustion step normally sets an injection amount of oxygen gas from the hole heating burner. The coal gasification gas may be burned by increasing the oxygen gas operation time and blowing the oxygen gas to the coal gasification gas.

In this case, during the normal operation of the coal gasifier, the slag discharge hole in the discharge tank is heated by the hole heating burner to suppress the occurrence of slag deposits themselves.
Further, since the coal gasification gas burned during the gas combustion process flows in a large amount by being drawn into the discharge tank, oxygen injected from the hole heating burner at the peripheral edge of the slag discharge hole in the discharge tank The gas can be reliably blown onto the coal gasification gas, and the coal gasification gas can be reliably burned.

  Moreover, the said drawing-in process may be performed based on the obstruction | occlusion state of the said slag discharge hole by the said slag deposit | attachment.

  In this case, since the drawing-in process is performed based on the blockage of the slag discharge hole due to slag deposits, for example, the drawing-in process can be reliably performed before the slag discharge hole is completely blocked. Therefore, it is possible to reliably prevent the slag discharge hole from being blocked by the slag deposit.

  Moreover, the coal gasification apparatus according to the present invention has a reaction furnace main body in which a coal combustion reaction occurs and a coal gasification gas containing at least hydrogen gas and carbon monoxide gas and slag are generated, A coal gasification apparatus comprising: a discharge tank that communicates with the inside of the reaction furnace main body through a slag discharge hole and from which the slag is discharged from the reaction furnace main body through the slag discharge hole; The coal gasification gas is drawn into the discharge tank through the slag discharge hole.

  According to the present invention, by drawing the coal gasification gas into the discharge tank from the reaction furnace body through the slag discharge hole by the drawing mechanism, the high-temperature coal gasification gas generated in the reaction furnace body is discharged into the discharge tank. The coal gasification gas can heat slag deposits attached around the slag discharge holes. Accordingly, it is possible to effectively remove the slag deposits, suppress the clogging of the slag discharge hole by the slag deposits, and smoothly discharge the slag from the reactor main body to the discharge tank.

  The discharge tank stores a cooling liquid that cools the slag discharged from the reactor main body, and the drawing-in mechanism lowers the liquid level of the cooling liquid in the discharge tank. May be provided.

In this case, since the cooling liquid is stored in the discharge tank, the slag discharged from the reactor main body to the discharge tank can be cooled by the cooling liquid.
Moreover, the inside of the discharge tank can be set to a negative pressure by lowering the liquid level of the cooling liquid in the discharge tank by the liquid level lowering means. Thereby, coal gasification gas can be drawn in in a discharge tank through a slag discharge hole from the inside of a reaction furnace main body.

  Moreover, the drawing-in mechanism may include a liquid level raising means for raising the liquid level of the cooling liquid in the discharge tank.

In this case, after the liquid level of the cooling liquid in the discharge tank is lowered by the liquid level lowering means, the liquid level of the cooling liquid in the discharge tank is raised by the liquid level raising means, thereby cooling the inside of the discharge tank. The liquid level position of the liquid can be secured within a predetermined height range. Thereby, the slag discharged | emitted from the reaction furnace main body to the discharge tank can be cooled effectively with a cooling liquid.
In addition, by alternately lowering and raising the level of the cooling liquid in the discharge tank, it becomes possible to repeatedly draw the coal gasification gas into the discharge tank from the reactor main body through the slag discharge hole. The slag deposits can be removed more effectively.

  The discharge tank may be provided with a gas combustion mechanism for burning the coal gasification gas drawn into the discharge tank.

In this case, slag deposits can be heated by burning the coal gasification gas drawn into the discharge tank by the gas combustion means. Therefore, in combination with heating the slag by drawing the coal gasification gas into the discharge tank through the slag discharge hole, it is possible to reliably prevent the slag discharge hole from being blocked by the slag.
Moreover, since the slag deposit can be heated by burning the coal gasification gas, it is not necessary to separately supply fuel gas into the discharge tank in order to heat the slag deposit from the gas combustion mechanism, Even in the case of supply, the amount of use can be suppressed.

  In addition, the gas combustion mechanism includes a hole heating burner that heats an opening peripheral portion of the slag discharge hole in the discharge tank, and the gas combustion mechanism sets an injection amount of oxygen gas from the hole heating burner during normal operation. The coal gasification gas may be burned by blowing the oxygen gas onto the coal gasification gas.

In this case, since the hole heating burner is provided in the discharge tank, the peripheral edge of the slag discharge hole in the discharge tank can be heated by the hole heating burner during normal operation. Thereby, generation | occurrence | production itself of slag deposits can be suppressed.
Further, since the coal gasification gas can be drawn into the discharge tank and flowed in a large amount by the drawing mechanism, the oxygen gas injected from the hole heating burner at the opening peripheral edge of the slag discharge hole in the discharge tank is converted into the coal gasification gas. The coal gasification gas can be surely combusted.

  Moreover, you may provide the control mechanism in which the said coal gasification gas is drawn in to the said drawing mechanism based on the obstruction | occlusion state of the said slag discharge hole by the slag deposit | attachment adhering to the said slag discharge hole periphery.

  In this case, since the control mechanism causes the drawing mechanism to draw the coal gasification gas based on the blockage of the slag discharge hole due to slag deposits, for example, before the slag discharge hole is completely blocked, The gas can be drawn in. Therefore, it is possible to reliably prevent the slag discharge hole from being blocked by the slag deposit.

  According to the present invention, it is possible to effectively remove slag deposits around the slag discharge hole and prevent the slag discharge hole from being blocked.

It is a block diagram of a coal gasification system provided with a coal gasification reaction furnace concerning one embodiment of the present invention. It is a schematic sectional drawing of the coal gasification reaction furnace concerning one embodiment of the present invention.

(Coal gasification system)
Hereinafter, with reference to drawings, a coal gasification system provided with a coal gasification reaction furnace (coal gasification device) concerning one embodiment of the present invention is explained.
As shown in FIG. 1, the coal gasification system 1 produces | generates coal gasification gas which has hydrogen gas and carbon monoxide gas as a main component from coal as a raw material, and finally methane and methanol from this coal gasification gas And plant equipment for producing products such as ammonia.

  The coal gasification system 1 includes a coal pulverization / drying facility 2, a coal supply facility 3, a coal gasification reaction furnace 4, a heat recovery facility 5, a char recovery facility 6, a shift reaction facility 7, and a gas purification facility. 8, a chemical synthesis facility 9, and an air separation facility 10.

  In general, the outer diameter of coal is not uniform, and depending on the type, coal may contain more water than desired. Therefore, first, in the coal pulverization / drying facility 2, the coal is pulverized so as to become, for example, pulverized coal having an average particle diameter of about 30 to 60 (μm), and further dried to have a predetermined water content. , Supplied to the coal supply facility 3. In addition, from the coal pulverization / drying facility 2 to the coal gasification reactor 4, the coal moves in a sealed space so that the moisture content in the dried coal does not change.

Subsequently, in order to supply the coal into the coal gasification reaction furnace 4, the coal is pressurized to a predetermined pressure with a carrier gas or the like in the coal supply facility 3, and then conveyed (airflow conveyance) to the coal gasification reaction furnace 4. The
On the other hand, the air separation facility 10 compresses and liquefies air, and separates dried oxygen gas, nitrogen gas, and the like from the liquid air due to a difference in boiling point. The oxygen gas separated by the air separation facility 10 is supplied to the coal gasification reactor 4.

  The coal gasification reactor 4 is composed of hydrogen gas and carbon monoxide gas as main components by thermally decomposing the coal conveyed from the coal supply facility 3 using oxygen supplied from the air separation facility 10. High temperature coal gasification gas or char (ungasified coal residue or pyrolysis residue) is generated. These coal gasification gas and char are supplied from the coal gasification reactor 4 to the heat recovery facility 5.

In the heat recovery facility 5, the coal gasification gas and char conveyed from the coal gasification reactor 4 are cooled by exchanging heat with the steam and the temperature of the steam is increased. The water vapor is supplied to the above-described coal pulverization / drying facility 2 or the like for the purpose of drying the coal.
The coal gasification gas and char cooled by the heat recovery facility 5 are supplied from the heat recovery facility 5 to the char recovery facility 6, and the char is recovered by the char recovery facility 6.

  The coal gasification gas that has passed through the char recovery facility 6 is supplied to the shift reaction facility 7. And in order to raise the ratio of the hydrogen gas with respect to the carbon monoxide gas in coal gasification gas to a fixed value, water vapor | steam is supplied in the shift reaction equipment 7, and shift reaction shown by following chemical reaction formula (1) As a result, carbon monoxide gas is consumed and hydrogen gas is generated instead.

CO + H ₂ O → CO ₂ + H ₂ (1)

The coal gasification gas whose components have been adjusted in the shift reaction facility 7 is supplied to the gas purification facility 8, and carbon dioxide gas contained in the coal gasification gas, gas containing sulfur as a component, and the like are recovered.
The coal gasification gas refined in the gas purification facility 8 is supplied to the chemical synthesis facility 9 to produce products such as methane and methanol.

(Coal gasification reactor)
Next, details of the coal gasification reactor 4 according to an embodiment of the present invention will be described.
As shown in FIG. 2, the coal gasification reaction furnace 4 includes a reaction furnace main body 11 in which a coal combustion reaction occurs to generate coal gasification gas and slag (ash) 25, and the reaction furnace main body 11. And a discharge tank 13 through which the slag 25 is discharged from the reactor main body 11 through the slag discharge hole 12.

The reactor main body 11 includes an upstream partial oxidation unit 14 and a downstream thermal decomposition unit 15.
The partial oxidation unit 14 gasifies the gasified coal 16 introduced into the interior using the oxygen-containing gas 17 as an oxidizing agent (gasifying agent), and mainly uses carbon monoxide gas, carbon dioxide gas, hydrogen gas, and water vapor. The gasification gas 18 comprised is produced | generated. Here, in the partial oxidation part 14, since it is necessary to melt and discharge the ash contained in the gasified coal 16 as described later, the temperature in the partial oxidation part 14 needs to be equal to or higher than the melting point of the ash. Therefore, the gasification gas 18 introduced from the partial oxidation unit 14 to the thermal decomposition unit 15 is also at a high temperature in the partial oxidation unit 14, and the reformed coal 19 is introduced into the gasification gas 18 in the thermal decomposition unit 15. By doing so, the reformed coal 19 is heated to cause a thermal decomposition reaction, and a product 20 containing a coal gasification gas can be obtained. This product 20 is supplied to the heat recovery facility 5 through a furnace outlet 21 provided in the thermal decomposition unit 15.

  Such a reactor main body 11 is a two-stage upper and lower two-stage system in which the partial oxidation unit 14 is provided in the lower stage and the thermal decomposition unit 15 is provided in the upper stage. The reactor main body 11 has a so-called throat structure in which the partial oxidation unit 14 and the thermal decomposition unit 15 are connected through a throat 22 having a small diameter. Thus, by having two chambers and two stages, the part for gasification of coal (partial oxidation part 14) and the part for thermal decomposition (pyrolysis part 15) can be completely separated. It is possible to freely set the operating conditions. That is, in the reactor main body 11, by restricting the gas flow path (throat 22) to partially increase the flow velocity, the coal particles (modified) introduced into the upper chamber (thermal decomposition unit 15) are modified. The quality coal 19) and the like are prevented from falling into the lower chamber (partial oxidation unit 14), and independent reaction conditions can be set in each chamber. In addition, the partial oxidation part 14, the thermal decomposition part 15, and the throat 22 have a cylindrical structure with a circular horizontal cross section.

  The partial oxidation unit 14 includes gasified coal 16 and an oxygen-containing gas 17 (for example, oxygen gas, oxygen gas, and water vapor) that is an oxidizing agent for partial oxidation (partial combustion, combustion reaction) of the gasified coal 16. ) Is installed, one or a plurality of gasification burners 23 are installed. The gasified coal 16 and the oxygen-containing gas 17 are blown into the partial oxidation unit 14 by the gasification burner 23 and rapidly mixed. The gasified coal 16 supplied from the gasification burner 23 into the partial oxidation unit 14 is pulverized and dried in the coal pulverization / drying facility 2, and the oxygen gas in the oxygen-containing gas 17 is air. The water vapor is separated by the separation equipment 10, and the water vapor is supplied from the heat recovery equipment 5.

In partial oxidation unit 14, the carbon and hydrogen components in the hydrocarbon contained in the gasification of coal 16 to be introduced, (increasing the gasification conversion) as much CO, is converted into H ₂ is preferable. For this purpose, it is necessary to quickly mix the gasified coal 16 and the oxygen-containing gas 17 so that the volatile matter generated from the gasified coal 16 reacts with the oxygen-containing gas 17 before soot. Therefore, for example, it is preferable to use a double pipe structure or the like as the gasification burner 23 and to introduce the gasified coal 16 and the oxygen-containing gas 17 from the same position.

In addition, when injecting the oxygen-containing gas 17 without using a double tube structure, it is preferable to blow into a portion having a high coal particle concentration in the partial oxidation portion 14. Therefore, it is preferable that the injection nozzle for the oxygen-containing gas 17 is positioned at the same height as the injection nozzle for the gasified coal 16, and the oxygen-containing gas 17 and the gasified coal 16 are input at the same level. Thereby, even if it separates a coal inlet and an oxygen containing gas inlet, it can suppress that the gasification conversion rate of the gasification coal 16 falls.
Moreover, as an airflow carrier gas of the gasified coal 16, a non-oxidizing gas, for example, a nitrogen gas or a gas generated from a process can be used, but is not limited thereto.

The operating pressure and temperature in the partial oxidation unit 14 are maintained at 0.1 to 20 MPa and 1300 to 1700 ° C., for example. The pressure is adjusted according to the pressure on the pyrolysis unit 15 side, and the temperature is maintained by partial oxidation of the gasified coal 16 in the partial oxidation unit 14.
As described above, the gasification gas 18 generated in the partial oxidation unit 14 passes through the throat 22 and is sent to the thermal decomposition unit 15.

  The pyrolysis unit 15 is provided with a coal supply nozzle 24 for supplying the modified coal 19 pulverized and dried in the coal pulverization / drying facility 2 inside the pyrolysis unit 15. In this pyrolysis section 15, a pyrolysis reaction of the reformed coal 19 introduced from the coal supply nozzle 24 occurs, and by this pyrolysis reaction, a coal gasification gas, char, tar, etc. from the reformed coal 19 as a product 20. Produces. Coal gasification gas can be used as fuel or chemical raw material, char as solid fuel, and tar as chemical raw material or fuel. Although it is possible to produce the product 20 by the pyrolysis reaction even when the reformed coal 19 is used alone to be put into the pyrolysis section 15, in addition to the reformed coal 19, hydrogen gas, water vapor, oxygen gas It is possible to change the properties and amount of coal gasification gas and tar produced by simultaneously adding one or more kinds.

The operating pressure and temperature in the thermal decomposition part 15 are maintained at 0.1-20 MPa and 500-1200 degreeC, for example. Since the thermal decomposition part 15 and the partial oxidation part 14 are connected up and down via the throat 22, they are operated at substantially the same pressure.
When the operating pressure is too low, it is necessary to increase the volume in order to secure the gas residence time in the partial oxidation unit 14, and as a result, the surface area of the inner surface of the partial oxidation unit 14 increases and the amount of heat dissipated increases. Since it increases, it is not preferable, and if it is too high, the equipment manufacturing cost becomes high. Therefore, it is preferable to set the operation pressure at about 1 to 3 MPa in accordance with the use of the coal gasification gas. Moreover, in operation on the high pressure side, gasification and hydrogenation can be advanced by introducing steam into the pyrolysis section 15 together with the reformed coal 19.

Regarding the temperature in the pyrolysis section 15, when the recovered product to be recovered is mainly coal gasification gas and tar among the products 20, a relatively low temperature condition of 500 to 800 ° C. is preferable. Is mainly a coal gasification gas, a relatively high temperature condition of 800 to 1200 ° C. is preferred.
Further, when the recovered material is mainly coal gasification gas, a reforming aid such as steam or hydrogen is added to the thermal decomposition unit 15, or a reforming aid such as steam is added to the partial oxidation unit 14. It is preferable to promote the gasification reaction in the thermal decomposition unit 15.
Further, it is preferable that the char generated in the thermal decomposition unit 15 is supplied as a fuel together with the gasified coal 16 as a fuel for the partial oxidation unit 14 and recycled.

Here, in the partial oxidation unit 14, the ash contained in the gasified coal 16 becomes a slag 25 in a molten state due to a high temperature due to partial oxidation of the gasified coal 16 in the partial oxidation unit 14, and is discharged through the slag discharge hole 12. 13 is discharged.
The discharge tank 13 is disposed below the reaction furnace body 11, and cooling water (cooling liquid) 26 for cooling the slag 25 discharged from the reaction furnace body 11 is stored in the discharge tank 13. The molten slag 25 discharged from the reactor main body 11 through the slag discharge hole 12 to the discharge tank 13 falls from the lower end of the inner peripheral surface 12a of the slag discharge hole 12, collides with the liquid surface of the cooling water 26 and is cooled. Cooled by water 26. Thereby, the slag 25 is solidified in a state of being pulverized in the cooling water 26 in a granular form.

  In this embodiment, the discharge tank 13 discharges coal gasification gas from the reactor main body 11 through the slag discharge hole 12 and the disposal mechanism 27 that discards the slag 25 in the cooling water 26 to the outside of the discharge tank 13. A drawing mechanism 28 that draws into the tank 13, a gas combustion mechanism 29 that burns the coal gasification gas drawn into the discharge tank 13, and a coal gasification gas to the drawing mechanism 28 based on the blockage of the slag discharge holes 12. And a control mechanism 30 to be pulled in.

  The disposal mechanism 27 extends downward from the discharge tank 13 and discharges the slag 25 in the cooling water 26 to the outside together with the cooling water 26, and is disposed below the discharge tank 13 and flows out of the disposal path 31. A lock hopper that is provided between the discharge tank 13 and the storage tank 32 in the disposal path 31 and filters the slag 25 in the cooling water 26 that flows through the disposal path 31. 33, and a valve 34 provided between the discharge tank 13 and the lock hopper 33 and between the lock hopper 33 and the storage tank 32 in the disposal path 31.

The drawing mechanism 28 includes a liquid level lowering means 35 for lowering the liquid level of the cooling water 26 in the discharge tank 13 and a liquid level raising means 36 for raising the liquid level of the cooling water 26 in the discharge tank 13. Yes.
The liquid level lowering unit 35 lowers the liquid level of the cooling water 26 by causing the cooling water 26 to flow out of the discharge tank 13. The liquid level lowering means 35 is provided in the outflow path 37, and the outflow path 37 extending downward from the discharge tank 13 and communicating between the discharge tank 13 and the storage tank 32. And a liquid level control valve 38.

The liquid level raising means 36 raises the liquid level of the cooling water 26 by causing the cooling water 26 to flow into the discharge tank 13. The liquid level raising means 36 includes the storage tank 32, an inflow path 39 that connects the storage tank 32 and the discharge tank 13, and cooling water 26 that is provided in the inflow path 39 and stored in the storage tank 32. And a flow rate adjusting valve 41 that is provided between the transfer pump 40 and the discharge tank 13 in the inflow path 39 and adjusts the flow rate of the cooling water 26 that flows through the inflow path 39.
In addition, the liquid level position (liquid level) of the cooling water 26 in the discharge tank 13 can be detected by a level meter 42 provided in the discharge tank 13.

  The gas combustion mechanism 29 includes a hole heating burner 43 that heats the opening peripheral edge portion 12 b of the slag discharge hole 12 in the discharge tank 13. The hole heating burner 43 mixes fuel gas (for example, methane gas) and oxygen gas, and injects it toward the opening peripheral part 12 b of the slag discharge hole 12 in the discharge tank 13. The injection amounts of the fuel gas and oxygen gas injected from the hole heating burner 43 can be adjusted.

  The control mechanism 30 is configured to block the slag discharge hole 12 due to slag deposits attached to the periphery of the slag discharge hole 12 (the inner peripheral surface 12a of the slag discharge hole 12 or the opening peripheral edge 12b of the slag discharge hole 12 in the discharge tank 13). Is detected. The control mechanism 30 sends a monitoring camera 44 for monitoring the slag discharge hole 12 from the discharge tank 13 side, and a monitoring result is sent out as monitoring data from the monitoring camera 44. Based on this monitoring data, the control state of the slag discharge hole 12 is determined. And a detection / control unit 45 for detection.

  The detection / control unit 45 detects the blockage of the slag discharge hole 12 by, for example, processing the monitoring data. The detection / control unit 45 opens and closes the liquid level control valve 38 of the liquid level lowering means 35 based on the detected blockage of the slag discharge hole 12. Further, the detection / control unit 45 is capable of sending the liquid level position data from the level meter 42 and controlling the flow rate adjusting valve 41 of the liquid level raising means 36.

(Slag removal method in coal gasification reactor)
Next, the slag removal method (slag removal method in the coal gasification apparatus) in the coal gasification reactor configured as described above will be described.

  Here, in the coal gasification reactor 4, as described above, the opening peripheral portion 12b of the slag discharge hole 12 in the discharge tank 13 is heated by the hole during the normal operation of producing the coal gasification gas in the coal gasification reactor 4. While performing the hole heating process heated with the burner 43, the disposal mechanism 27 is operated and the disposal process which discards the slag 25 in the cooling water 26 to the exterior of the discharge tank 13 is performed.

In the hole heating step, for example, the ejection amounts of fuel gas and oxygen gas from the hole heating burner 43 are determined in advance according to the temperature in the discharge tank 13 detected by a temperature detection mechanism (not shown).
In this way, the hole heating process is performed during the normal operation of the coal gasification reactor 4, and the slag discharge hole 12 in the discharge tank 13 is heated by the hole heating burner 43, thereby generating the slag deposit itself. Can be suppressed.

The discarding process is performed at regular intervals, for example. Thereby, the slag accumulated in the cooling water 26 is periodically discharged to the outside.
In this disposal step, first, water is supplied into the lock hopper 33 by a water supply means (not shown) provided in the lock hopper 33, and the lock hopper 33 is filled with water. Then, both valves 34 provided in the disposal path 31 are adjusted, and the slag 25 in the cooling water 26 in the discharge tank 13 is circulated through the disposal path 31 together with the cooling water 26. As described above, after the lock hopper 33 is filled with water, the slag in the discharge tank 13 is discharged, so that the change of the liquid surface position of the cooling water 26 in the discharge tank 13 can be suppressed.

  Moreover, the detection process which detects the obstruction | occlusion state of the slag discharge hole 12 with the control mechanism 30 is performed with these hole heating processes and disposal processes. Then, based on the detection result of the detection step, for example, when it is determined that the discharge of the slag 25 from the reactor main body 11 through the slag discharge hole 12 may be hindered, the coal gasification reaction according to the present invention is performed. Implement the slag removal method in the furnace.

  In this method, first, the disposal step is performed. Thereby, the slag 25 in the discharge tank 13 is discarded by the lock hopper 33, and the slag 25 is prevented from flowing through the outflow passage 37 of the liquid level lowering means 35 in the liquid level lowering step described later.

Next, a drawing-in process of drawing the coal gasification gas into the discharge tank 13 from the reaction furnace main body 11 through the slag discharge hole 12 is performed.
In this drawing-in step, first, the detection / control unit 45 of the control mechanism 30 opens the liquid level control valve 38 of the liquid level lowering means 35, so that the cooling water 26 in the discharge tank 13 is discharged to the outflow path 37. Then, a liquid level lowering process is performed in which the liquid level of the cooling water 26 in the discharge tank 13 is lowered by flowing out into the storage tank 32. By lowering the liquid level of the cooling water 26 in the discharge tank 13 in this way, the inside of the discharge tank 13 can be set to a negative pressure, and the inside of the discharge tank 13 is passed from the reactor main body 11 through the slag discharge hole 12. Coal gasification gas can be drawn into. Note that the coal gasification gas drawn in this way is mainly composed of high-temperature combustible gas (for example, hydrocarbon gas) generated by partial oxidation in the partial oxidation section 14 of the reactor main body 11. .

Here, the inner diameter of the upper end portion of the discharge tank 13 is gradually increased from the upper side to the lower side, and the portion of the discharge tank 13 located below the upper end part is a straight line extending in the vertical direction. In the liquid level lowering step, the liquid level of the cooling water 26 is lowered to such an extent that the coal gasification gas generated in the reactor main body 11 is drawn into the upper end of the discharge tank 13. Thus, the inside of the discharge tank 13 is made a negative pressure. At this time, the coal gasification gas, for example, 2 Nm ³ or more 10 Nm ³ or less, it is preferable to draw at once in about 60 seconds from 30 seconds.
Thereby, the temperature of the upper part in the discharge tank 13 rises to about 1100 ° C., for example, from about 800 ° C.

  When the lowering of the liquid level of the cooling water 26 in the discharge tank 13 is completed, the detection / control unit 45 of the control mechanism 30 adjusts the liquid level control valve 38 to cool the cooling water 26 from the outflow passage 37. By restricting the outflow of the water 26, the liquid level lowering step is completed.

  Thereafter, the detection / control unit 45 of the control mechanism 30 adjusts the flow rate adjustment valve 41 of the liquid level raising means 36 to cause the cooling water 26 in the storage tank 32 to flow into the discharge tank 13 through the inflow path 39 and be discharged. A liquid level raising step for raising the liquid level of the cooling water 26 in the tank 13 is performed. Thereby, it becomes possible to restore the liquid level position of the cooling water 26 in the discharge tank 13 lowered in the liquid level lowering process, for example, to the position before the liquid level lowering process, and the liquid level position is within a predetermined height range. Can be secured.

And a drawing-in process repeats these liquid level fall processes and liquid level rise processes alternately. As a result, the coal gasification gas in the reactor main body 11 can be drawn into the discharge tank 13 while ensuring the liquid level position of the cooling water 26 in the discharge tank 13 within a predetermined height range.
Thereafter, for example, by alternately repeating the liquid level lowering step and the liquid level rising step, the clogging state of the slag discharge hole 12 due to slag deposits is improved, or the liquid level lowering step and the liquid level rising step are set in advance. The drawing-in process ends when the predetermined number of times is repeated.

  Moreover, in this embodiment, the gas combustion process which burns the coal gasification gas which flowed in in the discharge tank 13 is performed with the said drawing-in process. At this time, in this embodiment, the injection amount of the oxygen gas from the hole heating burner 43 is increased, and the combustible gas in the coal gasification gas is burned by blowing the oxygen gas onto the coal gasification gas.

  As described above, according to the slag removal method in the coal gasification reactor and the coal gasification reactor 4 according to the present embodiment, the coal gasification is performed from the inside of the reactor main body 11 through the slag discharge hole 12 during the drawing process. Since the gas is drawn into the discharge tank 13, a large amount of high-temperature coal gasification gas generated in the reactor main body 11 can be allowed to flow into the discharge tank 13, and slag deposits are generated by this coal gasification gas. Can be heated. Therefore, it becomes possible to remove slag deposits effectively, suppress the clogging of the slag discharge holes 12 by the slag deposits, and smoothly discharge the slag 25 from the reactor main body 11 to the discharge tank 13. Can do.

  Moreover, since a drawing-in process is performed based on the obstruction | occlusion state of the slag discharge hole 12 by a slag deposit, for example, before the slag discharge hole 12 is obstruct | occluded completely, a drawing-in process can be performed reliably. Therefore, it is possible to reliably prevent the slag discharge hole 12 from being blocked by the slag deposit.

In addition, since the liquid level lowering step and the liquid level rising step are alternately repeated, the coal gasification gas can be repeatedly drawn into the discharge tank 13 from the reactor main body 11 through the slag discharge hole 12, and the slag deposits Can be removed more effectively.
In addition, since the liquid level lowering process and the liquid level rising process are alternately repeated instead of continuously performing the liquid level lowering process, the liquid level position of the cooling water 26 in the discharge tank 13 is set within a predetermined height range. Thus, the slag 25 discharged from the reactor main body 11 to the discharge tank 13 can be effectively cooled by the cooling water 26.

Moreover, a slag deposit can be heated by burning the coal gasification gas drawn in in the discharge tank 13 at the time of a gas combustion process. Therefore, in combination with heating the slag deposit by drawing the coal gasification gas into the discharge tank 13 through the slag discharge hole 12, the slag deposit can be further effectively removed.
Further, since the slag deposit can be heated by burning the coal gasification gas, it is not necessary to separately supply the fuel gas from the gas combustion mechanism 29 into the discharge tank 13 in order to heat the slag deposit. Even if it is a case where it supplies, the usage-amount can be restrained.

  Moreover, since the coal gasification gas burned at the time of the gas combustion process flows in a large amount by being drawn into the discharge tank 13, the hole heating burner 43 is formed at the opening peripheral edge 12 b of the slag discharge hole 12 in the discharge tank 13. It is possible to reliably blow the oxygen gas injected from the coal gasification gas toward the coal gasification gas and reliably burn the coal gasification gas.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the embodiment, the hole heating burner 43 is provided in the discharge tank 13, but the hole heating burner 43 may not be provided. In this case, you may employ | adopt the spray nozzle which blows oxygen gas to the coal gasification gas drawn in in the discharge tank 13 as a gas combustion mechanism.
Further, the gas combustion mechanism 29 may not be provided.

Moreover, in the said embodiment, based on the monitoring data from the monitoring camera 44 of the control mechanism 30, the detection / control part 45 shall detect the obstruction | occlusion state of the slag discharge hole 12 by a slag deposit, but it is restricted to this. It is not a thing. For example, the closed state of the slag discharge hole 12 may be detected by measuring the differential pressure between the upper end portion and the lower end portion of the slag discharge hole 12.
Furthermore, in the said embodiment, although the drawing-in process shall be performed based on the obstruction | occlusion state of the slag discharge hole 12 by a slag deposit | attachment, it is not restricted to this. For example, it is good also as what performs a drawing-in process regularly for every predetermined time decided beforehand.

Moreover, in the said embodiment, although the drawing-in process shall repeat a liquid level fall process and a liquid level rise process alternately, it is not restricted to this.
Furthermore, in the said embodiment, although the liquid level of the cooling water 26 in the discharge tank 13 was dropped by making the cooling water 26 in the discharge tank 13 flow out to the storage tank 32, it is not restricted to this.
Furthermore, in the above-described embodiment, the coal gasification gas in the reactor main body 11 is drawn into the discharge tank 13 by lowering the liquid level of the cooling water 26 in the discharge tank 13. It is not something that can be done.

  Moreover, in the said embodiment, although the reaction furnace main body 11 shall be the upper-and-lower two-chamber two-stage type which has the partial oxidation part 14 and the thermal decomposition part 15, it is not restricted to this, Inside of coal The present invention can be applied to any coal gasification apparatus including a reaction furnace main body in which a combustion reaction occurs and coal gasification gas and slag are generated.

  In addition, it is possible to appropriately replace the constituent elements in the embodiment with known constituent elements without departing from the spirit of the present invention, and the above-described modified examples may be appropriately combined.

Next, the verification test about the effect demonstrated above was implemented.
In this verification test, the slag removal method in the coal gasifier of a total of 3 examples, Example 1, 2 and a comparative example, was implemented.
Here, in Examples 1 and 2 and the comparative example, the coal gasification reactor 4 of the above embodiment was used. Further, gasified coal 16 was charged at 500 kg / h, oxygen gas at 280 Nm ³ / h, and water vapor at 50 kg / h from the gasification burner 23 into the partial oxidation unit 14. Further, the hole heating burners 43, a methane gas as the fuel gas 10 Nm ³ / h, and an oxygen gas were respectively injected at 25 Nm ³ / h.
At this time, it was confirmed by the monitoring camera 44 that the slag 25 was discharged from the slag discharge hole 12 at 20 kg / h and gradually started to adhere to and grow around the slag discharge hole 12.

(About Examples 1 and 2)
Therefore, in the first embodiment, the liquid level of the cooling water 26 in the discharge tank 13 is lowered by 30 mm in 30 seconds (that is, lowered at 1 mm / sec), then the liquid level is raised, and the liquid level is lowered and raised three times. , Repeated. In Example 2, the level of the cooling water 26 in the discharge tank 13 is lowered by 30 mm in 30 seconds (that is, lowered at 1 mm / sec), and the injection amount of oxygen gas in the hole heating burner 43 is set to 30 Nm ³ / h. Increased.
In each of Examples 1 and 2 and the comparative example, the state of the subsequent slag deposit was observed with the monitoring camera 44.

As a result, in Examples 1 and 2, it was confirmed that the slag deposit was melted and removed.
In Example 1, it was confirmed that the temperature measured by the thermocouple installed at the upper end of the straight body portion of the discharge tank 13 rose from 800 ° C. to 1200 ° C. before and after repeated lowering and raising of the liquid level. It was done. Further, in Example 2, it was confirmed that the temperature measured by the thermocouple rose from 800 ° C. to 1250 ° C. before and after increasing the oxygen gas injection amount of the hole heating burner 43 while lowering the liquid level. It was.

(Comparative example)
On the other hand, in the comparative example, after the slag was confirmed to adhere to the periphery of the slag discharge hole 12 by operating under the conditions described above, the oxygen gas in the hole heating burner 43 was not changed without changing the liquid level of the cooling water 26 in the discharge tank 13. Was increased to 30 Nm ³ / h, it was confirmed that the temperature at the top of the discharge tank 13 hardly changed, and no change was observed in the slag deposits attached to the slag discharge holes 12. This is presumably because the coal gasification gas was not drawn and the combustion reaction was not promoted because the liquid level was not changed.

4 Coal gasification reactor (coal gasifier)
DESCRIPTION OF SYMBOLS 11 Reaction furnace main body 12 Slag discharge hole 12b Opening peripheral part 13 Discharge tank 16, 19 Coal 25 Slag 26 Cooling water (cooling liquid)
28 Pull-in mechanism 29 Gas combustion mechanism 30 Control mechanism 35 Liquid level lowering means 36 Liquid level rising means 43 Hole heating burner

Claims (12)

A reaction furnace main body in which a combustion reaction of coal occurs and coal gasification gas containing at least hydrogen gas and carbon monoxide gas and slag are generated;
A slag removal method in a coal gasifier comprising: a reaction tank main body and a slag discharge hole, and a discharge tank in which the slag is discharged from the reaction furnace main body through the slag discharge hole,
Coal gas characterized by having a drawing step of drawing the coal gasification gas into the discharge tank from the reactor main body through the slag discharge hole, and removing slag deposits attached around the slag discharge hole For removing slag in the gasification apparatus. A cooling liquid for cooling the slag discharged from the reactor main body is stored in the discharge tank,
The method for removing slag in a coal gasifier according to claim 1, wherein the drawing-in step includes a liquid level lowering step of lowering the liquid level of the cooling liquid in the discharge tank.   The drawing step includes a liquid level raising step for raising the liquid level of the cooling liquid in the discharge tank after the liquid level lowering step, and alternately performing the liquid level lowering step and the liquid level rising step. It repeats, The slag removal method in the coal gasifier of Claim 2 characterized by the above-mentioned.   The method for removing slag in a coal gasifier according to any one of claims 1 to 3, further comprising a gas combustion step of burning the coal gasification gas drawn into the discharge tank. . The coal gasifier further includes a hole heating burner for heating an opening peripheral edge of the slag discharge hole in the discharge tank,
In the gas combustion step, the injection amount of oxygen gas from the hole heating burner is increased as compared with that during normal operation, and the coal gasification gas is burned by blowing the oxygen gas to the coal gasification gas. The slag removal method in the coal gasifier of Claim 4.   The slag removal method in a coal gasifier according to any one of claims 1 to 5, wherein the drawing-in step is performed based on a state of blockage of the slag discharge hole by the slag deposit. A reaction furnace main body in which a combustion reaction of coal occurs and coal gasification gas containing at least hydrogen gas and carbon monoxide gas and slag are generated;
A coal gasifier comprising: a reaction tank main body and a slag discharge hole, and a discharge tank in which the slag is discharged from the reaction furnace main body through the slag discharge hole;
A coal gasification apparatus comprising a drawing-in mechanism for drawing the coal gasification gas into the discharge tank from the reaction furnace main body through the slag discharge hole. A cooling liquid for cooling the slag discharged from the reactor main body is stored in the discharge tank,
The coal gasifier according to claim 7, wherein the drawing-in mechanism includes a liquid level lowering unit that lowers the liquid level of the cooling liquid in the discharge tank.   The coal gasifier according to claim 8, wherein the drawing-in mechanism includes a liquid level raising unit that raises a level of the cooling liquid in the discharge tank.   The coal gas according to any one of claims 7 to 9, wherein the exhaust tank is provided with a gas combustion mechanism for combusting the coal gasification gas drawn into the exhaust tank. Device. The gas combustion mechanism includes a hole heating burner that heats an opening peripheral edge of the slag discharge hole in the discharge tank,
The gas combustion mechanism increases the injection amount of oxygen gas from the hole heating burner than during normal operation, and burns the coal gasification gas by blowing the oxygen gas to the coal gasification gas. The coal gasifier according to claim 10.   8. A control mechanism for drawing the coal gasification gas into the drawing mechanism based on the blockage of the slag discharging hole due to slag deposits attached around the slag discharging hole is provided. 11. The coal gasifier according to any one of 11 above.

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