JP2006036806A - Method of thermal decomposition and apparatus for thermal decomposition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of thermal decomposition by which even a hard material to be heated is efficiently heated and the quantity of the heat transfer is grasped and an apparatus for the thermal decomposition. <P>SOLUTION: In a method of thermal decomposition in which wastes such as waste plastic are thermally decomposed by melting and gasification, the wastes are thermally decomposed by blowing low oxygen high temperature heated gas against them in a low oxygen atmosphere. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermal decomposition method and a thermal decomposition apparatus in which waste such as waste plastic is melted and gasified for thermal decomposition.

  Among the ever-increasing garbage disposal measures in recent years, one of the most important issues is the disposal of plastic parts and plastic containers used in most industrial products such as electrical products, household goods, automobiles, and PET bottles. There is.

  That is, since such waste plastics are difficult to biodegrade with microorganisms such as garbage and wood garbage, most of them are currently incinerated. There are problems such as the generation of a large amount of smoke and harmful gases during incineration and the adverse effect on the incinerator due to the high combustion temperature.

  Therefore, in recent years, it has been attempted to collect this waste plastic and reuse it as one of the valuable recycling resources. However, when it is recycled, for example, it is necessary to collect and sort by component, color, etc. Therefore, there is a problem that it requires a great deal of cost and labor and is not economically profitable.

  Therefore, the present applicant has developed a new waste plastic oil conversion system that can effectively dispose of such waste plastic that has been difficult to dispose and recycle, and that can be effectively used as recycled oil. (See Patent Document 1).

  This waste plastic oil conversion system is a waste plastic pyrolysis furnace that heats and melts and gasifies waste plastic with heat from a gas burner, etc., and the pyrolysis gas obtained in this pyrolysis furnace is cooled and condensed to make oil. It consists mainly of an oil tank, and after melting and pyrolyzing mainly thermoplastic waste plastic in this pyrolysis furnace, this pyrolysis gas is cooled in a gas-liquid contact with cooling water in the oil tank. It is condensed and re-liquefied, and then the decomposed liquid is separated and recovered from cooling water and effectively used as fuel for boilers, raw materials for new plastic products, and the like. The pyrolysis apparatus is mainly composed of the gas burner and the waste plastic pyrolysis furnace described above.

  According to such a waste plastic oil conversion system, it is possible to effectively treat waste plastic, which has been difficult to treat conventionally, and it can be effectively used as flammable recycled oil. Waste plastic can be recycled efficiently. In addition, since no harmful gas leaks to the outside in principle during this treatment, it is possible to exert excellent effects such as no risk of contaminating the local environment.

JP 2001-247874 A

  However, in the thermal decomposition apparatus used in the above-described waste plastic oil conversion system, heat transfer efficiency is poor because heat is transferred from the heat transfer surface of the metal pyrolysis furnace to the waste plastic inside. In particular, as in the case of the batch type waste plastic oiling device as described above, when the object to be heated (waste such as waste plastic) is hard and the contact area to the heat transfer surface is limited, the objects to be heated There was a problem that the amount of heat transfer was reduced.

  In order to solve this problem, it is conceivable to use sand or oil as a heat medium, or to use a stirrer. In this case, however, the amount of heat transfer cannot be grasped, and it has been arranged in engineering. Therefore, it was difficult to determine whether complete melting and gasification was performed.

  Therefore, the present invention has been devised in order to effectively solve such problems, and its purpose is to efficiently heat even hard waste and to grasp the amount of heat transfer. An object of the present invention is to provide a thermal decomposition method and a thermal decomposition apparatus.

  In order to solve the above-mentioned problem, the invention of claim 1 is a thermal decomposition method in which waste such as waste plastic is melted and gasified to thermally decompose, and the waste is heated to a high-temperature low oxygen heating gas in a low oxygen atmosphere. Is a thermal decomposition method in which the waste is thermally decomposed.

  The invention according to claim 2 is the thermal decomposition method according to claim 1, wherein the oxygen concentration of the low oxygen heating gas is 1% or less.

  The invention of claim 3 is a thermal decomposition apparatus that generates thermal decomposition gas by thermally decomposing waste such as waste plastic, and a thermal decomposition furnace that encloses and stores the waste, and And a heating means for blowing a high-temperature, low-oxygen heating gas to waste.

  According to a fourth aspect of the present invention, the heating means includes a heated gas supply device having a combustor that supplies heated gas into the pyrolysis furnace, and an air supply device that supplies combustion air to the combustor, The heating means includes a heating gas oximeter for measuring the oxygen concentration of the heating gas from the combustor, and heating by controlling the air supply amount of the air supply device according to the measurement value of the heating gas oximeter The thermal decomposition apparatus according to claim 3, further comprising a low oxygen reduction device that uses a gas as a low oxygen heating gas.

  The invention of claim 5 is a thermal decomposition apparatus that generates thermal decomposition gas by thermally decomposing waste such as waste plastic, and a pyrolysis furnace that contains the waste, and the waste in the pyrolysis furnace. Heating means for blowing a high-temperature low-oxygen heating gas, wherein the pyrolysis furnace supplies an inert gas to lower the oxygen concentration in the room, and communicates with the air replacement chamber to dispose the waste. A gasification chamber that thermally decomposes to generate pyrolysis gas; a cooling chamber that communicates with the gasification chamber to cool the residue of the waste that has not been gasified; and the waste from the air replacement chamber to the gas A gas transfer chamber, a transfer device for transferring to the cooling chamber, and an air displacement chamber oximeter for detecting the oxygen concentration in the air displacement chamber, and the air displacement according to the measured value of the air displacement chamber oximeter Supply an inert gas into the room and A pyrolysis apparatus configured to blow a high-temperature, low-oxygen heating gas to the waste in the gasification chamber with the heating means after setting the replacement chamber, the gasification chamber, and the cooling chamber to a low oxygen atmosphere. .

  According to a sixth aspect of the present invention, the heating means includes a heated gas supply device having a combustor that supplies a heated gas into the gasification chamber, and an air supply device that supplies combustion air to the combustor. The heating means includes a heated gas oximeter that measures the oxygen concentration of the heated gas from the combustor, and a heating gas that controls the air supply amount of the air supply device according to the measured value of the heated gas oximeter. The thermal decomposition apparatus according to claim 5, further comprising a oxygen reduction device that uses a low oxygen heating gas as a gas.

  According to this invention, even if it is a hard waste, while being able to heat efficiently, the outstanding effect that a heat transfer amount can be grasped | ascertained is exhibited.

  A preferred embodiment for carrying out the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing a waste treatment apparatus equipped with a thermal decomposition apparatus according to the present invention.

  As shown in the figure, a waste treatment apparatus 1 cools a pyrolysis apparatus 2 for melting and gasifying a waste such as waste plastic and thermally decomposing it, and a pyrolysis gas obtained by the pyrolysis apparatus 2. Thus, a jet scrubber 3 for re-liquefaction and an oil-water separation tank 4 for oil-water separation of the re-liquefied stock solution are provided.

  The thermal decomposition apparatus 2 includes a thermal decomposition furnace 5 that encloses and stores waste, and a heating unit 6 that blows high-temperature, low-oxygen heating gas to the waste in the thermal decomposition furnace 5. The heating means 6 includes a heated gas supply device 11. The heated gas supply device 11 includes a combustor 7 that supplies heated gas into the pyrolysis furnace 5, an air supply device 8 that supplies combustion air to the combustor 7, and a fuel supply that supplies fuel to the combustor 7. And a device 9.

  A heating gas supply line 12 is connected to the combustor 7, and a heating gas supply nozzle 14 is provided at the tip thereof. The heating gas supply nozzle 14 is provided so as to penetrate the body portion of the pyrolysis furnace 5 and is arranged so as to eject the heating gas toward the bottom of the pyrolysis furnace 5. The heated gas supply line 12 is provided with a heated gas oxygen concentration meter 15 that measures the oxygen concentration of the heated gas flowing inside, and a thermometer 16 that measures the temperature of the heated gas.

  The air supply device 8 includes an air supply line 17 connected to the combustor 7 and an air supply fan 18 provided in the air supply line 17. A control device 21 is electrically connected to the motor 19 of the air supply fan 18. The control device 21 is connected to the heating gas oximeter 15 and is used for combustion so that the heating gas becomes a low oxygen heating gas by changing the rotation amount of the supply fan 18 according to the oxygen concentration of the heating gas. The supply amount of air is adjusted. Specifically, the oxygen concentration of the heating gas is continuously measured by the heating gas oximeter 15, and the oxygen concentration of the heating gas (high temperature low oxygen heating gas) is 1% or less by the control device 21. The amount of combustion air supplied to the combustor 7 is controlled. The control device 21 constitutes the oxygen reduction device 20 that reduces the oxygen concentration of the heating gas by reducing the supply amount of combustion air.

  The fuel supply device 9 includes a fuel line 22 connected to the combustor 7, and a fuel tank (not shown) and a pump (not shown) connected to the fuel line 22. The fuel line 22 is provided with an on-off valve 23. The on-off valve 23 is electrically connected to an in-furnace thermometer 24 provided in the pyrolysis furnace 5 via a control device (not shown). The control device adjusts the amount of fuel supplied in accordance with the temperature in the pyrolysis furnace 5.

  Connected to the heated gas supply line 12 is a gas line 25 for returning the gas that has not been liquefied by the jet scrubber 3 to the thermal decomposition apparatus 2. A base end portion of the gas line 25 is connected to the oil / water separation tank 4. An opening / closing valve 26 is provided in the gas line 25. The on-off valve 26 is electrically connected to the thermometer 16 via a control device (not shown). The control device adjusts the supply amount of the cold inert gas from the jet scrubber 3 according to the temperature of the pyrolysis insertion port cooling gas during cooling.

  In the pyrolysis furnace 5, a stirrer 27 is provided for stirring the waste to make the temperature in the pyrolysis furnace 5 uniform.

  The stirrer 27 includes a drive shaft 28 located at the axial center of the pyrolysis furnace 5, a drive motor 29 attached to the top of the drive shaft 28 for rotationally driving the drive shaft 28, and a plurality of radially extending from the drive shaft 28. It consists of a single stirring blade 30. The stirrer 27 stirs the waste put into the pyrolysis furnace 5 and heats it uniformly and efficiently.

  A gas outlet 31 for discharging the pyrolysis gas and a water inlet 32 for returning the water separated in the oil / water separation tank 4 to the pyrolysis furnace 5 are provided at the upper part of the pyrolysis furnace 5. A gas line 33 connected to the jet scrubber 3 is connected to the gas outlet 31. The gas line 33 is provided with a pressure gauge 70 that detects the pressure in the gas line 33 and an on-off valve 50 that opens and closes according to the detected value of the pressure gauge 70. While keeping constant, the on-off valve 50 is opened and closed to discharge the pyrolysis gas. A water line 34 connected to the bottom of the oil / water separation tank 4 is connected to the water inlet 32. The water line 34 is provided with a pump 35, and the pump 35 is driven to pump water in the oil / water separation tank 4. A neutralization liquid supply pipe 36 is connected to the water line 34, and a neutralization liquid is injected according to the pH value of the water flowing inside. The water line 34 is provided with a branch line 37 extending to the jet scrubber 3, and water is supplied to the jet scrubber 3 by switching the opening and closing valves 38 and 39. In addition, a thermometer 40 that measures the temperature of the gas in the gas-liquid separation tank 4 is electrically connected to the on-off valve 39, and the amount of water supplied to the jet scrubber 3 is adjusted according to the gas temperature. It is like that.

  The oil / water separation tank 4 is provided with a regenerated oil line 41, and the oil separated in the oil / water separation tank 4 is pumped to a regenerated oil tank (not shown) by a pump 43. The gas line 25 connected to the oil / water separation tank 4 is branched from a discharge line 46 for releasing the gas to the atmosphere. The discharge line 46 is provided with a condenser 44, which cools the gas that has not been liquefied by the jet scrubber 3 and separates it into steam and water. The gas component (cold inert gas) is discharged out of the system by the fan 45. Moisture is sent to the bottom of the oil / water separation tank 4. The gas line 25 is provided with a fan 80, and the gas is returned to the thermal decomposition apparatus 2 by the fan 80.

  Next, a thermal decomposition method using the waste treatment apparatus 1 including the thermal decomposition apparatus 2 configured as described above and its operation will be described.

  First, after putting waste into the pyrolysis furnace 5, the on-off valve 50 is opened, and the residual air and the heated gas in the system are cooled by the condenser 44 and discharged to the atmosphere through the discharge line 46 by the fan 45. . Thereby, the air in the pyrolysis furnace 5 before heating is pushed out of the furnace, and the inside of the pyrolysis furnace 5 becomes a low oxygen atmosphere.

  Thereafter, fuel and combustion air are supplied to the combustor 7 and burned with the target of zero excess air ratio to obtain a heated gas. At this time, the temperature in the pyrolysis furnace 5 measured by the furnace thermometer 24 is obtained. The amount of fuel supply is adjusted accordingly. The combustor 7 continuously measures the oxygen concentration of the heating gas with the heating gas oxygen concentration meter 15 and the control device 21 so that the oxygen concentration of the heating gas (high temperature low oxygen heating gas) is 1% or less. The amount of combustion air supplied to the is controlled. At the same time, the thermometer 16 measures the temperature of the heated gas in the heated gas supply line 12 (high-temperature inert gas at the outlet of the combustor 7). When the heated gas is too hot due to low oxygen, that is, a low air ratio, the cold inert gas in the oil / water separation tank 4 is supplied to cool the heated gas, which is optimal for melting and gasification. An inert gas in a temperature region is ejected into the pyrolysis furnace 5. That is, the low oxygen gas in the system is lowered to a solidification temperature of PET of 300 ° C. or lower by the jet scrubber 3 and returned to the heating gas supply line 12 by the gas line 25, whereby the inert gas is used for temperature control of the heating gas. I use it.

  The high temperature inert gas is ejected to the waste at the bottom of the pyrolysis furnace 5 by the heated gas supply nozzle 14. At this time, since the waste is hard, there are many gaps between the wastes, and the area in contact with the inner surface of the pyrolysis furnace 5 is small. However, by spraying the high temperature inert gas on the waste, the high temperature inert gas flows into the gaps of the waste and can be heated by contacting from the periphery of the waste like fluid contact heat transfer. This greatly improves the heating efficiency.

  Further, since the waste is rotated and stirred by the stirrer 27, the heating gas is sprayed evenly over the whole and heated in a balanced manner, so that the waste is efficiently melted and gasified. Moreover, since the high-temperature low-oxygen heating gas is sprayed on the waste in a low-oxygen atmosphere, suitable thermal decomposition can be performed without oxidizing the waste. The high-temperature inert gas is obtained by continuously measuring and controlling the ratio of fuel and combustion air, for example, by the heated gas oximeter 15 and the control device 21. Therefore, the amount of heat generated can be easily calculated, the amount of heat transfer can be reliably grasped from an engineering viewpoint, and complete melting and gasification can be performed.

  If the combustor is easy to set, such as an oil burner, and the oxygen concentration can be set in advance to be 1% or less, the oxygen concentration meter must not be continuously measured and controlled. Also good.

  The gasified pyrolysis gas is cooled by the jet scrubber 3 and reliquefied. The re-liquefied stock solution is separated into oil and water in the oil / water separation tank 4, the oil is reused as regenerated oil, and the water is sent to the jet scrubber 3 to cool the pyrolysis gas and to a nozzle (not shown). It is used for cleaning and so on.

  In addition, you may equip the lower part of the pyrolysis furnace 5 with a combustor separately, and may heat the pyrolysis furnace 5 from a bottom part and a side part. According to this, even if the heating state of the waste by the heating means 6 is bad, it is possible to prevent the molten plastic from solidifying at the bottom of the pyrolysis furnace 5.

  In the above embodiment, the high-temperature inert gas is supplied into the pyrolysis furnace 5 through the heating gas supply nozzle 14 provided in the body of the pyrolysis furnace 5. It is not limited. For example, the drive shaft 28 of the stirrer 27 is formed in a pipe shape, a rotary joint (not shown) is provided on the drive shaft 28, and high-temperature inert gas is passed through the drive shaft 28 from the lower end thereof in the pyrolysis furnace 5. You may make it supply to. Further, a pipe (not shown) may be disposed around the drive shaft 28 so that the high temperature inert gas passes through the gap between the drive shaft 28 and the pipe. In any of these cases, the high-temperature inert gas flows from the upper part of the pipe and is released into the pyrolysis furnace 5 from the lower end, so that the distance between the lower end of the pipe and the upper surface of the molten plastic accumulated at the bottom of the pyrolysis furnace 5 It is necessary to ensure the pressure of the seal depth so that the hot inert gas is broken.

  FIG. 2 is a schematic configuration diagram showing another embodiment of the pyrolysis furnace of the pyrolysis apparatus according to the present invention.

  As shown in the figure, the pyrolysis furnace 51 has a mesh container 52 accommodated therein. The mesh container 52 is formed in a box shape having an open top, and the bottom surface and each side surface are made of a mesh material. The mesh container 52 is supported by a support member 53 provided on the inner wall of the pyrolysis furnace 51.

  The pyrolysis furnace 51 is used when the waste contains a metal such as a tire or a covered electric wire, or an inorganic material such as glass. That is, by storing and heating the above-mentioned waste in the mesh container 52, the plastics are melted and fall to the bottom of the pyrolysis furnace 51, but metal, glass, etc. are in the mesh container 52. Remain. Therefore, by removing the mesh container 52 after heating, the metal, glass, etc. can be easily separated and collected. Further, since the waste is accommodated in the mesh container 52 that is supported by being floated in the pyrolysis furnace 51, it can come into contact with the high-temperature inert gas from the surroundings, and the heating efficiency is improved.

  FIG. 3 is a schematic configuration diagram showing still another embodiment of the pyrolysis furnace of the pyrolysis apparatus according to the present invention.

  As shown in the figure, such a pyrolysis furnace 55 includes an air replacement chamber 56 that lowers the oxygen concentration in the room by supplying an inert gas, and communicates with the air replacement chamber 56 to thermally decompose waste to generate pyrolysis gas. And a cooling chamber 58 that communicates with the gasification chamber 57 and cools the residue of the waste that has not been gasified. The air replacement chamber 56, the gasification chamber 57, and the cooling chamber 58 are partitioned by partition walls 59 and 60, which are sequentially adjacent to each other in the row. Openings 61 and 62 are respectively formed in the partition walls 59 and 60, and a transfer device 63 described later is provided through the openings 61 and 62.

  The transfer device 63 is a device that transfers waste from the air replacement chamber 56 to the gasification chamber 57 and the cooling chamber 58. The transfer device 63 is configured by a mesh conveyor 64 using a mesh-like conveyor belt. The mesh conveyor 64 is formed of a heat resistant steel material or the like.

  A waste input port 66 is formed in the air replacement chamber 56. A rotary valve 65 is provided at the input port 66 and partitions the inside and outside of the room. An air replacement chamber oxygen concentration meter 67 for measuring the oxygen concentration in the room is provided in the air replacement chamber 56. The air replacement chamber oxygen concentration meter 67 is provided in the vicinity of the opening 61 connected to the gasification chamber 57. On the other hand, a control device 69 for controlling the rotation is connected to the drive motor 68 for driving the mesh conveyor 64. The control device 69 is electrically connected to the air displacement chamber oxygen concentration meter 67, and controls the speed of the mesh conveyor 64 so that the oxygen concentration near the opening 61 becomes a value close to 1%.

  A cold inert gas supply nozzle 71 is provided at the bottom of the air replacement chamber 56 to supply a cold inert gas for air replacement into the chamber. The cold inert gas supply nozzle 71 is configured by forming a plurality of holes in a pipe installed at the bottom of the air replacement chamber 56. The cold inert gas supply nozzle 71 is connected to a cold inert gas supply source (not shown) such as an oil / water separation tank.

  At the top of the air replacement chamber 56, an exhaust line 73 having an exhaust fan 72 for exhausting the indoor gas and a thermometer 74 are provided. The motor 94 of the exhaust fan 72 is electrically connected to the thermometer 74 via the control device 95. When the temperature in the air replacement chamber 56 rises, the control device 95 discharges the indoor air to keep the indoor temperature constant.

  In the gasification chamber 57, a high-temperature inert gas supply nozzle 75 for blowing high-temperature inert gas to waste on the mesh conveyor 64 is provided. The high temperature inert gas supply nozzle 75 is configured by forming a plurality of holes in a pipe installed under the mesh conveyor 64 in the gasification chamber 57. The high temperature inert gas supply nozzle 75 is connected to heating means (not shown). The configuration of the heating means is the same as that in FIG. The high temperature inert gas supply source may be provided separately. However, even if water is added to the combustion gas in a separate process of solidifying foamed polystyrene, a high temperature cannot be obtained and it cannot be employed.

  A recess 76 for storing molten plastic is formed at the bottom of the gasification chamber 57. A circulation line 78 including a pump 77 is connected to the bottom of the recess 76. The circulation line 78 extends in the vicinity of the top of the gasification chamber 57 so that molten plastic is ejected into the gasification chamber 57.

  Connected to the top of the gasification chamber 57 is a gas line 79 for supplying the gasified pyrolysis gas to a jet scrubber (not shown). A fan 81 is provided in the gas line 79. On the other hand, the gasification chamber 57 is provided with a pressure gauge 82 for detecting the pressure in the chamber. The pressure gauge 82 is electrically connected to a control device 84 connected to the motor 83 of the fan 81. When the pressure in the gasification chamber 57 reaches a predetermined value, the control device 84 rotates the fan 81 to supply the pyrolysis gas to the jet scrubber.

  In the cooling chamber 58, a cold inert gas supply nozzle 85 is provided for spraying a cold inert gas on the waste residue on the mesh conveyor 64. The cold inert gas supply nozzle 85 is configured by forming a plurality of holes in a pipe installed under the mesh conveyor 64 in the cooling chamber 58. The cold inert gas supply nozzle 85 is connected to a cold inert gas supply source (not shown) such as an oil / water separation tank.

  A discharge port 86 for discharging waste residue is formed at the bottom of the cooling chamber 58. A rotary valve 87 is provided at the discharge port 86.

  Connected to the top of the cooling chamber 58 is an exhaust line 88 for sending indoor gas to an exhaust treatment device (not shown). A fan 89 is provided in the exhaust line 88. On the other hand, the cooling chamber 58 is provided with a pressure gauge 91 for detecting the pressure in the chamber. The pressure gauge 91 is electrically connected to a control device 93 connected to the motor 92 of the fan 89. When the pressure in the cooling chamber 58 reaches a predetermined value, the control device 93 rotates the fan 89 to send the indoor gas to the exhaust treatment device.

  The wall surfaces and partition walls 59 and 60 of the air replacement chamber 56, the gasification chamber 57, and the cooling chamber 58 are made of carbon steel. The inner wall surfaces in the high temperature region of the gasification chamber 57 and the cooling chamber 58 have a structure in which a refractory is lined.

  When using the thermal decomposition apparatus provided with the thermal decomposition furnace 55 having the above configuration, first, waste is introduced into the air replacement chamber 56 through the rotary valve 65 and placed on the mesh conveyor 64. At this time, the control device 69 controls the speed of the mesh conveyor 64 so that the oxygen concentration in the vicinity of the opening 61 becomes a value close to 1%.

  Further, when the oxygen concentration in the air replacement chamber 56 is high, the supply amount of the cold inert gas is increased to expel oxygen and lower the oxygen concentration. Further, while the temperature in the air replacement chamber 56 is measured with the thermometer 74, the exhaust fan 72 is driven so that the temperature in the room becomes around 100 ° C. As a result, the gas in the air replacement chamber 56 is easily expanded and discharged, and waste can be preheated. Furthermore, gasification of plastic does not occur near 100 ° C.

  The waste transferred to the gasification chamber 57 by the mesh conveyor 64 is heated by being sprayed with high temperature inert gas from the high temperature inert gas supply nozzle 75. At this time, the inside of the gasification chamber 57 is in a low oxygen atmosphere, and the high temperature inert gas is blown onto the waste in this state, so that suitable thermal decomposition can be performed without oxidizing the waste. 1, the high-temperature inert gas is obtained by continuously measuring and controlling the ratio of fuel to combustion air, for example, by the heated gas oximeter 15 and the control device 21. Because this heat transfer method directly blows and contacts this high-temperature inert gas to the waste, the calorific value can be easily calculated, the heat transfer amount can be reliably determined from an engineering perspective, and complete melting and gasification are performed. be able to.

  Further, since the plastic melted in the gasification chamber 57 is stored in the recess 76 and ejected to the vicinity of the top of the gasification chamber 57 via the circulation line 78, the gasification efficiency is improved.

  While measuring the pressure in the gasification chamber 57 with the pressure gauge 82, the fan 81 is rotated in accordance with the detected value to supply the pyrolysis gas to the jet scrubber. Accordingly, the pressure in the gasification chamber 57 can be kept constant at a pressure preferable for gasification, and the gasification efficiency is further improved.

  After the gasified pyrolysis gas is supplied to a jet scrubber (not shown), it is cooled and reliquefied in the same manner as the waste treatment apparatus of FIG.

  The waste residue that has not been gasified is transferred into the cooling chamber 58, cooled by being sprayed with a cold inert gas from the cold inert gas supply nozzle 85, and then discharged from the discharge port 86.

  At this time, if the refrigerant is steam, an effect can be expected for activation of charcoal in the residue. Furthermore, if the exhaust from the air replacement chamber 56 and the cooling chamber 58 is cooled using steam as a refrigerant, facilities such as exhaust deodorization treatment can be reduced, and there is a cost merit. In that case, condensate is used as a steam source.

  In the above embodiment, a jet scrubber is used for cooling the pyrolysis gas, but this is to deal with waste including sublimation physical properties such as PET, and disposal without sublimation physical properties. In the case of an object, a simple heat exchanger may be used instead of the jet scrubber. According to this, the waste is not limited to the waste plastic, and can effectively cope with the thermal decomposition of the wooden waste.

  In addition, in the said embodiment, although the transfer apparatus 63 is comprised by the mesh conveyor 64, it is not restricted to this. For example, as shown in FIGS. 4 to 8, the truck 101 may be a transfer device 63. The truck 101 is formed of a mesh-like heat-resistant steel material or the like.

  As shown in FIG. 4, in the present embodiment, an input chamber 102 for introducing waste into the trolley 101, an air replacement chamber 103 that reduces the oxygen concentration in the room by supplying cold inert gas into the room, A gasification chamber 104 that thermally decomposes waste to generate pyrolysis gas and a cooling chamber 105 that cools and discharges the residue of the waste that has not been gasified are provided.

  The input chamber 102, the air replacement chamber 103, the gasification chamber 104, and the cooling chamber 105 are adjacent to each other and communicate with each other. The whole is arranged in an annular shape, and the charging chamber 102 is arranged next to the cooling chamber 105. The input chamber 102, the air replacement chamber 103, and the cooling chamber 105 are formed slightly longer than the truck 101, and the gasification chamber 104 is formed in an arc shape so as to connect the air replacement chamber 103 and the cooling chamber 105. The chambers 102 to 105 are partitioned by a partition wall 107 having an opening / closing door 106 that partitions the chambers in an airtight manner. A guide rail 108 of the trolley 101 is laid in an annular shape in each of the chambers 102 to 105 arranged in an annular shape.

  As shown in FIG. 5, an input device 109 is provided adjacent to the input chamber 102. The charging device 109 is configured by a bucket conveyor 111, and waste is dropped and charged from the upper part of the truck 101 through a charging chute 112.

  As shown in FIG. 6, the air replacement chamber 103 is provided with a cold inert gas supply nozzle 114. The cold inert gas supply nozzle 114 is disposed below the trolley 101 along the guide rail 108. An exhaust line 115 including an exhaust fan (not shown) is provided at the top of the air replacement chamber 103.

  As shown in FIG. 7, the gasification chamber 104 is provided with a high-temperature inert gas supply nozzle 116. The high-temperature inert gas supply nozzle 116 is disposed along the guide rail 108 at the lower part of the truck 101. A gas line 117 for supplying the gasified pyrolysis gas to a jet scrubber (not shown) is provided at the top of the gasification chamber 104. At the bottom of the gasification chamber 104, a recess 117 for storing molten plastic is formed. A circulation line 121 including a pump 119 is connected to the recess 118. The circulation line 121 extends near the top of the gasification chamber 104 so that molten plastic is ejected into the gasification chamber 104.

  As shown in FIG. 8, the cooling chamber 105 is provided with a cold inert gas supply nozzle 122. The cold inert gas supply nozzle 122 is disposed below the trolley 101 along the guide rail 108. The side wall 123 of the cooling chamber 105 is provided with an opening / closing door 124 that hermetically separates the inside and outside of the room. The opening / closing door 124 is opened, and the truck 101 is taken out by the forklift 125 to discharge waste residue. It has become. After discharging the residue, the trolley 11 is returned again onto the guide rail 108 and moves to the input chamber 102.

  Thus, by arranging the chambers 102 to 105 in an annular shape and providing the guide rail 108, the trolley 101 can be moved from the cooling chamber 105 to the charging chamber 102 in a short time. Therefore, the truck 101 can be continuously used without moving the truck 101 in the reverse direction.

  In the above embodiment, waste is input by the bucket conveyor 111, but the input of waste is not limited to this. For example, an opening / closing door having the same configuration as that shown in FIG. 8 may be formed in the input chamber, and the truck may be taken out by a forklift and the waste may be input into the truck.

It is the block diagram which showed the waste-processing apparatus provided with the thermal decomposition apparatus which concerns on this invention. It is the schematic block diagram which showed other embodiment of the thermal decomposition furnace of the thermal decomposition apparatus which concerns on this invention. It is the schematic block diagram which showed other embodiment of the thermal decomposition furnace of the thermal decomposition apparatus which concerns on this invention. It is the schematic structure top view which showed other embodiment of the thermal decomposition furnace of the thermal decomposition apparatus which concerns on this invention. It is sectional drawing which showed the injection | throwing-in chamber of the thermal decomposition apparatus of FIG. It is sectional drawing which showed the air substitution chamber of the thermal decomposition apparatus of FIG. It is sectional drawing which showed the gasification chamber of the thermal decomposition apparatus of FIG. It is sectional drawing which showed the cooling chamber of the thermal decomposition apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Pyrolysis apparatus 5 Pyrolysis furnace 6 Heating means 7 Combustor 8 Air supply apparatus 11 Heated gas supply apparatus 15 Heated gas oximeter 20 Deoxygenation apparatus 51 Pyrolysis furnace 55 Pyrolysis furnace 56 Air replacement chamber 57 Gasification chamber 58 Cooling room 67 Air displacement room oxygen meter

Claims (6)

In the pyrolysis method that melts and gasifies waste plastics and other wastes,
A thermal decomposition method characterized by thermally decomposing the waste by spraying a high-temperature low-oxygen heating gas on the waste in a low-oxygen atmosphere.   The thermal decomposition method according to claim 1, wherein the oxygen concentration of the low oxygen heating gas is 1% or less.   In a pyrolysis apparatus that pyrolyzes waste such as waste plastic to generate pyrolysis gas, a pyrolysis furnace that encloses and stores the waste, and the waste in the pyrolysis furnace has high temperature and low oxygen content. A thermal decomposition apparatus comprising a heating means for blowing heated gas.   The heating means includes a heating gas supply device having a combustor that supplies a heating gas into the pyrolysis furnace and an air supply device that supplies combustion air to the combustor, and the heating means includes the combustion A heating gas oximeter for measuring the oxygen concentration of the heating gas from the vessel, and the heating gas as a low oxygen heating gas by controlling the air supply amount of the air supply device according to the measured value of the heating gas oximeter The thermal decomposition apparatus according to claim 3, further comprising a low oxygen reduction device.   In a pyrolysis apparatus that pyrolyzes waste such as waste plastic to generate pyrolysis gas, a pyrolysis furnace that contains the waste, and a high-temperature low-oxygen heating gas is added to the waste in the pyrolysis furnace. And a heating means for spraying, wherein the pyrolysis furnace supplies an inert gas to lower the oxygen concentration in the room, and communicates with the air substitution chamber to pyrolyze the waste to pyrolyze the pyrolysis gas. A gasification chamber that generates gas, a cooling chamber that communicates with the gasification chamber and cools the residue of the waste that has not been gasified, and the waste from the air replacement chamber to the gasification chamber and the cooling chamber. A transfer device for transferring the air, and an air displacement chamber oxygen concentration meter for detecting the oxygen concentration in the air displacement chamber, and supplying an inert gas into the air displacement chamber according to the measured value of the air displacement chamber oxygen concentration meter The air replacement chamber and the gas After gasification chamber and said cooling chamber and a low oxygen atmosphere, in the heating means, the pyrolysis apparatus characterized by being configured to spray the low-oxygen heating gas having a high temperature in the waste of the gasification chamber. The heating means includes a heating gas supply device having a combustor for supplying a heating gas into the gasification chamber and an air supply device for supplying combustion air to the combustor, and the heating means includes the combustor. A heated gas oximeter for measuring the oxygen concentration of the heated gas from the gas, and the heating gas is made a low oxygen heated gas by controlling the air supply amount of the air supply device according to the measured value of the heated gas oximeter The thermal decomposition apparatus according to claim 5, further comprising a low oxygen reduction apparatus.

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