JP2007147270A - Processing method, and gasifying and melting device for waste - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a processing method and a gasifying and melting device producing a combustible gas including a large amount of combustible components from the combustible material such as waste and coal with high efficiency, and melting the combustion ash by self heat quantity of the produced combustible gas. <P>SOLUTION: A fluidized bed furnace 2 comprises a fluidized-gas supplying means for supplying a fluidized gas, the waste is supplied to the fluidized bed furnace 2, and gasified to produce the gas and char, and a melting furnace melts the ash contents by supplying the gas and char discharged from the fluidized bed furnace 2. The fluidized bed furnace 2 comprises an inclined furnace bottom, and a noncombustible material discharge port 5 for discharging the noncombustible material included in the waste and a bed material to a lower part of the inclined furnace bottom, and further comprises a chute 16 for discharging the noncombustible material and the bed material, and a quantitative discharger 17 for quantitatively discharging the noncombustible material and the bed material to the horizontal direction from a lower part of the chute 16, at a lower part of the noncombustible material discharge port 5, and the quantitatively discharged noncombustible material and the bed material are separated so that the separated bed material is returned to the fluidized bed furnace 2, and the metal in the noncombustible material is recovered in an un-oxidized state. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method and apparatus for gasifying combustibles in a fluidized bed furnace and burning the generated combustible gas and fine particles at a high temperature in a melting combustion furnace to melt ash.

  In recent years, it has been desired to incinerate and reduce the amount of municipal waste and waste plastics generated in large quantities, and to effectively use the incineration heat. Since waste incineration ash usually contains harmful heavy metals, in order to treat incineration ash by landfill, measures such as solidification of heavy metal components are required. In order to cope with these problems, a method and an apparatus for burning solids have been proposed in Japanese Patent Publication No. 62-35004. In the combustion method of this publication, the solid material is pyrolyzed in a fluidized bed pyrolysis furnace, and pyrolysis products, that is, combustible gas and particles, are introduced into the cyclone combustion furnace. In the cyclone combustion furnace, the combustible component is burned with high load by pressurized air, and the ash collides with the wall surface by the swirling flow, melts down, flows down the wall surface, becomes molten slag, falls from the discharge port to the water chamber, and is solidified. .

  In the method of Japanese Examined Patent Publication No. 62-35004, since the fluidized bed as a whole is in an active fluidized state, there is a large amount of unreacted combustible matter that is entrained with the product gas and scattered outside the furnace, so that high gasification efficiency is obtained. There were shortcomings such as not being possible. Conventionally, gasification raw materials that can be used in a fluidized bed furnace have been pulverized coal having a particle size of 0.5 to 3 mm in the case of coal or the like, and pulverized material of several tens mm in the case of waste. If it is larger than this, fluidization will be inhibited, and if it is smaller than this, it will not be completely gasified, but will be scattered outside the furnace along with the product gas as an unreacted combustible component. Therefore, in the conventional fluidized bed furnace, it is indispensable to use a pulverizer or the like in advance as a pretreatment before putting the gasification raw material into the furnace, and it does not fall within the predetermined particle size range. Gasification raw materials could not be used, and yields had to be sacrificed to some extent.

  In order to solve the above problems, a fluidized bed gasification method and a fluidized bed gasification furnace disclosed in JP-A-2-147692 have been proposed. In the fluidized bed gasification method of this publication, the horizontal section of the furnace is rectangular, and the mass velocity of the fluidized gas ejected upward from the center of the furnace bottom into the furnace is from the two side edges of the furnace bottom. The mass velocity of the fluidized gas to be supplied is smaller, the upward flow of the fluidized gas is turned to the center of the furnace above the furnace bottom side edge, and a moving bed in which the fluidized medium settles is formed in the center of the furnace, A fluidized bed in which the fluidized medium actively fluidizes is formed on both side edges of the furnace, and combustibles are supplied to the moving bed. The fluidizing gas is a mixture of air and steam, or a mixture of oxygen and steam, and the fluidizing medium is silica sand.

However, the method of Japanese Patent Laid-Open No. 2-147692 has the following disadvantages. That is, (1) in the moving bed and fluidized bed as a whole, gasification endothermic reaction and combustion reaction occur at the same time, and volatile components that are easily gasified are gasified and burned at the same time. And the like are entrained in the product gas as unreacted substances and scattered outside the furnace, and high gasification efficiency cannot be obtained. (2) When the product gas is burned and used in a steam and gas turbine combined power plant, it is necessary to make the fluidized bed furnace a pressurized type. Have difficulty. The preferred internal pressure of the gasifier is determined by the use of the product gas. When used as a general combustion gas, it may be about several thousand mmAq. However, when used as a fuel for a gas turbine, it requires several kgf / cm ² or more, and further for high-efficiency gasification combined power generation. When used as a fuel, a dozen or more kgf / cm ² or more is appropriate.

  Regarding the disposal of waste such as municipal waste, the reduction of combustible waste still plays an important role, and accompanying this, in recent years dioxin countermeasures, detoxification of dust, and improvement of energy recovery efficiency The need for environmentally friendly waste disposal technology is increasing. The amount of incineration of municipal waste in Japan is about 100,000 tons / day, and the total amount of energy in municipal waste is equivalent to about 4% of the amount of electricity consumed in Japan. Currently, the utilization rate of municipal waste energy is only about 10%. However, if the utilization rate can be increased, the consumption of fossil fuels can be reduced accordingly, which can contribute to the prevention of global warming.

  However, current incineration systems include the following problems. That is, (1) There is a problem of corrosion by HCl, and power generation efficiency cannot be increased. (2) Pollution prevention facilities for HCl, NOx, SOx, mercury, dioxin, and the like are complicated and cost and space are increasing. (3) The installation of incineration ash melting equipment is increasing due to stricter regulations and land-use difficulties at the final disposal site. Therefore, it is necessary to construct separate equipment and consume a large amount of power. Yes. (4) To remove dioxins, expensive equipment is required. (5) It is difficult to recover valuable metals.

  An object of the present invention is to eliminate the above-mentioned problems of the prior art, and to generate combustible gas containing a large amount of combustible matter from waste such as municipal waste and waste plastics and combustibles such as coal with high efficiency. Another object of the present invention is to provide a treatment method and a gasification and melting apparatus capable of melting combustion ash by the self-heat amount of the generated combustible gas. In the present invention, the product gas supplied to the melting furnace has a sufficient amount of heat to generate a high temperature of 1300 ° C. or higher due to the amount of self-heating, and is a homogeneous gas containing char and tar. The incombustible material can be discharged from the control device without any trouble. Another object of the present invention is to provide a gasification method and apparatus capable of taking out and recovering valuable metals in waste from a fluidized bed furnace in a reducing atmosphere without being oxidized. Further objects of the present invention will become apparent in the description of the embodiments with reference to the drawings.

  In order to achieve the above-mentioned object, the gasification and melting apparatus of the present invention is an apparatus that melts ash in a melting furnace after gasifying waste in a fluidized bed furnace. Fluidized gas supply means for supplying gas, supplying the waste to the fluidized bed furnace, gasifying it to generate gas and char, and the melting furnace and the gas discharged from the fluidized bed furnace The ash is melted by supplying char, and the fluidized bed furnace has an inclined furnace bottom, and an incombustible material discharge port for discharging incombustible substances and fluid medium contained in the waste at a lower part of the inclined furnace bottom. Provided with a chute for discharging the incombustible material and the fluidized medium below the incombustible material discharge port, and a quantitative discharger for quantitatively discharging the incombustible material and the fluidized medium in a horizontal direction from below the chute. The discharged incombustible material and the fluidized medium are separated, and the separated fluidized medium is returned to the fluidized bed furnace. Metal in the incombustible is characterized in that recovered in non-oxidized.

An elevator for conveying the sorted fluid medium is provided.
When discharging the incombustible material and the fluidized medium from the fluidized bed furnace, a valve is provided for sealing the furnace pressure.
The fluidized bed furnace has a furnace pressure of not more than atmospheric pressure.
The separated fluidized medium is returned to the fluidized bed furnace via a lock hopper.
In the fluidized bed furnace, the pressure in the furnace is equal to or higher than atmospheric pressure.

  The waste treatment method of the present invention is a method in which waste is gasified in a fluidized bed furnace, and then ash is melted in a melting furnace. The waste is supplied to the fluidized bed furnace and gasified to gas. The incombustible material and the fluid medium contained in the waste are taken out from the incombustible material outlet at the bottom of the slanted bottom of the fluidized bed furnace and discharged in the horizontal direction. The separated fluid medium is returned to the fluidized bed furnace, the metal in the incombustible material is recovered unoxidized, and the gas discharged from the fluidized bed furnace and the char are melted. It is supplied to a furnace and melts ash.

The separated fluid medium is conveyed by an elevator and returned to the fluidized bed furnace.
The incombustible material and the fluidized medium are discharged from the fluidized bed furnace while sealing the furnace pressure.
The internal pressure seal is a valve.
In the fluidized bed furnace, the pressure in the furnace is set to atmospheric pressure or lower.
The separated fluidized medium is returned to the fluidized bed furnace via a lock hopper.

In the fluidized bed furnace, the pressure in the furnace is set to atmospheric pressure or higher.
In the fluidized bed furnace, the fluidized bed temperature is maintained at 450 ° C to 650 ° C.
The incombustible material and the fluid medium contained in the waste are taken out from the incombustible material outlet at the lower part of the inclined bottom of the fluidized bed furnace, and then quantitatively discharged in the horizontal direction.

  The waste gasification furnace of the present invention is a gasification furnace for gasifying waste, the gasification furnace is a fluidized bed furnace having a circular horizontal section, and the fluidized bed furnace is a central portion of the furnace. A central fluidized gas supply means for forming a moving bed in which the fluidized medium settles, and a peripheral fluidized gas supply means for forming a fluidized bed in which the fluidized medium rises at the periphery of the furnace, the fluidized medium being the moving bed And forming a circulating flow through the fluidized bed, supplying the waste to the fluidized bed furnace for gasification, and the fluidized bed furnace discharges the incombustible contained in the waste and the fluidized medium. A discharge port, and a valve for sealing the in-furnace pressure of the fluidized bed furnace when discharging the incombustible material contained in the waste and the fluidized medium, and separating the separated incombustible material and the fluidized medium You may make it return the made fluidized medium to this fluidized bed furnace.

  The waste gasification method of the present invention is a method of gasifying waste in a fluidized bed furnace, wherein the horizontal section of the fluidized bed furnace is circular, and the fluidized medium settles in the center of the fluidized bed furnace. And a fluidized bed in which the fluidized medium rises at the periphery of the furnace, forms a circulating flow of the fluidized medium through the fluidized bed and the fluidized bed, and disposes the waste as the fluidized bed furnace. The incombustible material and the fluidized medium contained in the waste are discharged from the bottom of the fluidized bed furnace while sealing the furnace pressure, and the fluidized medium is separated from the incombustible material and the fluidized medium. May be returned to the fluidized bed furnace.

  In the present invention, combustible materials are gasified into combustible gas in a fluidized bed furnace. In the method of the present invention, the horizontal section of the fluidized bed furnace is substantially circular, and the fluidized gas supplied to the fluidized bed furnace is supplied from the central part of the furnace bottom into the furnace and around the central fluidized gas and the furnace bottom. It consists of peripheral fluidized gas supplied from the section into the furnace, the mass velocity of the central fluidized gas is made smaller than the mass velocity of the peripheral fluidized gas, and the upward flow of fluidized gas above the periphery of the furnace is It is turned by an inclined wall so as to go to the center of the furnace, thereby forming a moving bed in which the fluid medium (usually using dredged sand) settles and diffuses in the center of the furnace and flows to the periphery of the furnace A combustible gas is formed while a fluidized bed in which the medium is actively fluidized is formed and the combustible material supplied into the furnace circulates with the fluidized medium from the bottom of the moving bed to the fluidized bed and from the top of the fluidized bed to the moving bed. The oxygen content of the central fluidizing gas is Or less oxygen content of sides fluidizing gas, the temperature of the fluidized bed is maintained at 450 to 650 ° C..

  In the present invention, the central fluidizing gas is one of three kinds of gases: water vapor, a mixed gas of water vapor and air, and air. The peripheral fluidizing gas is one of three gases, oxygen, a mixed gas of oxygen and air, and air. Therefore, as shown in Table 1, there are nine combinations of the central fluidization gas and the peripheral fluidization gas. Which combination is selected depends on whether gasification efficiency is important or economic is important.

ガス化効率の最も高い組合せは、Ｎｏ．１の組合せであるが酸素消費量が多いのでコスト高である。酸素消費量、次に水蒸気消費量を少なくする順に、ガス化効率が低下するが、コストも低くなる。本発明において使用される酸素は、高純度のものでも良く、また酸素富化膜を使用して得られる低純度のものでも良い。Ｎｏ．９の空気と空気の組合せは、従来の焼却炉の燃焼空気として公知であるが、流動層炉の水平断面を円形とした本発明においては、炉内周辺部上方に設けられる傾斜壁の下方投影面積が、流動層炉の水平断面を矩形とする場合の傾斜壁の下方投影面積より大きいので、周辺流動化ガスの流量を増大し、従って、酸素供給量を増大できるので、ガス化効率を向上させることができる。

The combination with the highest gasification efficiency is No. Although it is a combination of 1, the amount of oxygen consumption is large, so the cost is high. In order of decreasing the oxygen consumption and then the water vapor consumption, the gasification efficiency decreases, but the cost also decreases. The oxygen used in the present invention may be high-purity or low-purity obtained using an oxygen-enriched film. No. 9 is known as the combustion air of the conventional incinerator, but in the present invention in which the horizontal section of the fluidized bed furnace is circular, the projection below the inclined wall provided above the periphery in the furnace. Since the area is larger than the projected area below the inclined wall when the horizontal section of the fluidized bed furnace is rectangular, the flow rate of the surrounding fluidized gas can be increased, thus increasing the oxygen supply amount and improving the gasification efficiency Can be made.

  Preferably, the method of the present invention further includes an intermediate fluidizing gas in which the fluidizing gas is supplied into the furnace from the center of the furnace bottom between the center of the furnace bottom and the periphery of the furnace bottom. The mass velocity of the intermediate fluidizing gas is between the mass velocity of the central fluidizing gas and the mass velocity of the peripheral fluidizing gas. The intermediate fluidizing gas is one of two kinds of gases, a mixed gas of water vapor and air, and air. Therefore, there are 18 combinations of central fluidization gas, intermediate fluidization gas, and ambient fluidization gas, but it is convenient that the oxygen content increases in order from the center of the furnace to the periphery, The preferred combinations are 15 in Table 2.

第２表の組合せにおいて、どれを選定するかは、ガス化効率を重視するか、経済性を重視するかにより、決められる。第２表の組合せの内、ガス化効率の最も高い組合せは、Ｎｏ．１の組合せであるが、酸素消費量が多いのでコスト高である。酸素消費量、次に水蒸気消費量を少なくする順に、ガス化効率が低下するが、コストも低くなる。第１表及び第２表において使用される酸素は、高純度のものでも良く、また酸素富化膜を使用して得られる低純度のものでも良い。

Which of the combinations in Table 2 is selected is determined depending on whether the gasification efficiency is important or the economy is important. Among the combinations in Table 2, the combination with the highest gasification efficiency is No. 1. Although it is a combination of 1, the cost is high because of the large amount of oxygen consumption. In order of decreasing the oxygen consumption and then the water vapor consumption, the gasification efficiency decreases, but the cost also decreases. The oxygen used in Tables 1 and 2 may be high-purity or low-purity obtained using an oxygen-enriched film.

  When the fluidized bed furnace is large, the intermediate fluidized gas is preferably a plurality of fluidized gases supplied from a plurality of concentric intermediate portions provided between the center of the furnace bottom and the periphery of the furnace bottom. . In this case, it is preferable that the oxygen concentration of the fluidizing gas is the lowest in the furnace center and higher as it approaches the periphery.

  In the method of the present invention, preferably, the fluidizing gas supplied to the fluidized bed furnace contains an air amount of 30% or less of the theoretical combustion air amount necessary for combustion of the combustible material. Incombustible materials are taken out from the vicinity of the bottom of the fluidized bed furnace, classified, and the obtained sand is returned to the fluidized bed furnace. The combustible gas and fine particles generated in the fluidized bed furnace are burned at a high temperature at 1300 ° C. or higher in the melt combustion furnace, and the ash is melted. The gas turbine is driven by the exhaust gas from the melt combustion furnace. The pressure in the fluidized bed furnace is maintained below atmospheric pressure or above atmospheric pressure depending on the application. Combustible materials are waste, coal, and others.

  The present invention also provides an apparatus in which combustibles are gasified in a fluidized bed furnace. In the apparatus of the present invention, the fluidized bed furnace includes a side wall having a substantially circular horizontal cross section, a fluidized gas dispersion mechanism disposed at the bottom of the furnace, an incombustible material outlet disposed on the outer periphery of the fluidized gas dispersion mechanism, and fluidization. Central supply means for supplying fluidized gas from the vicinity of the center of the gas dispersion mechanism into the furnace so as to flow upward in the vertical direction. Fluidization gas flows from the periphery of the fluidization gas dispersion mechanism into the furnace in the vertical direction. Peripheral supply means to supply, a sloping wall for turning the fluidizing gas flowing vertically upward from the peripheral supply means to the furnace center, and a free board arranged above the slant wall, The fluidizing gas having a relatively low mass velocity and a relatively low oxygen concentration is supplied, and the peripheral supply means supplies a fluidizing gas having a relatively large mass velocity and a relatively high oxygen concentration.

  In the apparatus of the present invention, intermediate supply means for supplying the fluidizing gas vertically upward into the furnace from the ring-shaped intermediate part between the central part and the peripheral part of the fluidizing gas dispersion mechanism is provided. The intermediate supply means includes an intermediate mass velocity of the mass velocity of the fluidized gas supplied from the central supply device and the peripheral supply device, and an intermediate oxygen concentration of the fluidized gas supplied from the central supply device and the peripheral supply device. Supply a concentration of fluidizing gas. The peripheral supply means can be formed by a ring-shaped supply box. The combustible material inlet may be disposed above the fluidized bed furnace, the combustible material inlet may drop the combustible material above the central supply means, and the fluidizing gas dispersion mechanism may be formed with a lower peripheral portion than the central portion. it can.

  The incombustible material outlet may include a ring portion disposed on the outer periphery of the dispersion mechanism and a conical portion that decreases downward from the ring-shaped portion. The non-combustible material outlet may include a quantitative discharger, a first seal swing valve, a swing cut valve, and a second seal swing valve arranged in series.

  The apparatus of the present invention can include a fusion combustion furnace in which combustible gas and fine particles generated in a fluidized bed furnace are combusted at a high temperature to melt ash. A melt combustion furnace has a cylindrical primary combustion chamber having a substantially vertical axis, and a combustible gas inlet for supplying the cylindrical primary combustion chamber with the combustible gas and fine particles generated in the fluidized bed furnace so as to swirl around the axis. A secondary combustion chamber communicated with the cylindrical primary combustion chamber, and a discharge port provided in a lower portion of the secondary combustion chamber and capable of discharging molten ash. The exhaust gas in the secondary combustion chamber of the melt combustion furnace is introduced into the waste heat boiler and the air preheater, and the waste heat is recovered. The gas turbine can be driven by the exhaust gas in the secondary combustion chamber of the melt combustion furnace. The exhaust gas can be released into the atmosphere after being introduced into the dust collector and removed. The exhaust gas in the secondary combustion chamber of the melt combustion furnace is introduced into a waste heat boiler and an air preheater, and the waste heat can be recovered. The gas turbine can be driven by the exhaust gas in the secondary combustion chamber of the melt combustion furnace. The exhaust gas is introduced into the dust collector and released into the atmosphere after the dust is removed.

In the gasifier of the present invention, heat is diffused by the circulating flow of the fluidized bed furnace, so that the load can be increased and the furnace can be downsized.
In the present invention, since the fluidized bed furnace can maintain combustion with a small amount of air, the fluidized bed furnace is set to a low air ratio and low temperature (450 to 650 ° C.), and the heat generation is minimized and the combustion is performed gently. Thus, a homogeneous product gas containing a large amount of combustible components can be obtained, and most of the combustible components of gas, tar and char can be used in the next-stage molten combustion furnace.
In the present invention, large incombustibles can be easily discharged by the circulating flow of the fluidized bed furnace. Moreover, iron and aluminum in incombustibles can be used as unoxidized valuables.

  In the method or apparatus of the present invention, since the horizontal section of the fluidized bed furnace is substantially circular, the furnace has a pressure-resistant structure, the fluidized bed furnace is in a pressurized state at atmospheric pressure or higher, and combustible material supplied into the furnace. It is easy to set the pressure of the combustible gas generated from the high pressure. High-pressure combustible gas can be used as fuel for gas turbines and boiler gas turbine combined plants that can operate at high efficiency. Therefore, by using combustible gas in such plants, energy from combustibles can be used. Recovery efficiency can be improved. In the method or apparatus of the present invention, when mainly treating waste, in order to prevent odors and harmful combustion gases from leaking from the fluidized bed furnace, the furnace pressure is preferably set to atmospheric pressure or lower. However, since the horizontal section of the fluidized bed furnace is circular, the furnace wall can easily withstand external pressure.

  In the present invention, the mass velocity of the central fluidizing gas supplied to the fluidized bed furnace is made smaller than the mass velocity of the peripheral fluidizing gas, and the upward flow of the fluidizing gas above the inner periphery of the furnace is the central portion of the furnace. As a result, a moving bed in which the fluidized medium settles and diffuses is formed in the center of the furnace, and a fluidized bed in which the fluidized medium is actively fluidized is formed in the periphery of the furnace. The combustible material supplied into the furnace is gasified into a combustible gas while circulating with the fluidized medium from the lower part of the moving bed to the fluidized bed and from the top of the fluidized bed to the moving bed. The combustibles are first gasified mainly by the heat of a fluid medium (generally using dredged sand) in a moving bed descending in the center of the furnace. And since the oxygen content of the central fluidizing gas forming the moving bed is small, the combustible gas generated in the moving bed is almost burned and is raised to the freeboard together with the central fluidizing gas, and the calorific value is high. It becomes a high quality product gas.

  The combustible material that has lost its volatile content in the moving bed and has been heated, that is, fixed carbon (char), tar, etc., is then circulated into the fluidized bed, where the fluidized bed has a relatively high oxygen content. Combusted in contact with the gas, it turns into combustion gas and ash, and generates heat of combustion that maintains the interior of the furnace at 450-650 ° C. The fluidized medium is heated by this combustion heat, and the heated fluidized medium is turned to the center of the furnace above the periphery of the furnace and descends in the moving bed, so that the temperature in the moving bed is the temperature necessary for gasification of volatile matter. To maintain. Since the center of the furnace into which the combustible material is charged is in a lower oxygen state, a product gas having a high combustible content can be generated. Further, the metal in the combustible material can be recovered from the incombustible material outlet as an unoxidized valuable material.

  In the present invention, when the gas generated in the fluidized bed furnace and the ash and other fine particles are burned in the melt combustion furnace, the generated gas contains a highly combustible component. Can be raised to a high temperature of 1300 ° C. or higher, and the ash can be sufficiently melted in the melting furnace. The melted ash can be taken out of the melting furnace and easily solidified by a known method such as water cooling. Therefore, the volume of ash is remarkably reduced, and harmful metals in the ash are solidified, so that the ash is in a form that can be landfilled. Other effects of the present invention will become apparent from the description of the embodiments with reference to the claims and drawings.

(1) In the gasifier of the present invention, heat is diffused by the circulating flow of the fluidized bed furnace, so that the load can be increased and the furnace can be downsized.
(2) In the present invention, since the fluidized bed furnace can maintain the combustion with a small amount of air, the fluidized bed furnace is set to a low air ratio and low temperature (450 to 650 ° C.), and the heat generation is minimized and the combustion is performed gently. Thus, a homogeneous product gas containing a large amount of combustible components can be obtained, and most of the combustible components of gas, tar, and char can be used in the next-stage molten combustion furnace.

(3) In the present invention, large incombustibles can be easily discharged by the circulating flow of the fluidized bed furnace. Moreover, iron and aluminum in incombustibles can be used as unoxidized valuables.
(4) According to the present invention, there is provided a method or equipment that renders waste treatment harmless and has a high energy utilization rate.

  Examples of the present invention will be described below with reference to the drawings. However, the present invention is not limited to these examples, and is defined by the claims. 1 to 14, the members denoted by the same reference numerals are the same members or corresponding members, and redundant descriptions are omitted in the descriptions of the drawings.

  FIG. 1 is a schematic longitudinal sectional view of a main part of a gasification apparatus according to a first embodiment for carrying out the gasification method of the present invention, and FIG. 2 is a schematic horizontal sectional view of the gasification apparatus of FIG. is there. In the gasifier shown in FIG. 1, the fluidized gas supplied through the fluidized gas dispersion mechanism 106 arranged at the bottom of the fluidized bed furnace 2 flows upward from the vicinity of the center 4 of the furnace bottom into the furnace. And a peripheral fluidizing gas 8 supplied as an upward flow from the furnace bottom peripheral part 3 into the furnace.

  As shown in Table 1, the central fluidizing gas 7 is one of three kinds of gases: water vapor, a mixed gas of water vapor and air, and air, and the peripheral fluidizing gas 8 is composed of oxygen, oxygen and It is one of three kinds of gases, air mixed gas and air. The oxygen content of the central fluidizing gas is less than or equal to the oxygen content of the peripheral fluidizing gas. The amount of air in the entire fluidized gas is 30% or less of the theoretical amount of combustion air necessary for combustion of the combustible material 11, and the inside of the furnace is in a reducing atmosphere.

  The mass velocity of the central fluidizing gas 7 is made smaller than the mass velocity of the peripheral fluidizing gas 8, and the upward flow of the fluidizing gas above the inner peripheral portion of the furnace is turned by the deflector 6 toward the central portion of the furnace. . As a result, a moving bed 9 in which a fluid medium (usually using dredged sand) settles and diffuses is formed in the center of the furnace, and a fluidized bed 10 in which the fluid medium is actively fluidized is formed in the periphery of the furnace. Is done. The fluidized medium ascends the fluidized bed 10 at the periphery of the furnace as shown by an arrow 118, is then turned by the deflector 6, flows into the upper part of the moving bed 9, moves down in the moving bed 9, and then moves to the arrow. As indicated by 112, the gas moves along the gas dispersion mechanism 106 and flows into the lower part of the fluidized bed 10 to circulate in the fluidized bed 10 and the moving bed 9 as indicated by arrows 118 and 112.

  The combustible material 11 supplied from the combustible material supply port 104 to the upper part of the moving bed 9 is heated by the heat of the fluidized medium while descending the moving bed 9 together with the fluidized medium, and mainly volatile components are gasified. . Since there is no or little oxygen in the moving bed 9, the product gas composed of the gasified volatile matter is not burned and escapes through the moving bed 9 as shown by an arrow 116. Therefore, the moving bed 9 forms a gasification zone G. The generated gas that has moved to the free board 102 rises as indicated by an arrow 120 and is discharged from the gas outlet 108 as the generated gas 29.

  The char (fixed carbon) and tar 114 that are not gasified in the moving bed 9 move from the lower part of the moving bed 9 to the lower part of the fluidized bed 10 at the periphery of the furnace as indicated by the arrow 112 together with the fluidized medium. It is burned and partially oxidized by the surrounding fluidized gas 8 having a relatively high oxygen content. The fluidized bed 10 forms an oxidation zone S for combustible materials. In the fluidized bed 10, the fluidized medium is heated to high temperature by the combustion heat in the fluidized bed. As shown by the arrow 118, the fluidized medium that has reached a high temperature is reversed by the inclined wall 6, moves to the moving bed 9, and again becomes a heat source for gasification. The temperature of the fluidized bed 10 is maintained at 450 to 650 ° C. so that the suppressed combustion reaction continues.

  According to the gasification furnace 1 shown in FIGS. 1 and 2, the gasification zone G and the oxidation zone S are formed in the fluidized bed furnace 2, and the fluidized medium serves as a heat transfer medium in both zones. , A high-quality combustible gas having a high calorific value is generated, and in the oxidation zone S, char and tar 114 that are difficult to gasify can be burned efficiently. Therefore, the gasification efficiency of the combustible material can be improved, and a high-quality combustible gas can be generated.

  In the horizontal section of the fluidized bed furnace 2 shown in FIG. 2, the moving bed 9 that forms the gasification zone G is circular in the center of the furnace, and the fluidized bed 10 that forms the oxidation zone S is around the moving bed 9. It is formed in a ring shape. A ring-shaped incombustible discharge port 5 is disposed on the outer periphery of the fluidized bed 10. By making the gasification furnace 1 cylindrical, a high furnace pressure can be easily supported. A pressure vessel (not shown) can be separately provided outside the gasification furnace, instead of the structure that receives the furnace pressure by the gasification furnace itself.

  FIG. 3 is a schematic longitudinal sectional view of the main part of the gasification apparatus of the second embodiment for carrying out the gasification method of the present invention, and FIG. 4 is a schematic horizontal sectional view of the gasification apparatus of FIG. is there. In the gasification apparatus of the second embodiment shown in FIG. 3, in addition to the central fluidizing gas 7 and the peripheral fluidizing gas 8, the fluidizing gas is the middle part of the furnace bottom between the center of the furnace bottom and the peripheral part of the furnace bottom. The intermediate fluidized gas 7 'supplied from the inside into the furnace. The mass velocity of the intermediate fluidizing gas 7 ′ is selected between the mass velocity of the central fluidizing gas 7 and the mass velocity of the peripheral fluidizing gas 8. The intermediate fluidizing gas is any one of three kinds of gases: water vapor, a mixed gas of water vapor and air, or air.

  In the gasifier of FIG. 3, as in the case of the gasifier of FIG. 1, the central fluidizing gas 7 is one of three kinds of gases: water vapor, a mixed gas of water vapor and air, and air. The peripheral fluidizing gas 8 is one of three kinds of gases, oxygen, a mixed gas of oxygen and air, and air. The oxygen content of the intermediate fluidization gas is selected between the oxygen content of the central fluidization gas and the oxygen content of the peripheral fluidization gas. Therefore, 15 suitable combinations of fluidizing gases are shown in Table 2. In each combination, it is important that the oxygen supply increases as it expands from the center to the periphery of the fluidized bed furnace. The amount of air in the entire fluidized gas is 30% or less of the theoretical amount of combustion air necessary for combustion of the combustible material 11, and the inside of the furnace is in a reducing atmosphere.

  As in the case of the gasifier of FIG. 1, in the gasifier of FIG. 3, a moving bed 9 in which the fluid medium settles is formed in the center of the furnace, and a fluidized bed 10 in which the fluid medium rises in the periphery of the furnace. Is formed. A fluid medium circulates through the moving and fluidized beds as indicated by arrows 112 and 118. Between the moving bed 9 and the fluidized bed 10, an intermediate layer 9 'is formed in which the fluidized medium diffuses mainly in the lateral direction. The moving bed 9 and the intermediate layer 9 ′ form a gasification zone G, and the fluidized bed 10 forms an oxidation zone S.

  The combustible material 11 thrown into the upper part of the moving bed 9 is heated while descending the moving bed 9 together with the fluidized medium, and its volatile components are gasified. Char and tar that have not been gasified in the moving bed 9 and some volatiles move together with the fluidized medium to the intermediate layer 9 ′ and fluidized bed 10 and are partially gasified and partially burned. Char and tar, which are not mainly gasified in the intermediate layer 9 ', move together with the fluid medium into the fluidized bed 10 at the periphery of the furnace and are combusted in the ambient fluidized gas 8 having a relatively high oxygen content. The fluidized medium is heated in the fluidized bed 10 and circulates to the moving bed 9 to heat the combustibles in the moving bed 9. Regarding the oxygen concentration in the intermediate layer, depending on the type of combustible material (whether it has a large amount of volatile matter, char or tar, etc.), etc. It is selected whether to mainly use oxidative combustion.

  In the horizontal section of the fluidized bed furnace shown in FIG. 4, the moving bed 9 forming the gasification zone is circular in the center of the furnace, and the intermediate zone 9 formed by the intermediate fluidized gas 7 ′ along the outer periphery thereof. The fluidized bed 10 that forms the oxidation zone is formed in a ring shape around the intermediate zone 9 ′. A ring-shaped incombustible discharge port 5 is disposed on the outer periphery of the fluidized bed 10. By making the gasification furnace 1 cylindrical, a high furnace pressure can be easily supported. The pressure inside the furnace can be received by the gasification furnace itself, or can be received by providing a separate pressure vessel outside the gasification furnace.

  FIG. 5 is a schematic vertical sectional view of a gasifier according to a third embodiment of the present invention. In the gasification apparatus 1 of FIG. 5, the gasification raw material 11 made of combustible material such as garbage is supplied to the fluidized bed furnace 2 of the gasification apparatus 1 by a double damper 12, a compression feeder 13, and a dust supply feeder 14. . The compression feeder 13 compresses the gasification raw material into a plug shape, and thereby the furnace pressure is sealed. Garbage compressed in a plug shape is separated by a loosening device (not shown) and sent into the furnace by a dust feeder 14.

  In the gasifier of FIG. 5, the central fluidizing gas 7 and the peripheral fluidizing gas 8 are supplied in the same manner as in the embodiment of FIG. 1, and therefore reduced to the fluidized bed furnace 2 as in the embodiment of FIG. An atmosphere gasification zone and an oxidation zone are formed. The fluidized medium becomes a heat transfer medium in both zones, and a high-quality combustible gas with a high calorific value is generated in the gasification zone, and char and tar 114 that are difficult to gasify are efficiently combusted in the oxidation zone, resulting in high gasification. Efficiency and good quality combustible gas can be obtained. In the embodiment of FIG. 5, a roots blower 15 communicating with the double damper 12 and the free board 102 of the gasification furnace 1 is provided, and when the dust is not sufficiently compressed, it leaks from the furnace through the compression feeder to the double damper 12. Return the gas to the furnace. Preferably, the roots blower 15 draws an appropriate amount of air and gas from the double damper 12 and returns it to the furnace so that the upper part of the double damper 12 is at atmospheric pressure.

  In the gasifier of FIG. 5, in order to discharge non-combustible materials from the fluidized bed furnace 2, the non-combustible material discharge port 5, the conical chute 16, the quantitative discharger 17, the first sealing swing valve 18, the swing cut valve 19, the seal The second swing valve 20 and the ejector 23 with the trommel are arranged in order and operated as follows.

  (1) In a state in which the first swing valve 18 for sealing is opened, the second swing valve 20 is closed, and the furnace pressure is sealed by the second swing valve 20, the quantitative discharger 17 is operated, and the fluid medium Incombustible material including the sand is discharged from the conical chute 16 to the swing cut valve 19. (2) When the swing cut valve 19 receives a predetermined amount of incombustible material, the quantitative discharger 17 is turned off, the first swing valve 18 is closed, and the furnace pressure is sealed by the first swing valve 18. Then, the discharge valve 22 is opened and the inside of the swing cut valve 19 is returned to the atmospheric pressure. Next, the second swing valve 20 is completely opened, and the swing cut valve 19 is opened, so that the incombustible material is discharged to the continuous discharger 23 with trommel. (3) After the second swing valve 20 is completely closed, the pressure equalizing valve 21 is opened, and the pressure inside the first swing valve 18 and the inside of the conical chute 16 is equalized before the first swing. The valve 18 is opened and the process returns to the first step (1). These steps (1) to (3) are automatically repeated.

  The continuous discharger 23 with a trommel is operated continuously, discharges a large incombustible material 27 out of the system by a trommel, transports sand and small incombustible material by a sand circulation elevator 24, and removes a fine incombustible material 28 by a classifier 25. After that, the sand is returned to the gasification furnace 1 through the lock hopper 26. Such an incombustible discharge mechanism prevents the inflammables from being caught in the seal portions of the first and second swing valves 18 and 20 because the two swing valves have only a pressure sealing function without receiving the incombustibles. Can do. When the furnace pressure is slightly negative, the sealing function is unnecessary.

  FIG. 6 is a schematic vertical sectional view of a gasifier according to a fourth embodiment of the present invention. In the gasification apparatus shown in FIG. 6, the supply of the gasification raw material 11 and the sealing of the furnace pressure related thereto are performed in the same manner as the mechanism for discharging incombustibles in FIG. This is done using a combination of first and second swing valves 18. The compression feeder 13 is removed. In the embodiment of FIG. 6, the gas leaked from the furnace into the first swing valve 18 is returned to the furnace through the discharge valve 22 and the blower (not shown). Further, after the first swing valve 18 is completely closed, the pressure equalizing valve 21 is opened, and the pressure in the swing cut valve 19 is made equal to the furnace pressure.

  FIG. 7 is a flowchart showing an example of the purification process of the product gas produced by the gasifier of the present invention. 7, the gasification raw material 11 and the fluidized gases 7 and 8 are supplied to the gasifier 1 to the gasifier 1. The combustible product gas generated in the gasifier 1 is recovered and cooled by the waste heat boiler 31 and sent to the cyclone separator 32, where the solids 37 and 38 are separated. Thereafter, the product gas is washed with water in the water washing tower 33 and cooled, hydrogen sulfide is removed in the alkali washing tower 34, and then stored in the gas holder 35. The unreacted char 37 in the solid content separated by the cyclone separator 32 is returned to the gasifier 1, and the remaining solid content 38 is discharged out of the system. As in the embodiment of FIG. 5, among the incombustibles discharged from the gasifier 1, the large incombustible 27 is discharged out of the system, and the sand is returned to the gasifier 1. Waste water discharged from the cleaning towers 33 and 34 is introduced into the waste water treatment device 36 and detoxified.

  FIG. 8 is a flowchart showing an example of a process in which combustible product gas and fine particles generated in the gasifier 1 are introduced into the melting combustion furnace 41 and burned at a high temperature, and ash is melted. In the process of FIG. 8, the combustible product gas produced by the gasifier 1 is introduced into the molten combustion furnace 41. Oxygen, a mixed gas of oxygen and air, or air is blown into the melting combustion furnace 41, the generated gas and fine particles are combusted at 1300 ° C or higher, ash is melted, and harmful substances such as dioxin and PCB are decomposed. The The ash 44 melted in the melt combustion furnace 41 is rapidly cooled to slag and reduced in weight. The combustion exhaust gas generated in the melt combustion furnace 41 is rapidly cooled by the scrubber 42, thereby preventing dioxin resynthesis. The exhaust gas rapidly cooled by the scrubber 42 is further removed from the dust 38 in the filter 43 and discharged from the exhaust tower 55 to the atmosphere.

  FIG. 9 is a vertical sectional perspective view of the gasification and fusion combustion apparatus of the fifth embodiment of the present invention. In FIG. 9, the gasifier 1 is almost the same as the embodiment of FIG. 1, but the gas outlet 108 is communicated with the combustible gas inlet 142 of the molten combustion furnace 41. The melt combustion furnace 41 includes a cylindrical primary combustion chamber 140 having a substantially vertical axis, and a secondary combustion chamber 150 inclined in the horizontal direction. The combustible gas 120 and the fine particles generated in the fluidized bed furnace 2 are supplied to the primary combustion chamber 140 through the combustible gas inlet 142 so as to swirl around its axis.

  The primary combustion chamber 140 includes a start burner at the upper end and a plurality of air nozzles 134 that supply combustion air to swirl around an axis. The secondary combustion chamber 150 communicates with the primary combustion chamber 140 at the lower end thereof, and is disposed at a lower portion of the secondary combustion chamber and is disposed above the discharge port 152 and a discharge port 152 that can discharge molten ash. An auxiliary combustion burner 136 disposed in the vicinity of the port 154, a portion communicating with the primary combustion chamber, and an air nozzle 134 for supplying combustion air are provided. The exhaust port 154 includes a radiation plate 162 and reduces the amount of heat lost from the exhaust port 154 due to radiation.

  FIG. 10 is a layout diagram of a fluidized bed gasification and melt combustion apparatus of an embodiment of the present invention used in combination with a waste heat boiler and a turbine. In FIG. 10, the gasifier 1 includes a conveyor 172 that conveys together a large incombustible material 27 discharged from the discharger 23 and a fine incombustible material 28 discharged from the classifier 25. An air jacket 185 is disposed around the conical chute 16 for taking out the noncombustible material from the lower part of the fluidized bed furnace 2, and the air in the air jacket 185 is heated by the hot extraction sand. The auxiliary fuel F is supplied to the primary and secondary combustion chambers 140 and 150 of the molten combustion furnace 41. The molten ash 44 discharged from the discharge port 152 of the molten combustion furnace 41 is received in the water chamber 178, quenched, and discharged as slag 176.

  In FIG. 10, the combustion gas discharged from the melting combustion furnace 41 is discharged to the atmosphere through the waste heat boiler 31, the economizer 183, the air preheater 186, the dust collector 43, and the induction ventilator 54. Prior to entering the dust collector 43, the combustion gas emitted from the air preheater 186 is added with a neutralizing agent N such as slaked lime. After the water W is supplied to the economizer 183 and preheated, the water W is heated by the boiler 31 into steam and drives the steam turbine ST. After the air A is supplied to the air preheater 186 and heated, it is further heated by the air jacket 185 and supplied to the molten combustion furnace 41 and, if necessary, the free board 102 via the air pipe 184.

  The fine particles 180 and 190 accumulated at the bottom of the waste heat boiler 31, the economizer 183, and the air preheater 186 are conveyed to the classifier 25 by the sand circulation elevator 24 to remove the fine noncombustible material 28 and returned to the fluidized bed furnace 2. . Since the fly ash 38 separated in the filter 43 contains alkali metal salts such as Na and K volatilized at a high temperature, the fly ash 38 is treated with chemicals in the processor 194.

  In the apparatus of FIG. 10, combustion in the fluidized bed furnace 2 is performed as low temperature partial combustion with a low air ratio, and the fluidized bed temperature is maintained at 450 ° C. to 650 ° C., thereby generating high calorific combustible gas. it can. Moreover, since combustion is performed in a reducing atmosphere at a low air ratio, iron and aluminum are obtained as unoxidized valuables in the incombustible material. The high calorific amount of combustible gas and char generated in the fluidized bed furnace 2 can be burned at a high temperature of 1300 ° C. or higher in the melting combustion furnace 41, and ash can be melted and dioxins can be decomposed.

  FIG. 11 is a layout diagram of a fluidized bed gasification and melt combustion apparatus according to an embodiment of the present invention used in combination with the gas cooling chamber 280. In FIG. 11, the gasifier 1, the melting combustion furnace 41, the water chamber 178, the dust collector 43, the induction fan 54, and the like are the same as those in FIG. In FIG. 11, a gas cooler 280 and an independent air preheater 188 are provided in place of the waste heat boiler, and the gas cooler 280 is provided via a high-temperature duct 278 covered with a refractory heat insulation coating from the melting combustion furnace 41. To introduce. In the gas cooler 280, the combustion gas is instantaneously reduced in temperature by the spray of fine water, and dioxin resynthesis is prevented. The exhaust gas flow rate of the high temperature duct 278 is set to a low speed of 5 m / sec or less. A hot water generator 283 is disposed on the gas cooler 280. The air heated by the air preheater 188 is supplied to the free board 102 and the molten combustion furnace 41 of the gasification furnace 1.

  FIG. 12 is a layout diagram of the fluidized bed gasification and melt combustion apparatus of the embodiment of the present invention used in combination with the waste heat boiler 31 and the reaction tower 310. In FIG. 12, the gasifier 1, the melting combustion furnace 41, the water chamber 178, the waste heat boiler 31, the steam turbine ST, the economizer 183, the air preheater 186, the dust collector 43, the induction fan 54, and the like are as shown in FIG. It is the same. In FIG. 12, a reaction tower 310 and a super heater heating combustor 320 are disposed between the waste heat boiler 31 and the economizer 183. In the reaction tower 310, a neutralizing agent N such as slaked lime slurry is added to the combustion exhaust gas, and HCl is removed. The solid fine particles 312 discharged from the reaction tower 310 are sent to the classifier 25 by the sand circulation elevator 24 together with the solid fine particles 180 discharged from the waste heat boiler 31. In the heating combustor 320, the unburned gas and the auxiliary fuel F are burned, and the steam temperature is raised to about 500 ° C. In the apparatus of FIG. 12, the power generation efficiency can be about 30% due to the high temperature and high pressure of the steam and the small air ratio and low sensible heat of exhaust gas.

  FIG. 13 is a layout diagram of a gasification cogeneration type fluidized bed gasification and melt combustion apparatus according to an embodiment of the present invention. In FIG. 13, the gasifier 1, the melting combustion furnace 41, the water chamber 178, the waste heat boiler 31, the dust collector 43, the induction ventilator 54 and the like are the same as those in the apparatus of FIG. 10. In FIG. 13, a reaction tower 310 is arranged between the waste heat boiler 31 and the dust collector 43, and in the reaction tower 310, a neutralizing agent N such as slaked lime slurry is added to the combustion exhaust gas, and HCl is removed. The exhaust gas from the reaction tower 310 is used in the gas turbine 420 through the dust collector 43. In the gas turbine 420, the air A is compressed by the compressor C and supplied to the combustor CC, and the fuel F is combusted in the combustor CC. The combustion gas and the compressor 410 are compressed and supplied to the combustor CC. Becomes the working fluid of the turbine T. The exhaust gas from the gas turbine 420 sequentially passes through the super heater 430, the economizer 440, and the air preheater 450, and is released to the atmosphere by the induction fan 54. The steam generated in the waste heat boiler 31 is heated by the exhaust gas of the gas turbine 420 in the super heater 430 and supplied to the steam turbine ST.

  FIG. 14 is a flow chart showing the steps of the pressurized gasification combined power generation fluidized bed gasification and melt combustion method of the embodiment of the present invention. The high-temperature and high-pressure product gas 29 produced in the pressurized gasification furnace 1 is introduced into the waste heat boiler 31 'to generate steam and cool itself. The product gas exiting the waste heat boiler is divided into two parts, one is added to the melt combustion furnace 41 and the other is added with the neutralizing agent N, and the HCl is neutralized and introduced into the dust collector 43 '. In the dust collector 43 ′, the low melting point substance in the product gas solidified by the temperature drop is separated from the product gas, sent to the melting combustion furnace 41, and melted. The product gas from which the low melting point material has been removed is used as a fuel gas in the gas turbine GT. Exhaust gas from the gas turbine GT is heat-exchanged by the super heater SH and the economizer ECo, then processed by the exhaust gas treatment device 510, and released into the atmosphere. Exhaust gas from the melt combustion furnace 41 is introduced into the exhaust gas treatment device 510 through the heat exchanger EX and the dust collector 43. The molten ash 44 discharged from the melting furnace is rapidly cooled to be slag. The solid content 38 discharged from the dust collector 43 is treated with chemicals in the processor 194.

  According to the process of FIG. 14, the gas generated from the waste is used as fuel after the removal of HCl and solids, so that the gas turbine is not corroded and the HCl is removed. Therefore, high temperature steam can be generated by the gas turbine exhaust gas.

1 is a schematic vertical sectional view of a main part of a gasifier according to a first embodiment of the present invention. FIG. 2 is a schematic horizontal sectional view of a fluidized bed furnace of the gasifier of FIG. 1. FIG. 6 is a schematic vertical sectional view of a main part of a gasifier according to a second embodiment of the present invention. FIG. 3 is a schematic horizontal sectional view of a fluidized bed furnace of the gasifier of FIG. 2. FIG. 6 is a schematic vertical sectional view of a gasifier according to a third embodiment of the present invention. FIG. 6 is a schematic vertical sectional view of a gasifier according to a fourth embodiment of the present invention. The flowchart which shows an example of the refinement | purification process of product gas. The flowchart which shows one example of the process by which ash is fuse | melted. FIG. 10 is a schematic vertical sectional perspective view of a gasification and fusion combustion apparatus according to a fifth embodiment of the present invention. 1 is a layout diagram of a fluidized bed gasification and fusion combustion apparatus according to an embodiment of the present invention used in combination with a waste heat boiler and a turbine. The layout of the fluidized-bed gasification and fusion combustion apparatus of the Example of this invention used in combination with a gas cooling chamber. The layout of the fluidized-bed gasification and fusion combustion apparatus of the Example of this invention used in combination with a waste heat boiler and a reaction tower. The layout of the fluidized-bed gasification and fusion combustion apparatus of the Example of the gasification cogeneration type | mold of this invention. The flowchart which shows the process of the fluidized-bed gasification and the melt combustion method of the Example of the pressurization gasification combined cycle type of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Gasification apparatus, 2; Fluidized bed furnace, 3; Periphery part of furnace bottom, 4; Center part of furnace bottom, 5: Incombustible discharge port, 6; Inclined wall, 7: Central fluidization gas, 7 '; Gasified gas, 8; peripheral fluidized gas, 9; moving bed, 9 ′; intermediate layer (intermediate zone), 10; fluidized bed, 11; gasified raw material (combustible), 12; double damper, 13; compression feeder, 14; Dust feeder, 15; Roots blower, 16; Conical chute, 17; Metered discharger, 18, 20; Swing valve, 19, 19 '; Swing cut valve, 22; Discharge valve, 23; , 24; Sand circulation elevator, 25; Classifier, 27, 28; Incombustible material, 29; Product gas, 31, 31 ′; Waste heat boiler, 32; Cyclone separator, 36; Waste water treatment device, 37; 38; Solid content 41; Melt combustion furnace 43, 43 ' Dust collector, 44; molten ash, 54; induction fan, 55; exhaust tower, 102; free board, 104; combustible supply port, 106; gas dispersion mechanism, 108; gas outlet, 114; char tar, 134 Air nozzle, 136; auxiliary burner, 140; primary combustion chamber, 142; combustible gas inlet, 150; secondary combustion chamber, 162; radiation plate, 176; slag, 178; water chamber, 183; economizer, 185; 186, 188; Air preheater, 194, 510; Processor, 280; Gas cooler, 310; Reaction tower, 320; Superheater heated combustor, 420; Gas turbine, A; Air, C; Compressor, CC Combustor, ECo; Economizer, F; Auxiliary fuel, G; Gasification zone, N; Neutralizer, S; Oxidation zone, SH; Superheater, ST; Steam turbine, T; Turbine, W; water.

Claims (15)

In an apparatus that melts ash in a melting furnace after gasifying waste in a fluidized bed furnace,
The fluidized bed furnace includes fluidized gas supply means for supplying fluidized gas,
Supplying the waste to the fluidized bed furnace and gasifying it to produce gas and char;
The melting furnace supplies the gas discharged from the fluidized bed furnace and the char to melt ash,
The fluidized bed furnace comprises an inclined furnace bottom, and an incombustible material discharge port for discharging the incombustible material and the fluid medium contained in the waste at a lower part of the inclined furnace bottom,
A chute for discharging the incombustible material and the fluid medium below the incombustible material outlet, and a quantitative discharger for quantitatively discharging the incombustible material and the fluid medium from below the chute in a horizontal direction;
The gasification and melting apparatus characterized in that the incombustible material and the fluidized medium that have been quantitatively discharged are separated, the separated fluidized medium is returned to the fluidized bed furnace, and the metal in the incombustible material is recovered unoxidized.   The gasification and melting apparatus according to claim 1, further comprising an elevator that conveys the sorted fluid medium.   3. The gasification and melting apparatus according to claim 1, further comprising a valve that seals a pressure in the furnace when the incombustible material and the fluidized medium are discharged from the fluidized bed furnace.   The gasification and melting apparatus according to any one of claims 1 to 3, wherein the fluidized bed furnace has an inner pressure of atmospheric pressure or less.   The gasification and melting apparatus according to any one of claims 1 to 4, wherein the separated fluidized medium is returned to the fluidized bed furnace via a lock hopper.   6. The gasification and melting apparatus according to claim 5, wherein the fluidized bed furnace has an inner pressure of atmospheric pressure or higher. In the method of melting ash in a melting furnace after gasifying the waste in a fluidized bed furnace,
Supplying the waste to the fluidized bed furnace and gasifying it to produce gas and char;
The incombustible material and the fluid medium contained in the waste are taken out from the incombustible material outlet at the lower part of the inclined bottom of the fluidized bed furnace and discharged in a horizontal direction. The separated fluid medium is returned to the fluidized bed furnace, the metal in the incombustible material is recovered unoxidized,
A waste treatment method comprising melting the ash by supplying the gas discharged from the fluidized bed furnace and the char to a melting furnace.   8. The waste processing method according to claim 7, wherein the sorted fluid medium is conveyed by an elevator and returned to the fluidized bed furnace.   The waste disposal method according to claim 7 or 8, wherein the incombustible material and the fluidized medium are discharged from the fluidized bed furnace while sealing the furnace pressure.   The waste treatment method according to claim 9, wherein the sealing of the furnace pressure is performed by a valve.   The waste fluid processing method according to any one of claims 7 to 10, wherein the fluidized bed furnace is configured such that the pressure in the furnace is set to atmospheric pressure or lower.   12. The waste processing method according to claim 7, wherein the sorted fluid medium is returned to the fluidized bed furnace through a lock hopper.   The waste fluid processing method according to claim 12, wherein the fluidized bed furnace has a furnace pressure of atmospheric pressure or higher.   The waste fluid treatment method according to any one of claims 7 to 13, wherein the fluidized bed furnace is maintained at a fluidized bed temperature of 450C to 650C.   The incombustible material and the fluid medium contained in the waste are taken out downward from the incombustible material outlet at the lower part of the inclined bottom of the fluidized bed furnace, and then quantitatively discharged in a horizontal direction. The waste disposal method according to any one of 7 to 14.

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