JP2003042417A - Gasifying furnace system, gasifying/melting furnace system, and method for interruption of its operation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gasifying furnace apparatus, and a method of interruption of its operation wherein in a gasifying apparatus including a combustible substance supply apparatus and a fluidized bed gasifying furnace, a fluid medium in a fluidized bed is prevented from being locally heated to high temperature and from producing clinker owing to combustion of non-combusted carbon component such as char remaining in the fluidized bed upon the interruption of the operation. SOLUTION: In a gasifying furnace apparatus wherein it includes a combustible substance supply apparatus 12 and a fluidized bed gasifying furnace 10, and a combustible substance 15 is thrown into a fluidized bed in the fluidized bed gasifying furnace 10 from the combustible substance supply apparatus 12 to gasifying the combustible substance 15, there is provided a control apparatus 21 having at least one or more of a function where the amount of the combustible substance 15 thrown into a fluidized bed 11 is reduced upon the stoppage of the operation continuously or stepwise gradually after the elapse of a predetermined time, a function where the supply of the combustible substance 15 is stopped, and water is poured into the fluidized bed 11, and a function where the supply of the combustible substance 15 is stopped, and oxygen concentration of fluid gas 16 for fluidizing a fluid medium in the fluidized bed 11 is reduced.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a combustible product gas obtained by gasifying combustible substances such as municipal solid waste, industrial waste, biomass waste, medical waste, automobile waste such as waste tires or shredder dust. The present invention relates to a gasification furnace apparatus equipped with a fluidized bed gasification furnace, a gasification melting furnace apparatus, and a method for stopping the operation thereof.

[0002]

2. Description of the Related Art In recent years, for the treatment of municipal solid waste, industrial waste, biomass waste, medical waste, automobile waste such as waste tires or shredder dust, etc., these wastes are fluidized bed gasification. The gasified gas in the fluidized bed of the furnace is gasified, the gasified product gas is burned at a high temperature in a melting furnace, and unburned carbon components such as char contained in the product gas are burned and contained in the product gas. There is a gasification and melting facility that melts the ash generated and melts it into slag.

In such a gasification and melting facility, the fluidized bed gasification furnace gasifies combustible components (mainly volatile components) such as waste supplied from the waste supply device in a reducing atmosphere of the fluidized bed. In a fluidized bed gasification furnace, heat is used to dry the water content of the combustible material that has been input, and part of the combustible material burns to generate heat, while the combustible material is thermally decomposed (endothermic) Heat is used to transform. That is, the operating state of the fluidized bed gasification furnace is established on the balance of these heats.

Further, when comparing the fluidized bed gasification furnace and the fluidized bed incinerator with respect to the state of the fluidized bed, in the fluidized bed incinerator, all the combustible substances to be charged are burned, so that unburned carbon is contained in the fluidized bed. In contrast to the remaining amount, the fluidized bed gasification furnace heats the fluidized medium with the heat generated by burning a part of it.
Since the rest is pyrolyzed, gasified and not burned, a large amount of unburned carbon such as char exists inside the fluidized bed.

In the above fluidized bed gasification furnace, when the supply of combustibles such as waste is suddenly stopped when the operation is stopped, no new combustibles are supplied, so that the combustibles are reduced and The drying of the moisture in the combustible material that consumed the generated heat and the gasification reaction disappear. However,
The amount of oxygen in the fluidized gas is relatively large with respect to the unburned carbon components such as char that remain in the fluidized medium of the fluidized bed. That is, the oxygen-deficient reduced state is changed to the oxidizing atmosphere state in which oxygen necessary for combustion exists.

The unburned carbon components such as char burn in the fluidized medium of the fluidized bed, the heat balance established during operation is lost, and the inside of the fluidized bed is locally heated to a high temperature, Clinker, that is, fusion of fluid medium (mainly silica sand) occurs. When this clinker is generated in large numbers, fluidization of the fluidized medium is obstructed, which hinders restarting of the gasifier apparatus, and in the worst case, there is a problem that restarting is not possible.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned points, and in a gasification furnace apparatus equipped with a combustible material supply device and a fluidized bed gasification furnace, it remains in the fluidized bed when the operation is stopped. Combustion of unburned carbon components, such as char, locally heats the fluidized medium in the fluidized bed to a high temperature, and a gasification furnace device, a gasification melting furnace device and a method of shutting down the clinker that do not generate clinker are provided. The purpose is to provide.

[0008]

In order to solve the above-mentioned problems, the invention according to claim 1 is provided with a combustible substance supply device and a fluidized bed gasification furnace, and from the combustible substance supply device to the inside of the fluidized bed gasification furnace. In a gasification furnace apparatus that puts a combustible material into the fluidized bed and gasifies the combustible material, when the operation is stopped, the amount of the combustible material charged into the fluidized bed is gradually reduced continuously or stepwise after a predetermined time. At least one or more of a function, a function of stopping the supply of a combustible material and injecting water into the fluidized bed, and a function of stopping the supply of a combustible material and reducing the oxygen concentration of the fluidizing gas that fluidizes the fluidized medium of the fluidized bed It is characterized in that a control means including is provided.

By providing the control means having the above-mentioned function, the amount of combustible substances is gradually or continuously reduced after a predetermined time when the operation is stopped, water is injected into the fluidized bed, and the oxygen concentration of the fluidized gas is reduced. Since either of them can be carried out, the combustion of unburned carbon components such as char remaining in the fluidized medium of the fluidized bed can be prevented, and the occurrence of clinker can be prevented.

The invention according to claim 2 is provided with a combustible material supply device and a fluidized bed gasification furnace, and the combustible material is introduced into the fluidized bed in the fluidized bed gasification furnace from the combustible material supply device to produce the combustible material. A method of shutting down a gasification furnace apparatus for gasifying a substance, wherein when the operation is stopped, the amount of combustible material to be fed from the combustible material supply device to the fluidized bed in the fluidized bed gasification furnace is gradually and continuously maintained for a predetermined time. Alternatively, it is characterized by stopping while gradually decreasing.

As described above, when the operation is stopped, the amount of the combustible material to be put into the fluidized bed is gradually or continuously reduced over a predetermined time, so that the heat of vaporization of water and the heat of absorption by gasification are maintained to some extent. It will reduce the supply of combustibles. For this reason, unburned carbon components such as char in the fluidized bed are gradually reduced, and the supply of combustibles is stopped when the amount of unburned carbon components is reduced, so that clinker does not occur.

The invention according to claim 3 is provided with a combustible material supply device and a fluidized bed gasification furnace, and the combustible material is introduced into the fluidized bed in the fluidized bed gasification furnace from the combustible material supply device to produce the combustible material. A method for stopping the operation of a gasification furnace apparatus for gasifying a substance, characterized in that when the operation is stopped, the supply of combustible substances is stopped and water is injected into the fluidized bed.

Since water is poured into the fluidized bed when the operation is stopped as described above, the temperature of the fluidized bed is lowered and combustion of unburned carbon components such as char in the fluidized bed can be prevented. Since the temperature is not high enough to cause fusion, no clinker occurs.

The invention according to claim 4 is provided with a combustible material supply device and a fluidized bed gasification furnace, and the combustible material is charged from the combustible material supply device into the fluidized bed in the fluidized bed gasification furnace to produce the combustible material. A method for stopping the operation of a gasification furnace apparatus for gasifying a substance, characterized in that when the operation is stopped, the supply of combustibles is stopped and the oxygen concentration of the fluidizing gas that fluidizes the fluidized medium in the fluidized bed is reduced. And

As described above, when the operation is stopped, the supply of combustible substances is stopped and the oxygen concentration of the fluidized gas is reduced, whereby the reducing atmosphere in the fluidized bed, that is, the oxygen deficient state can be maintained, and Combustion of unburned carbon components such as char remaining in the fluidized medium can be prevented, and clinker does not occur.

The invention according to claim 5 is provided with a combustible material supply device and a fluidized bed gasification furnace, and the combustible material is introduced from the combustible material supply device into the fluidized bed in the fluidized bed gasification furnace to produce the combustible material. A method for stopping the operation of a gasification furnace apparatus for gasifying an object, characterized in that any two or more of the operation stopping methods according to claims 2 to 4 are used together when the operation is stopped.

As described above, by using at least two of the operation stopping methods according to claims 2 to 4 when the operation is stopped, the unburned carbon components such as char in the fluid medium of the fluidized bed can be more effectively used. It is possible to prevent the combustion of the oil and prevent the occurrence of clinker. The supply of the combustible material is stopped, and the oxygen concentration of the fluidizing gas that fluidizes the fluidized medium in the fluidized bed is reduced.

According to a sixth aspect of the present invention, a combustible material is supplied to a gasification furnace, gas from the gasification furnace and ash are supplied to a melting furnace, the gas is burned, and the ash is mixed with molten slag. In the method of stopping the operation of the gasification and melting furnace apparatus for combustibles, the heating of the melting furnace is stopped after the gasification furnace is stopped.

As described above, after stopping the gasification furnace,
By stopping the heating of the melting furnace, the molten slag does not stay in the melting furnace, and it is possible to maintain the distribution space in the melting furnace with a sufficient space. Further, when the melting furnace is restarted, the generated gas sent from the gasification furnace is circulated in the melting furnace without any trouble, so that uniform combustion and temperature distribution in the furnace can be obtained.

The invention according to claim 7 is a gasification furnace for gasifying a combustible material, a gas obtained by gasifying a combustible material in the gasification furnace, and ash are supplied and burned to melt the ash and the ash. In the gasification and melting furnace apparatus including the melting furnace, the melting furnace includes a heating device and a combustion gas supply device, and the gasification and melting furnace includes the heating device or the combustion gas supply device after the gasification furnace is stopped. Is provided with a control device for stopping.

By including the above control device, the control device can stop the heating device or the combustion gas supply device after the gasification furnace is stopped, so that the molten slag does not remain in the melting furnace and the melting It is possible to keep the distribution space in the furnace sufficiently secured. Further, when the melting furnace is restarted, the generated gas sent from the gasification furnace is circulated in the melting furnace without any trouble, so that uniform combustion and temperature distribution in the furnace can be obtained.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration example of a gasification furnace device for carrying out an operation stop method according to the present invention. In FIG. 1, 10 is a fluidized bed (fluidized bed) 11 at the bottom.
Is a fluidized bed gasification furnace having a combustible material supply device (for example, a screw conveyor) 12 for charging (supplying) the combustible material 15 onto the fluidized bed 11 of the fluidized bed gasification furnace 10.
Is a drive device (motor) for driving the combustible material supply device 12,
Reference numeral 14 is a hopper that supplies a combustible material 15 to the combustible material supply device 12. Here, as the combustible material 15, municipal waste, industrial waste, biomass waste, medical waste,
There are automobile waste such as waste tires or shredder dust.

The fluidized bed gasification furnace 10 blows a fluidized gas (mainly air) 16 from the bottom of the fluidized bed 11 via a flow control valve 17 to form a fluidized medium (mainly silica sand) forming the fluidized bed 11.
Is designed to be fluidized. Further, as described later in detail, an inert gas such as steam may be blown as the flowing gas 16 through the flow rate control valve 18. A water injection nozzle 19 is provided at the top of the fluidized bed gasification furnace 10, and water can be injected into the furnace by supplying water through a flow control valve 20. Further, the example of providing the water injection nozzle 19 at the top of the fluidized bed gasification furnace 10 is an example, and water may be injected from near the upper part of the hearth.

Reference numeral 21 is a control device, which is a flow control valve 17,
18, 20 and the motor 13 are controlled to control the flow rate of the flowing gas 16, the amount of water injected into the furnace, and the amount of the combustible material 15 charged into the furnace. A temperature sensor 22 measures the temperature in the fluidized bed 11, and the measurement output is input to the control device 21.

In the fluidized bed gasification furnace apparatus having the above structure,
A combustible material 15 is blown onto the fluidized bed 11 in a state where the fluidized medium is fluidized by blowing the fluidized gas 16 from the bottom of the fluidized bed 11.
Throw in. Since the amount of oxygen in the fluidized gas 16 is equal to or less than the amount for completely burning combustible materials (air ratio is 1 or less), the fluidized bed 11
There is a reducing atmosphere inside. Part of the combustible material burns to become a heat source, heating the fluidized medium. The remaining combustibles are heated and pyrolyzed by the heat of the heated fluidized medium to be gasified. The gasified product gas 23 passes through the inside of the fluidized bed 11 to the freeboard 24, is further discharged outside the furnace, and is supplied to a melting furnace (not shown).

In a fluidized bed incinerator for incinerating combustibles, the amount of oxygen (air ratio of 1 or more) enough to completely combust the combustibles charged into the furnace is supplied to the furnace, so Everything burns. When the amount of fluidized gas is made larger than the amount of air required for complete combustion, the air that has not contributed to combustion takes heat generated by combustion and contributes to cooling. Therefore, there is almost no unburned ash such as char in the fluidized bed, and the temperature of the fluidized bed does not rise even when the supply of combustibles is stopped when the operation is stopped. Therefore, the blowing of the fluidized gas 16 may be stopped when the combustible material is burned out. However, in the fluidized bed gasification furnace 10, the amount of oxygen in the fluidized gas 16 is the following amount (air ratio of 1 or less) that completely burns the amount of combustible material to be input, and the fluidized bed 11 is in a reducing atmosphere. In the fluidized medium of the fluidized bed 11, there are many unburned carbon components such as char.

As described above, when a large amount of unburned carbon such as char is present in the fluidized medium of the fluidized bed 11, when the operation of the combustible material supply device 12 is stopped and the supply of combustible material is stopped, the combustible material is combusted. There is no endotherm such as evaporation of water in the material or thermal decomposition gasification of combustible material. On the other hand, with respect to the amount of unburned carbon such as char remaining in the fluidized medium of the fluidized bed 11, the fluidized gas 1
The amount of oxygen in 6 becomes relatively large, and unburned carbon such as char burns in the fluid medium to generate heat. Then, the fluidized medium is locally heated to a high temperature (for example, 1000 ° C.). As a result, there is a problem in that the fluidized medium is fused at the high temperature heating portion to cause clinker.

Therefore, when the control device 21 is stopped,
Immediately, the motor 13 is not stopped to stop the operation of the combustible material supply device 12, but the drive frequency of the drive device is controlled to be gradually reduced as shown in FIG. That is,
The rotation speed N (combustible material supply amount) of the motor constituting the drive device 13 is gradually reduced over a predetermined time T, whereby the supply amount of the combustible material from the combustible material supply device 12 is gradually reduced, The supply is stopped after the lapse of the predetermined time T. As a result, the unburned carbon content such as char remaining in the fluidized medium within the predetermined time T is reduced, after which the supply of combustibles is completely stopped, and further the supply of the fluidized gas 16 is stopped to fluidize the fluidized bed gas. The operation of the furnace 10 is stopped. This can prevent the generation of clinker due to the combustion of unburned carbon such as char.
Note that, in the above example, the number of times the drive device 13 is driven and the amount of combustible material supplied is reduced stepwise, but it goes without saying that it may be continuously reduced.

When the control device 21 is stopped,
At the same time as stopping the operation of the combustibles supply device 12 by stopping the motor 13, a predetermined flow rate of water is supplied to the water injection nozzle 19 through the flow rate control valve 20 to inject water into the furnace (on the fluidized bed 11). You may As a result, the fluidized bed 11
Since the temperature inside decreases, it is possible to prevent the combustion of unburned carbon content such as char remaining in the fluidized medium, and the temperature is not so high that the fluidized medium is fused because water is injected even if it is burned. It can prevent the occurrence of clinker. In this case, the water injection from the water injection nozzle 19 is performed by monitoring the temperature of the fluidized bed 11 measured by the temperature sensor 22 and injecting the water from the water injection nozzle 19 before reaching the temperature at which the clinker is generated. Good.

When the control device 21 is stopped,
At the same time that the motor 13 is stopped to stop the operation of the combustible material supply device 12, the flow control valve 17 is controlled and the flowing gas 16
The amount of air (oxygen amount) contained in is reduced to an amount such that unburned carbon content such as char remaining in the fluidized medium cannot be combusted, and the reduced amount is controlled by the flow control valve 18 to remove an inert gas such as steam. You may make it blow. As a result, the oxygen concentration in the fluidized gas 16 is reduced, so that combustion of unburned carbon such as char remaining in the fluidized medium can be prevented, and clinker can be prevented from occurring.

When the operation is stopped, the control device 21 gradually reduces the combustible material over a predetermined time, a method of injecting water from the water injection nozzle 19, and flow rate control valves 17 and 18.
It is also possible to use any two or more methods out of the three methods of controlling the oxygen concentration of the flowing gas 16 by controlling the above.

Regarding the relationship between the method of reducing the amount of oxygen contained in the fluidized gas 16 and the operation of the combustible substance supply device 12, there are several patterns as described below.

The driving frequency of the driving device 13 (motor) of the combustible substance supply device 12 is gradually reduced in a stepwise or continuous manner over a predetermined time T to reduce the supply of the combustible substance stepwise or continuously. The flow control valve 17 is controlled in proportion to the flow rate to reduce the amount of oxygen stepwise.
The amount of the inert gas (steam, exhaust gas after combustion, CO ₂ or N ₂ ) that is controlled instead is increased according to the decrease in oxygen.

The driving frequency of the driving device 13 (motor) of the combustible material supplying device 12 is changed stepwise or continuously for a predetermined time T.
The amount of combustibles supplied is gradually or continuously reduced, but the amount of air in the flowing gas 16 remains unchanged during the time T.

A method in which the fluidized gas 16 is switched to an inert gas such as 100% steam at a time, and at the same time as the switching, the supply of waste is stopped 100% at a time.

The above method is a particularly excellent method in the case of an emergency stop, since char remains in the fluidized bed or a large amount of inert gas such as steam is used, but it can be stopped in the shortest time.

The gasification furnace is stopped in the following manner. First, the supply of combustible material is stopped by any of the above methods. However, since the fluidizing medium itself is still high at 600 to 400 ° C., the fluidizing gas 16 introduced from the dispersion plate or the diffuser pipe which is the fluidizing gas supply device at the furnace bottom is continuously flown through the fluidizing medium. In the case of a fluidized bed furnace of the type that circulates the fluidized medium inside the furnace by increasing the flow rate of the fluidized gas supplied from the fluidized gas supply device more than in other parts of the furnace bottom, The heat transfer is further promoted, heat exchange between the cooling portion such as the furnace wall and the cooled and returned fluid medium, which will be described in detail later, and the other high heat portion progresses, and the temperature of the entire fluid medium is rapidly and averagely cooled. Therefore, the circulation of the fluid medium continues.

In addition, as shown in FIG. 1, the fluidized medium discharged from the incombustibles outlet 25 at the bottom of the furnace is a cooling device (eg, an internal cooling device) for cooling the fluidized medium by indirect gas cooling, indirect water cooling, direct gas cooling, or the like. Cooling jacket for flowing cooling water to 2)
It is discharged to the outside of the furnace by a chute 28 provided with 6, 27, a conveyor (screw conveyor) 29, and the like. This cooled fluidized medium is transported upward by an elevator (elevator,
Pneumatic, conveyor etc.) 30 for fluidized bed gasification furnace 1
It is carried above the surface height of the flowing medium in zero. Even when the fluidized medium is being conveyed upward, the temperature of the fluidized medium is lowered by radiating heat or by providing a device that further removes heat.
The temperature becomes about 0 to 200 ° C., and the gas is supplied again into the furnace of the fluidized bed gasification furnace 10. By returning the cooled fluidized medium to the inside of the furnace, the temperature of the fluidized bed inside the furnace is lowered. The temperature of the fluidized bed is detected by the temperature sensor 22 which detects the bed temperature.
When the temperature reaches 00 to 300 ° C., the flow control valve 17 that controls the flow of the flowing gas 16 is closed. As described above, the fluidized medium in the furnace is discharged to the outside and cooled, and the cooled fluidized medium is returned to the furnace again (external circulation), whereby the cooling of the fluidized medium is accelerated.

Next, a method of stopping the gasification and melting furnace will be described. The gasification and melting furnace introduces a product gas obtained by gasifying in a gasification furnace or a pyrolysis furnace to a melting furnace, and converts the product gas and unburned carbon components (including ash) contained in the gas into air or oxygen. It is a furnace that burns at a high temperature (1300 ° C or higher) while being supplied to melt the ash contained in the produced gas to form slag. The molten slag is discharged outside the melting furnace at a slag discharge port provided in the melting furnace. Examples of the gasification furnace and the pyrolysis furnace used here include a kiln furnace in addition to the fluidized bed gasification furnace. Regarding how to stop the gasification and melting furnace, if you stop the supply of waste to the gasification furnace and stop the heating device of the melting furnace or oxygen or air at the same time, the fluidized medium that comes out of the gasification furnace Unburned carbon and fly ash derived from the inside char may be coagulated and solidified and deposited on the inner wall of a melting furnace that is gradually cooled from a temperature equal to or higher than the melting temperature of the ash, making restart impossible.

Therefore, in the present embodiment, after stopping the gasification furnace or the pyrolysis gasification furnace by the control device as described above, the heating device such as the burner of the melting furnace or the oxygen or air This is done by stopping the supply device. Until the ash transport from the gasification furnace to the melting furnace is stopped by stopping the flowing gas in the gasification furnace, the temperature of the melting furnace is maintained above the melting temperature of the ash content (1300 ° C or higher) and heated by a burner etc. until that time. Continue. Here, the case of a fluidized bed gasification furnace will be exemplified. In this case, the stop of the melting furnace is performed by the following operation after stopping the fluidized bed gasification furnace as described above. By the above, the ash and unburned carbon sent from the gasification furnace will not be coagulated and solidified and deposited in the melting furnace. Therefore, it can be initialized and maintained in a state where a sufficient distribution space in the melting furnace is secured.

Further, in such a gasification and melting furnace, how to stop the fluidized bed gasification furnace 10 depends on whether or not the combustible material 15 having a large amount of ash has been processed, in other words, whether or not the slag has been processed in large quantity. Changing. When the ash content is low, the combustion gas supply device (valve) for air or oxygen to be supplied to the gasification and melting furnace is closed immediately after the gasification furnace is stopped to stop the supply thereof. However, in the case of shredder dust or the like containing a large amount of ash, fuel is supplied to a burner, which is a heating device provided in the gasification and melting furnace, and burned to melt the slag remaining in the gasification and melting furnace. Usually, the burner is burned for 4 hours to 10 hours, preferably 5 hours to 7 hours after starting to burn. The molten slag in the melting furnace remains in the melting furnace and is discharged from the slag discharge port of the melting furnace without solidifying. By doing so, the molten slag does not stay in the melting furnace, and the flow space in the melting furnace can be initialized and maintained in a sufficiently secured state. After that, the air or oxygen supply valve for supplying to the burner and the gasification melting furnace is stopped.

Due to the above-described processing of the melting furnace, when the gasification melting furnace is restarted, the generated gas sent from the gasification furnace is circulated in the melting furnace without hindrance, so that uniform combustion and temperature distribution in the furnace are achieved. Can be obtained.

[0043]

As described above, according to the invention described in each claim, the following excellent effects can be obtained.

According to the first aspect of the present invention, the amount of combustible material is gradually or continuously reduced over a predetermined time when the operation is stopped, water is injected into the fluidized bed, and the oxygen concentration of the fluidized gas is reduced. Since it can be carried out, when the operation is stopped,
It is possible to provide a gasification furnace device capable of preventing the combustion of unburned carbon components such as char remaining in the fluidized medium of a fluidized bed and preventing the occurrence of clinker.

According to the second aspect of the present invention, the amount of combustible material charged into the fluidized bed at the time of operation stop is gradually or continuously reduced over a predetermined period of time. The amount of combustible material supplied is reduced while maintaining some heat absorption. For this reason, unburned carbon components such as char in the fluidized bed are gradually reduced, and the supply of combustibles is stopped when the amount of unburned carbon components is reduced, so that clinker does not occur.

According to the third aspect of the present invention, since water is poured into the fluidized bed when the operation is stopped, the temperature of the fluidized bed is lowered, combustion of unburned carbon components such as char in the fluidized bed can be prevented, and combustion is performed. Even so, the clinker does not occur because the temperature is not high enough to cause fusion of the fluid medium.

According to the fourth aspect of the present invention, the supply of combustibles is stopped when the operation is stopped, and the oxygen concentration of the fluidized gas is reduced to maintain the reducing atmosphere in the fluidized bed, that is, the oxygen-deficient state. Therefore, combustion of unburned carbon components such as char remaining in the fluidized medium in the fluidized bed can be prevented, and clinker does not occur.

According to the invention described in claim 5, when any two or more of the operation stopping methods of claims 2 to 4 are used together when the operation is stopped, the char and the like in the fluidized bed are effectively prevented. Combustion of fuel carbon components can be prevented, and clinker can be prevented.

According to the invention described in claim 6, by stopping the heating of the melting furnace after stopping the gasification furnace,
The molten slag does not stay in the melting furnace, and it can be maintained in a state in which the circulation space in the melting furnace is sufficiently secured. Further, when the melting furnace is restarted, the generated gas sent from the gasification furnace is circulated in the melting furnace without any trouble, so that uniform combustion and temperature distribution in the furnace can be obtained.

According to the invention described in claim 7, since the control device is provided, the heating device or the combustion gas supply device can be stopped by the control device after the gasification furnace is stopped, and the melting is performed. The molten slag does not remain in the furnace, and the molten slag can be maintained in a state in which the circulation space in the melting furnace is sufficiently secured. Further, when the melting furnace is restarted, the generated gas sent from the gasification furnace is circulated in the melting furnace without any trouble, so that uniform combustion and temperature distribution in the furnace can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a schematic configuration of a gasification furnace apparatus for carrying out an operation shutdown method according to the present invention.

FIG. 2 is a diagram showing the number of revolutions of the motor of the combustible material supply device and the passage of time when the gasification furnace device according to the present invention is stopped.

[Explanation of symbols]

10 Fluidized bed gasifier 11 fluidized bed 12 Combustible material supply device 13 Drive device (motor) 14 hopper 15 Combustibles 16 Flowing gas 17 Flow control valve 18 Flow control valve 19 Water injection nozzle 20 Flow control valve 21 Control device 22 Temperature sensor 23 Product gas 24 freeboard 25 Incombustibles outlet 26 Cooling system 27 Cooling device 28 shoots 29 Conveyor 30 carrier

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B09B 3/00 ZAB F23G 5/16 E 4D004 F23C 10/22 5/30 C 4K046 F23G 5/16 5/44 B 5/50 E 5/30 F 5/44 G 5/50 H F23J 1/00 B F27B 15/09 B09B 3/00 ZAB F23J 1/00 303L F27B 15/09 F23C 11/02 309 (72) Inventor Kei Nakajima 11-1 Haneda-Asahi-cho, Ota-ku, Tokyo (72) Inventor Yasushi Nakano 11-11 Haneda-Asahi-cho, Ota-ku, Tokyo F-term (reference) 3K061 AA11 AB02 AB03 in Ebara, Ltd. AC01 AC13 AC14 AC17 BA03 FA03 FA21 FA26 NB03 NB30 3K062 AA11 AA24 AB02 AB03 AC01 AC03 AC13 AC14 AC17 BA02 CA01 CB05 DA01 DA32 DB01 DB07 DB28 3K064 AA04 AA08 AB03 AC06 AD01 AD08 AE06 A F01 BA07 BA22 3K065 AA11 AA24 AB02 AB03 AC02 AC03 AC13 AC14 AC17 BA03 BA05 EA14 EA23 3K078 AA03 AA06 BA03 BA08 CA02 CA07 CA11 4D004 AA02 AA11 AA26 AA28 AA46 AA48 CA27 CA29 CA32 CB31 CB43 DA02 DA20 4K046 HA12 HA13 JA10 JD06 JD10 JE01 JE04 JE08 KA03 LA01

Claims (7)

[Claims] 1. A gasification system comprising a combustible substance supply device and a fluidized bed gasification furnace, wherein the combustible substance is introduced into the fluidized bed in the fluidized bed gasification furnace from the combustible substance supply device to gasify the combustible substance. In the furnace device, when the operation is stopped, a function of gradually or continuously decreasing the amount of combustibles to be charged into the fluidized bed over a predetermined time, a function of stopping the supply of the combustibles and injecting water into the fluidized bed, Gasification characterized by comprising a control means having at least one function of stopping the supply of the combustible material and reducing the oxygen concentration of the fluidizing gas for fluidizing the fluidized medium of the fluidized bed. Furnace equipment. 2. A gasification system comprising a combustible material supply device and a fluidized bed gasification furnace, wherein the combustible material is fed into the fluidized bed in the fluidized bed gasification furnace to gasify the combustible material. A method for stopping the operation of a furnace device, wherein the amount of combustibles to be fed from the combustibles supply device to the fluidized bed in the fluidized bed gasification furnace when the operation is stopped is gradually or continuously reduced over a predetermined time. A method for stopping the operation of a gasification furnace apparatus, which is characterized in that the operation is stopped while the operation is performed. 3. A gasification system comprising a combustible substance supply device and a fluidized bed gasification furnace, wherein the combustible substance is charged into the fluidized bed in the fluidized bed gasification furnace from the combustible substance supply device to gasify the combustible substance. A method of stopping the operation of a furnace, wherein the supply of the combustible material is stopped and water is injected into the fluidized bed when the operation is stopped. 4. A gasification system comprising a combustible material supply device and a fluidized bed gasification furnace, wherein the combustible material is fed into the fluidized bed in the fluidized bed gasification furnace to gasify the combustible material. A method for shutting down an operation of a furnace device, characterized in that when the operation is stopped, the supply of the combustible material is stopped and the oxygen concentration of a fluid gas for fluidizing the fluid medium of the fluidized bed is reduced. How to stop the equipment. 5. A gasification system comprising a combustible substance supply device and a fluidized bed gasification furnace, wherein the combustible substance is introduced into the fluidized bed in the fluidized bed gasification furnace from the combustible substance supply device to gasify the combustible substance. A method for shutting down a furnace, wherein at least two of the shutting down methods according to claims 2 to 4 are used together when shutting down. 6. A combustible material is supplied to a gasification furnace, gas from the gasification furnace and ash are supplied to a melting furnace, the gas is burned, and gasification and melting of the combustible material using ash as a molten slag. In the method for stopping the operation of the furnace device, the method for stopping the operation of the gasification melting furnace device is characterized in that the heating of the melting furnace is stopped after stopping the gasification furnace. 7. A gas comprising a gasification furnace for gasifying a combustible material, a gas obtained by gasifying the combustible material in the gasification furnace, and a melting furnace for supplying and burning ash to melt the ash. In the chemical melting furnace apparatus, the melting furnace includes a heating device and a combustion gas supply device,
The gasification and melting furnace apparatus comprises a control device that stops the heating device or the combustion gas supply device after the gasification and melting furnace is stopped.