Waste treatment device

Abstract

This waste treatment device comprises: a gasification / reforming furnace in which waste is thermally decomposed and gasified and a generated gas is reformed to produce a reformed gas; a cooling / cleaning water circulation device for cooling and cleaning the reformed gas produced in the gasification / reforming furnace; a gas purification device for purifying the reformed gas cooled and cleaned in the cooling / cleaning water circulation device; and a chemical-product production device for producing liquid chemical products from, as a raw material, the gas purified in the gas purification device. The cooling / cleaning water circulation device includes a heat collector for collecting some of the sensible heat of the reformed gas and is configured so that the sensible heat collected by the heat collector is supplied to the chemical-product production device.

Description

waste treatment equipment

[0001] The present invention relates to a waste treatment device.

[0002] In the gasification and reforming furnace for decomposing hazardous materials such as waste in a high-temperature oxidizing atmosphere described in Patent Document 1, an oxygen-containing gas, which is a combustion-supporting gas, is blown into the lower part of the furnace in a high-temperature reaction furnace to create a high-temperature state and gasify and melt the waste. Furthermore, in the upper part of the furnace, in order to maintain the temperature of the generated gas, an oxygen-containing gas is blown in to combust a portion of the gas, creating a high-temperature state of about 1200°C and reforming the gas, which is mainly composed of carbon monoxide (CO) and carbon dioxide (CO ２ ), hydrogen (H ２ The reformed gas is then cooled and refined for use as fuel gas, etc.

[0003] JP 2010-223526 A

[0004] Conventionally, the reformed gas discharged from the gasification and reforming furnace is rapidly cooled with a large amount of cooling water to prevent the resynthesis of dioxins. As a result, the sensible heat of the reformed gas, which reaches approximately 1100°C or more at the outlet of the gasification and reforming furnace, is discarded without being recovered or reused, leaving room for improvement in terms of effective energy utilization.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a waste treatment device that can recover and reuse a portion of the sensible heat of the reformed gas produced in a gas reforming furnace.

[0006] In order to solve the above-mentioned problems and achieve the object, (1) a waste treatment device according to the present invention is a waste treatment device comprising: a gasification reforming furnace that thermally decomposes and gasifies waste and reforms the generated gas to produce reformed gas; a cooling and cleaning water circulation device that cools and cleans the reformed gas produced in the gasification reforming furnace; a gas purification device that purifies the reformed gas cooled and cleaned by the cooling and cleaning water circulation device; and a chemical product manufacturing device that produces liquid chemical products using the purified gas purified by the gas purification device as a raw material, wherein the cooling and cleaning water circulation device has a heat recovery device that recovers a portion of the sensible heat of the reformed gas, and is configured to supply the sensible heat recovered by the heat recovery device to the chemical product manufacturing device.

[0007] (2) The waste treatment device according to the present invention is the waste treatment device according to the invention (1) above, wherein the cooling and cleaning water circulation device is provided with a quenching and cleaning device that quenches and cleans the reformed gas, from which a portion of the sensible heat has been recovered by the heat recovery device, with quenching and cleaning water, and the heat recovery device recovers sensible heat from the reformed gas to a temperature not lower than 300°C from the temperature of the reformed gas at the outlet side of the gasification and reforming furnace.

[0008] (3) The waste treatment device according to the present invention is characterized in that, in the invention (2) above, the heat recovery device is a boiler having a structure consisting of a plurality of water pipes arranged in a cylindrical shape, a plurality of connecting fins connecting adjacent water pipes in the circumferential direction, an annular upper header connected to the upper ends of each of the plurality of water pipes and the plurality of connecting fins, and an annular lower header connected to the lower ends of each of the plurality of water pipes and the plurality of connecting fins.

[0009] (4) The waste treatment device according to the present invention is the invention (3) above, characterized in that an upper flange is provided on the upper part of the boiler for connecting to a gas duct through which the reformed gas sent from the gasification reforming furnace passes, and an upper compensator is provided between the upper flange and the upper header, which can absorb the thermal expansion difference between the upper flange and the upper header.

[0010] (5) The waste treatment device of the present invention is the invention of (4) above, characterized in that a gas supply port is provided in the radial center of the upper flange for supplying the reformed gas from the gas duct into the boiler, a water channel for flowing cooling water is provided inside the upper flange near the gas supply port, the part of the upper flange exposed to the reformed gas sent from the gas supply port into the boiler is made of a material that is heat-resistant and corrosion-resistant, and the part of the upper flange that is inside the exposed part and comes into contact with the cooling water flowing through the water channel is made of a material that has high thermal conductivity.

[0011] (6) The waste treatment device according to the present invention is characterized in that, in the invention (3) above, the boiler is equipped with a solid matter removal device that removes solid matter adhering to the inner surface of the structure.

[0012] (7) The waste treatment device according to the present invention is characterized in that, in the invention (6) above, the solid matter removal device is provided with a water injection device that injects water toward the inner surface of the structure.

[0013] (8) The waste treatment device according to the present invention is the above-mentioned (6) invention, characterized in that the solid matter removal device comprises a hammer device that strikes the outer peripheral surface of the structure.

[0014] (9) The waste treatment device according to the present invention is characterized in that, in any one of the above (3) to (8), the water pipe is made of low alloy steel.

[0015] (10) The waste treatment device according to the present invention is characterized in that, in any one of the above-mentioned inventions (3) to (8), a thermal spray coating made of a material having heat resistance and corrosion resistance is formed on the outer surface of the water pipe.

[0016] (11) The waste treatment device according to the present invention is any one of the above (3) to (8), characterized in that the surface of the water pipe that comes into contact with the reformed gas is a polished surface.

[0017] (12) The waste treatment device of the present invention is any one of the inventions (4) to (11) above, characterized in that the boiler is provided with upper flange-side suspension fins provided on the underside of the upper flange, upper water pipe-side suspension fins provided on the outer peripheral surface of the upper part of the water pipe, and fastening members fastening the upper flange-side suspension fins and the upper water pipe-side suspension fins, and the water pipes are suspended from the upper flange.

[0018] (13) The waste treatment device according to the present invention is any one of the inventions (3) to (12) above, characterized in that a flow guide plate is provided at the bottom of the boiler to guide and collect the molten slag that has flowed down the inner surface of the structure toward the center in the radial direction of the structure.

[0019] The waste treatment device according to the present invention has the advantage of being able to recover and reuse a portion of the sensible heat of the reformed gas discharged from the gas reforming furnace.

[0020] Fig. 1 is a block diagram showing a schematic configuration of a waste treatment device according to an embodiment. Fig. 2 is a perspective view showing a schematic configuration of a boiler according to an embodiment. Fig. 3 is a partially enlarged view of an upper part of a boiler according to an embodiment. Fig. 4 is a cross-sectional view of a lower part of a boiler according to an embodiment. Fig. 5 is a partial cross-sectional view of an upper part of a boiler when a water injection device is provided as a solid removal device. Fig. 6 is a partial cross-sectional view of an upper part of a boiler when a hammer device is provided as a solid removal device.

[0021] Hereinafter, an embodiment of the waste treatment device according to the present invention will be described, but the present invention is not limited to the embodiment.

[0022] FIG. 1 is a block diagram showing a schematic configuration of a waste treatment device 1 according to an embodiment.

[0023] As shown in FIG. 1, the waste treatment device 1 according to the embodiment includes a waste input device 10, a gasification reforming furnace 50, a cooling and cleaning water circulation device 70, a gas purification device 80, a cleaning water treatment device 90, and a chemical product manufacturing device 100.

[0024] The waste input device 10 inputs waste into the gasification and reforming furnace 50. The gasification and reforming furnace 50 thermally decomposes and gasifies the waste, and reforms the generated gas to produce reformed gas. The gasification and reforming furnace 50 is a vertical furnace, and its approximately lower half is formed as a thermal decomposition section 52 and a melting section 54 located below the thermal decomposition section 52, and its approximately upper half is formed as a gas reforming section 53.

[0025] In the pyrolysis section 52, waste is piled up to form a waste pile layer Q. The waste that forms the waste pile layer Q is gasified by pyrolysis and the incombustibles are melted. At the bottom of the side wall of the gasification and reforming furnace 50, oxygen (O ２ ) are provided. The gas supply members 20 also function as gas burners for burning liquefied natural gas (LNG) to keep the pyrolysis section 52 at a high temperature. Note that FIG. 1 illustrates one of the gas supply members 20 provided at the bottom of the side wall of the gasification and reforming furnace 50. When the waste is pyrolyzed in the pyrolysis section 52, hydrogen (H ２ ) and carbon monoxide (CO), etc. are generated.

[0026] In the gas reforming section 53, in order to maintain the temperature of the gas generated from the waste deposition layer Q in the thermal decomposition section 52, an oxygen-containing gas is blown in to burn a part of the gas, and the gas is reformed at a high temperature of about 1200°C to produce carbon monoxide (CO), carbon dioxide (CO ２ ), hydrogen (H ２ ) is supplied into the furnace from the gas supply member 20. ２ ) reacts with carbon (C) in the waste to produce carbon monoxide (CO) and carbon dioxide (CO ２ ) is generated. In addition, because there is high-temperature steam generated from the waste or supplied as water from the outside, carbon (C) and water vapor (H ２ O) to form hydrogen (H ２ ) and carbon monoxide (CO). Furthermore, hydrocarbons generated by the thermal decomposition and partial oxidation of waste materials are converted into water vapor (H ２ O) to form hydrogen (H ２) and carbon monoxide (CO). Hydrogen (H ２ The gasification and reforming furnace 50 has a gas reforming section 53 at the top of its side wall, which is filled with oxygen (O ２ ) are provided. The gas supply members 20 also function as gas burners for burning liquefied natural gas (LNG) to keep the gas reforming section 53 at a high temperature. Note that FIG. 1 illustrates one of the gas supply members 20 provided at the upper part of the side wall of the gasification reforming furnace 50.

[0027] In the melting section 54, the molten material produced in the pyrolysis section 52 is further heated, and carbon and other substances contained in the molten material are gasified and removed. In the melting section 54, a molten material outlet 58 for discharging the molten material to the outside is provided at the bottom of the gasification and reforming furnace 50.

[0028] A gas duct 60 is provided at the top of the gasification reforming furnace 50, extending from a reformed gas outlet 59 formed at the top for discharging the reformed gas generated in the gas reforming section 53 to the outside of the furnace. A cooling and cleaning water circulating device 70 for cooling and cleaning the reformed gas is provided downstream of the gas duct 60. The cooling and cleaning water circulating device 70 has a boiler 71 as a first heat exchanger that is a heat recovery device, a cooling and cleaning device 72, a settling tank 73, and a second heat exchanger 74.

[0029] The boiler 71 is connected to the gas duct 60 and recovers a portion of the sensible heat from the reformed gas. The boiler 71 recovers the sensible heat of the reformed gas by heating water flowing through a plurality of water pipes 7107 provided in the boiler 71 with the sensible heat of the reformed gas to generate steam. The steam generated by the boiler 71 is supplied to the chemical production apparatus 100 through piping 75 and the like. Furthermore, the condensate obtained after using the steam in the chemical production apparatus 100 is returned to the boiler 71 through piping 76 and the like. The method for recovering the sensible heat of the reformed gas by the first heat exchanger is not limited to using the boiler 71, and heat transfer to hot water or brine may also be employed. Furthermore, the steam / condensate piping system may include a steam drum, a deaerator, a condensate tank, a chemical feeder, a safety valve, and the like.

[0030] A cooling and washing device 72 is disposed downstream of the boiler 71. The cooling and washing device 72 is connected to the boiler 71 and uses cooling and washing water to rapidly cool the reformed gas from which part of the sensible heat has been recovered by the boiler 71, and removes water-soluble components, dust, carbon fines, and the like from the reformed gas. The settling tank 73 stores the cooling and washing water used to cool and wash the reformed gas in the cooling and washing device 72, and separates solids contained in the cooling and washing water by settling. The second heat exchanger 74 cools the cooling and washing water from which the solids have been separated. The cooling and washing water cooled in the second heat exchanger 74 is returned to the cooling and washing device 72.

[0031] In the waste treatment device 1 according to the embodiment, a boiler 71 recovers a portion of the sensible heat of the reformed gas, which is a high-temperature synthesis gas synthesized in the gasification and reforming furnace 50 from waste as a chemical raw material. In this case, in the waste treatment device 1 according to the embodiment, the boiler 71 recovers sensible heat from the reformed gas until the temperature of the reformed gas at the outlet of the gasification and reforming furnace 50 reaches a temperature of 1100°C or higher but not lower than 300°C. This allows the cooling and washing device 72, located downstream of the boiler 71, to rapidly cool the reformed gas from a temperature sufficiently higher than the resynthesis temperature of dioxins, thereby preventing the resynthesis of dioxins. In other words, the waste treatment device 1 according to the embodiment is capable of recovering the sensible heat of the reformed gas, which would previously have been discarded, while also preventing the resynthesis of dioxins, which is essential when handling waste-derived reformed gas. In addition, since the sensible heat of the reformed gas is recovered in the boiler 71 to lower the temperature of the reformed gas, the cooling load of the reformed gas in the cooling and cleaning device 72 is reduced, and the amount of water and electricity used in the cooling and cleaning device 72 can be significantly reduced.

[0032] A gas purification device 80 is provided downstream of the cooling and cleaning device 72 to purify the reformed gas cooled and cleaned by the cooling and cleaning device 72, and generate purified gas that can be used as fuel gas.

[0033] The chemical product manufacturing apparatus 100 receives purified gas from the gas purification apparatus 80 and extracts hydrogen (H ２ ) and carbon monoxide (CO) as raw materials, for example, by catalytic reaction to synthesize and produce ethanol as a liquid chemical product. In addition, in the chemical product manufacturing apparatus 100, steam supplied from the boiler 71 through a pipe 75 or the like is used, for example, in a distillation process when producing ethanol. In addition to ethanol, the chemical product manufacturing apparatus 100 also uses hydrogen (H ２ Liquid chemical products such as dimethyl ether and methanol may be produced using ethanol (O2) and carbon monoxide (CO) as raw materials.

[0034] Fig. 2 is a perspective view showing a schematic configuration of a boiler 71 according to an embodiment. Fig. 3 is a partially enlarged view of an upper part of the boiler 71 according to an embodiment. Fig. 4 is a cross-sectional view of a lower part of the boiler 71 according to an embodiment.

[0035] 2, the boiler 71 according to the embodiment includes an upper flange 7101, an upper header 7102, steam exhaust pipes 7103A and 7103B, a lower flange 7104, a lower header 7105, feed water pipes 7106A and 7106B, a plurality of water pipes 7107, and a plurality of connecting fins 7108. Furthermore, the boiler 71 according to the embodiment includes upper flange-side suspension fins 7109A and 7109B, upper water pipe-side suspension fins 7110A and 7110B, lower flange-side suspension fins 7112A and 7112B, lower water pipe-side suspension fins 7113A and 7113B, and bolts 7111A, 7111B, 7114A, and 7114B.

[0036] The upper flange 7101 is fastened to the flange of the gas duct 60 by bolts 7141 and nuts 7142 (see FIG. 3 ), etc. A gas supply port 7101a is provided in the radial center of the upper flange 7101, for supplying the reformed gas sent from the gasification reformer furnace 50 through the gas duct 60 into the boiler 71. The lower flange 7104 is fastened to the flange of the cooling and cleaning device 72 by bolts and nuts, etc. A gas discharge port 7104a is provided in the radial center of the lower flange 7104, for discharging the reformed gas from inside the boiler to the cooling and cleaning device 72.

[0037] The multiple water pipes 7107 are arranged in a cylindrical shape, and multiple connecting fins 7108 connect adjacent water pipes 7107 in the circumferential direction. The upper header 7102 is annular and is connected to the upper ends of the multiple water pipes 7107 and the multiple connecting fins 7108. One ends of a pair of steam exhaust pipes 7103A, 7103B are connected to the outer circumferential surface of the upper header 7102. The other ends of the steam exhaust pipes 7103A, 7103B are connected to piping 75 for sending steam to the chemical product manufacturing apparatus 100. As a result, steam generated by heating the water flowing through each of the multiple water pipes 7107 with the sensible heat of the reformed gas is discharged from the steam exhaust pipes 7103A, 7103B to piping 75 via the upper header 7102.

[0038] Lower header 7105 is annular and connected to the lower ends of the multiple water pipes 7107 and the multiple connecting fins 7108. One ends of a pair of water supply pipes 7106A, 7106B are connected to the outer circumferential surface of lower header 7105. The other ends of water supply pipes 7106A, 7106B are connected to piping 76 for sending condensate from chemical manufacturing equipment 100 to boiler 71. As a result, condensate generated by using the sensible heat of steam in chemical manufacturing equipment 100 is supplied to lower header 7105 from piping 76 through water supply pipes 7106A, 7106B, and is used again for heat recovery (heat exchange) in the multiple water pipes 7107.

[0039] In the boiler 71 according to the embodiment, the structure including the plurality of water pipes 7107, the plurality of connecting fins 7108, the upper header 7102, the lower header 7105, the steam discharge pipes 7103A, 7103B, and the water supply pipes 7106A, 7106B is also referred to as the boiler body. The inner surface of the side wall formed by the plurality of water pipes 7107 and the plurality of connecting fins 7108 in the circumferential direction of the boiler body forms a heat transfer surface for heat exchange (heat recovery) by transferring heat from the reformed gas passing through the internal space 710 of the boiler body to the water (steam) passing through the plurality of water pipes 7107. In the boiler 71 according to the embodiment, the side wall is formed by the plurality of water pipes 7107 and the plurality of connecting fins 7108 in the circumferential direction of the boiler body, so that leakage of the reformed gas to the outside between adjacent water pipes 7107 can be prevented even when the internal space 710 of the boiler body is in a positive pressure state.

[0040] Additionally, upper flange-side suspension fins 7109A and 7109B are provided radially outward on the underside of the upper flange 7101 at the upper portion of the boiler 71. Furthermore, in the boiler 71 according to the embodiment, upper water tube-side suspension fins 7110A and 7110B are provided on the outer peripheral surface of the upper portion of any of the plurality of water tubes 7107, corresponding to the upper flange-side suspension fins 7109A and 7109B. The upper flange-side suspension fins 7109A and 7109B are fastened to the upper water tube-side suspension fins 7110A and 7110B with fastening members such as bolts 7111A and 7111B and nuts. Thus, in the boiler 71, the water tubes 7107 (boiler body) are suspended from the upper flange 7101 by fastening the upper flange-side suspension fin 7109A to the upper water tube-side suspension fin 7110A. In FIG. 2, two sets of upper flange side suspension fins 7109A, 7109B and upper water pipe side suspension fins 7110A, 7110B are provided, but the present invention is not limited to this.

[0041] 3, for example, bolt hole 7115A provided in upper flange-side suspension fin 7109A and bolt hole (not shown) provided in upper water tube-side suspension fin 7110A for inserting bolt 7111A are elongated holes extending in the radial direction of upper flange 7101 (boiler body). Although not shown, upper flange-side suspension fin 7109B and upper water tube-side suspension fin 7110B also have bolt holes formed as elongated holes extending in the radial direction of upper flange 7101 (boiler body) for inserting bolt 7111B. This allows radial thermal expansion during operation of boiler 71 to be absorbed by each bolt hole formed as an elongated hole, thereby enabling the water tubes 7107 (boiler body) to be suspended from the upper flange 7101 while avoiding structural damage due to thermal expansion.

[0042] Furthermore, lower flange-side suspension fins 7112A and 7112B are provided radially outward on the upper surface of the lower flange 7104 at the lower part of the boiler 71. Furthermore, lower water tube-side suspension fins 7113A and 7113B are provided on the outer peripheral surface of the lower part of any of the water tubes 7107 among the plurality of water tubes 7107 in correspondence with the lower flange-side suspension fins 7112A and 7112B. The lower flange-side suspension fins 7112A and 7112B and the lower water tube-side suspension fins 7113A and 7113B are fastened together with fastening members such as bolts 7114A and 7114B and nuts. Thus, in the boiler 71, the lower flange 7104 is suspended from the water tubes 7107 (the boiler body) by fastening the lower flange-side suspension fins 7112A and 7112B to the lower water tube-side suspension fins 7113A and 7113B. In FIG. 2, two sets of lower flange side suspension fins 7112A, 7112B and lower water pipe side suspension fins 7113A, 7113B are provided, but the present invention is not limited to this.

[0043] Although not shown, the lower flange-side suspension fins 7112A, 7112B and the lower water pipe-side suspension fins 7113A, 7113B are each provided with bolt holes formed as elongated holes extending in the radial direction of the lower flange 7104 (boiler body) for inserting bolts 7114A, 7114B. This allows the radial thermal expansion that occurs during operation of the boiler 71 to be absorbed by each bolt hole formed as an elongated hole, and allows the lower flange 7104 to be suspended from the water pipe 7107 (boiler body) while avoiding structural damage caused by thermal expansion.

[0044] 3, at the top of the boiler 71, the upper header 7102 is airtightly connected to the upper flange 7101 by an upper compensator 7130. As a result, even when the internal space 710 of the boiler 71 is in a positive pressure state, the upper compensator 7130 can prevent the reformed gas from leaking to the outside from between the upper header 7102 and the upper flange 7101.

[0045] Furthermore, at the top of boiler 71, upper flange side suspension fins 7109A, 7109B and upper water tube side suspension fins 7110A, 7110B are fastened to each other, independently of upper compensator 7130, thereby suspending water tube 7107 from upper flange 7101. This makes it possible to suppress the action of stress other than thermal stress (such as stress due to the load of the boiler body) on upper compensator 7130, thereby realizing a structure in which upper compensator 7130 is less likely to break.

[0046] 4, at the bottom of the boiler 71, the lower flange 7104 is airtightly connected to the lower header 7105 by the lower compensator 7180. As a result, even when the internal space 710 of the boiler 71 is in a positive pressure state, the lower compensator 7180 can prevent the reformed gas from leaking to the outside from between the lower header 7105 and the lower flange 7104.

[0047] Furthermore, at the bottom of boiler 71, lower flange 7104 is suspended from water tube 7107 (boiler body) by fastening lower flange-side suspension fins 7112A, 7112B and lower water tube-side suspension fins 7113A, 7113B independently of lower compensator 7180. This makes it possible to suppress the action of stress other than thermal stress (such as stress due to the load of the boiler body) on lower compensator 7180, thereby realizing a structure in which lower compensator 7180 is less likely to break.

[0048] The boiler 71 according to the embodiment must have an airtight structure to prevent the reformed gas supplied from the gasification reformer furnace 50 through the gas duct 60 to the internal space 710 of the boiler 71 from leaking to the outside. However, the upper flange 7101 and the upper header 7102, and the lower flange 7104 and the lower header 7105, have significantly different temperatures during operation of the boiler 71. Therefore, if they are joined by welding or the like, there is a concern that the welds may be damaged due to differential thermal expansion in the radial direction. In contrast, the boiler 71 according to the embodiment can absorb the differential thermal expansion during operation of the boiler 71 by the upper compensator 7130 provided between the upper flange 7101 and the upper header 7102 and the lower compensator 7180 provided between the lower flange 7104 and the lower header 7105. Therefore, the boiler 71 according to the embodiment can ensure airtightness while avoiding structural damage due to differential thermal expansion during operation.

[0049] 3, the upper part of the boiler 71 according to the embodiment has a plurality of water channels 7120 for flowing cooling water provided inside the upper flange 7101, near the gas supply port 7101a in the radial direction of the upper flange 7101. In the upper flange 7101, a portion 7121 exposed to the reformed gas sent from the gas supply port 7101a to the internal space 710 of the boiler body is made of a heat-resistant and corrosion-resistant material such as Hastelloy. In addition, a portion of the upper flange 7101 that is closer to the exposed portion 7121 and comes into contact with the cooling water flowing through the water channels 7120 is made of a copper member 7122, which is a material with high thermal conductivity. This allows the upper flange 7101 to be prevented from corrosion due to trace components derived from waste in the reformed gas or damage due to heat over a long period of time.

[0050] 4, a plurality of water channels 7170 for flowing cooling water are provided inside the lower flange 7104 near the gas outlet 7104a in the radial direction of the lower flange 7104. In the lower flange 7104, the portion exposed to the reformed gas discharged from the internal space 710 of the boiler body to the outside through the gas outlet 7104a is made of a heat-resistant and corrosion-resistant material such as Hastelloy. In addition, the exposed portion of the lower flange 7104 is also on the internal side, and the portion in contact with the cooling water flowing through the water channels 7170 is made of a copper member as a material with high thermal conductivity. This allows the lower flange 7104 to be prevented from corrosion due to trace components derived from waste in the reformed gas or damage due to heat over a long period of time.

[0051] Furthermore, in the boiler 71 according to the embodiment, the water tubes 7107 may be made of low-alloy steel. This makes it easier for molten slag that has flown into the internal space 710 of the boiler body together with the reformed gas and adhered to the water tubes 7107 to peel off under its own weight, making it possible to maintain a stable heat transfer capacity in the water tubes 7107 for a long period of time.

[0052] Furthermore, in the boiler 71 according to the embodiment, a heat-resistant and corrosion-resistant material such as Hastelloy may be sprayed onto the outer peripheral surface of the water pipe 7107 to form a sprayed coating on the outer peripheral surface of the water pipe 7107. This makes it easier for molten slag adhering to the sprayed coating of the water pipe 7107 to peel off due to its own weight, and it is possible to maintain a stable heat transfer capacity in the water pipe 7107 for a long period of time.

[0053] Furthermore, in the boiler 71 according to the embodiment, the surface of the water pipe 7107 that comes into contact with the reformed gas may be polished. This makes it easier for molten slag adhering to the polished surface of the water pipe 7107 to peel off under its own weight, and it is possible to maintain a stable heat transfer capacity of the water pipe 7107 for a long period of time.

[0054] 4, a flow guide plate 7190 is provided at the bottom of the boiler 71 according to the embodiment. The flow guide plate 7190 guides and collects molten slag, which has separated from the water tubes 7107 and flowed down the inner circumferential surface of the boiler body, toward the center in the radial direction of the boiler body. The flow guide plate 7190 is disposed at an angle relative to the radial direction of the boiler body so that its lower end is in contact with the edge of the gas outlet 7104a at the upper end of the lower flange 7104 and its upper end is in contact with the inner circumferential surface of the boiler body. This allows the molten slag, which has flowed down the inner circumferential surface of the boiler body, to be guided by the flow guide plate 7190 to the gas outlet 7104a of the lower flange 7104 and to fall into the cooling and cleaning device 72 without accumulating at the bottom of the boiler 71. This enables the boiler 71 to operate stably for a long period of time.

[0055] Furthermore, the boiler 71 according to the embodiment may be provided with a solid matter removal device that removes solid matter such as molten slag adhering to the plurality of water tubes 7107 .

[0056] FIG. 5 is a partial cross-sectional view of the upper part of the boiler 71 when a water injection device 7150 is provided as a solid matter removal device.

[0057] 5, the boiler 71 according to the embodiment may include a water injection device 7150 that injects water supplied from an internal space 710 of the boiler body via a water supply pipe 7151 from a nozzle 7150a toward the inner circumferential surface of the boiler body. The water injection device 7150 is provided, for example, at the tip of the water supply pipe 7151 that is inserted into the internal space 710 of the boiler body from the gas supply port 7101a of the upper flange 7101. The position and orientation of the nozzle 7150a of the water injection device 7150 relative to the inner circumferential surface of the boiler body can be changed by moving the water supply pipe 7151 up and down or rotating it in the internal space 710 of the boiler body.

[0058] The water injection device 7150 injects water from a nozzle 7150a toward the molten slag, which is, for example, solid matter adhering to the water pipe 7107. The injected water collides with the high-temperature molten slag and evaporates, and the energy and heat shock generated by the evaporation cause the molten slag to peel off and be removed from the water pipe 7107. This allows the boiler 71 according to the embodiment to maintain a stable heat transfer capacity in the water pipe 7107 for a long period of time.

[0059] FIG. 6 is a partial cross-sectional view of the upper part of the boiler 71 when a hammer device 7160 is provided as a solid matter removal device.

[0060] 6, the boiler 71 according to the embodiment may be provided with a hammering device 7160 operated by compressed air from the outside of the boiler 71 as the solid removal device. The hammering device 7160 periodically strikes the outer circumferential surface of the boiler body with compressed air supplied from a compressed air supply pipe 7161, impacting the molten slag, which is a solid matter adhering to the water tubes 7107, and removing the molten slag from the water tubes 7107. This allows the boiler 71 according to the embodiment to maintain a stable heat transfer capacity in the water tubes 7107 for a long period of time.

[0061] The present invention can provide a waste treatment device that can recover and reuse a portion of the sensible heat of the reformed gas discharged from a gas reforming furnace.

[0062] REFERENCE SIGNS LIST 1 Waste treatment device 10 Waste input device 20 Gas supply member 50 Gasification reforming furnace 52 Pyrolysis section 53 Gas reforming section 54 Melting section 58 Melt outlet 59 Reformed gas outlet 60 Gas duct 70 Cooling and cleaning water circulation device 71 Boiler 72 Cooling and cleaning device 73 Settling tank 74 Second heat exchanger 80 Gas purification device 90 Cleaning water treatment device 100 Chemical product manufacturing device 710 Internal space 7101 Upper flange 7101a Gas supply port 7102 Upper header 7103A, 7103B Steam outlet pipe 7104 Lower flange 7104a Gas outlet 7105 Lower header 7106A, 7106B Water supply pipe 7107 Water pipe 7108 Connecting fin 7109A, 7109B Upper flange side suspension fins 7110A, 7110B Upper water pipe side suspension fins 7111A Bolt 7115A Bolt hole 7120 Water channel 7121 Exposed portion 7122 Copper member 7130 Upper compensator 7141 Bolt 7142 Nut 7150 Water injection device 7150a Nozzle 7151 Water supply pipe 7160 Hammer device 7161 Compressed air supply pipe 7170 Water channel 7180 Lower compensator 7190 Flow guide plate

Claims

1. A waste treatment apparatus comprising: a gasification reforming furnace that pyrolyzes and gasifies waste and reforms the generated gas to produce a reformed gas; a cooling and washing water circulation device that cools and washes the reformed gas generated in the gasification reforming furnace; a gas purification device that purifies the reformed gas cooled and washed by the cooling and washing water circulation device; and a chemical product manufacturing device that manufactures liquid chemical products using the purified gas purified by the gas purification device as a raw material, wherein the cooling and washing water circulation device has a heat recovery device that recovers a part of the sensible heat of the reformed gas, and the waste treatment apparatus is characterized in that the sensible heat recovered by the heat recovery device is configured to be supplied to the chemical product manufacturing device.

2. The waste treatment apparatus according to claim 1, wherein the cooling and washing water circulation device includes a quenching and washing device that quenches and washes the reformed gas from which a part of the sensible heat has been recovered by the heat recovery device with quenching washing water, and the heat recovery device recovers sensible heat from the reformed gas to a temperature not lower than 300 [°C] below the temperature of the reformed gas at the outlet side of the gasification reforming furnace.

3. The waste treatment apparatus according to claim 2, wherein the heat recovery device is a boiler including a structure composed of a plurality of water pipes arranged in a cylindrical shape, a plurality of connection fins connecting the adjacent water pipes in the circumferential direction, an annular upper header connected to the upper ends of the plurality of water pipes and the plurality of connection fins, and an annular lower header connected to the lower ends of the plurality of water pipes and the plurality of connection fins.

4. The waste treatment apparatus according to claim 3, wherein an upper flange for connecting to a gas duct through which the reformed gas sent from the gasification reforming furnace passes is provided above the boiler, and an upper compensator capable of absorbing the difference in thermal expansion between the upper flange and the upper header is provided between the upper flange and the upper header.

5. In the central part of the upper flange in the radial direction, a gas supply port for supplying the reformed gas from the gas duct into the boiler is provided. A water passage for flowing cooling water is provided inside the upper flange in the vicinity of the gas supply port. In the upper flange, the exposed part in contact with the reformed gas sent from the gas supply port into the boiler is made of a material having heat resistance and corrosion resistance. The part on the inner side of the upper flange rather than the exposed part and in contact with the cooling water flowing through the water passage is made of a material having high thermal conductivity. The waste treatment device according to claim 4, characterized in that.

6. The boiler is provided with a solid matter removing device for removing solid matter adhering to the inner peripheral surface of the structure. The waste treatment device according to claim 3, characterized in that.

7. As the solid matter removing device, a water injection device for injecting water toward the inner peripheral surface of the structure is provided. The waste treatment device according to claim 6, characterized in that.

8. As the solid matter removing device, a hammering device for hammering the outer peripheral surface of the structure is provided. The waste treatment device according to claim 6, characterized in that.

9. The waste treatment device according to claim 3, characterized in that the water pipe is made of low alloy steel.

10. A thermal spraying coating made of a material having heat resistance and corrosion resistance is formed on the outer peripheral surface of the water pipe. The waste treatment device according to claim 3, characterized in that.

11. The surface of the water pipe in contact with the reformed gas is a polished surface. The waste treatment device according to claim 3, characterized in that.

12. The boiler includes an upper flange side suspension fin provided on the lower surface of the upper flange, an upper water pipe side suspension fin provided on the outer peripheral surface of the upper part of the water pipe, and a fastening member for fastening the upper flange side suspension fin and the upper water pipe side suspension fin. The waste treatment device according to claim 4, characterized in that the water pipe is suspended from the upper flange.

13. The waste treatment apparatus according to claim 3, characterized in that a deflector plate is provided below the boiler to deflect and collect the molten slag flowing down the inner peripheral surface of the structure toward the center in the radial direction of the structure.

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