JPH08296830A - Volume reduction treating method and apparatus for ash - Google Patents

Abstract

PURPOSE: To enable an easier maintenance and a conservation of heat energy with a simple system. CONSTITUTION: This volume reduction treating method of ash preheats ash by a burning means 7 in melting furnace 13 while melting the ash to reduce the volume thereof. At least a part of a high temperature exhaust gas from the melting furnace 13 is induced by an ejector 25 to mix the high temperature exhaust gas and a drive fluid of the ejector 25 with the ejector 25, a mixed gas mixed and adjusted in temperature is discharged to an outlet piping 18 from the ejector 25 and the ash is introduced into the outlet piping 18 while being conveyed on current being preheated by the mixed gas to be separated and recovered. The ash thus obtained is supplied to the melting furnace 13. This can prevent trouble such as gas leakage from the melting furnace with a simple structure, thereby improving safety and reliability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to equipment for melting and reducing the volume of incinerated ash such as municipal solid waste, and particularly to a method for reducing volume of ash suitable for simplifying the equipment and saving energy and a method thereof. Regarding the device.

[0002]

2. Description of the Related Art Conventionally, incineration ash of municipal solid waste has been used for landfills, etc., but recently it has become difficult to secure a landfill site due to an increase in the amount of waste treated, so ash (for example, incinerated ash). ) Is required to reduce the volume by melting and solidifying. However, since the melting temperature of ash is very high at 1300 to 1500 ° C, it is 1500 to 1700 ° C to melt ash.
A burner with a high temperature flame is used. Since the temperature of the molten ash itself is as high as 1300 to 1500 ° C, the temperature of the high temperature exhaust gas discharged from the melting furnace is also 1300 to 1500
℃ or more.

Since the high-temperature exhaust gas contains a large amount of chlorine and alkalis vaporized when the ash is melted, it is highly corrosive to metal materials, and it is difficult to recover heat with an ordinary heat exchanger. The high-temperature exhaust gas from the melting furnace was not recovered by heat, but was simply discharged by injecting water into the flue to lower the gas temperature to remove dust, and then discharged into the atmosphere. As one of the few heat recovery techniques for ash melting furnaces, the technique shown in FIG. 3 in which ash and high-temperature combustion gas are directly contacted to preheat and reduce the volume of the ash is known.

As shown in FIG. 3, the valve 1 is fed from the ash hopper 16.
The ash sent via No. 7 is sent to the granulator 32 via the feeder 31. At that time, water, or water containing a solidifying agent in some cases, is supplied to the feeder 31 via the pipe 30,
Mixed with ash. The granulated ash 11 granulated by the granulator 32 enters the receiving hopper 34 of the melting furnace 13. The granulated ash 11 flowing out from the lower part of the receiving hopper 34 forms a slope having an inclination angle determined by the angle of repose. The slope is heated by the burner 7 to melt the surface. The melted granulated ash 11 flows down the slope and is dropped in the ash pit 15. Water is put in the ash pit 15, and the dropped molten ash is rapidly cooled, reduced in volume, and deposited on the bottom.

The oil from the fuel pipe 6 is combusted in the burner 7 together with the air blown from the blower 1, and the high temperature combustion gas from the burner 7 flows through the unmelted portion of the slope of the granulated ash 11 in the ash preheating zone 35. As seen from the bottom of the receiving hopper 34, granulated ash 11
While flowing preheated into high temperature exhaust gas, and passes through the exhaust pipe 33 to enter the smoke exhaust treatment facility at the latter stage (not shown).
That is, the downwardly flowing granulated ash and the upwardly flowing high temperature combustion gas flow in countercurrent contact with each other and exchange heat.

However, the above-mentioned conventional ash melting and volume reducing equipment has the following various problems. a. If the entire surface of the slope of the granulated ash 11 flowing out from the lower part of the receiving hopper 34 into the furnace of the melting furnace 13 is covered with the molten ash, the high temperature combustion gas passes through the slope of the granulating ash 11 and enters the receiving hopper 34. I can't. As a result, there is no escape place for the high-temperature combustion gas from the burner 7, so the internal pressure of the melting furnace 13 becomes high, and gas leakage may occur outside the furnace. b. Since the temperature of the high-temperature combustion gas passing through the layer (moving bed) of the granulated ash 11 in the receiving hopper 34 reaches 1300 to 1500 ° C., the particles of the granulated ash 11 in the lower part of the moving bed become a semi-molten state and are sintered. As a result, the granulated ash 11 in the receiving hopper 34 may not be able to move downward smoothly and may be blocked. c. The low-boiling substances (alkali salts, lead, cadmium, etc.) in the high-temperature combustion gas are condensed and adhere to the surface of the granulated ash 11 as the temperature in the receiving hopper 34 drops, so that the granulated ash 11 in the receiving hopper 34 is It is sticky and cannot move smoothly, which may lead to blockage.

D. The strength of the granulated ash 11 decreases due to changes in ash composition and properties, etc., and the granulated ash is pulverized in the moving bed, or the amount of high temperature combustion gas temporarily increases due to incorrect operation, and the gas flow velocity passing through the moving bed increases. However, there is a risk that a large amount of the granulated ash 11 in the receiving hopper 34 will flow out all at once (flushing) due to trouble such as fluidization of the moving bed portion in the receiving hopper 34 and the melting furnace 13 will be inoperable. is there. e. It can be said that the characteristics of ash, especially granulation and solidification, vary widely depending on the type of waste to be incinerated, and it varies greatly both regionally and seasonally and is difficult to predict in advance. Therefore, using only water cannot reliably granulate and solidify ash throughout the year. If you try to surely granulate and solidify the incineration ash of garbage whose properties are almost impossible to understand in advance,
It is necessary to constantly add a large amount of solidifying agent. However, in this case, the amount of ash is increased by adding an extra solidifying agent, and the original purpose of the volume reduction effect of ash due to melting is diminished. f. Depending on the type of ash, it may not be possible to obtain sufficient strength unless it is cured for several days after granulation.When treating such ash, additional curing equipment must be added. May occur.

[0008]

In the conventional ash volume reduction treatment method, when the entire surface of the slope of the granulated ash flowing out into the melting furnace is covered with the molten ash, the high temperature combustion gas causes the granulated ash to fall. It is not possible to pass through the slope of No. 1 and enter the receiving hopper, and the high temperature combustion gas from the burner may increase the pressure in the melting furnace, resulting in gas leakage outside the furnace. Also, the high temperature combustion gas passing through the receiving hopper causes the granulated ash in the lower part of the bed to become semi-molten and sticky, or the low boiling point substances in the high temperature combustion gas condense on the surface of the granulated ash and become sticky. There is a risk that it will be blocked and cannot move smoothly downward.

A large amount of granulation in the receiving hopper is caused by troubles such as pulverization in the bed due to changes in the composition and properties of ash, and temporary increase in the amount of high-temperature combustion gas due to incorrect operation and fluidization. The ash may flow out all at once, filling the melting furnace and making it inoperable.

Further, it is difficult to predict the properties of ash in advance, and it may be impossible to surely granulate and solidify the ash by using only water. However, there is a problem in that the volume reduction effect of ash due to melting is reduced.

An object of the present invention is to provide a ash volume reduction method and apparatus for the ash, which has a simple system, is easy to maintain, and can save heat energy.

[0012]

In order to achieve the above-mentioned object, the method for reducing volume of ash according to the present invention is directed to preheating and melting and reducing volume of ash by combustion means in a melting furnace. In the treatment method, at least part of the high-temperature exhaust gas discharged from the melting furnace is attracted by an ejector, and the mixed gas whose temperature is adjusted by mixing the driving fluid of the ejector and the high-temperature exhaust gas is discharged from the ejector to the outlet pipe, and inside the outlet pipe. The ash is introduced into and the ash is preheated by the mixed gas and conveyed by air flow, and the ash is separated and collected and supplied to the melting furnace.

A solid gas two-phase flow is formed in the outlet pipe of the ejector by the introduced ash and the mixed gas, and the solid gas two-phase flow is passed through a dust collector to separate and collect the ash into the melting furnace. It may be configured to supply.

Further, the gas after the ash is separated and recovered by forming the melting furnace by a burner type melting furnace and the combustion means by a burner and passing through a dust collector is used as a part of the combustion air of the burner. It may be configured to be used.

Further, the melting furnace is formed by an electric resistance type melting furnace, the combustion means is formed by an electrode, and a gas after separating and collecting ash by passing through a dust collector is generated in the electric resistance type melting furnace. It may be configured to be used as a part of combustion air for combustible components in the generated gas.

[0016] Then, an atmospheric suction pipe provided with a control valve is connected to a communication flue which is connected to the high temperature flue for discharging the high temperature exhaust gas from the melting furnace and the ejector, and the amount of atmospheric suction is adjusted by the control valve to control the ejector. It may be configured to control the temperature and pressure of the discharged mixed gas.

Furthermore, the amount of drive fluid for the ejector may be controlled so that the temperature and pressure of the mixed gas discharged from the ejector are maintained within a predetermined range.

In the ash volume reducing apparatus, in the ash volume reducing apparatus in which the ash is preheated and melted by the combustion means in the melting furnace, at least a part of the high temperature exhaust gas from the melting furnace is attracted by the driving fluid. An ejector for discharging a mixed gas of a driving fluid and a high-temperature exhaust gas, a control means for controlling the mixed gas by adjusting the driving fluid and a high-temperature exhaust gas, and an ash introducing means for introducing the ash into an outlet pipe through which the mixed gas flows. And a conveying means connected to the outlet pipe for conveying an air stream while preheating the ash by the mixed gas.

The conveying means is a conveying pipe for forming a solid-gas two-phase flow which conveys the introduced ash in an air stream while preheating the mixed ash, and melts the ash separated and recovered by passing through the solid-gas two-phase flow. It may be configured with a dust collector for supplying to the furnace.

Further, the melting furnace is formed by a burner type melting furnace, and the combustion means is formed by a burner.
The gas after separating and recovering the ash may be introduced to the burner type melting furnace so that it can be used as a part of the combustion air of the burner.

Then, the melting furnace is formed by an electric resistance type melting furnace and the combustion means is formed by electrodes, and the dust collecting device is
The gas after separating and recovering the ash may be introduced to the electric resistance type melting furnace so that it can be used as a part of the combustion air for combustible components in the gas generated in the electric resistance type melting furnace.

Further, an atmosphere suction pipe provided with a control valve is connected to a high temperature flue for discharging the high temperature exhaust gas from the melting furnace and a connecting flue connected to the ejector, and the control means controls the suction amount of the atmosphere by the control valve. It may be configured to adjust the temperature and pressure of the mixed gas discharged from the ejector.

Further, the control means may be configured so as to control the drive fluid amount of the ejector so that the temperature and pressure of the mixed gas discharged from the ejector are maintained within a predetermined range.

[0024]

According to the present invention, an ejector which has no mechanical moving parts and can withstand high temperature is used, and the driving fluid attracts the high temperature exhaust gas, and the driving fluid and the high temperature exhaust gas are mixed and discharged as a mixed gas from the ejector to obtain a fine powder. The ash and the mixed gas are brought into contact with each other to cause heat exchange between the ash particles and the mixed gas during transportation. At that time, room temperature air or low temperature exhaust gas attracted from the downstream of the smoke treatment equipment is used as a driving fluid. The mixed gas conveys ash particles and preheats them while preventing problems such as sintering. If the high temperature exhaust gas is not sufficiently cooled by the driving fluid alone, connect the atmosphere suction pipe with a control valve to the connecting flue that connects the high temperature exhaust gas flue and the ejector, and suck the atmosphere to bring the temperature of the mixed gas And the pressure is controlled. Then, the ash that has been carried by the mixed gas in an air stream and subjected to heat exchange is sent to the dust collector, and the separated ash is supplied to the melting furnace.

As described above, since it is not necessary to pass the high temperature combustion gas through the ash moving layer, it is not necessary to carry out a pretreatment such as granulation for improving the air permeability of ash which is originally a fine powder and has poor air permeability. . Therefore, the problems of maintaining and improving the solidification property and granulation property of ash due to the granulation of ash, and the maintenance of a stable moving layer that does not cause flushing are avoided. Further, since the high temperature combustion gas is not brought into direct contact with the ash, troubles such as partial melting and combustion of the ash can be avoided.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, a method for reducing the volume of ash, in which ash is preheated and melted by a combustion means (burner or electrode) in a melting furnace (burner type melting furnace or electric resistance type melting furnace) to reduce its volume, , At least a part of the high-temperature exhaust gas from the melting furnace 13 is attracted by the ejector 25, the high-temperature exhaust gas and the driving fluid of the ejector 25 are mixed by the ejector 25, and the mixed gas whose temperature is adjusted and mixed is exited from the ejector 25. The ash is discharged to 18, the ash is introduced into the outlet pipe 18, and the ash is preheated by the mixed gas while being conveyed by air flow, and the ash is separated and collected and supplied to the melting furnace 13. Then, in the outlet pipe 18 of the ejector 25, a solid gas two-phase flow is formed by the introduced ash and the mixed gas, and this solid gas two-phase flow is passed through a dust collector 9 such as a cyclone to separate and collect the ash. Shall be supplied to the melting furnace 13.

That is, the combustion air in the melting furnace (burner type melting furnace) 13 is sent from the blower 1 to the burner 7 via the valve 4 and the pipe 3. Oil, which is fuel, is sent to the burner 7 via the pipe 6. The hot combustion gases from the burner 7 are used for heating and melting the ash and then discharged via the hot flue 14. The molten ash 11 flows down the slope and drops in the ash pit 15. The dropped molten ash 11 is cooled and solidified by the water in the ash pit 15.

The ejector 25, which uses air as a driving fluid, the pressure of which is increased by the blower 27 and which is adjusted by the control valve 24, passes from the high temperature flue 14 through the connecting flue 10 to 1300 to 1500 ° C.
The high temperature combustion gas of the
A mixed gas of 800 ° C. or lower is sent to the outlet pipe 18. At that time, it is economical to install the ejector 25 close to the high temperature flue 14 in that the expensive high temperature flue portion is shortened. Further, as the driving fluid for the ejector 25, instead of air, combustion gas sucked from another low temperature flue and pressurized may be used.

The control means is connected to an atmosphere suction pipe 26 provided with a control valve 23 between the ejector 25 and the high temperature flue 14, and a thermometer 20 and a pressure gauge 21 are provided inside the outlet pipe 18 of the ejector 25. The temperature and pressure of the mixed gas are detected, and the arithmetic controller 22 is operated according to the detected temperature and pressure.
The temperature and pressure of the mixed gas discharged from the ejector 25 are controlled within a predetermined range by opening and closing the control valve 24 and / or the control valve 23 via the.

When the temperature of the mixed gas at the outlet of the ejector 25 becomes higher than the set temperature, the arithmetic controller 2
The control valve 24 and / or the control valve 23 are opened via 2 to increase the suction amount of atmospheric air at room temperature. The pressure in the outlet pipe 18 of the ejector 25 fluctuates depending on the amount of ash supplied from the ash hopper 16 through the double rotary valve 29, but within a certain pressure fluctuation range if it is conveyed normally. . When the ash transport amount is 0, the pressure is the lowest due to only the pressure loss in the pipe. When a large amount of ash is constantly supplied, the ash cannot be transported and the double rotary valve 29
The transfer pipe 19 from the outlet of the to the cyclone 9 is blocked,
The pressure in the outlet pipe 18 of the ejector 25 exceeds the set upper limit value. In this case, the control valve 24 is opened to perform an operation such as blowing off the ash blocked in the transfer pipe 19.

Ash is sent to the outlet pipe 18 of the ejector 25 via the ash introducing means composed of the ash hopper 16 and the double rotary valve 29, and heat is exchanged with the gas in the carrier pipe 19 connected to the outlet pipe 18. The air flow is carried to the cyclone 9 which forms a carrying means together with the carrying pipe 19. In the cyclone 9, the ash and the carrier gas are separated and the ash is sent to the receiving hopper 34 of the melting furnace 13, and the melting furnace 1
It reaches the inside of 3 and is melted by the burner 7. On the other hand, the separated carrier gas is blown into the vicinity of the burner 7 via the pipe 8 and used as combustion air.

According to this embodiment, by contacting the ash with the temperature-controlled mixed gas in the transfer pipe and exchanging heat, troubles such as partial melting and sintering due to excessive preheating of the ash can be avoided, And does not require a process of granulating with water and a solidifying agent to improve the air permeability of the ash,
Preheat ash with high reliability with a simple system.

Next, another embodiment of the present invention will be described with reference to FIG. FIG. 2 is a system diagram when the present invention is applied to an electric resistance type melting furnace. As shown in FIG. 2, the ash hopper 1
The ash discharged from 6 through the double rotary valve 29 in a fixed amount enters the outlet pipe 18 and is carried by the mixed gas from the ejector 25 in the carrying pipe 19 and separated into gas and ash by the cyclone 9 and doubled. Rotary valve 44
It is supplied to the electric resistance type melting furnace 40 while performing pressure sealing with.

In the electric resistance melting furnace 40, a voltage is applied to the electrode 41 to energize the ash 45 and the Joule heat at that time causes the ash 4 to flow.
This is a melting furnace of the type in which 5 is heated and melted. Therefore, no combustion air is required. However, the low boiling point alkali salts, lead and cadmium contained in the ash 45 are gasified by high heat and gas is generated. In order to purge these, a small amount of air is sent from the blower 27 into the electric resistance type melting furnace 40 via the valve 46 and the pipe 47. Oxygen contained in this air reacts with unburned carbon contained in ash to form CO ₂ and CO. When the amount of air is too large, the inside of the electric resistance melting furnace 40 becomes an oxidizing atmosphere due to the residual O ₂ . In that case,
Since the electrode 41 containing carbon as a main component is rapidly oxidized and burnt out, the purge air amount needs to be suppressed to such an extent that oxygen does not remain in the electric resistance melting furnace 40. That is, the pipe 4
The operation is performed in a so-called reducing atmosphere in which a large amount of CO remains in the generated gas discharged from No. 8.

Normally, LP is used to completely burn this CO.
The generated gas is processed by the duct burner 42 using G as a fuel. The melting furnace generated gas is sent to the duct burner 42 through the pipe 48, and the oxygen contained in the gas separated by the cyclone 9 is supplied to the duct burner 42 using the LPG supplied through the pipe 43 as fuel. Completely incinerate with combustibles. The high-temperature exhaust gas from the duct burner 42 is guided to the flue gas treatment facility (not shown) via the high-temperature flue 14. The communication flue 10 is connected to the high temperature flue 14 and communicates with the ejector 25. Further, an atmospheric suction pipe 26 provided with a control valve 23 is connected to the communication flue 10, and the atmospheric suction amount is controlled according to the temperature and pressure of the mixed gas at the outlet of the ejector 25. Air is sent from the blower 27 to the ejector 25 as a driving fluid via the control valve 24. High-temperature exhaust gas from the high-temperature flue 14, air sucked from the air suction pipe 26, and a blower 27
Three types of air, which are sent from the air, are mixed by the ejector 25 and the temperature is adjusted. This mixed gas is used in the outlet pipe 18
And, it is sent to the cyclone 9 via the transfer pipe 19, and the ash hopper 16 and the double rotary valve 29 are provided on the way.
The ash is quantitatively supplied into the outlet pipe 18 via the ash introducing means consisting of. The ash is sent to the cyclone 9 while being preheated by heat exchange between the ash and the mixed gas in the transfer pipe (conveying means) 19 connected to the outlet pipe 18. In the cyclone 9, the ash and the mixed gas are separated as described above, and the ash is sent to the electric resistance melting furnace 40 through the double rotary valve 29.

The present invention has the following effects. a. There is no need to use a device with many mechanically moving parts such as a granulator and a fee with a kneading function of water and ash,
Since the structure is simple and the ejector uses almost no maintenance, the equipment cost and operating cost can be reduced. b. Because of the structure, the troubles shown in (a), (b), (c), and (d) below can be eliminated, so the safety and reliability of the equipment can be improved.

(A) When the entire surface of the granulated ash that has flowed into the melting furnace from the lower part of the receiving hopper is covered with the molten ash, the high temperature combustion gas passes through the surface of the granulating ash and enters the receiving hopper. I can't. As a result, there is no escape area for the high-temperature combustion gas in the burner, so the pressure inside the melting furnace becomes high and gas leaks outside the furnace.

(B) The temperature of the high-temperature combustion gas passing through the layer (moving bed) of granulated ash in the receiving hopper is 1300 to 150.
Since the temperature is also 0 ° C., the granulated ash particles in the lower part of the moving layer are in a semi-molten state and sinter and become sticky, and the granulated ash in the receiving hopper cannot be smoothly moved downward and is blocked.

(C) Since the low boiling point substances (alkali salts, lead, cadmium, etc.) in the combustion gas are condensed and adhere to the surface of the granulated ash as the temperature in the receiving hopper drops, the granulated ash receiving hopper 34 The granulated ash becomes sticky and cannot move smoothly, resulting in blockage.

(D) The strength of the granulated ash decreases due to changes in the composition and properties of the ash, and the granulated ash is pulverized in the moving bed. Alternatively, a large amount of granulation in the receiving hopper was caused by troubles such as the combustion gas amount temporarily increasing due to incorrect operation and the flow velocity of the gas passing through the moving bed increased, and the moving bed section in the receiving hopper became fluidized. The ash may flow out at once (flushing) and fill the melting furnace, resulting in the inoperability.

C. Since it is not necessary to add a solidifying agent which is extra water for melting ash, the amount of melt processing can be suppressed to a minimum, and it is possible to save melting energy and reduce the amount of molten ash discharged.

D. Since the ash can be preheated and melted regardless of the ash properties such as granulation property and solidification property, no extra equipment or chemicals are required to cope with the ash property change, and operation and maintenance are facilitated.

[0043]

According to the present invention, since the high temperature exhaust gas of the melting furnace is attracted by the ejector, the ash is preheated by the mixed fluid of the ejector driving fluid and the high temperature exhaust gas, and the ash is conveyed and supplied to the melting furnace, The structure is simplified, and troubles such as gas leakage in the melting furnace, blockage and flushing of granulated ash are prevented, safety and reliability are improved, and heat energy can be saved.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a system of a burner type melting furnace to which an embodiment of the present invention is applied.

FIG. 2 is a configuration diagram showing a system of an electric resistance melting furnace to which another embodiment of the present invention is applied.

FIG. 3 is a diagram showing a system of a conventional ash preheating type melting furnace.

[Explanation of symbols]

 7 burner 10 connecting flue 9 dust collector 11 molten ash 13 burner type melting furnace 14 high temperature flue 15 ash pit 16 ash hopper 18 outlet pipe 19 transfer pipe 23 control valve 24 control valve 25 ejector 29 double rotary valve 40 electric resistance type Melting furnace 41 Electrode 44 Double rotary valve 45 Ash

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Hiromichi Fujiwara Inventor Hiromichi Fujiwara 1-10-10 Isogo, Isogo-ku, Yokohama-shi, Kanagawa Yokohama Engineering Center, Babcock Hitachi Ltd. (72) Toru Senju Isogo-ku, Yokohama-shi, Kanagawa 1-2-10 Isogo Babcock Hitachi Co., Ltd. Yokohama Engineering Center

Claims (12)

[Claims] 1. A method for reducing volume of ash in which a ash is preheated by a combustion means in a melting furnace and melted to reduce the volume, at least a part of high-temperature exhaust gas discharged from the melting furnace is attracted by an ejector, and the ejector is used. The mixed gas, the temperature of which is adjusted by mixing the driving fluid and the high-temperature exhaust gas, is discharged from the ejector to the outlet pipe, the ash is introduced into the outlet pipe, and the ash is preheated by the mixed gas to be conveyed by air flow. Then, the ash volume reduction method is characterized in that the ash is separated and recovered and supplied to the melting furnace. 2. The method for reducing volume of ash according to claim 1, wherein a solid gas two-phase flow is formed in the outlet pipe of the ejector by the introduced ash and the mixed gas, and the solid gas two-phase flow is A method for reducing the volume of ash, which comprises supplying the ash that has been separated and collected through a dust collector to a melting furnace. 3. The method for reducing volume of ash according to claim 1 or 2, wherein the melting furnace is formed by a burner type melting furnace, the combustion means is formed by a burner, and the ash is separated by passing through a dust collector. A method for reducing volume of ash, characterized in that the recovered gas is used as a part of combustion air for the burner. 4. The method for reducing volume of ash according to claim 1 or 2, wherein the melting furnace is formed by an electric resistance type melting furnace, the combustion means is formed by electrodes, and the ash is generated by passing through a dust collector. A method for reducing volume of ash, characterized in that the gas after being separated and recovered is used as a part of combustion air for combustible components in the gas generated in the electric resistance melting furnace. 5. The method for reducing volume of ash according to any one of claims 1 to 4, wherein a control valve is provided in a communication flue connected to a high temperature flue for discharging high temperature exhaust gas from the melting furnace and an ejector. A method for reducing volume of ash, characterized in that the air suction pipe provided is connected, and the temperature and pressure of the mixed gas discharged from the ejector are controlled by adjusting the amount of atmospheric suction by the control valve. 6. The method for reducing volume of ash according to claim 1, wherein the amount of driving fluid for the ejector is adjusted so that the temperature and pressure of the mixed gas discharged from the ejector are maintained within a predetermined range. A method for reducing the volume of ash, which comprises controlling 7. A ash volume reducing apparatus for preheating and melting ash by combustion means in a melting furnace, wherein at least a part of the high temperature exhaust gas from the melting furnace is attracted by a driving fluid, and the driving fluid and the high temperature exhaust gas. An ejector that discharges a mixed gas of, a control unit that controls the mixed gas by adjusting the driving fluid and the high-temperature exhaust gas, and an ash introduction unit that introduces the ash into an outlet pipe through which the mixed gas flows, A volume reducing apparatus for ash, comprising: a transport means connected to the outlet pipe to transport the ash by preheating with the mixed gas. 8. The volume reduction apparatus for ash according to claim 7, wherein the conveying means forms a solid-gas two-phase flow for conveying the introduced ash in an air stream while preheating the mixed ash, and the solid pipe. An ash volume reduction apparatus comprising a dust collector that supplies ash separated and collected by passing a gas two-phase flow to a melting furnace. 9. The volume reduction apparatus for ash according to claim 7 or 8, wherein the melting furnace is formed by a burner type melting furnace and the combustion means is formed by a burner, and the dust collecting apparatus separates and collects the ash. The ash volume reduction processing apparatus, wherein the gas of 1 is led to the burner-type melting furnace so that it can be used as a part of the combustion air of the burner. 10. The apparatus for reducing volume of ash according to claim 7 or 8, wherein the melting furnace is formed of an electric resistance type melting furnace and the combustion means is formed of electrodes, and the dust collector separates and collects the ash. Of the ash, which is characterized in that the latter gas is led to the electric resistance type melting furnace so that it can be used as a part of the combustion air for combustible components in the generated gas generated in the electric resistance type melting furnace. Volume reduction processing device. 11. The volume reduction apparatus for ash according to any one of claims 7 to 10, wherein a control valve is provided in a communication flue connected to a high temperature flue for discharging high temperature exhaust gas from the melting furnace and an ejector. Connect the provided atmospheric suction pipe, the control means,
A method for reducing volume of ash, characterized in that the control valve controls the amount of atmospheric suction to control the temperature and pressure of the mixed gas discharged from the ejector. 12. The ash volume reduction processing apparatus according to claim 7, wherein the control means maintains the temperature and pressure of the mixed gas discharged from the ejector within a predetermined range. An ash volume reduction processing device, characterized in that it controls the amount of driving fluid of the ash.