WO2002021047A1 - Waste-gasified fusion furnace and method of operating the fusion furnace - Google Patents

Abstract

A waste-gasified fusion furnace (1), comprising a gasified furnace body (2) of shaft furnace type for inputting waste A in order from the top thereof into the furnace (1) to thermally cracking the waste after drying by hot gas and a fusion chamber furnace (3) connected integrally with the lower end opening (2b) of the gasified furnace body (2), accepting the thermally cracked slag of the waste (A), and having a heating and melting burner disposed toward the inclined surface of the thermally cracked slag, wherein an outlet (6) for taking out the melt formed of molten slag and metal is provided in the fusion chamber furnace (3), and a gas feed pipe (8) for feeding the hot gas, produced in the fusion chamber furnace (3) when the thermally cracked slag is heated and fused, to the gasified furnace body (2) is connected to the fusion chamber furnace (3) together with a header duct (9).

Description

 Description Waste gasification melting furnace and operating method of the melting furnace [Technical field]

 This invention heats and removes municipal waste and industrial waste by heating and drying and pyrolyzing them to remove incombustible components into slag, and the gas generated in the furnace is treated and exhausted by an exhaust gas treatment device. The present invention relates to a melting furnace and its operation method. Specifically, waste gas is dried in a single furnace. Waste gas with improved system fluctuations and instability due to the dispersion of garbage (waste) when melting ash generated by pyrolysis The present invention relates to a chemical melting furnace and an operation method of the melting furnace. (Background technology)

In addition to kilns and fluidized-bed furnaces, shaft furnaces are generally used for this type of gasification and melting furnace. There are two types of shaft furnaces, one of which is as shown in Fig. 12;!: Only waste A is charged into door 51, and fuel R is supplied from the bottom of furnace 51. And oxygen-rich air P is blown through a combustion parner 52 to heat and melt the waste A. The pressure of the high-temperature (for example, 170 ° C) combustion gas Q introduced from the furnace bottom As a result, the waste A that is being heated and melted is balanced, and a melting zone that is a boundary with the combustion gas Q is formed in a dome shape 53. Then, the molten slag S flows down and is taken out of the furnace. On the other hand, the combustion gas Q rises between the wastes (gap) in the furnace, and the rising combustion gas Q causes the waste A to be dried in the upper layer in the furnace, and the dried waste A in the middle layer. Is thermally decomposed, and the gas G Is exhausted from the exhaust port 5 5. The waste A in the furnace 51 undergoes a drying process and a pyrolysis process, and the pyrolysis residue gradually descends to the vicinity of the furnace bottom under gravity, where it is heated and melted by high-temperature combustion gas to form slag S as described above. To take out.

 In general, a feature of shaft furnaces is that they efficiently achieve high-temperature conditions. In other words, the refuse injected into the shaft furnace flows down while burning, and the generated gas is used to heat the refuse injected while rising. Solid garbage descends according to gravity, while gaseous gas rises because it is light. Since heat is exchanged directly, heat efficiency is high. Also, the long convection time has the effect of reducing fluctuations in garbage quality on average.

By the way, as shown in Fig. 14 (a), the dome-shaped melting zone 53 has the load of the waste A in the furnace body and the combustion which is blown from the furnace bottom and tries to rise to the top of the furnace. Gas (hot gas) When the pressure of Q is balanced, it is kept in a dome shape. However, depending on the shape of the incombustibles contained in the waste A, depending on the quality of the waste, the dome surface 53 is disturbed as shown in Fig. 14 (b), and a part of the combustion gas Q is May break through through 5 3 In addition, there are various fluctuation factors in garbage. For example, when watery garbage is thrown in, steam is actively generated. If the waste is plastic, it will significantly increase the amount of gas generated, cause molten waste to adhere to the furnace wall, etc., and if the waste contains sheet or plate-like waste, In other words, the gas flow becomes uneven, and the quality of the waste (that is, the amount of heat generation) increases or decreases the amount of generated gas, or the temperature of generated gas becomes higher or lower, which causes a disturbance in the reaction. I have. As a result, deposits are formed on a part of the furnace, and the waste layer located on top of the furnace does not flow down and is suspended from the shelf. Eventually, a cavity is formed at the bottom and the shelf becomes unsupported and slips, A so-called shelf drop phenomenon may occur. Then, the dome-shaped melting zone 53 may be destroyed by these effects.

 Thus, the reaction between the waste A in the furnace 51 and the combustion gas Q rising from the bottom is disturbed, and as a result, the amount and composition of the exhaust gas G exhausted from the furnace vary.

 As shown in Fig. 13, the other type of the shaft furnace method is to add limestone M and coke N together with waste A through a charging chute 64 to dry and pyrolyze it. Oxygen gas O and air P are blown in from nearby to burn continuously. Since the input waste A may contain a large amount of water (for example, 30 to 50%), the water was evaporated by the combustion gas Q from below in the upper layer in the furnace 61 and dried. After that, the intermediate layer below it pyrolyzes to gasify the combustible components in the waste, and the pyrolysis residue is passed through the lower layer of the furnace to remove oxygen 〇 and air P from the tuyere 63 and tuyere 62. Injection actively burns and heats and melts it, converts it into slag and removes it with a slag machine 65, etc., and exhausts combustible gas G mainly generated during thermal decomposition from an exhaust port 66. This combustible gas is used as fuel, generates steam by a boiler, etc., generates electricity with a steam turbine, and generates unnecessary exhaust gas.

 In the kiln-type or fluidized-bed gasification melting method, drying and thermal decomposition are performed in a kiln or a fluidized bed, and the generated unburned char and non-flammable components are heated to a high temperature and melted.

In addition to the above-mentioned gasification and melting furnace method, there is a waste-storage device of a single-stroke furnace method, but in this method, the residue after burning the waste is generated as ash. In the past, processing such as filling the ash was performed. In recent years, with the tightening of regulations on pollution, the ash has been melted in another ash melting furnace to further reduce its volume. The situation is changing so that heavy metals should be slagged so that they do not easily elute outside. The ash melting furnace has the advantage that ash can be melted stably, but the disadvantage is that the high-temperature gas generated during melting cannot be used effectively for waste treatment. In the shaft furnace method, the melting and gasification are performed in a single furnace by the heat of the garbage, so the shaft furnace method is advantageous from this viewpoint.

 Conventionally, the following technologies have been proposed, but the following problems still remain with those technologies.

1) As described in Japanese Patent Application Laid-Open No. 11-218183, the waste was pyrolyzed by heating it at about 600 ° C in a tunnel type heating / pyrolysis furnace. A structure has been proposed in which the generated pyrolysis residue (including combustibles) is charged into a shaft furnace-type melting furnace, and oxygen gas is blown into the pyrolysis residue to burn and melt. In the case of this equipment, the equipment cost is enormous due to the indirect heating method. For example, in a standard-scale facility with a tunnel type heating furnace of 150 ton / day, width: 1.5 m, height : 0.5 m, length: 10 number irf, etc. Furthermore, the rate at which heat is conducted through such a thick waste layer is extremely slow as compared with the direct heating method of the shaft furnace method, and the heat efficiency of the tunnel furnace is extremely poor, so a large amount of heating fuel is required. . In addition, the melting reaction zone in the shaft melting furnace has the same problems as those described above. In other words, since a larger amount of oxygen gas and the like than tuyeres 62 and 63 is blown into the pyrolysis residue that has fallen to the lower part of the melting furnace 61, the part where the blown gas contacts the pyrolysis residue melts. As shown in Fig. 15 (a), a molten film 68 is formed. However, if there is a change in the properties of the pyrolysis residue in the vicinity, for example, debris of setomono, a melting reaction zone 67 will be formed in Fig. 15 ( b) turbulence, resulting in burning Melting becomes unstable, and the effect appears as fluctuations in the amount and composition of the exhaust gas.

2) As described in Japanese Patent Application Laid-Open No. H11-11332, a dome-shaped melt is formed at the reduced-diameter opening at the bottom of the furnace. In the zone, a structure that burns and melts by contacting with oxygen gas has been proposed and has been successfully operated for many years. With this device, as described above, when a high melting point foreign substance mixed in the pyrolysis residue, for example, a large piece of setomono, reaches the dome-shaped melting zone, it melts as shown in Fig. 14 (b). 53 The part of 3 is broken and the combustion gas Q blown from below penetrates into the upper unburned cracking layer from the broken point, and the reaction in the entire furnace is disturbed. As a result, the operation becomes unstable due to fluctuations in the flow rate and properties of the exhaust gas exhausted from the furnace top. As described above, in any type of shaft furnace melting furnace, turbulence due to the quality of waste may occur, and as a result, fluctuations in exhaust gas may cause various problems. For example, if the flue gas is burned and heat is recovered as steam by a poiler, and the steam is introduced into a steam turbine generator to generate electricity, if the flow rate or properties of the flue gas fluctuate, it should be sent to the steam turbine The amount of steam will fluctuate rapidly. When the steam fluctuation is large in this way, the turbine itself is mechanically damaged, and even if there is no mechanical problem, the power generation amount fluctuates rapidly with the steam fluctuation. Adversely affect In order to prevent this, it is wasteful to waste heat such as putting excess steam directly into the condenser (pseudo-condenser) and discarding heat. Also, since exhaust gas contains dioxins, nitrogen oxides, chlorine and sulfur oxides, such harmful substances are removed by injecting chemicals into the gas. However, if the exhaust gas fluctuates rapidly, the amount of chemicals injected must always be higher than the usual value, which not only wastes but also increases final waste. Therefore, it is a major problem in the current situation where it is increasingly difficult to secure landfill sites. Also, in general, furnace gas is flammable, so when mixing and burning air, if the gas fluctuates, if the amount of air is small, unburned C〇 may exceed environmental regulation values. It is necessary to mix more air. As a result, not only does combustion exhaust gas increase, equipment costs increase, but also the amount of waste heat that is released when heat is recovered by the boiler, resulting in a poor heat recovery rate. In addition, if combustion is not stable, NO x is generated, so a large amount of chemicals such as urea water are required to remove it. Furthermore, sufficient equipment capacity must be ensured to cope with fluctuations in exhaust gas, resulting in higher equipment costs. Thus, despite the importance of how to stabilize the process in waste treatment facilities, conventional technologies cannot completely cope with it.

 3) In any of the shaft furnace type melting furnaces described in the above publications, a high temperature (about 140 to 160 ° C) region is formed in the furnace and heated and melted. If this region is disturbed and becomes abnormal, for example, the molten portion of the pyrolysis residue may adhere to the furnace inner wall and hinder the continuation of operation, and the operating rate will decrease.

4) For the reasons described in 3) above, the refractory in the furnace was easily damaged by exposure to molten slag and high-temperature gas.In order to repair the damaged refractory, the internal waste was removed. It is necessary to lower the furnace temperature first. For this reason, the operation rate of the equipment decreases. Furthermore, in order to deal with refractory damage under severe conditions, the furnace wall is made to be a water-cooled wall, and a thin refractory is attached to the water-cooled wall to reduce the adhesion of the slag itself and the melting equilibrium (self-coating) effect. Use May be. In this case, thermal loss becomes enormous.

 5) As shown in Fig. 16, the incineration ash D generated by the stoker-type waste combustion device described above is put into the furnace 71 through the input chute 73, and the combustion Some melting furnaces have a structure in which fuel is blown together with oxygen-enriched air and heated and melted. In this melting furnace, as described above, incineration ash D can be stably melted and turned into slag.However, since the high-temperature gas Q after being melted is discharged from the furnace as it is, the boiler etc. There is no use other than heat recovery. In other words, the high-temperature gas Q cannot be used for drying or pyrolysis of waste or used for preheating incineration ash, so its thermal efficiency is poor. In addition, there is a method of melting incineration ash by electric arc or plasma instead of the above combustion burner, but it is uneconomical due to large power consumption.

 SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and two furnace bodies (processes) of a conventional melting furnace and an ash melting furnace of the above-described shaft furnace method are organically combined and integrated to form a conventional melting furnace. The char (pyrolysis residue or incinerated ash) generated in the furnace section is melted in the ash melting furnace section, and the high-temperature combustion gas (hereinafter, also referred to as high-temperature gas) generated there is introduced (supplied) to the melting furnace section. It aims to provide a stable waste gasification and melting furnace (process) with high thermal efficiency by heating and pyrolyzing waste, and at the same time replace expensive gas fuel used in conventional melting furnaces. The objective is to provide a method for operating a waste gasification and melting furnace that can use inexpensive oil as fuel.

[Disclosure of the Invention]

In order to achieve the above object, the waste gasification and melting furnace according to claim 1 of the present invention is configured to sequentially charge waste into the furnace from above. A shaft furnace type or a fluidized bed type gasification furnace body for drying and pyrolysis after drying with high-temperature gas, and a pyrolysis of the waste material integrally connected to the lower end discharge port of the gasification furnace body A melting chamber furnace provided with a heating / melting parner toward an inclined surface of the pyrolysis residue; and a melting chamber furnace for taking out a molten material of molten slag and metal. An outlet is provided, and a mechanism is provided for supplying high-temperature gas generated during heating and melting of the pyrolysis residue in the melting chamber furnace to the gasification furnace main body.

 According to the waste gasification / melting furnace having the above configuration, high-concentration oxygen and fuel are blown into the pyrolysis residue by heating and melting the pyrolysis residue in the melting furnace, and remain in the pyrolysis residue. By burning with carbon, a high temperature of about 165 ° C. is obtained, and the incombustible components in the residue are turned into molten slag. Oxygen is supplied in excess of the theoretical combustion amount, and metal salts in the residue are oxidized. For example, iron can be discharged in the form of iron oxide and copper in the form of copper oxide in a molten and mixed state. If oxygen is supplied in a shortage state, it becomes a reducing flame, and when the metal in the residue becomes molten metal, it is heavier than slag and is stored in the lower part of slag. Since the present invention is basically in an oxidizing atmosphere, and therefore the molten metal is oxidized, there is no useful industrial application by itself, and there is no need to separate the molten metal from the slag separately. For example, molten metal can be used together with slag for applications such as roadbed paving stones.

In addition, the high-temperature gas used to melt the pyrolysis residue in the melting chamber furnace is supplied to the furnace body for drying and pyrolysis of the waste. Most of the sensible heat possessed by the high-temperature gas is It is used for reaction with waste. The temperature of the exhaust gas exhausted from the furnace is reduced to, for example, about 300 ° C, so that the energy is lower than that of a conventional melting-only furnace (see Fig. 16). Since there is no waste and the high thermal efficiency of the shaft furnace melting furnace can be inherited, fuel consumption, power consumption and oxygen consumption are all low, and running costs are low.

 On the other hand, oxygen is left in the gas used for the melting, and the gas is supplied to the gasification furnace main body so that the exhaust gas temperature becomes about 300 ° C., so that the temperature of the residue is about 800 ° C. However, it is possible to keep the temperature at which the residue hardly melts and adheres. In other words, since it is not melted in the gasifier main body, there is no occurrence of abnormal adhesion of pyrolysis residues or shelf hanging phenomenon, which are likely to occur in a conventional shaft furnace type melting furnace, and stable operation can be achieved. The life of the refractory inside the gasifier itself will be dramatically extended, and the operating rate of the facility will be improved. In addition, since the melting chamber furnace is separate from the gasification furnace main body and only the refractory in the space inside the melting chamber furnace is mainly damaged, it can be easily repaired by spraying the refractory for repair, and the operation rate is reduced. Extremely high. Moreover, the structure of the whole device is simple, the operation is simple, and the operation and maintenance are easy.

Therefore, stable operation is possible even if the fluctuation range of the amount of waste input per unit time is expanded. In addition, since the flow rate and properties of the exhaust gas from the furnace top are stable, it is possible to process the exhaust gas properly.In other words, the generated gas flow rate, gas composition and temperature, which are the points of operation of the gasification and melting furnace, are stabilized, The proportion of excess air to respond to sudden gas fluctuations can be minimized. Therefore, abnormality of carbon monoxide is suppressed, and dioxin and NO x, generation of S_〇 _x is suppressed, thus it is possible to reduce the gas cleaning chemicals consumption as urea or activated carbon or anti lime, fly ash Can also be reduced. In addition, since the amount and properties of the exhaust gas are stabilized, stable and high-quality electric power can be obtained, for example, by power generation equipment such as a boiler and a steam turbine. In addition, reducing the amount of excess combustion air As a result, the steam generated from the waste heat boiler can be used effectively, and most of the steam can be sent to the steam turbine, enabling more efficient power generation. The burner may be not only a method for burning fossil fuels and various gas fuels, but also a plasma method.

 As described in claim 2, an introduction path for oxygen or oxygen-enriched air (also referred to as an oxygen-containing gas) is connected to a high-temperature gas supply path from the melting chamber furnace to the gasification furnace main body. In addition, it is preferable that the temperature of the high-temperature gas supplied to the gasification furnace main body be lowered and the oxygen concentration be increased.

 In the melting furnace according to claim 2, the temperature of the high-temperature gas can be reduced by blowing a normal-temperature oxygen-containing gas into the high-temperature gas supplied into the gasification furnace main body. As a result, it is possible to prevent damage to the refractory attached to the inner wall, such as the gas supply pipe, duct, and header in the high-temperature gas supply path. In addition, it is difficult to sufficiently react with waste even if the room temperature oxygen-containing gas is directly blown from the outside into the furnace body.However, by blowing the oxygen-containing gas at a high temperature together with the high-temperature gas, the waste is converted into oxygen. It reacts and is partially burned. If the amount of oxygen injected is large, the temperature of the mixed gas decreases, but the temperature of this part increases due to the heat of reaction with the waste. By adjusting the amount of oxygen blown so that the thermal decomposition residue does not soften, the residue can be stably supplied to the melting chamber.

 As described in claim 3, in order to supply a high-temperature gas from the melting furnace to the gasification furnace main body, a supply path is provided at a connection point between the gasification furnace main body and the melting chamber furnace. It can be provided or a lower part in the gasification furnace main body and a space in the melting chamber furnace can be connected by duct.

In the melting furnace described in claim 3, the high-temperature gas generated in the melting chamber furnace is supplied to the gasification furnace main body and used for drying and pyrolysis of waste. As a result, the energy possessed by the high-temperature gas can be used without waste, and the thermal efficiency is high.

 As described in claim 4, a pyrolysis residue delivery mechanism such as a screw type, a rotary blade type, a pusher type, or the like is provided near a connection point between the gasification furnace main body and the melting chamber furnace. Is desirable. The residue is continuously supplied as it descends by gravity according to the angle of repose by an amount corresponding to the amount melted in the melting furnace. However, it is desirable to prepare for abnormal obstructions such as large foreign objects and hanging shelves.

 With this configuration, the pyrolysis residue generated in the gasification furnace body is sent out into the melting chamber furnace by the feed mechanism by a fixed amount, and the amount of the pyrolysis residue sent out is adjusted according to the melting state of the pyrolysis residue in the melting chamber furnace. Can be.

 As described in claim 5, a tuyere for blowing an oxygen-containing gas into the thermal decomposition residue can be provided in the melting chamber furnace.

 With this configuration, oxygen-containing gas such as oxygen can be blown from the tuyere into the pyrolysis residue deposited in the melting chamber furnace and burned, and heated to a temperature close to the melting temperature. By adjusting the amount of oxygen, the temperature of the pyrolysis zone generated in the gasifier main body can be adjusted, for example, to around 800 ° C.

 As described in claim 6, the temperature of the high-temperature gas supplied from the melting chamber furnace to the gasification furnace main body is adjusted to 100 to 130 ° C., and the gas is In order to adjust the supply amount of oxygen so that the waste put into the furnace and dried is heated at a temperature of 500 to 100 ° C to generate pyrolysis residues. It is preferable to provide a control device.

With this configuration, waste that has been removed after drying Since the temperature is controlled within the range of 500 to 100 ° C, the minimum temperature of 500 ° C required to thermally decompose the combustible components in the waste is secured, and the temperature of 100 ° C is maintained. Since it is below C, there is no risk that the pyrolyzed residue (ash) will begin to soften. In addition, the high-temperature gas generated in the melting chamber furnace is at a very high temperature of around 160 ° C, but the temperature of the high-temperature gas falls within the range of 100 ° C to 130 ° C. The problem of the quality and life of the refractory adhered to the inner wall such as the gas supply pipe, duct, and header in the supply path is eliminated.

 The temperature of the high-temperature gas supplied from the melting chamber furnace to the gasification furnace main body is 100 ° C. or more, and the waste in the gasification furnace main body is as described in claim 7. It is preferable to adjust the temperature and supply amount of the high-temperature gas so that the gas is heated at a temperature of 800 ° C. or less to generate a pyrolysis residue.

 In the waste gasification and melting furnace according to claim 7, since the waste in the gasification furnace body is heated at a temperature of 800 ° C or less to generate a pyrolysis residue, the gasification furnace is There is no abnormal adhesion of pyrolysis residues on the main unit and no hanging on the shelves, stabilizing the operation and dramatically extending the life of refractories.

 As set forth in claim 8, a charging port for incombustible substances such as ash or sludge is provided below a middle portion of the gasification furnace main body in a height direction, and a screw is provided near the charging port. Type · Rotating blade type · Pushing mechanism such as a set of pushers or a gas blowing mechanism for accompanying gas can be added.

In the waste gasification and melting furnace described in claim 8, incombustible substances such as ash or sludge is charged into the waste layer in the middle part of the furnace by a pushing mechanism or a blowing mechanism of accompanying gas. Since the waste accumulated above the charging position acts as a filter, the high-temperature gas supplied into the furnace body does not scatter ash etc. And is efficiently heated. Thus, the invention according to claim 8 can efficiently treat a wide variety of wastes. As described in claim 9, an inlet for injecting incombustibles alone or together with fuel and oxygen-containing gas can be provided in the melting chamber furnace.

 According to the waste gasification and melting furnace described in claim 9, ash and the like can be directly charged into the melting furnace and melted together with the pyrolysis residue to form slag.

 As set forth in claim 10, a hot cyclone is provided in the middle of a high-temperature gas supply path from the melting chamber furnace to the gasification furnace main body, and is provided at an inlet of the cyclone or in the cyclone. An inlet for incombustible substances such as ash or sludge can be provided, and a feed path for the collection by the cyclone can be provided from the cyclone to the melting chamber furnace.

 In the waste gasification and melting furnace described in claim 10, after the ash or sludge blown into the hot cyclone comes into contact with the high-temperature gas and is heated instantaneously, it is charged into the melting chamber furnace. The hot gas in the hot cyclone is supplied to the furnace body in a state where the heat is taken away by the ash and sludge and the temperature is lowered, and the supply pipe and header are damaged. It is difficult to damage the refractory inside the furnace body.

 As set forth in claim 11, a level meter for properly maintaining a melt flow rate and a level of a pyrolysis residue layer during heat melting by the heat melting furnace in the melting chamber furnace. Either an industrial television camera, a microwave measuring device or a radiation measuring device can be deployed as a side device.

According to the waste gasification / melting furnace set forth in claim 11, according to the measurement by the level measurement device, the waste gasification / melting furnace is heated by a parner in the melting chamber furnace. Since the level of the pyrolysis residue layer during thermal melting can be maintained at an appropriate level, the pyrolysis residue can be reliably and accurately melted and turned into slag. In addition, if a TV camera is installed, it is possible to grasp not only the status of slag generation and flow, but also the status of damage to the refractory in the melting furnace, so that the repair time can be accurately determined. As set forth in claim 12, a charging hole for a repair refractory spraying device is provided in the melting chamber furnace wall, and a damaged portion of the refractory in the melting chamber furnace is repaired from outside. It is preferable to configure it so that it can be used.

 According to the waste gasification and melting furnace described in claim 12, a damaged portion of a refractory wall such as a ceiling is detected, and the repair refractory is sprayed by a gun as a spraying device and repaired. The operation time is about 20 minutes and the operation is easy. In addition, the time required to stop operations for repairing refractories is greatly reduced compared to conventional melting furnaces, thus improving equipment utilization. As described in claim 13, in the vicinity of the middle part in the height direction of the gasification furnace main body, whether the gasification furnace is rapidly expanded or contracted in a tapered shape as compared with a portion immediately above the furnace inner wall. Thus, an annular space that is not filled with waste is formed, and high-temperature gas supplied from the melting furnace to the gasification furnace main body can be guided to the annular space.

 With this configuration, a gas header can be provided inside the furnace as part of the furnace body, instead of the header duct that is installed outside the furnace.This simplifies the structure of the equipment and improves the durability of the header. It is improved and installed inside the furnace, so there is little thermal loss of the supplied gas. Furthermore, hot gas can be evenly introduced into the waste layer.

As set forth in claim 14, deposited in the melting chamber furnace A plurality of gas suction ports are provided on an inner wall in contact with the pyrolysis residue layer that is formed. It is preferable that each of the gas suction ports is connected to the gas supply pipe, and the waste gasification and melting according to claim 14, wherein According to the furnace, the high-temperature gas generated in the melting chamber furnace can be supplied into the furnace body not through the space but through the layer of the pyrolysis residue, so that the high-temperature gas can be used for preheating the pyrolysis residue. In addition, if each gas inlet is set at a depth of, for example, about 100 mm from the surface of the pyrolysis residue layer, the flow rate of gas flowing into each suction port becomes slow, and the pyrolysis residue is entrained in the high-temperature gas. It is possible to reduce scattering and mixing.

 As set forth in claim 15, the main body of the gasification and melting chamber furnace is a fluidized bed furnace, and a pyrolysis residue layer sieved from a fluid medium such as sand circulating in the furnace body. The residue accompanying the top gas generated in the gasification furnace main body and the dust collected at the cycle port or the like can be supplied to the melting chamber furnace.

 As in the case of the waste gasification and melting furnace described in claim 15, if a larger amount of garbage (consisting of carbon and ash) is circulated than the amount of garbage to be supplied, moisture and non-combustible Fluctuations in combustion due to minute fluctuations can be averaged and absorbed (that is, the fluctuation width can be reduced), thus stabilizing combustion.

The method for operating a waste gasification / melting furnace according to claim 16 is characterized in that air, oxygen or oxygen-enriched air is provided at an upper part in the gasification furnace main body at an air ratio of 0.5 to 2.5. In order to raise the temperature of the exhaust gas exhausted from the furnace top by adding an oxygen-containing gas such as the flow rate of the hot gas supplied from the solvent Torushitsu furnace was adjusted to introduce to N ₂ + 0 ₂ flow rate and the gasification furnace body, said exhaust gas (gas exiting the waste bed of the gasification furnace body the C_〇 ₂ concentration) is characterized in that to control a high concentration. In the gasification smelting reduction furnace, when the temperature of the exhaust gas is controlled at, for example, 300 ° C. and the temperature of the pyrolysis residue is 800 ° C., the amount of oxygen is increased to increase the amount of thermal decomposition. If the temperature of the residue increases, the temperature of the exhaust gas can be increased. Moreover, by keeping the temperature of the exhaust gas at 500 ° C. or less, refuse (waste) does not burn up due to blown air or oxygen, and stable gasification can be performed. Since the spontaneous ignition temperature of many gases is around 700 ° C, the safe temperature for partial combustion without generating a flame is as described above, taking into account fluctuations in the quality of garbage, etc. It is desirable to keep the temperature below ° C. If the temperature of the gasification gas coming out from the gasification area and the low temperature of 3 0 0~ 5 0 0 ° C , since the C_〇 ₂ is more than C_〇, in the first 6 wherein the scope of the claims, The gasification gas temperature is kept low in order to achieve a small amount of fuel.

 Oxygen or air can be further blown into the partial combustion gas generated from dust in the gasification furnace main body from the outside to reburn the combustion exhaust gas. At this time, since the calorific value of the partial combustion gas varies depending on the calorific value of the refuse, the air ratio is increased when the calorific value is high. Further, by recycling the treated cold combustion exhaust gas, the heat generation of the partial combustion gas can be diluted to 800 to 950 ° C. For example, a method of adjusting the temperature by spraying water can be used.

In order to finally bring the reburning temperature within the range of 800 to 950 ° C. The natural combustion temperature range of 700 to 800 ° C by adding oxygen or air from the outside at the top of the gasification furnace It is preferable to perform combustion in such a manner that combustion of oil, tar, organic matter, and the like proceeds, and clogging of a gas analysis conduit, a pressure gauge pressure pipe, and the like is eliminated. In this case, by adjusting the air ratio, the oxygen amount, and the spray water amount of the exhaust gas recirculation amount in the subsequent reburning furnace, the reburning temperature of 800 to 950 ° C is finally reached. realizable.

 According to this method, since the combustion temperature is controlled to 700 to 800 ° C. in advance, it is easy to adjust the subsequent reburning. The flammable gas such as hydrocarbons, carbon monoxide, and hydrogen contained in the gasification gas is higher than the natural ignition point (ignition temperature), and is easily completely burned by blowing air or oxygen at room temperature. This eliminates the need for a complicated structure such as a wrench. By paying attention to the direction of air or oxygen injection, fly ash can be easily prevented from sticking or accumulating on the furnace wall.

Also, according to this method, the combustion temperature can be kept constant, so that there is no generation of C〇 due to incomplete combustion. Too high a temperature does not increase the generation of N〇 _x .

 According to the method of operating this waste gasification and melting furnace, the temperature of the reburning of exhaust gas is reduced to 850 to 900 ° C, so that the material of the tube equipment of the subsequent boiler and air preheater can be reduced. Inexpensive materials can be used, and dioxins can be reduced. As a result, while the combustion temperature of the waste layer in the furnace body is lower than in the conventional method, the temperature of the pyrolysis residue generated in the pyrolysis zone is slightly higher than in the conventional method. The amount of LP gas used is reduced, and the calorific value of exhaust gas is also reduced. Therefore, the amount of combustion air supplied is reduced, and the amount of exhaust gas generated is also reduced.

 As set forth in claim 17, a part of the high-temperature gas generated in the melting chamber furnace is guided near the upper surface of a waste layer in the gasification furnace main body, and air, oxygen, or oxygen-rich gas is supplied. Oxygen-containing gas such as chemical vapor is added and burned, and the temperature of exhaust gas exhausted from the furnace top can be adjusted.

According to the operation method of the waste gasification and melting furnace described in claim 17, combustion starts in the gasification furnace regardless of the presence or absence of waste Can operate. In addition, since the temperature of the exhaust gas can be kept constant, it is possible to respond to changes in the amount of waste input over a wide range, and to minimize fluctuations and blow-through of exhaust gas.

 As described in claim 18, a part of the high-temperature gas generated in the melting chamber furnace is guided to an intermediate portion in the height direction of the gasification furnace main body, and further, Air near the upper surface of the waste layer. High-temperature gas generated in the melting chamber furnace, which burns by adding oxygen or oxygen-enriched air, is guided to the middle part in the height direction of the melting furnace main body, and air, oxygen or The combustion may be performed by adding an oxygen-containing gas such as oxygen-enriched air.

 According to the method for operating a waste gasification and melting furnace described in claim 18, the temperature and properties of the gas used for drying and pyrolysis of the waste in the furnace body are arbitrarily adjusted to improve efficiency. Good operation is possible, and it is possible to respond to changes in the amount of waste input over a wide range, and to minimize fluctuations and blow-through of exhaust gas.

 As described in claim 19, a part of the high-temperature gas generated in the furnace for the gasification and melting chamber is spaced apart in the height direction at a middle portion in the height direction of the gasification furnace main body. To a plurality of locations, and air, oxygen, or oxygen-enriched air can be added to the vicinity of the upper surface of the waste layer in the gasification furnace body and burned.

 According to the method for operating a waste gasification and melting furnace described in claim 19, the same effect as the operation method described in claim 18 can be obtained, but this effect covers almost the entire area inside the furnace body. So it is more effective.

As described in the second 0 term claims, controlling the total oxygen flow fed to the gasifier unit according to CO / CO ₂ ratio in the exhaust gas generated from the waste layer of the gasifier unit Can be. In other words, in the exhaust gas generated from the waste layer of the gasifier main body, It is preferable to adjust the total flow rate of oxygen fed into the gasifier body according to the C〇ZC〇 ₂ ratio so that the change in the C 0 / C〇 ₂ ratio is minimized.

 According to the invention set forth in claim 20, the following operation and effect can be obtained. That is,

 (1) Conventionally, when the quality of the garbage is high (the calorific value is large), the air ratio has been increased to prevent the combustion temperature from becoming excessively high. As a result, the temperature and flow rate of the flue gas fluctuated.

(2) Therefore, the invention described in the second 0 term the claims, the gas composition of the partially combusted gases _{(CO, C0 2, H 2} , H 2 0, CH 4) results of investigation focusing on,

(a) When the C〇 / C〇 ₂ ratio is large, the calorific value of the partial combustion gas (that is, the gas coming out of the waste layer of the gasification furnace itself) increases, and conversely, the C〇 / CO ₂ ratio This is based on the finding that when the value is small, the calorific value decreases.

(b) In this process, the partial combustion gas is reburned by adding air in the subsequent step, but at a temperature that is not too high to suppress N 抑 え る_x and high-temperature corrosion, the generation of dioxins and CO Usually, incineration is carried out in the range of 850 to 950 ° C, because it must be completely burned at a high temperature in order to suppress it.

 (c) The water spray amount, air ratio, and exhaust gas recirculation amount are controlled to keep the reburn temperature constant, but these methods involve fluctuations in the amount of exhaust gas.

 (d) It was found that the flow rate of total oxygen sent to the gasifier body should be adjusted to keep the CO / CO 2 ratio constant.

(e) For example, the calorific value rises suddenly or When the combustion of garbage becomes active, the combustion temperature rises and the amount of generated gas increases, so it can be suppressed by reducing the supply of oxygen.

 (f) Conversely, when the calorific value of the garbage decreases or the combustion becomes unsatisfactory, increasing the oxygen supply increases the amount of generated gas and can recover the combustion temperature.

(g) The gas flow rate is large when the C〇zco ₂ ratio contained in the gas coming out of the waste layer in the gasification furnace is large, and the gas flow rate is small when the COZC O: ratio is small.

) Therefore, the flow rate of gasification gas just before the re-combustion, can be controlled by indirect adjusting the total oxygen supply amount of C 0 / C_〇 to the gasification furnace body to the ₂ ratio is constant understood.

(i) CO, co ₂ can be measured fast読的by infrared spectroscopy. In addition, since the ratio is treated as the ratio (c〇 / co ₂ ratio), there is also the advantage that there is little malfunction for the trouble.

(j) Since this process accumulates a considerable amount of dust in the gasification furnace itself, the fluctuation cycle of the gasification reaction is about 10 times per hour. This period is sufficiently longer than the gas sampling delay (about 10 seconds) of the infrared spectrometer in (i) above, and can be used to control the gas composition (COZC 比₂ ratio) by the oxygen supply amount. Wear.

 (k) If the oxygen used for melting the residue is kept substantially constant while monitoring the molten state (slag flow), a constant molten state can be maintained. Also, since the amount of oxygen required to melt the slag is smaller than the amount supplied to the gasifier itself, it is unlikely to cause disturbance.

(1) When the gas generated by the gasification furnace is recombusted in the subsequent process, the composition and the gas amount of the gasification gas can be made substantially constant while adjusting the reburning temperature and the air ratio. And finally relapse The flow rate of the flue gas can be made substantially constant.

 (III) In other words, according to the present invention, when the calorific value of the dust is high, the incineration capacity of the dust is suppressed, and when the calorific value of the dust is low, the incineration capability of the dust is increased.

 (n) In the conventional incinerator, there is no effective method of controlling the amount of combustion exhaust gas, and good and uniform combustion has been achieved by frequently inputting garbage according to the change of garbage. However, according to the present invention, the temperature and the flow rate of the reburning exhaust gas can be finally controlled simply by controlling the gasification oxygen supply so as to keep the composition of the gasification gas constant.

 (0) The change in the amount of exhaust gas of the conventional incinerator due to the dispersion of the garbage causes a change in the garbage treatment capacity in the present invention. In other words, dust with a high calorific value reduces the processing capacity, and dust with a low calorific value increases the processing capacity. It is known that the change in the combustion state of garbage falls within a certain range because the conventional incinerator had a large enough garbage receiving hopper and the capacity of the furnace to keep a sufficient residence time. I have. On the other hand, in the present invention, the processing capacity of the refuse varies, but since a considerable amount of refuse is accumulated in the gasifier main body as described in (j) above, this serves as a buffer and has an effect of absorbing the fluctuation. . As a step-wise change in waste quality, there is usually a large-capacity waste receiving hopper, and this becomes a buffer.

 (P) Thus, according to the present invention, the temperature and flow rate of the final reburning exhaust gas can be made substantially constant, so that an excessive equipment margin, a limitation of the processing amount, and an extension of the life of the furnace can be expected.

[Brief description of drawings]

FIG. 1 shows a waste gasification and melting furnace according to a first embodiment of the present invention, wherein FIG. 1 (a) is a central longitudinal sectional view, and FIG. 1 (b) is FIG. 2 is a cross-sectional view taken along line bb in FIG.

 FIG. 2 is a central longitudinal sectional view showing a waste gasification / melting furnace according to a second embodiment of the present invention.

 FIG. 3 is a central longitudinal sectional view showing a waste gasification and melting furnace according to a third embodiment of the present invention.

 FIG. 4 is a central longitudinal sectional view showing a waste gasification / melting furnace according to a fourth embodiment of the present invention.

 FIG. 5 is a central longitudinal sectional view showing a waste gasification and melting furnace according to a fifth embodiment of the present invention.

 FIG. 6 is a central longitudinal sectional view showing a waste leaf gasification and melting furnace according to a sixth embodiment of the present invention.

 FIG. 7 is a central longitudinal sectional view showing a waste gasification and melting furnace according to a seventh embodiment of the present invention.

 FIG. 8 is a central longitudinal sectional view showing a waste gasification and melting furnace according to an eighth embodiment of the present invention.

 FIG. 9 is a central longitudinal sectional view showing a waste gasification and melting furnace according to a ninth embodiment of the present invention.

 FIG. 10 is a central longitudinal sectional view showing another embodiment of the welding chamber furnace in an enlarged manner.

 FIG. 11 is a central longitudinal sectional view showing a waste gasification melting furnace according to a tenth embodiment of the present invention.

 FIG. 12 is a central longitudinal sectional view showing a first type of a conventional general gasification and melting furnace of a shaft furnace type.

 FIG. 13 is a central longitudinal sectional view showing a second type of conventional one-piece gasification and melting furnace of the shaft furnace type.

Fig. 14 is an enlarged cross-sectional view of the melting reaction zone of the gasification and melting furnace shown in Fig. 12. Fig. 14 (a) shows a normal state, and Fig. 14 (b) shows an abnormal state. Represents time respectively. Fig. 15 is an enlarged cross-sectional view of the dome-shaped melting zone of the gasification and melting furnace shown in Fig. 13. Fig. 15 (a) shows a normal state, and Fig. 15 (b) ) Indicates abnormal time.

 FIG. 16 is a central longitudinal cross-sectional view showing a conventional general melting furnace.

[Best mode for carrying out the invention]

 Hereinafter, embodiments of the waste gasification and melting furnace and the operation method of the present invention will be described with reference to the drawings.

 FIG. 1 (a) is a central longitudinal sectional view showing a waste gasification melting furnace according to a first embodiment of the present invention, and FIG. 1 (b) is a sectional view taken along line bb of FIG. 1 (a). It is.

 As shown in Fig. 1 (a), the gasification and melting furnace 1 of this example includes a gasification furnace main body 2 composed of a vertical shaft furnace in which a refractory (not shown) is lined with a steel shell. And a melting chamber furnace 3 which heats and melts a pyrolysis residue called a char finally generated by the gasification furnace main body 2 at a high temperature. The upper part of the gasifier main body 2 is formed in a shape in which the diameter is gradually reduced toward the upper end, and an exhaust port 4 for the furnace top gas is opened at the upper end. Although not shown, one end of the duct is connected to the exhaust port 4, and an exhaust gas treatment device is connected downstream of the duct. This exhaust gas treatment system consists of a reburner, energy recovery equipment such as a heat exchanger such as a boiler * steam turbine, and a dust collector.

At the upper part of the gasification furnace main body 2, a waste charging shot 5 is provided through the furnace wall 2a. The lower part of the gasification furnace main body 2 is formed in a shape in which the diameter is gradually reduced downward, and a melting chamber furnace 3 is combined with a melting chamber furnace 3 at the bottom of the furnace below the lower end opening 2b. As shown in Fig. 1 (b), the melting furnace 3 consists of a horizontally long rectangular cylinder, An upper end opening 3a communicating with a lower end opening (discharge port) 2b of the furnace body 2 is provided, and a slag outlet 6 is provided at a lower end of one side wall 3b. The slag outlet 6 is provided with a weir 6a, and the slag S overflowing the weir 6a automatically flows out. <Thermal decomposition flowing into the melting chamber furnace 3 from the upper end opening 3a As shown in Fig. 3, the residue has a lateral length inside the melting chamber furnace 3 where the slope of the angle of repose is sufficiently formed to one side (right side of the figure). It is configured such that a space is formed above. A heating / melting parner 7 is provided in the space with the combustion gas outlet at the tip facing the inclined surface of the pyrolysis residue. It is particularly preferable to mount the flame at an angle such that the lower end of the flame blown out from the panner 7 is 50 to 300 mm from the upper surface of the pyrolysis residue layer, but the present invention is not limited to this. The heating and melting parner 7 is used by mixing low-priced fuel such as heavy oil with oxygen, air or oxygen-enriched air. Note that a brass burner can also be used. One end of an upward gas supply pipe 8 is connected from the space inside the melting chamber furnace 3, and the other end is connected to a header duct 9 arranged around the lower part of the gasification furnace main body 2. One end of a gas blowing pipe 10 is connected to the header duct 9 at equal intervals in the circumferential direction, and the other end penetrates the furnace wall 2 a of the gasification furnace main body 2 and faces the inside of the furnace 2. You. In other words, the position where the high-temperature gas is injected from the gas injection pipe 10 corresponds to the pyrolysis area Y of the waste A. In this example, the drying zone X in the upper part of the gasification furnace main body 2 was dried at a temperature of 300 to 400 ° C. after removing the moisture of the injected waste A and drying it. The temperature and flow rate of the hot gas generated in the melting chamber furnace 3 so that the substance A can be thermally decomposed at a temperature in the range of 500 to: L0000 ° C, preferably slightly lower than 800 ° C. Is adjusted and introduced into the pyrolysis zone Y of the gasification furnace main body 2. Set the temperature of the pyrolysis zone Y in the range of 500 to 100 ° C. It is necessary to control the temperature in the enclosure to a minimum of 500 ° C to thermally decompose the combustible components in waste A, and above 100 ° C to decompose the residue (ash). Begins to soften.

 The gasification and melting furnace 1 according to the first embodiment of the present invention is configured as described above.In this melting furnace 1, while the waste injected in the upper drying zone X in the furnace is dried, The gas slowly descends to the lower pyrolysis zone Y, where it is pyrolyzed and the combustible components in waste A are gasified. This gas is sent from the melting chamber furnace 3 to the gasification furnace body 2 together with the high-temperature gas, and then used for drying the waste A in the drying zone X. The gas is exhausted from the exhaust port 4 and used by power generation facilities, etc., and energy is recovered. After that, it is exhausted by a bag filter etc. and then discharged outside. After the pyrolysis residue generated in the gasification furnace body 2 flows into the melting chamber furnace 3, the inclined surface of the pyrolysis residue layer is sequentially melted by the flame of the heating / melting parner 7 to form slag. Is melted together with the alumina, silica, etc. contained in Waste A, and flows out of the slag outlet 6.The spilled melt solidifies, so it can be disposed of or buried as it is. Can be used as a standing material. In addition, the refractory on the bottom surface is hardly damaged due to the accumulation of pyrolysis residues on the bottom surface in the melting chamber furnace 3. The symbol Z in the figure indicates the heat melting zone, in which pyrolysis residue C is deposited.

 FIG. 2 is a central longitudinal sectional view showing a waste gasification and melting furnace according to a second embodiment of the present invention.

The difference between the melting furnace 1 and 2 of the second embodiment and the melting furnace 1 is that the header duct 9 provided outside the furnace is replaced with a gas header 11 as a part of the gasification furnace body 2. Was installed in the furnace. That is, the furnace wall 2a of the gasification furnace main body 2 is projected radially outward in a triangular cross section and annularly over the circumferential direction, An annular space that is not filled with waste layer B is configured in the gas header 11. Other configurations and operations are the same as those in the first embodiment, and thus the same reference numerals are used for the same components, and the description will be omitted.

 FIG. 3 is a central longitudinal sectional view showing a waste gasification and melting furnace according to a third embodiment of the present invention.

 The difference between the melting furnace 13 of the third embodiment and the above-mentioned melting furnace 1 is that an inlet pipe 1 2 for blowing an oxygen-containing gas such as oxygen, air or oxygen-enriched air into a gas supply pipe 8 is provided. Is connected.

With this configuration, the following functions and effects can be obtained. In other words, the amount of heat required to melt the pyrolysis residue in the melting furnace 3 basically corresponds to the amount of the pyrolysis residue flowing into the melting furnace 3 from the gasifier main body 2. However, when the amount of moisture and combustible components in the waste A increases, the waste A cannot be completely dried and pyrolyzed only by the high-temperature gas generated in the melting furnace 3. For that purpose, it is necessary to blow oxygen into the waste layer B in the gasifier main body 2 to burn combustible components and generate heat. Also, the conversion of combustible components in the waste material A as light as possible a gas is desirable in the exhaust gas treatment system, for example, rather than the tar or oil is converted to a hydrocarbon gas to the CO, H ₂ and CH about ₄ Requires additional heat and oxygen. For this reason, it is necessary to blow oxygen into the gasification furnace main body 2.

Further, when an ordinary temperature oxygen-containing gas is blown from the introduction pipe 12, the effect of lowering the temperature of the high-temperature gas supplied into the gasification furnace main body 2 is produced. In other words, the high-temperature gas generated in the melting furnace 3 is at a very high temperature of about 160 ° C., but if such a high-temperature gas is supplied to the gasification furnace body 2 without lowering the temperature, Gas supply pipes in the supply path Attached to the inner wall, such as 8 ducts and headers The refractory may be damaged, but by adding the oxygen-containing gas to lower the gas temperature to, for example, 130 ° C, the problem of refractory damage is eliminated. In addition, even if an ordinary temperature oxygen-containing gas is directly blown into the gasification furnace main body 2 from the outside, it is difficult to sufficiently react with the waste A. However, as in this example, together with the high-temperature gas, for example, 130 ° C. When oxygen-containing gas is blown in at high temperature of C, waste A reacts with oxygen and burns reliably.

 Other configurations and operations are the same as those of the first embodiment, and therefore, the same reference numerals are used for the common components, and the description will be omitted.

 FIG. 4 is a central longitudinal sectional view showing a waste gasification and melting furnace according to a fourth embodiment of the present invention.

 The difference between the melting furnaces 114 of the fourth embodiment and the above-mentioned melting furnaces 13 is that the openings (discharge outlets) 2 b and 3 a connecting the gasification furnace main body 2 and the melting chamber furnace 3 are located immediately adjacent to each other. A screw-type extrusion device 13 is provided below.

With this configuration, the following functions and effects can be obtained. That is, by rotating the screw shaft 13a by the drive unit 14 in the melting chamber furnace 3, the pyrolysis residue generated in the gasification furnace body 2 is quantitatively and gradually determined. It is pushed out to sneak in. Although the illustration is omitted, the main part of the screw shaft 13a (including the screw) is cooled with a water-cooled structure. In addition, since the temperature of the pyrolysis residue in this example is a relatively low temperature of 1000 ° C. to 800 ° C. or less, not only the screw type but also various types of mechanical extrusion such as a pusher type. Apparatus can be applied. In particular, in steel facilities, for example, in the shaft-type direct reduction iron-making furnace Ya rotary furnace type steel reactor, may be applied extrusion device used in the extraction of reduced iron 9 0 0 ~ 1 1 0 0 ° C t Since other configurations and operations are common to those of the third embodiment, common components are shown with the same reference numerals, and description thereof is omitted.

 FIG. 5 is a central longitudinal sectional view showing a waste gasification / melting furnace according to a fifth embodiment of the present invention.

 The difference between the melting furnaces 15 of the fifth embodiment and the melting furnaces 1-4 of the fourth embodiment is that the high-temperature gas Q generated in the melting furnace 3 is supplied to the gas supply pipe 8 and the header duct 9. Instead, the gas is passed through the pyrolysis residue layer in the melting furnace 3 and guided to the gasification furnace main body 2 from the connection ports 2 b and 3 a with the gasification furnace main body 2. Although the screw-type extrusion device 13 is shown slightly below the connection ports 2b and 3a, in this example, the extrusion device 13 is slightly above the connection ports 2b and 3a, that is, It is more preferable to provide it on the gasification furnace main body 2 side.

 With this configuration, the following functions and effects can be obtained. That is,

 (1) Since the high-temperature gas Q passes through the pyrolysis residue layer and flows into the gasifier main body 2, the pyrolysis residue C is efficiently heated. In other words, in Examples 1 to 4 described above, the heat transfer to the pyrolysis residue layer in the welding chamber furnace 3 is radiative transfer, so that the efficiency is lower than in this example.

 -② Oxygen contained in the high-temperature gas reacts with combustibles (mainly carbon) remaining in the pyrolysis residue and burns, so that the temperature of the pyrolysis residue layer can be raised to a higher temperature. The fuel used for PANA 7 can be reduced.

(3) The melting furnace 115 of this example has a simpler structure than the melting furnaces according to the other examples described above. Also, in the above-mentioned prior art (Japanese Patent Laid-Open No. 11-11332), melting occurs in an unstable dome-shaped melting zone. While melting is performed, melting is performed on the inclined surface of the pyrolysis residue layer in the melting furnace 3, so that the operation is stably performed.

 In addition, in the melting furnace 115 of this example, the temperature of the pyrolysis residue near the extruder 13 is controlled so as to be 1000 ° C. or less. In addition, the pyrolysis residue in the vicinity of the extruder 13 is not only a char, but also a layer of waste that accumulates in the gasification furnace main body 2 so that pyrolysis is not completely completed and contains a relatively large amount of combustible components. Set so that the height of B becomes shallow.

 Since other configurations and operations are common to the above-described fourth embodiment, common components are shown using the same reference numerals, and description thereof is omitted.

 FIG. 6 is a central longitudinal sectional view showing a waste gasification and melting furnace according to a sixth embodiment of the present invention.

 The melting furnace 116 of the sixth embodiment differs from the melting furnace 114 of the fourth embodiment in two points.

 First, similarly to the second embodiment, a gas header 16 is provided in the furnace as a part of the gasifier main body 2. That is, the furnace wall 2a of the gasification furnace main body 2 is protruded annularly inward in the radial direction and in the circumferential direction in a triangular cross section, and an annular space in which the waste layer B is not filled is formed in the gas header 16. It was done.

Second, the high-temperature gas generated in the melting chamber furnace 3 is supplied into the gasification furnace main body 2 not through the space but through the pyrolysis residue layer. That is, a plurality of gas inlets 17 provided on the inner wall in contact with the pyrolysis residue layer deposited in the melting chamber furnace 3 are connected to the gas supply pipe 8. Each suction port 17 is located approximately 100 mm (indicated by L in Fig. 6) from the surface of the pyrolysis residue layer, in order to prevent the pyrolysis residue from scattering and mixing in the high-temperature gas. The gas flow rate flowing into each suction port 17 is very low, 0.1 lm / sec. I'm late.

 With this configuration, the same functions and effects as described in (1) and (2) above for the fifth embodiment can be obtained. Since other configurations and operations are common to the above embodiment, the same reference numerals are used for the common components, and the description will be omitted.

 FIG. 7 is a central longitudinal sectional view showing a waste gasification / melting furnace according to a seventh embodiment of the present invention.

 The difference between the melting furnace 117 of the seventh embodiment and the melting furnace 114 of the above-described fourth embodiment is that the oxygen-containing gas introduced into the gas supply pipe 8 is of two systems, oxygen and air, and that the furnace body 2 The temperature of the lower pyrolysis residue layer and the temperature of the high-temperature gas supplied through the gas supply pipe 8 are measured, for example, the temperature of the pyrolysis residue layer becomes 800 ° C and the temperature of the high-temperature gas, respectively. The controller 18 and 19 and the solenoid on-off valves 20 and 21 are configured to adjust the flow rate of oxygen and the flow rate of air so that the temperature is set to 1300 ° C. That is, the temperature of the high-temperature gas supplied to the furnace body 2 can be generally adjusted by the flow rates of oxygen and air, and the temperature of the pyrolysis residue layer can be generally adjusted by the ratio of oxygen and air. When the total amount of heat required in the gasification and melting furnaces 1 to 7 is insufficient, the amount of fuel and the amount of air and oxygen introduced into the melting furnace 3 may be increased while increasing the amount of fuel added from the parner 7. In this case, oxygen and air may be blown from the Pana 7.

 FIG. 8 is a central longitudinal sectional view showing a waste gasification / melting furnace according to an eighth embodiment of the present invention.

The difference between the melting furnace 1-8 of the eighth embodiment and the melting furnace 114 of the fourth embodiment is that the ash can be positively pushed into the furnace body 2 from the outside to perform the melting process. That is. That is, as shown in FIG. 8, the ash injection chute 22 is arranged at a position slightly higher than the high-temperature gas injection port of the gasifier main body 2, and A screw feeder 23 is connected to the upper end of the chute 22 so that ash C can be pushed into the furnace body 2 from the outside so that it can be treated.

With this configuration, for example, when ash C is injected into the upper part of the gasifier main body 2, the ash C is scattered with the flow of the exhaust gas Q, whereas in this example, the waste A deposited above the ash input position Has the advantage of preventing ash from scattering as a filter. Other configurations and operations are the same as those of the above-described fourth embodiment. Therefore, the same reference numerals are used for the same components, and description thereof is omitted ₍ FIG. 9 shows the ninth embodiment of the present invention). FIG. 1 is a central longitudinal sectional view showing a waste gasification and melting furnace according to an example.

 The melting furnace 114 of the ninth embodiment differs from the melting furnace 114 of the fourth embodiment in the following points. That is, a cyclone suspension preheater 24 is provided in the middle of the gas supply pipe 8, and an ash inlet 25 is provided upstream of the cyclone suspension preheater 24.

 With this configuration, the high-temperature gas Q supplied from the melting chamber furnace 3 into the gasification furnace main body 2 is introduced into the cyclone suspend preheater 24, and is also injected into the gas supply pipe 8 from the input port 25. The ashes are instantaneously heated by the high-temperature gas flowing into the cyclone suspend preheater 24, fall into the melting chamber furnace 3, flow into the furnace, and are melted. On the other hand, the temperature of the high-temperature gas Q is decreased by being used for heating the ash C, and is supplied to the gasification furnace main body 2 at an appropriate temperature. The method of injecting ash from the cyclone suspension preheater 24 into the melting chamber furnace 3 may be as simple as blowing from the inlet 26 as shown in FIG. 9 or as fuel or air from the burner 7. It may be blown together.

FIG. 10 is an enlarged central longitudinal section showing another embodiment of the melting furnace. FIG. In the melting chamber furnace 3 ′ of this example, a through hole 28 through which a spray gun 27 of the refractory E for repair can be inserted is formed in the side wall 3 c, and the gun 27 is inserted through the through hole 28. It is loaded and can be moved back and forth and left and right. Then, measuring instruments such as a TV camera (not shown) and a thermometer (not shown) are installed in the space U inside the melting chamber furnace 3 ', and the damaged parts of the refractory wall such as the ceiling are detected. Spray refractory E for repair with gun 27 and repair. The operation time of the gun 27 used in this case is about 20 minutes, and the operation is easy. <With this configuration, the time to stop the operation for repairing the refractory is greatly reduced, and the melting furnace The operation rate of 1 improves.

 Next, FIG. 11 is a central longitudinal sectional view showing a tenth embodiment of the gasification and melting furnace.

 The following points are different from each of the above embodiments in the welding furnace 1-10 of this example. <That is, the communication openings 2b and 3a between the gasification furnace main body 2 and the melting chamber furnace 3 are not narrowed, It is connected to the gasification furnace main body 2 with the same cross section as the opening, and one side wall 3 d (left side in the figure) of the melting furnace 3 is formed on an inclined surface close to the angle of repose of the pyrolysis residue C. A metal belt conveyor (with a crossbar) 29 is provided along the inclined surface 3d as a transfer device having excellent heat resistance. A slag storage room 30 with an open top is installed below the slag outlet 6, and a metal belt conveyor 31 with excellent heat resistance is also installed in the slag storage room 30, and slag etc. Can be automatically discharged. Furthermore, three burners 7 are provided in the space inside the melting furnace 3, and LP gas or oil is blown from each of the burners 7 as oxygen-enriched air and auxiliary fuel.

The furnace walls 1a at the middle part (drying area X) and the lower part (pyrolysis area Y) in the height direction of the gasification furnace main body 2 are each radially outward in a triangular cross section as in the second embodiment. And annular in the circumferential direction The unfilled annular space above the slope formed by the waste A inclined at the angle of repose is formed in the gas headers 32, 33. The gas supply pipe 8 branches from the space inside the melting chamber furnace 3 to the upper and lower gas headers 32, 33, and the respective branch pipes 34.35 are connected. A branch pipe 36 is connected to the section T, and dampers 37, 38, and 39 are interposed in the respective branch pipes 34 to 36. Further, the inlet pipes 40 to 42 for oxygen-containing gas such as oxygen and nitrogen are connected to the furnace top space T and the gas headers 132, 33, and an opening / closing valve 4 is provided in the middle of each of the inlet pipes 40 to 42. 3, 4 4 and 4 5 are interposed. Further, an input port 46 for waste A is opened in the upper furnace wall 2a of the furnace body 2, and a pusher 48 provided with a hopper 47 for inputting waste A is connected to the input port 46. ing. Other configurations are the same as those of the first embodiment, and thus the same reference numerals are used for the common components, and the description will be omitted. The gasification furnace may be a rotary kiln or the like instead of the shaft furnace / fluidized bed furnace.

 The melting furnace 1-10 constructed as described above is operated according to the following procedure. The melting method (operating method) of this example was compared with the melting method (hereinafter referred to as the conventional method) using the above-described conventional melting furnace (Japanese Patent Laid-Open No. 11-132432, hereinafter referred to as the conventional furnace). While explaining.

The conventional method (Fig. 12) produces hydrogen and carbon monoxide from the exhaust gas generated from the furnace because the exhaust gas contains relatively large amounts of CO. Dome melting zone 5 3 (first 2 view) from becoming around 1 6 5 0 ° C, the composition of the exhaust gas calculated predicted from chemical equilibrium at this temperature, CO 1 7%, C_〇 ₂ 1 4%, a H ₂ 1 4%, generally consistent with the actual furnace operating data. The amount of LP gas used as auxiliary fuel is about 20% of the total calorific value of waste A. %.

On the other hand, in the melting furnace 1-10 of this example, the ratio of C 割 合_{2 in} the composition of the exhaust gas was increased. This is because the combustion temperature of the waste leaf layer B in the furnace body 2 is set lower than in the conventional method. That is, the high-temperature gas Q generated in the melting furnace 3 is introduced into the furnace top space T and the gas headers 32 and 33 together with the oxygen-containing gas, and reacts with the waste layer B in the furnace main body 2 to perform the conventional method. Although it burns at a lower temperature than that of, the temperature of the pyrolysis residue generated in the pyrolysis zone Y is slightly higher than in the conventional method, so that the amount of LP gas or oil used as a fuel for auxiliary combustion is reduced. Also, the calorific value of the exhaust gas is reduced. Therefore, the amount of combustion air supplied is reduced, and the amount of exhaust gas generated is also reduced. Table 1 below shows (1) the amount of LP gas used as auxiliary fuel, (2) the amount of oxygen used in the entire melting furnace, and (3) the amount of reburning gas required to burn exhaust gas, in the conventional method and the operation method of this example. table 1】

本例の操業方法によれば、 次のような優れた効果を奏する。 すなわち、 従来法に比べて c〇₂ の割合が高い排ガスが発生す る。 熱分解残渣 Cの溶融に必要な温度は 1 6 5 0 °Cで従来法と 同じである。 廃棄物 Aの単位当たりの発熱量は両者とも同じで あるが、 発生する排ガスの L H V (熱量） は （従来法） > (本 例の操業法） となる。 排ガス中の炭素量は同じであるが、 助燃 燃料の L Pガス使用量が減少することによる水素の減少により - ガス容量は （従来法） > (本例の操業法） となる。 排ガス Gの再燃焼の温度が 8 5 0〜 1 1 0 0 °Cに低下するこ とで、 後続のボイラゃ空気予熱器の管機材の材質を落とせ安価 な材料が使用できるようになり、 かつダイォキシンの低減が図 れる。 また、 ガスヘッダー 3 2、 3 3への高温ガス Qの供給量 を排ガス Gの二酸化炭素濃度が一定になるようにダンパー 3 7 . 3 8にて調節するとともに、 乾燥域 Xと熱分解域 Yの温度が目 的の温度になるように導入管 4 1、 4 2からの酸素含有ガスの 導入量を決定する。 酸素含有ガスを炉本-体 2内に導入すると、 二酸化炭素の発生量が増える。

According to the operation method of this example, the following excellent effects are obtained. That is, the proportion of C_〇 ₂ is higher exhaust gas that occur as compared with the conventional method. The temperature required for melting the pyrolysis residue C is 1650 ° C, which is the same as the conventional method. The calorific value per unit of waste A is the same for both, but the LHV (calorific value) of the generated exhaust gas is (conventional method)> (operating method in this example). The amount of carbon in the exhaust gas is the same, but due to a decrease in hydrogen due to a decrease in the amount of LP gas used as auxiliary fuel, the gas capacity becomes (conventional method)> (operating method in this example). By reducing the temperature of the reburning of the exhaust gas G to 850 to 110 ° C, the material of the tube equipment of the subsequent boiler and air preheater can be reduced, and inexpensive materials can be used. Dioxin can be reduced. The supply amount of the high-temperature gas Q to the gas headers 32, 33 is adjusted by the damper 37.38 so that the carbon dioxide concentration of the exhaust gas G becomes constant, and the drying zone X and the pyrolysis zone Y are adjusted. The amount of the oxygen-containing gas introduced from the introduction pipes 41 and 42 is determined so that the temperature of the mixture becomes the target temperature. When an oxygen-containing gas is introduced into the furnace body 2, the amount of carbon dioxide generated increases.

 Furthermore, in order to keep the temperature of the exhaust gas G constant, high-temperature gas Q was introduced into the furnace top space from the branch pipe 36, and oxygen-containing gas was introduced from the introduction pipe 40 and mixed, thereby disposing of the waste gas. This makes it possible to respond to changes in the input amount of substance A over a wide range, and to minimize fluctuations and blow-off of exhaust gas G. Furthermore, if the high-temperature gas Q is introduced into the furnace top space T from the branch pipe 36 at the start of the combustion of the waste A, the combustion can be started regardless of the presence or absence of the waste A.

 As is clear from the above description, the waste gasification and melting furnace and the operation method according to the present invention have the following excellent effects.

 (1) The advantages of shaft furnace-type waste gasification and melting furnaces, such as good thermal efficiency and the effect of averaging gas generation, can be inherited. In other words, the high-temperature gas used to melt the pyrolysis residue is sent into the furnace body, where it is subjected to drying and pyrolysis of refuse. The sensible heat of the high-temperature gas is almost equivalent to waste. Recovered in the reaction, for example, the temperature of the exhaust gas reaches about 300 ° C. As a result, fuel consumption, electricity consumption and oxygen consumption are all low.

(2) The operation and equipment are simple, and operation and maintenance are easy. In addition, the amount of molten waste per hour can be stably changed over a wide range. Can be obtained.

(3) Since the flow rate and properties of the exhaust gas from the melting furnace are stable, appropriate treatment of exhaust gas is possible, and as a result, the amount of air mixed in for downstream combustion is minimized. can be the generation of CO is suppressed, and the dioxin and N_〇 _x generation is suppressed Ruue, possible to reduce the consumption of gas cleaning chemicals such as urea or activated carbon, slaked lime, addition, fly ash amount can be reduced .

 (4) When the exhaust gas is burned in order to stabilize the amount and properties of the exhaust gas, stable and high-quality electric power can be obtained by power generation equipment such as a boiler and a steam turbine. Furthermore, as described above, the amount of combustion air to be mixed can be reduced, so that waste heat from the boiler is small, and there is no heat loss because the generated steam can be effectively sent to the entire steam turbine.

 (5) It is possible to cope with any fluctuations in the input amount of waste, that is, even if the input amount is less than the normal 1Z10, the waste can be stably gasified and melted.

 (6) Sludge, incineration ash and fly ash can be treated, and the heat of the exhaust gas generated at that time can be effectively recovered.

 (7) Since the waste is not melted in the furnace body, the temperature of the waste layer in the furnace body is much lower than that of the above-mentioned prior art melting furnace, and the temperature at which the ash starts melting (softening). There is a temperature lower than 100 ° C, and as a result, there is no abnormal adhesion of pyrolysis residues in the furnace body and no shelving phenomenon, and the operation is stable, and the life of the refractory is dramatically extended. The rate is improved.

(8) Since the melting chamber furnace is outside the furnace body and the refractory to be worn is located in the gas space, it can be easily repaired by spraying the refractory for repair, so the equipment utilization rate will increase dramatically To improve. [Possibility of industrial use]

 Since the present invention is configured as described above, the two furnace bodies of the melting furnace and the ash melting furnace are integrated, and the char generated in the melting furnace portion is melted in the ash melting furnace portion, and generated there. It is suitable as a stable waste gasification and melting furnace with high thermal efficiency, which can introduce high-temperature combustion gas into the melting furnace and heat and pyrolyze the waste.

Claims

Claims. A shaft furnace type or a fluidized bed type gasification furnace body for sequentially charging waste from above into the furnace, drying it with high-temperature gas, and then thermally decomposing it, and a lower end of the gasification furnace body A melting chamber furnace provided integrally with the discharge port to receive a pyrolysis residue of the waste, and provided with a heating and melting parner toward an inclined surface of the pyrolysis residue; and In addition to providing an outlet for taking out the molten material of the molten slag and metal, a high-temperature gas generated during heating and melting of the pyrolysis residue in the melting chamber furnace is supplied to the gasification furnace main body. Waste gasification and melting furnace characterized by having a mechanism. A high-temperature gas supply path from the melting chamber furnace to the gasification furnace main body. An oxygen or oxygen-enriched air introduction path is connected to lower the temperature of the high-temperature gas supplied to the gasification furnace main body, and oxygen 2. The waste gasification and melting furnace according to claim 1, wherein the furnace is configured to increase the concentration. In order to supply a high-temperature gas from the melting chamber furnace to the gasification furnace main body, a supply path is provided at a connection point between the gasification furnace main body and the melting chamber furnace, or a lower portion in the gasification furnace main body. 3. The waste gasification / melting furnace according to claim 1 or 2, wherein the space and the space in the melting chamber furnace are connected by a duct. 4. A method according to any one of claims 1 to 3, wherein a pyrolysis residue delivery mechanism such as a screw type, a rotary blade type, or a pusher type is provided near a connection point between the gasification furnace main body and the melting chamber furnace. The waste gasification and melting furnace described in the crab. The waste gasification / melting furnace according to any one of claims 1 to 3, wherein a tuyere for blowing an oxygen-containing gas into the pyrolysis residue is provided in the melting chamber furnace. The temperature of the high-temperature gas supplied from the melting furnace to the gasification furnace main body was adjusted to 100 to 130 ° C., and the hot gas was introduced into the gasification furnace main body and dried. Claims 1 to 3 in which a control device for adjusting the supply amount of the high-temperature gas is provided so that the waste is heated at a temperature of 500 to 100 ° C to generate a pyrolysis residue. 6. A waste gasification and melting furnace according to any one of the above items 5. The temperature of the high-temperature gas supplied from the melting chamber furnace to the gasification furnace main body is 100 ° C. or higher, and the waste in the gasification furnace main body is 800 ° C. or lower. 7. The waste gasification and melting furnace according to claim 6, further comprising a control device capable of adjusting a temperature and a supply amount of the high-temperature gas so that the pyrolysis residue is generated by heating. An inlet for incombustible substances such as ash or sludge is provided below the middle part in the height direction of the gasification furnace main body, and a pushing mechanism such as a screw type, a rotary blade type, a pusher type, etc. is provided near the inlet. 6. The waste gasification / melting furnace according to any one of claims 1 to 5, further comprising an accompanying gas blowing mechanism. The waste gasification / melting furnace according to any one of claims 1 to 5, wherein an inlet for injecting incombustibles alone or together with fuel and an oxygen-containing gas is provided in the melting chamber furnace. 0. A hot cyclone is provided in the middle of a high-temperature gas supply path from the melting chamber furnace to the gasification furnace main body, and a non-combustible substance such as ash or sludge is inserted into the cyclone inlet or the cyclone. The waste gasification / melting furnace according to any one of claims 1 to 5, further comprising a supply path for collecting the collected matter by the cyclone from the cyclone to the melting chamber furnace. 1. In the melting chamber furnace, heat and melt by the heating and melting Claim 1 in which an industrial TV camera, microwave measuring device, or radiation measuring device was deployed as a level measuring device to maintain the level of the pyrolysis residue layer during melting properly. 6. A waste gasification and melting furnace according to any one of claims 1 to 5. 12. The rechargeable furnace furnace wall is provided with a charging hole for a refractory spraying device for repair so that a damaged portion of the refractory in the melter furnace can be repaired from outside. 6. The waste gasification and melting furnace according to any one of items 5 to 5. 1 3. In the vicinity of the middle part in the height direction of the gasification furnace main body, an annular space where waste is not filled due to a sudden expansion or contraction in a tapered shape compared to a part immediately above the furnace inner wall. The waste gasification welding according to any one of claims 1 to 5, wherein a high-temperature gas supplied from the melting chamber furnace to the gasification furnace main body is guided to the annular space portion. Furnace. 14. A plurality of gas suction ports are provided on an inner wall in contact with a pyrolysis residue layer deposited in the melting chamber furnace, and each of the gas suction ports is communicated with the gas supply pipe. 6. The waste gasification and melting furnace according to any one of items 5 to 5. 15. The gasification and melting chamber furnace body is a fluidized bed furnace, and a pyrolysis residue layer sieved from a fluidized medium such as sand circulating in the furnace body and a furnace top generated in the gasification furnace body. The waste gas according to any one of claims 1, 2 or 5, wherein the waste gas associated with the gas and the dust collected by a cyclone or the like can be supplied to the melting furnace. Chemical melting furnace. 16. Exhaust gas discharged from the furnace top by adding oxygen-containing gas such as air, oxygen, or oxygen-enriched air from the outside at an air ratio of 0.5 to 2.5 in the upper part of the gasification furnace body To increase the temperature of the gasification furnace to 800 to 110 ° C. Wherein adjusting the flow rate of the hot gas supplied from the melter furnace N 2 + 〇 second flow and the gasification furnace body for introducing from outside, controls the C 0 ₂ concentration of the exhaust gas at a high concentration according The method for operating a waste gasification / melting furnace according to any one of Items 1 to 14 (17. A part of the high-temperature gas generated in the melting chamber furnace is converted into a waste in the gasification furnace body. The method according to any one of claims 1 to 14, wherein the gas is guided to the vicinity of the upper surface of the bed, burns by adding an oxygen-containing gas such as air, oxygen, or oxygen-enriched air, and adjusting the temperature of exhaust gas exhausted from the furnace top. 3. The method for operating a waste gasification and melting furnace according to item 1. 1 8. A part of the high-temperature gas generated in the melting furnace is guided to the middle part in the height direction of the gasification furnace main body, and further, air and oxygen are placed near the upper surface of the waste layer in the gasification furnace main body. Alternatively, the method for operating a waste gasification / melting furnace according to any one of claims 1 to 14, wherein the combustion is performed by adding oxygen-enriched air. 1 9. A portion of the high-temperature gas generated in the furnace for the gasification and melting chamber is led to a plurality of locations spaced in the height direction at an intermediate portion in the height direction of the body of the gasification furnace, and further gasified. 15. The method for operating a waste gasification / melting furnace according to any one of claims 1 to 14, wherein air, oxygen, or oxygen-enriched air is added near the upper surface of the waste layer in the furnace body and burned. 2 0. Of the gasifier unit of the waste gas generated from the layer of CO / C 0 claims for controlling the total oxygen flow fed to the gasifier unit according to ₂ ratio first 6-1 9 wherein Operation method of waste gasification and melting furnace described in any of the above.