Roasting furnace, processing device and roasting method for resin-containing composite material

Abstract

Provided is a roasting furnace which, when heat-treating a resin-containing composite material such as a solar cell panel, can prevent corrosion of a roasting furnace main body during heat recovery, is easy to maintain, has a heating structure for removing the resin of the resin-containing composite material (3) by thermally decomposing the resin, and is capable of heating the resin-containing composite material (3) by heating the resin-containing composite material (3) by heating the resin-containing composite material (3). The heating structure heats the roasting furnaces (13, 15) by means of the heat of exhaust gas from a combustion device (4) for combusting decomposition gas obtained by thermally decomposing resin discharged from the roasting furnaces (13, 15). The heating structure has an indirect heat exchanger (812, 822).

Description

Technical Field

[0001] The present invention relates to a calcining furnace for a resin-containing composite material, a processing device for the resin-containing composite material, and a calcining method for the resin-containing composite material. Background Art

[0002] Removing resin from resin-containing composite materials, such as those used in solar panels, through thermal decomposition for valuable recovery and resource recovery has been a long-standing practice. Unburned gases generated during thermal decomposition of resin can contain harmful substances and are therefore required to be burned in an afterburner (combustion device) to reduce them to harmless gases such as CO2 and H2O before being released into the atmosphere.

[0003] For example, Patent Document 1 discloses a method for recycling constituent materials of a solar cell assembly contained in a solar cell module, the method being characterized by comprising the following process: transporting a solar cell assembly comprising at least a cell portion and a glass substrate, and an ethylene-vinyl acetate copolymer (EVA) sealing material bonding them together, to a continuous heat treatment furnace in which the oxygen concentration in the furnace is maintained at a range of from 1.0 volume % to 3.0 volume %, releasing and removing acetic acid gas, one of the EVA decomposition gases, in a preliminary heating decomposition section set at 300-400°C, and then releasing EVA decomposition gases other than acetic acid in a heat treatment section set at 400-550°C to remove the EVA sealing material from the solar cell assembly, thereby separating the cell portion from the glass substrate.

[0004] Furthermore, Patent Document 2 discloses a method for separating the constituent components of laminated glass, wherein laminated glass, which is composed of at least an inorganic glass sheet and a plastic layer bonded thereto, is subjected to heat treatment in a gaseous environment to thereby separate the constituent components. The method is characterized in that the laminated glass is heated at a maximum heating rate of 50°C / min in a heating stage to a final temperature of at least 300°C; and in a holding stage, the laminated glass is held at the final temperature until the plastic layer is substantially thermally decomposed and / or evaporated.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent No. 6297254

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 11-165150 Summary of the Invention

[0009] [Problems to be solved by the invention]

[0010] Patent Documents 1 and 2, for example, reuse the high-temperature gas generated after combustion in the combustion device for heating the thermal decomposition furnace, for example, from the perspective of energy conservation. However, depending on the type of resin to be thermally decomposed, such as the fluororesin backsheet of a solar panel, the thermal decomposition process may generate corrosive gases such as fluorine. Furthermore, depending on the processing conditions in the combustion device, corrosive gases such as unburned gas and NOx may be generated. This corrosive gas can corrode the gas flow path of the thermal decomposition furnace during thermal recycling, leading to maintenance costs and labor.

[0011] In view of the above circumstances, an object of the present invention is to provide a calciner that can prevent corrosion of the calciner body caused by corrosive gas during heat recovery associated with thermal decomposition of a resin-containing composite material and that facilitates maintenance of the device.

[0012] [Technical means to solve the problem]

[0013] The present inventors have made tireless research to solve the above problems and have found that the following invention meets the above purpose, thereby completing the present invention. Specifically, the present invention relates to the following invention contents.

[0014] <1> A calciner for removing resin from a resin-containing composite material by thermal decomposition, the calciner having a heating structure that heats the calciner using heat from exhaust gas discharged from a combustion device, wherein the combustion device is configured to combust decomposition gas generated by thermally decomposing the resin discharged from the calciner, and the heating structure includes an indirect heat exchanger.

[0015] <2> The roasting furnace according to <1>, wherein the indirect heat exchanger is any one selected from the group consisting of a multi-tube heat exchanger, a serpentine heat exchanger, and a heating wall.

[0016] <3> The roasting furnace according to <1> or <2>, further comprising an electric heater whose output is controlled according to the temperature of the roasting furnace to adjust the temperature of the roasting furnace.

[0017] <4> The firing furnace according to any one of <1> to <3>, wherein the resin-containing composite material is any one selected from the group consisting of a solar panel, a liquid crystal panel, and laminated glass.

[0018] <5> The roasting furnace according to any one of <1> to <4>, wherein the roasting furnace includes a muffle and an outer wall, and the indirect heat exchanger is provided between the muffle and the outer wall.

[0019] <6> A device for processing a resin-containing composite material, comprising: a detoxification tower provided downstream of the gas flow path of the indirect heat exchanger; and the calcining furnace according to any one of <1> to <5>.

[0020] <7> A method for calcining a resin-containing composite material, wherein resin in the resin-containing composite material is removed by thermal decomposition, wherein the calcination is performed in a calcination furnace having a heating structure that heats the calcination furnace by heat from exhaust gas discharged from a combustion device, wherein the combustion device is used to burn decomposition gas generated by thermally decomposing the resin discharged from the calcination furnace, and the heating structure has an indirect heat exchanger.

[0021] [Effects of the Invention]

[0022] The roasting furnace of the present invention can prevent the corrosion of the roasting furnace body caused by corrosive gas during heat recovery, and the maintenance of the device is easy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of a processing apparatus for a resin-containing composite material using the baking furnace of the present invention.

[0024] Figure 2 It is a perspective schematic diagram for explaining the roasting furnace of the present invention.

[0025] Figure 3 This is a schematic diagram for explaining the outline of the roasting furnace of the present invention, viewed from the inlet side of the roasting furnace. DETAILED DESCRIPTION

[0026] The following describes the embodiments of the present invention in detail. However, the following description of the components is merely an example (representative example) of the embodiments of the present invention. Unless the subject matter of the present invention is modified, the present invention is not limited to the following. In addition, when "to" is used in this specification, it is used to express the numerical value before and after inclusive.

[0027] [Baking furnace of the present invention]

[0028] The calcining furnace of the present invention is used to remove the resin of a resin-containing composite material by thermal decomposition, and has a heating structure that heats the calcining furnace by using the heat of the exhaust gas discharged from a combustion device, wherein the combustion device burns the decomposition gas generated by thermally decomposing the resin discharged from the calcining furnace, and the heating structure has an indirect heat exchanger.

[0029] [Calcination method of the present invention]

[0030] The calcination method of the present invention is a calcination method for a resin-containing composite material, that is, a calcination method for removing the resin of the resin-containing composite material by thermal decomposition. The calcination is performed by using a calcination furnace, which has a heating structure. The heating structure heats the calcination furnace by using the heat of exhaust gas discharged from a combustion device, wherein the combustion device burns the decomposition gas generated by thermally decomposing the resin discharged from the calcination furnace, and the heating structure has an indirect heat exchanger.

[0031] Furthermore, the calcination method of the present invention can also be performed by the calcination furnace of the present invention, and the respective configurations of the present invention can be utilized mutually.

[0032] [Solar cell panel recycling device]

[0033] Figure 1 This schematic diagram shows an apparatus for processing resin-containing composite materials that can utilize the processing apparatus of the present invention. This apparatus is used, as an example, to heat a solar cell module, such as a solar cell panel (PV (Photovoltaic) panel), which is a resin-containing composite material, to recover its constituent materials.

[0034] The processing device 100 is connected to the conveyor line 21 from Figure 1 The resin-containing composite material 3 is transported from the left side to the right side. In each chamber, the resin-containing composite material 3 is processed by heat treatment or the like. The processing device 100, from Figure 1 From the left side, there are an inlet chamber 11, an inlet sealed chamber 12, a first roasting furnace 13, a switching unit 14, a second roasting furnace 15, an air cooling chamber 16, a cooling chamber 17, an outlet sealed chamber 18, and an outlet chamber 19. Exhaust gas generated in each chamber is preferably processed in a scrubber 91 through a pipe 71 or a pipe 72, and then exhausted from an exhaust line 92.

[0035] Resin-containing composite materials 3, such as PV panels to be recycled, are transported to a processing device 100, where they are calcined in first and second calcining furnaces 13 and 15 to thermally decompose the resin and other materials. The residue is cooled in air cooling chambers 16 and 17 and then recovered from an outlet chamber 19. Valuable materials are recovered from the resin-containing composite materials in outlet chamber 19. For details on this processing device, see Patent Document 1 and other publications.

[0036] The resin undergoes heat treatment by calcining in the first calcining furnace 13 or the second calcining furnace 15, generating pyrolysis gas from the thermal decomposition of the resin. This pyrolysis gas contains various organic substances and may cause odor and environmental pollution. Therefore, it is heated in the combustion device 4 to produce exhaust gas. This exhaust gas is also high in temperature. The present invention relates to heat recovery using the exhaust gas from the combustion device 4.

[0037] Figure 2 It is a perspective schematic diagram for explaining the roasting furnace of the present invention. Figure 3 This is a schematic diagram for explaining the outline of the roasting furnace of the present invention, viewed from the inlet side of the roasting furnace.

[0038] Figure 2 This is a partially enlarged schematic diagram of the first calcining furnace 13, the switching unit 14, and the second calcining furnace 15. In the first calcining furnace 13, the resin-containing composite material 3 is calcined to generate pyrolysis gas. The pyrolysis gas is supplied from the pyrolysis gas pipe 61 to the combustion chamber of the combustion device 4, where it is mixed with air or LPG (liquefied petroleum gas) gas and burned. The exhaust gas after combustion is discharged from the exhaust pipe 51. The exhaust pipe 51 is provided at the front and rear sides of the combustion device 4. The exhaust gas discharged from the combustion device 4 is high in temperature, so it is supplied to the reheating line 811 or the reheating line 821 from the respective exhaust pipes 51.

[0039] The exhaust gas discharged from the combustion device 4 is used to heat the first roasting furnace 13 on the front side in the following manner. Exhaust gas is supplied from the reheating line 811 connected to the exhaust pipe 51. In addition, this exhaust gas participates in the heating of the first roasting furnace 13 through the indirect heat exchanger 812 connected to the reheating line 811, thereby supplying heat. The exhaust gas that has passed through the indirect heat exchanger 812 passes through the reheating line 813 and then through the exhaust line 73 ( Figure 1 ), is treated in the pest removal tower 91 and is discharged.

[0040] Similarly, the exhaust gas discharged from the combustion device 4 is used to heat the second roasting furnace 15 at the rear side in the following manner. Exhaust gas is supplied from the reheating line 821 connected to the exhaust pipe 51. In addition, this exhaust gas participates in the heating of the second roasting furnace 15 through the indirect heat exchanger 822 connected to the reheating line 821, thereby supplying heat. The exhaust gas that has passed through the indirect heat exchanger 822 passes through the reheating line 823 and then through the exhaust line 73 ( Figure 1 ), is treated in the pest removal tower 91 and is discharged.

[0041] [Processing device]

[0042] The treatment device is a device for treating the resin of the resin-containing composite material by thermal decomposition, etc., and a device for treating the thermal decomposition gas of the resin generated during the thermal decomposition by burning, etc. The combustion device is used to treat Figure 1The combustion device can be installed in any configuration that allows for the recovery and treatment of the pyrolysis gas. For example, the combustion device can be installed near a calciner, for example, where the pyrolysis gas is primarily generated.

[0043] The combustion device at least has a combustion chamber, where the pyrolysis gas is burned. It can also be designed with ignition means for combustion, a fuel supply unit (e.g., gas) for adjusting the combustion temperature, heating or heat-insulating means for adjusting or maintaining the temperature within the furnace, a control unit for controlling these, or sensors for monitoring. The combusted gas is discharged from an outlet as exhaust gas.

[0044] [Thermal decomposition gas]

[0045] Pyrolysis gas is generated when the resin in a resin-containing composite material is thermally decomposed. Resin-containing composite materials, depending on the type of resin used, can contain a variety of organic compounds, including polymers. These resins contain elements such as carbon, nitrogen, fluorine, hydrogen, and oxygen. The chemical bonds of these elements, when heated, decompose and vaporize to form pyrolysis gas.

[0046] When performing thermal decomposition, considerations such as gasification efficiency, gasification reactions, and the characteristics of the gasified components may dictate whether gasification is performed under an inert gas atmosphere, such as a nitrogen atmosphere, or in the presence of oxygen, such as air. While the present invention can be applied to the pyrolysis gas produced under any of these conditions, it is particularly suitable for pyrolysis gas produced by vaporizing the resin under an inert gas atmosphere, such as a nitrogen atmosphere, as this gas is more likely to participate in combustion more efficiently through a reaction with oxygen. The gas flowing into the inner cylinder of the supply unit is a mixture of the pyrolysis gas of the resin and the ambient gas (nitrogen, etc.) generated by the pyrolysis gas.

[0047] [Resin-containing composite materials]

[0048] The resin-containing composite material may be any composite material containing resin. Resin is used in structural components, matrix resins, sealants, and the like of the resin-containing composite material. The present invention can be used in an apparatus for treating the resin by thermal decomposition when the resin cannot be separated by simple physical removal or screening methods such as sieving. Figure 1 Although a PV panel is described as an example, other applications may include, for example, fiber-reinforced resin, or printed wiring boards, liquid crystal panels, and laminated glass.

[0049] [Resin]

[0050] The resin of the resin-containing composite material can be a thermally decomposable resin used in composite materials, such as a thermosetting resin or a thermoplastic resin. Target materials include fluororesins, ethylene-vinyl acetate copolymer (EVA), epoxy resins, unsaturated polyesters, polyvinyl alcohol (PVA), cellulose triacetate (TAC), polyethylene terephthalate (PET), acrylic resin (PMMA; Poly(methyl methacrylate)), polycarbonate (PC; polycarbonate), polyethylene terephthalate (PET), polyvinyl chloride (PVC; polyvinyl chloride), polystyrene (PS; polystyrene), polyimide, and polyvinyl butyral (PVB; poly(vinyl butyral)). In particular, fluororesins, ethylene-vinyl acetate copolymer (EVA), epoxy resins, and unsaturated polyesters are particularly suitable. Target materials include fluororesins and ethylene-vinyl acetate copolymer (EVA).

[0051] [Supply rate of thermal decomposition gas / air]

[0052] Pipe 62 is a pipe for supplying air. The oxygen contained in the air is used for the combustion of the pyrolysis gas. Therefore, anything containing oxygen can be used, but the consumption tends to increase due to continuous combustion, so it is economical and reasonable to use air. The mixed gas of pyrolysis gas and air is continuously supplied to the combustion chamber. Within the range of pyrolysis gas combustion, the ratio of pyrolysis gas to air is adjusted by their respective flow rates. Their ratio is appropriately set based on the degree of ease of combustion, taking into account the type of pyrolysis gas, or the temperature and residence time of the combustion chamber. Depending on the specific situation, for example, converted to Nm 3 (standard cubic meter) flow rate (unit: Nm 3 / hour), the ratio of the flow rate of the pyrolysis gas to the flow rate of air can be 1:0.5 to 1:100, or 1:5 to 1:30. In addition, this flow rate ratio is the flow rate of the pyrolysis gas converted to include the pyrolysis gas of the resin during baking and the ambient gas (nitrogen, etc.) that generates the pyrolysis gas.

[0053] [Gas flow rate]

[0054] The flow rates of the pyrolysis gas and air can be appropriately set based on the ease of combustion, such as the amount and type of pyrolysis gas, and the specifications of the combustion chamber. In particular, since the residence time in the combustion chamber is expected to have a significant impact on proper combustion management, an estimated flow rate can be set based on the combustion chamber capacity.

[0055] [Combustion device]

[0056] The combustion device includes a combustion chamber, which is a furnace that burns the gas supplied from the supply unit. The combustion chamber has a volume that allows for a residence time suitable for the reaction time required for combustion of the pyrolysis gas, and can be of any shape that allows the gas to flow evenly and circulate leak-free within the chamber. The combustion chamber is preferably located around the calcining furnace to rapidly process the pyrolysis gas generated by the resin-containing composite material processing device. Therefore, to facilitate device layout, piping and other connections can be made within the roughly square furnace.

[0057] The combustion chamber is connected to a pipe supplying a mixed gas containing pyrolysis gas. The combustion chamber is designed to operate at a combustion temperature of approximately 800-1400°C. In addition to the supply pipes, the combustion chamber can also be connected to pipes for fuels such as LPG gas and to an ignition source.

[0058] The combustion chamber is heated to a high temperature (approximately 1000°C) by the LPG burner (including an ignition source). Pyrolysis gas and air are then supplied to the chamber, and combustion of the pyrolysis gas begins. Even if the LPG burner is turned off after combustion of the pyrolysis gas begins, the heat from the combustion of the pyrolysis gas will still maintain the high temperature in the combustion chamber.

[0059] In the combustion chamber, the pyrolysis gas containing the pyrolysis gas or the mixed gas of air is burned to produce the processing gas. The burned processing gas is discharged from the outlet. This processing gas is high temperature and may contain fluorine, unburned gas, nitrogen oxides (NO x ) etc., these gases may also become highly corrosive gases.

[0060] [Corrosive gas]

[0061] Examples of corrosive gases include hydrocarbons, nitrogen oxides such as NO and NO 2 , halogen gases such as fluorine and chlorine, halogenated gases such as HF and HCl, sulfur oxides such as SO 2 , NH 3 , and H 2 S.

[0062] [First roasting furnace 13, second roasting furnace 15]

[0063] The first calcining furnace 13 and the second calcining furnace 15 (sometimes collectively referred to as simply "calcining furnace") heat and thermally decompose the resin-containing composite material 3. The first calcining furnace 13 and the second calcining furnace 15 are appropriately set to the processing temperature according to the type of resin-containing composite material 3, and are heated to approximately 500°C for calcination, for example. The heating structure is configured to heat these calcining furnaces (13, 15) to the required calcination temperature.

[0064] Figure 3 This is a schematic diagram of the roasting furnace as viewed from the entrance side, used to illustrate the outline of the roasting furnace of the present invention. The roasting furnace has a muffle chamber and an outer wall. The resin-containing composite material is heat-treated by passing through the muffle chamber. An electric heater is provided, whose output is controlled according to the temperature of the roasting furnace to adjust the temperature of the roasting furnace. The outer wall covers the muffle chamber or heater, indirect heat exchanger, etc., and is used to suppress thermal fluctuations in the outer wall and keep the temperature at the heat treatment temperature. The electric heater is controlled according to the temperature of the roasting furnace, especially the temperature of the muffle chamber through which the resin-containing composite material passes, to adjust the temperature of the roasting furnace.

[0065] [Indirect heat exchangers 812, 822]

[0066] Indirect heat exchangers 812 and 822 are heat exchangers that transfer heat between two types of fluids with different temperatures through a space divided by a wall. The heat is transferred from the high-temperature fluid to the wall, through heat conduction through the wall, and from the wall to the low-temperature fluid. Therefore, the exhaust gas discharged from the combustion device 4 does not directly enter the roasting furnace, but is used for heating by heat exchange. Although the exhaust gas discharged from this combustion device 4 may contain fluorine, unburned gas, or NO x Although corrosive, the heat will pass through the interior of indirect heat exchangers 812 and 822. Indirect heat exchangers 812 and 822 are any type selected from the group consisting of a multi-tube heat exchanger, a coiled tube heat exchanger, and a heating wall. The indirect heat exchanger is provided between the muffle and the outer wall.

[0067] Conventionally, the exhaust gas from the combustion device is passed through the cavity between the flame chamber and the outer wall surrounding the conveyor line of the calcining furnace, where the resin-containing composite material is conveyed for calcination. The exhaust gas also undergoes combustion in the combustion device, so it is generally assumed that the gas is fully treated. However, the results of further verification by the present invention team have shown that, depending on the type of resin-containing composite material or the conditions such as the airflow and temperature in the combustion device, there may be unexpected fluorine, unburned gas, or NO. x If these corrosive gases are directly supplied to the cavity as in the past, the muffle or the outer wall will corrode, requiring the entire roasting furnace to be replaced or cleaned, making maintenance difficult.

[0068] According to the present invention, the indirect heat exchangers 812 and 822 can be selectively replaced even if they are corroded, and the roasting furnace body (the outside of the flame chamber and the inside of the outer wall) will not be corroded, so it becomes a roasting furnace that is easy to maintain.

[0069] [Pest Control Tower 91]

[0070] The detoxification tower 91 is provided downstream of the gas flow path of the indirect heat exchanger, etc., and is used to remove harmful substances contained in the gas generated in various areas within the processing device 100 and exhausted through the pipes 71, 72, and 73, and then discharge it to the outside.

[0071] Therefore, the present invention provides a calciner that is less susceptible to corrosion during heat recovery and easier to maintain. However, depending on the type of resin being pyrolyzed, the pyrolysis may generate corrosive gases that can corrode the gas flow path during heat recovery, leading to labor-intensive maintenance. However, the present invention can address this issue.

[0072] [Industrial Applicability]

[0073] The present invention can be used for processing resin-containing composite materials such as solar cell panels and has industrial applicability.

[0074] Description of Reference Numerals

[0075] 100: Processing device

[0076] 11: Entrance Room

[0077] 12: Entrance sealing chamber

[0078] 13: First roasting furnace

[0079] 14: Switching unit

[0080] 15: Second roasting furnace

[0081] 16: Air cooling room

[0082] 17: Cooling room

[0083] 18: Exit sealing chamber

[0084] 19: Exit Room

[0085] 21: Conveyor line

[0086] 3: Resin-containing composite materials

[0087] 4: Combustion device

[0088] 51: Exhaust pipe

[0089] 61: Thermal decomposition gas piping

[0090] 62: Air piping

[0091] 63: LPG piping

[0092] 631: LPG tank

[0093] 71, 72, 73: Exhaust lines

[0094] 811, 813, 821, 823: Reheating lines

[0095] 812, 822: Indirect heat exchanger

[0096] 91: Pest Control Tower

[0097] 92: Exhaust line

Claims

1. A calcining furnace for removing resin from a resin-containing composite material by thermal decomposition, A heating structure is provided for heating the calcining furnace by heat of exhaust gas discharged from a combustion device, wherein the combustion device is used to burn decomposition gas discharged from the calcining furnace and generated by thermal decomposition of the resin, The heating structure has an indirect heat exchanger.

2. The roasting furnace according to claim 1, wherein The indirect heat exchanger is any one selected from the group consisting of a multi-tube heat exchanger, a coil heat exchanger and a heating wall.

3. The roasting furnace according to claim 1, wherein The device further comprises an electric heater, the output of which is controlled according to the temperature of the roasting furnace to adjust the temperature of the roasting furnace.

4. The roasting furnace according to claim 1, wherein The resin-containing composite material is any one selected from the group consisting of a solar panel, a liquid crystal panel, and laminated glass.

5. The roasting furnace according to claim 1, wherein The roasting furnace comprises a muffle chamber and an outer wall, and the indirect heat exchanger is arranged between the muffle chamber and the outer wall.

6. A processing device for a resin-containing composite material, comprising: a harm removal tower, which is provided downstream of the gas flow path of the indirect heat exchanger; And a roasting furnace according to any one of claims 1 to 5.

7. A method for calcining a resin-containing composite material, wherein the resin in the resin-containing composite material is removed by thermal decomposition, wherein The calcination is performed in a calcination furnace having a heating structure that heats the calcination furnace by heat of exhaust gas discharged from a combustion device, wherein the combustion device is used to burn decomposition gas discharged from the calcination furnace and generated by thermal decomposition of the resin, and the heating structure has an indirect heat exchanger.

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