JP2003302022A - Melting furnace, operation method for melting furnace and gasification melting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a melting furnace which utilizes a burner seat as a combustion gas introducing seat of a temperature rise supplementary firing burner during continuous combustion of generated gas after stopping the temperature rise supplementary firing burner for introducing optimum combustion air into the furnace, improves the formation rate of slag, and requires less combustion air introducing seats, and also to provide an operation method for the melting furnace and a gasification melting system. <P>SOLUTION: The melting furnace 10 has a temperature rise supplementary firing burner 14 for introducing the generated gas 18 containing ashes and unburnt carbon, burning the unburnt carbon and the generated gas 18 at a high temperature and melting the ashes. It comprises a fuel supply system 25 for supplying a fuel to the temperature rise supplementary firing burner 14, a combustion air supply system 27 for supplying the combustion air 19 thereto, and control means for making the combustion air supply system 27 continuously supply the combustion air to the temperature rise supplementary firing burner 14 during the continuous combustion of the generated gas even after the fuel supply system 25 stops to supply the fuel to the temperature rise supplementary firing burner 14. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention thermally decomposes waste such as municipal solid waste, industrial waste, shredder dust, medical waste, old tires, waste plastics, etc. to generate high-temperature gas containing combustibles and ash. The present invention relates to a gasification and melting system that melts and slags ash while burning, a melting furnace used in the gasification and melting system, and a method of operating the melting furnace.

[0002]

2. Description of the Related Art It is desired to incinerate and reduce the amount of waste such as municipal solid waste, industrial waste, medical waste, shredder dust and old tires, and to effectively utilize the incineration heat. Since the incinerated ash of waste usually contains harmful heavy metals, in order to treat the incinerated ash by landfill, it is necessary to take measures such as solidifying the heavy metal components. Furthermore, downscaling of the entire facility is also required. As equipment that can cope with such problems, various metals can be recovered, ash can be melted to generate slag, and this slag can be recovered, and energy such as heat and power can be recovered. In recent years, a gasification and melting furnace that enables material recycling, not just incineration, has been receiving attention.

This gasification and melting furnace gasifies the waste in the gasification furnace and contains unburned carbon and ash at a temperature of 500.degree.
After generating unburned gas at about 600 ° C., this generated gas is introduced into the melting furnace and the secondary air (combustion air) introduced in the melting furnace causes a low air ratio (about 1.3 to 1.5) and high temperature. The ash is collected on the furnace wall to produce a molten slag-forming flow.

A case where a fluidized bed type gasification furnace is adopted as a gasification device will be described below. FIG. 1 is a diagram showing a schematic configuration example of this type of melting furnace. The melting furnace 10 includes a primary combustion chamber 11, a secondary combustion chamber 12, and a tertiary combustion chamber 13. The furnace top is provided with a temperature raising / combustion burner 14, and a temperature raising / combustion burner 15 is provided between the primary combustion chamber 11 and the secondary combustion chamber 12 between the furnace side walls. Is equipped with a plurality of combustion air inlets 16.

In the melting furnace having the above structure, the waste is gasified in a gasification furnace (not shown), and the generated gas 18 containing ash and unburned carbon is introduced from the generated gas inlet 17 in the tangential direction of the furnace wall surface, A swirling flow is formed in the furnace, and the combustion air is introduced from the combustion air introducing port 16 provided at the top of the furnace or the combustion air introducing port 16 provided at the side wall of the furnace to form a swirling flow in the furnace. Merge into 18 swirl flows. The mixed gas of the generated gas 18 and the combustion air 19 burns with the primary combustion chamber 11, the secondary combustion chamber 12, and the tertiary combustion chamber 13, and the combustion exhaust gas 20 has an exhaust gas outlet 21 at the top of the tertiary combustion chamber 13.
And is introduced into a waste heat boiler or the like (not shown) in the subsequent stage.

The temperature inside the melting furnace 10 during operation is a temperature at which ash can be melted, that is, 1200 ° C to 1400 ° C.
Since it is (preferably about 1300 ° C.), it is necessary to activate the temperature raising / assisting combustion burner 14 and the temperature raising / assisting combustion burner 15 before operating the melting furnace 10 to raise the temperature inside the furnace to a high temperature. is there. When the main melting furnace is adopted in the gasification and melting system, preferably the temperature raising / assisting combustion burner 15 of the melting furnace is started to raise the temperature inside the furnace. In the gasification and melting system, when the present melting furnace is adopted, preferably, the temperature raising / assisting combustion burner 15 of the melting furnace 10 is started to raise the temperature in the furnace, and then the gasification furnace is not covered. It is advisable to supply combustion products. High temperature in the furnace (temperature of primary combustion chamber 1300 ° C-1
Once the temperature can be maintained at about 350 ° C,
The auxiliary combustion burner 14 and the temperature raising / auxiliary combustion burner 15 are stopped, and the combustion of the mixture itself of the generated gas 18 and the combustion air 19 is continued.

Ash and unburned carbon in the produced gas 18 introduced into the furnace are collected on the wall surface of the furnace by the centrifugal force of the swirling flow of the produced gas 18, the unburned carbon burns, and the ash has a high temperature ( 130
It melts at 0 ° C. to 1350 ° C.), becomes molten slag 22, flows down along the furnace wall surface, and is discharged from the slag discharge port 23. The discharged molten slag 23 falls into a water granulation trough (not shown) to become water granulation slag.

As described above, in the conventional melting furnace, when the temperature inside the furnace is maintained at a predetermined high temperature, the temperature raising / assisting combustion burner 14 and the temperature raising / assisting combustion burner 15 are stopped. Was there. Since the burner seat of the temperature raising / combustion burner 14 is provided at the center of the furnace top, the position of this burner seat is the optimum position as a combustion air seat for introducing combustion air into the furnace, for example, This is also the optimum position where the combustion air 19 can be uniformly introduced while forming a swirling flow in the primary combustion chamber 11. However, in the past, the burner 1 for heating and auxiliary combustion was used.
Since the burner seat is not used during the continuous combustion of the mixture of the produced gas 18 and the combustion air 19 after the stop of No. 4, the burner seat is used beneficially while the temperature raising / burning burner 14 is stopped. Will not be. The same applies to the temperature raising / burning aid burner 15.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned points, and the burner seat of the temperature increasing / assisting burner is continued during the combustion of the generated gas after the temperature increasing / assisting combustion burner is stopped. By using as a seat for introducing combustion air, it is possible to introduce optimum combustion air into the furnace, and at the same time, it is possible to improve the slag formation rate and reduce the seat for introducing combustion air, and its operating method. The purpose is to provide. Another object of the present invention is to provide a gasification and melting system equipped with the above melting furnace.

[0010]

In order to solve the above-mentioned problems, the invention according to claim 1 is provided with a temperature raising / burning burner for introducing a produced gas containing ash and unburned carbon, In a melting furnace that burns combustion carbon and generated gas at a high temperature and melts the ash, a fuel supply system that supplies fuel to a temperature raising / burning burner and a combustion gas supply system that supplies combustion gas, To continue the supply of combustion gas from the combustion gas supply system to the temperature raising / burning burner while the produced gas is still burning after the fuel supply system stops supplying fuel to the temperature raising / burning burner. And a control means of.

As described above, even after the fuel supply system stops supplying fuel to the temperature raising / combustion burner, the combustion gas supply system combusts the temperature raising / combustion burner while the produced gas continues to burn. Equipped with a control means for continuing the supply of the working gas,
By continuing to supply the combustion gas during the combustion of the generated gas even after the fuel supply to the temperature raising / combustion burner is stopped, the burner seat of the temperature raising / combustion burner is a seat for introducing the combustion gas. Will be available as. Normally, this burner seat is provided at the center of the furnace top, so that the combustion gas can be optimally introduced (blown) into the furnace, and it becomes easy to maintain the furnace temperature at an optimum state. Further, since the burner seat is used as the seat for introducing the combustion gas, the seat for introducing the combustion air can be reduced accordingly.

According to a second aspect of the present invention, in the melting furnace according to the first aspect, the melting furnace introduces a generated gas and / or a combustion gas in a tangential direction of a furnace wall surface to form a swirling flow in the furnace. In the swirling melting furnace, the swirling direction of the swirling flow and the swirling direction of the swirling flow of the combustion gas from the temperature raising / combustion burner are made to coincide with each other.

As described above, the swirling direction of the swirling flow of the generated gas and / or the combustion gas and the swirling direction of the swirling flow of the combustion gas from the temperature raising / combustion burner are made to coincide with each other.
The swirling flow of the product gas and / or the combustion gas will be promoted, and the ash will be more effectively collected on the furnace wall surface.
The molten slag formation rate is further improved.

According to a third aspect of the present invention, a burner for heating and auxiliary combustion is provided, and a produced gas containing ash and unburned carbon is introduced, and the unburned carbon and the produced gas are burned at a high temperature.
In the method of operating the melting furnace for melting the ash, after stopping the fuel supply to the temperature raising / combustion burner, the combustion gas is continuously supplied from the temperature raising / combustion burner during the combustion of the produced gas. It is characterized by

After the fuel supply to the temperature raising / assisting combustion burner is stopped as described above, the temperature raising / burning is continued during combustion of the produced gas.
By continuing to supply the combustion gas from the auxiliary combustion burner, it becomes possible to operate the melting furnace capable of optimally introducing (blowing) the combustion gas into the furnace. Further, it is possible to reduce the number of seats for introducing combustion gas.

The invention according to claim 4 is a gasification furnace for gasifying waste to produce a product gas containing ash and unburned carbon, and introducing a product gas containing the ash and unburned carbon, In a gasification and melting system that includes a melting furnace for melting the ash at a high temperature while burning a produced gas containing combustion carbon, the melting furnace supplies a fuel supply system for supplying fuel to a burner and a combustion gas. A combustion gas supply system, and a control means for continuing the supply of the combustion gas from the combustion gas supply system to the burner during the combustion of the generated gas even after the fuel supply to the burner by the fuel supply system is stopped. It is characterized by having.

As described above, the burner seat of the burner can be used as a seat for introducing the combustion gas by continuing to supply the combustion gas while the combustion of the produced gas continues even after the fuel supply to the burner of the melting furnace is stopped. It is possible to provide a gasification and melting system equipped with a melting furnace capable of optimally introducing combustion gas into the furnace and maintaining the temperature inside the furnace at an optimum state.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram showing a part (upper part) of the melting furnace according to the present invention, FIG. 2 (a) is a side sectional view,
FIG. 2B is a plan sectional view (AA sectional view). As shown in the figure, here, the product gas inlet 17 is provided with its axis aligned or parallel to the tangent line of the furnace wall surface so that the flow of the inflowing product gas 18 matches the tangential direction of the furnace wall surface.
As a result, the produced gas 18 introduced into the furnace (flowing into the furnace) forms a swirl flow in the furnace.

Further, the combustion air introducing port 16 opening on the inner surface of the furnace side wall also introduces (blown) combustion air 19 into the furnace.
Is provided so that its axis coincides with or is parallel to the tangent line of the furnace wall surface. As a result, the combustion air 19 introduced into the furnace forms a swirling flow in the furnace.

A fuel supply system 25 for supplying fuel 24 such as oil and gas and a combustion air supply system 27 for supplying burner combustion air 26 are provided in the temperature raising / auxiliary burner 14 provided at the center of the furnace top. It is provided individually. The fuel supply system 25 is provided with a flow rate control valve 28 for controlling the flow rate of the fuel 24 to be supplied,
The combustion air supply system 27 is provided with a damper 29 for adjusting the flow rate of the burner combustion air 26 supplied. The openings of the flow rate control valve 28 and the damper 29 can be controlled automatically or manually by the control unit 30.

In the melting furnace having the above construction, the generated gas 18 containing ash and unburned carbon is introduced from the generated gas inlet 17, and the combustion air 19 is blown from the combustion air inlet 16 to burn the generated gas 18. However, as described above, at the beginning of operation, the temperature raising / assisting combustion burner 14 and the temperature raising / assisting combustion burner 15 (see FIG. 1) are started to raise the temperature in the furnace to a high temperature. After that, the generated gas 18 is introduced and burned. When the inside of the furnace can be maintained at a high temperature (preferably 1200 ° C. or higher, more preferably about 1300 ° C.), the control unit 30 closes the flow rate control valve 28 of the fuel supply system 25 to raise the temperature / assisting combustion burner 14. The supply of fuel 24 to the

Then, the burner combustion air 26 is continuously sent to the temperature raising / assisting combustion burner 14 as combustion air for continuing the combustion of the generated gas 18. At that time, the control unit 30 adjusts the opening of the damper 29 to adjust the flow rate of the combustion air. The opening degree of the damper 29 may be manually adjusted.

The temperature raising / combustion burner 14 is provided with a swirler, that is, a swirler.
The swirl flow is formed by giving a swirl force to the combustion air blown into the furnace from the burner seat. Then, the swirling direction of the swirling flow of the combustion air is changed to the generated gas 18 and the combustion air introducing port 16 on the furnace side wall.
The swirling flow of the produced gas 18 is promoted by matching the swirling direction of the swirling flow of the mixed gas of the combustion air 19 introduced from. As a result, ash and unburned carbon contained in the mixed gas are subjected to the strong centrifugal force of this promoted swirling flow,
It is effectively collected on the wall surface of the furnace, the unburned carbon burns, and the ash melts at a high temperature, which improves the molten slag conversion rate.

FIG. 3 is a diagram showing an example of the structure of a temperature raising / assisting combustion burner. As shown in the figure, the temperature raising / assisting combustion burner 14 includes a wind box 31 and a fuel injection pipe 32 arranged at the center of the wind box 31, and a burner seat 10 a provided at the center of the top of the melting furnace 10. Is attached to. A swirler (swirler) 33 is attached near the tip of the fuel injection pipe 32. The fuel 24 is supplied to the fuel injection pipe 32 from the fuel supply system 25, and the burner combustion air 26 is supplied to the wind box 31 from the combustion air supply system 27. As a result, the fuel 24 is injected from the tip of the fuel injection pipe 32, and the burner combustion air 26 is radiated toward the front of the tip of the fuel injection pipe 32 while forming a swirling flow through the swirler 33 and mixed with the fuel 24. . By igniting with a spark plug (not shown),
The fuel 24 burns to form a flame. In addition, a normal burner has a function of stably holding a flame by a swirling flow generated by a swirler.

FIG. 4 is a view showing an example of the structure of a swirler (swirler) for a burner. As shown, the swirler 33 has a plurality of swirl vanes 33b inside a ring-shaped frame 33a.
It is a configuration in which is arranged. The burner combustion air 26 from the wind box 31 is given a swirl force by the swirl vanes 33b while passing through a space surrounded by the frame 33a and the swirl vanes 33b, and is radiated while forming a swirl flow. Therefore, even when the fuel 24 supplied to the fuel injection pipe 32 is stopped as described above, by supplying only the burner combustion air 26 to the wind box 31, the burner combustion air 26 passing from the burner seat 10a to the swirler 33 is supplied. Is discharged into the furnace while forming a swirling flow as combustion air that burns the produced gas 18.

As described above, the fuel supply system 25 for supplying the fuel 24 to the temperature raising / assisting combustion burner 14 and the burner combustion air 2
A combustion air supply system 27 for supplying 6 is individually provided, and the burner combustion air 26 is continuously supplied by the combustion air supply system 27 while the produced gas is being combusted even after the supply of the fuel 24 from the fuel supply system 25 is stopped by the control unit 30. By this, burner seat 10
Therefore, a can be used as a seat for introducing combustion air.
Normally, this burner seat 10a is provided at the center of the furnace,
Combustion air can be optimally introduced (blown) into the furnace.

Further, a swirler 33 is provided in the temperature raising / auxiliary burner 14 to introduce the burner combustion air 26 into the furnace as a swirl flow, so that the centrifugal force of the swirl flow of the burner combustion air 26 causes the generated gas Ash is collected on the wall of the furnace,
The molten slag formation rate is improved. Further, by making the swirling direction of the swirling flow of the mixed gas in the furnace coincide with the swirling direction of the burner combustion air 26, the swirling flow of the produced gas 18 is promoted, and the ash in the produced gas 18 is generated in the furnace. Since it can be more effectively collected on the wall surface, the molten slag formation rate is further improved.

In the above embodiment, the generated gas 18
Although an example was shown in which the gas was introduced into the furnace while forming a swirl flow from the generated gas introduction port 17, the molten slag formation rate was slightly inferior, but even if the swirl melting furnace that introduces the generated gas 18 as a swirl flow is used, The invention is applicable. That is, even when the burner seat 10a is provided at a position slightly off the center of the furnace top,
This is because the swirling effect is reduced, but a synergistic effect with the combustion gas can be expected.

Although not shown, a fuel supply system and a combustion air supply system are separately provided for the temperature raising / combustion burner 15 (see FIG. 1), and the fuel supply system stops the fuel supply to the combustion assist burner. After that, the combustion air may be continuously supplied to the auxiliary burner by the combustion air supply system. In this case, the temperature raising / assisting combustion burner 15 is also usually provided with a swirler, and the combustion air supplied from the temperature raising / assisting combustion burner 15 is introduced into the furnace as a swirl flow. By making the swirling direction of the combustion air from the auxiliary combustion burner 15 coincident with the swirling direction of the swirling flow of the mixed gas, the molten slag formation rate can be improved.

Even in the conventional melting furnace,
There is one in which a variable air ratio burner is used for the auxiliary combustion burner and the fuel supply system and the combustion air supply system can be controlled individually. The present invention is characterized in that the combustion air supply system continues to be used even when the fuel supply to the temperature raising / assisting combustion burner is zero (the burner is in a stopped state in the conventional usage method).

Also in the conventional method of use, a small amount of combustion air is caused to flow when the temperature raising / assisting combustion burner is stopped (for example, the damper opening is 10%) to prevent burner burnout.
That is, even if the burner output is 0%, the components of the burner are cooled by the air leak amount without fully closing the damper. The present invention is characterized in that the combustion air is supplied into the furnace more positively than the damper leak. Of course, even if the burner seat is used as an air blowing port and the air volume is increased or decreased according to the combustion state, there is no problem in terms of thermal protection of the burner components.

Further, in the above-described embodiment, an example in which air is used as the combustion gas introduced into the melting furnace 10 has been shown, but the combustion gas is not limited to air, and oxygen-activated air or oxygen can be used. But it's okay. It is also possible to use a preheated gas before introducing the combustion gas into the melting furnace.

The product gas 1 introduced into the melting furnace 10
The gasifier producing 8 is a fluidized bed gasifier, kiln furnace,
Any external circulation type fluidized bed gasification furnace or the like may be used.
Further, although not shown, when a gasification furnace is provided in the preceding stage of the melting furnace 10 to configure the gasification and melting system according to the present invention, the gasification furnace is similar to the above, the fluidized bed gasification furnace and the kiln furnace. Any external circulation type fluidized bed gasification furnace may be used.

[0034]

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

According to the first aspect of the invention, the temperature is raised from the combustion gas supply system while the combustion of the generated gas is continued even after the fuel supply to the temperature raising / assisting combustion burner is stopped by the fuel supply system. A control means for continuing the supply of the combustion gas to the combustion / auxiliary burner, and continuing to supply the combustion gas during the continuation of the combustion of the generated gas even after the fuel supply to the temperature-increasing / combustion burner is stopped. As a result, the burner seat of the heating / assisting combustion burner can be used as a seat for introducing combustion gas. Normally, this burner seat is provided at the center of the furnace top, so that the combustion gas can be optimally introduced (blown) into the furnace, and it becomes easy to maintain the furnace temperature at an optimum state. Further, since the burner seat is used as the seat for introducing the combustion gas, the seat for introducing the combustion air can be reduced accordingly.

According to the second aspect of the invention, the swirling direction of the swirling flow of the produced gas and / or the combustion gas is made to coincide with the swirling direction of the swirling flow of the combustion gas from the temperature raising / assisting combustion burner. As a result, the swirling flow of the produced gas and / or the combustion gas is promoted, and the ash is more effectively collected on the furnace wall surface, so that the molten slag formation rate is further improved.

According to the invention described in claim 3,
After stopping the fuel supply to the auxiliary combustion burner, the combustion gas is optimally introduced (blown) into the furnace by continuing to supply the combustion gas from the temperature increasing / auxiliary combustion burner during the combustion of the produced gas. It is possible to operate the melting furnace. Further, it is possible to reduce the number of seats for introducing combustion gas.

According to the fourth aspect of the invention,
By continuing to supply the combustion gas during the combustion of the generated gas even after the supply of fuel to the auxiliary combustion burner is stopped, the burner seat of the temperature raising / assisting combustion burner can be used as a seat for introducing the combustion gas, It is possible to provide a gasification and melting system including a melting furnace that can optimally introduce a working gas into the furnace and can maintain the temperature inside the furnace at an optimum state.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration example of a melting furnace.

FIG. 2 is a diagram showing a configuration example of a part (upper part) of a melting furnace according to the present invention, FIG. 2 (a) is a side sectional view, and FIG. 2 (b) is AA.
FIG.

FIG. 3 is a diagram showing a configuration example of a temperature raising / assisting combustion burner used in the melting furnace according to the present invention.

FIG. 4 is a diagram showing a configuration example of a swirler (swirler) for a burner.

[Explanation of symbols]

10 melting furnace 11 Primary combustion chamber 12 Secondary combustion chamber 13 tertiary combustion chamber 14 Temperature rising / burning burner 15 Temperature raising / burning burner 16 Combustion air inlet 17 Product gas inlet 18 Product gas 19 Combustion air 20 Combustion exhaust gas 21 Exhaust gas outlet 22 Molten slag 23 Slag outlet 24 fuel 25 Fuel supply system 26 burner combustion air 27 Combustion air supply system 28 Flow control valve 29 damper 30 control unit 31 wind box 32 Fuel injection pipe 33 Burner swirler

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F23G 5/16 F23G 7/00 103Z 7/00 103 7/06 101D 7/06 101 B09B 3/00 303L ( 72) Inventor Tetsuya Ando 11-1 Haneda-Asahi-cho, Ota-ku, Tokyo F-term in EBARA CORPORATION (reference) 3K061 AB03 AC01 BA06 CA01 DB16 EB11 EB14 FA25 FA28 3K062 AB03 AC01 AC03 BA01 3K078 AA06 BA03 CA02 CA08 CA12 CA18 4D004 AA07 AA11 AA28 AA46 AA48 AB03 CA27 CA29 CB34 DA02 DA06

Claims (4)

[Claims] 1. A melting furnace equipped with a burner for raising temperature and for supporting combustion, introducing a produced gas containing ash and unburned carbon, burning the unburned carbon and produced gas at a high temperature, and melting the ash. A fuel supply system for supplying fuel to the temperature raising / combustion burner and a combustion gas supply system for supplying combustion gas, and even after the fuel supply to the temperature raising / combustion burner is stopped by the fuel supply system A melting furnace, comprising: a control unit for continuing to supply the combustion gas from the combustion gas supply system to the temperature raising / burning burner while the generated gas continues to burn. 2. The melting furnace according to claim 1, wherein the melting furnace is a swirling melting furnace that introduces the generated gas and / or the combustion gas in a tangential direction of a furnace wall surface to form a swirl flow in the furnace. The melting furnace is characterized in that the swirling direction of the swirling flow and the swirling direction of the swirling flow of the combustion gas from the temperature raising / assisting combustion burner are matched. 3. A melting furnace provided with a burner for raising temperature and supporting combustion, introducing a produced gas containing ash and unburned carbon, burning the unburned carbon and produced gas at a high temperature, and melting the ash. In the operating method, after stopping the fuel supply to the temperature raising and auxiliary combustion burners,
A method for operating a melting furnace, characterized in that the combustion gas is continuously supplied from the temperature raising / assisting combustion burner while the generated gas is continuously burned. 4. A gasification furnace for gasifying waste to produce a product gas containing ash and unburned carbon, and a product gas containing the ash and unburned carbon are introduced to produce a product gas containing unburned carbon. In a gasification melting system provided with a melting furnace for melting high temperature combustion and melting the ash, the melting furnace includes a fuel supply system for supplying fuel to a burner and a combustion gas supply system for supplying combustion gas. A control means for continuing the supply of the combustion gas from the combustion gas supply system to the burner while the combustion of the generated gas continues even after the fuel supply to the burner by the fuel supply system is stopped. Gasification melting furnace system characterized by.