JP4434305B2 - Plastic decomposition apparatus and cleaning method thereof - Google Patents

Description

The present invention relates to a plastic decomposing apparatus and a cleaning method thereof .

  Conventionally, in order to recover and reuse inorganic and organic valuables in plastic molded products represented by FRP (fiber reinforced plastics), they are decomposed by a supercritical or subcritical hydrothermal reaction. A method (for example, see Patent Document 1) has been proposed.

  In such a method, in general, FRP and water as a solvent are put into a pressure-resistant decomposition tank, and after decomposition in a supercritical or subcritical state, the decomposition liquid is discharged from the decomposition tank and recovered. is doing. Here, from the viewpoint of improving the decomposition rate in the decomposition tank and discharging the decomposition solution, FRP is pulverized into a size of about 2 to 20 mm as a pretreatment and put into the decomposition tank. FRP may be pre-mixed with water added together with FRP, but a separate mixing tank is required. Therefore, from the viewpoint of economy, the FRP is directly applied to the decomposition tank from the raw material supply line connected to the decomposition tank. It has been done.

  However, FRP generally contains inorganic powder such as calcium carbonate and aluminum hydroxide in addition to inorganic fiber such as glass fiber as an inorganic substance, and is subcritical water or supercritical while stirring this in a decomposition tank. When the decomposition treatment is performed with water, there is a problem that the solid content mainly composed of inorganic substances adheres to the inner wall of the decomposition tank, particularly the draft surface, the heating performance is lowered, and the decomposition efficiency is lowered in the next batch. In addition, there is a problem in that the solid content mainly composed of an inorganic substance adheres to the discharge pipe of the decomposition tank, causing clogging.

International Publication No. 2004/041917 Pamphlet

In view of the above background, the present invention eliminates the conventional problems, and easily and reliably removes the solid content adhering to the decomposition tank and the discharge pipe, and its cleaning. The challenge is to provide a method .

  The present invention is characterized by the following.

First, a decomposition tank that decomposes plastic with a solvent in a supercritical or subcritical state is provided, a raw material supply pipe that supplies the plastic to the decomposition tank, and a plastic decomposition solution decomposed in the decomposition tank After disassembling the plastic in a state where the open / close valve is closed with a discharge pipe that takes out the discharge pipe and the open / close valve in the discharge pipe , and then opening the open / close valve and taking out the decomposition solution from the decomposition tank The cleaning liquid is supplied to the decomposition tank to clean the decomposition tank and the discharge pipe. After the decomposition liquid is taken out from the decomposition tank, the on-off valve is closed and the cleaning liquid is supplied to the decomposition tank. Washing the inside of the decomposition tank with the cleaning liquid while storing the cleaning liquid in the tank, and then supplying air to the decomposition tank until the internal pressure of the decomposition tank exceeds the atmospheric pressure, then opening the on-off valve and opening the decomposition tank In the decomposition tank by the internal pressure of Characterized by washing the internal discharge line to discharge the cleaning liquid discharge line.
Second, the cleaning liquid is supplied to the decomposition tank from the raw material supply line, and third, the cleaning liquid is supplied to the decomposition tank from the secondary side of the safety valve of the decomposition tank. Fourth, before the cleaning liquid in the decomposition tank is discharged to the discharge pipe by the internal pressure of the decomposition tank, the cleaning liquid is further supplied to the discharge pipe in addition to the decomposition tank. Fifth, the cleaning liquid is supplied from the downstream side to the upstream side of the discharge pipe, and the cleaning liquid is stored in the discharge pipe. Sixthly, the supply of air to the decomposition tank is performed until the internal pressure of the decomposition tank reaches a pressure in the range of 150 to 500 kPa.

Seventh, a decomposition tank for decomposing plastic in a supercritical or subcritical state with a solvent is provided, a raw material supply pipe for supplying the plastic to the decomposition tank, and a plastic decomposition solution decomposed in the decomposition tank In a plastic decomposing apparatus in which a discharge pipe is formed, a cleaning apparatus for cleaning the inside of the decomposition tank and the inside of the discharge pipe with the cleaning liquid, a cleaning liquid detecting means for detecting the amount of the cleaning liquid in the decomposition tank, and the decomposition tank A pressure detecting means for detecting the internal pressure of the liquid and a means for controlling the inflow of the cleaning liquid into the discharge pipe, wherein the cleaning device includes a first cleaning liquid supply means for supplying the cleaning liquid to the decomposition tank and air to the decomposition tank. An air supply means for supplying, and the first cleaning liquid supply means supplies a predetermined amount of cleaning liquid based on the amount of cleaning liquid detected by the cleaning liquid detection means, and the air supply means is provided in the decomposition tank. Predetermined In a state where the cleaning liquid is being supplied, which pressure decomposition tank based on the internal pressure in the decomposition vessel detected by the pressure detecting means to supply air to a pressure above atmospheric pressure, the discharge pipe The means for controlling the inflow of the cleaning liquid into the passage is such that the on-off valve provided in the discharge pipe causes the internal pressure in the decomposition tank to exceed the atmospheric pressure in a state where a predetermined amount of cleaning liquid is supplied into the decomposition tank. The air supply means is closed during the supply of air to the decomposition tank, and after the internal pressure in the decomposition tank reaches a pressure exceeding the atmospheric pressure , it is opened and the decomposition tank is pressurized. Control is performed such that the cleaning liquid is discharged to the discharge pipe.

Eighth , in the seventh invention, the cleaning liquid supply port of the first cleaning liquid supply means in the cleaning apparatus is provided in the raw material supply pipe.

Eighth , in the seventh invention, the cleaning liquid supply port of the first cleaning liquid supply means in the cleaning device is provided on the secondary side of the safety valve of the decomposition tank.

Ninth , in the seventh invention, an injection nozzle is provided at the tip of a pipe extending into the decomposition tank from the cleaning liquid supply port of the first cleaning liquid supply means in the cleaning device, and the cleaning liquid is injected to a specific part inside the decomposition tank. It is characterized by washing by.

Eleventh , in any one of the seventh to tenth aspects of the invention, it has a drainage storage tank on the outlet side of the discharge pipe, and stores the cleaning liquid discharged from the decomposition tank so that it can be reused. It is characterized by being.

The first 12, water flow in the eleventh invention, had a solids separation device for separating solids from decomposition solution downstream of the decomposition tank, the cleaning liquid stored in the waste solution storage tank, the solid content separation device Then, the solid content is separated from the cleaning liquid, and the cleaning liquid from which the solid content has been removed is made reusable as a solvent or a cleaning liquid .

In a thirteenth aspect, in any one of the seventh to twelfth inventions, the cleaning device further includes a second cleaning liquid supply unit that supplies the cleaning liquid to the discharge conduit, and the second cleaning liquid supply unit includes: Supplying a predetermined amount of cleaning liquid according to the volume of the discharge pipe, and the means for controlling the flow of the cleaning liquid into the discharge pipe includes an on-off valve, and a predetermined amount of cleaning liquid is supplied into the decomposition tank. In an open state after the internal pressure in the decomposition tank reaches a pressure exceeding the atmospheric pressure due to the supply of air from the air supply means and a predetermined amount of cleaning liquid is supplied from the second cleaning liquid supply means to the discharge pipe The cleaning liquid in the discharge pipe is controlled so as to be discharged by the pressurized cleaning liquid in the decomposition tank.

According to the first to the sixth invention, the solid adhering to the inside of the decomposition vessel interior and the discharge pipe can be easily and reliably removed.

According to the seventh invention, the decomposition tank has a cleaning device for cleaning the inside of the decomposition tank and the inside of the discharge pipe, so that the solid content attached to the inside of the decomposition tank and the inside of the discharge pipe can be easily and It can be removed reliably.

According to the eighth invention, the cleaning liquid supply port of the first cleaning liquid supply means in the washing apparatus, by which is provided in the material supply line, in addition to the seventh inventions of the effect, the raw material supply pipe The inside of the passage can be cleaned, and blockage of the raw material supply conduit can be prevented.

According to the ninth invention, the cleaning liquid supply port of the first cleaning liquid supply means in the washing apparatus, by which is provided on the secondary side of the safety valve of the decomposition vessel, in addition to the seventh inventions of the effect The safety valve can be cleaned and the safety valve can be prevented from being blocked.

According to the tenth invention, the injection nozzle is provided at the tip of the pipe extending from the cleaning liquid supply port of the first cleaning liquid supply means in the cleaning apparatus into the decomposition tank, and the specific part inside the decomposition tank is cleaned by the injection of the cleaning liquid. it makes it possible in addition to the seventh inventions of the effect, easily and reliably cleaned and removed solids adhering to the specific site in the decomposition tank.

According to the eleventh aspect , since the drainage storage tank is provided on the outlet side of the discharge pipe, the cleaning liquid discharged from the decomposition tank can be reused.

According to the twelfth invention, the solid content separation device that separates the solid content from the decomposition liquid is provided at the subsequent stage of the decomposition tank, so that the solid content is reliably removed from the cleaning liquid, and the cleaning liquid is effectively reused. be able to.

According to the thirteenth invention, in addition to the effects of the seventh to twelfth inventions, the solid content adhering to the inside of the discharge pipe can be further reliably removed.

It is the outline | summary block diagram which showed one Embodiment of the plastics decomposition | disassembly apparatus based on this invention. It is the outline | summary block diagram which showed another one Embodiment of the plastics decomposition | disassembly apparatus based on this invention. It is the outline | summary block diagram which showed another one Embodiment of the plastics decomposition | disassembly apparatus based on this invention. It is the outline | summary block diagram which showed another one Embodiment of the plastics decomposition | disassembly apparatus based on this invention. It is the outline | summary block diagram which showed another one Embodiment of the plastics decomposition | disassembly apparatus based on this invention. It is the outline | summary block diagram which showed another one Embodiment of the plastics decomposition | disassembly apparatus based on this invention. It is the outline | summary block diagram which showed another one Embodiment of the plastics decomposition | disassembly apparatus based on this invention.

  FIG. 1 is a schematic configuration diagram showing an embodiment of a plastic disassembling apparatus according to the present invention.

  The plastic decomposition apparatus according to the present embodiment includes a cylindrical pressure-resistant decomposition tank 1 that decomposes plastic with a solvent in a supercritical or subcritical state, and supplies the plastic to the upper part of the decomposition tank 1. Pipes are connected to form a raw material supply pipe 2. A supply valve 21 is provided on the side of the raw material supply pipe 2 on the decomposition tank 1, and the plastic is supplied to the decomposition tank 1 by opening the supply valve 21. The plastic is, for example, a plastic molded product such as FRP containing inorganic fillers such as calcium carbonate and aluminum hydroxide, and inorganic fibers such as glass fibers, and reacts by increasing the stirring and mixing properties with the solvent in the decomposition tank 1. In order to improve the efficiency, it is preferable to use after pulverizing so that the particle size is about 1-20 mm, preferably the maximum particle size is 10 mm or less. The pulverized powdery plastic is supplied to the decomposition tank 1 through the raw material supply pipe 2.

  A discharge pipe 3 composed of piping is formed at the bottom of the decomposition tank 1, and a discharge opening / closing valve 31 is provided in the middle thereof. The contents of the decomposition tank 1 are discharged by opening the discharge on-off valve 31.

  The decomposition tank 1 has a cleaning device 4 for cleaning the inside of the decomposition tank 1 and the inside of the discharge pipe 3, and the cleaning device 4 is a cleaning liquid supply means for supplying the cleaning liquid 100 by a pressure pump, for example. And air supply means for supplying air by a compressor or the like. Specifically, the cleaning device 4 includes a cleaning liquid supply port 5 that supplies the cleaning liquid 100 as cleaning liquid supply means, and an air supply port 6 that increases the internal pressure of the decomposition tank 1 by supplying air to the decomposition tank 1 as air supply means. have. Such a cleaning liquid supply port 5 is not particularly limited as long as it can supply the cleaning liquid 100 into the decomposition tank 1 and may be disposed at any location of the decomposition tank 1. Similarly, the air supply port 6 may be disposed at any location in the decomposition tank 1 as long as it can supply air into the decomposition tank 1 and is not particularly limited. By supplying a predetermined amount of the cleaning liquid 100 from the cleaning liquid supply port 5 to the decomposition tank 1 by a pressure pump or the like, the solid content adhering to the inner wall of the decomposition tank 1 is cleaned and removed. Next, air is supplied from the air supply port 6 by a compressor or the like until the internal pressure of the decomposition tank 1 reaches a predetermined pressure. After the internal pressure of the decomposition tank 1 reaches a predetermined pressure, the supply of air is stopped and the discharge on-off valve 31 of the discharge pipe 3 is opened. When the discharge opening / closing valve 31 is opened, the cleaning liquid 100 is vigorously discharged to the outside through the discharge pipe 3 by the internal pressure of the decomposition tank 1. Therefore, the solid content adhering to the inside of the discharge pipe 3 can be washed and removed by the cleaning liquid 100 discharged by the internal pressure of the decomposition tank 1 in this way. Here, the predetermined pressure is an internal pressure of the decomposition tank 1 such that all the cleaning liquid 100 in the decomposition tank 1 is discharged to the discharge pipe 3, for example, a pressure exceeding normal pressure (atmospheric pressure). However, considering the cleaning effect of the discharge pipe 3, it can be about 150 to 500 kPa.

  As the type of the cleaning liquid 100, the same solvent as that used for decomposing plastics can be used, and examples thereof include fluids such as water and alcohol. An alkali such as sodium hydroxide may coexist in this fluid.

  In the present embodiment, as shown in FIG. 1, a pipe having an air supply port 6 is connected to a pipe constituting the raw material supply pipe 2 on the upstream side of the supply valve 21, and a pipe having the cleaning liquid supply port 5 is supplied with air. It is connected in the middle of the pipe having the port 6. Thus, in this embodiment, since the cleaning liquid supply port 5 is provided in the raw material supply line 2, the cleaning liquid 100 is supplied from the cleaning liquid supply port 5 toward the decomposition tank 1, whereby the inside of the raw material supply line 2. Can also be washed, and blockage of the raw material supply pipe 2 can be prevented.

  The piping having the cleaning liquid supply port 5 is provided with a cleaning liquid supply valve 51. By opening this, the cleaning liquid 100 is introduced from the cleaning liquid supply port 5 by a high pressure pump or the like, and the raw material supply line 2 including the supply valve 21 is provided. The inside of the tank is washed and supplied to the decomposition tank 1 so that the inside of the decomposition tank 1 is also washed. When the diameter of the raw material supply pipe 2 is large and a sufficient cleaning effect cannot be obtained with a constant amount of cleaning liquid, the supply valve 21 of the raw material supply pipe 2 is temporarily closed, and the cleaning liquid is supplied to the raw material supply pipe 2. After storing 100, the supply valve 21 may be opened for cleaning.

  The pipe having the air supply port 6 is provided with an air supply valve 61. After cleaning the raw material supply pipe 2 with the cleaning liquid 100, the air supply valve 61 is opened and dried from the air supply port 6 by a compressor or the like. Introduce air. As a result, the inside of the raw material supply pipe 2 wet with the cleaning liquid 100 is dried, and it is possible to prevent the plastic from being easily attached to the inside of the raw material supply pipe 2 when the plastic is supplied in the next batch. The supply of the dry air from the air supply port 6 is performed until the internal pressure of the decomposition tank 1 reaches a predetermined pressure as described above.

  A pipe for supplying a solvent is connected to the upper part of the decomposition tank 1 of the present embodiment, and a solvent supply line 7 having a solvent supply valve 71 and a solvent supply port 72 is formed. The solvent is supplied into the decomposition tank 1 from the solvent supply port 72 through the solvent supply pipe 7 by opening the solvent supply valve 71, and acts as a plastic reaction catalyst in a supercritical or subcritical state to decompose the plastic. . Such a solvent is a fluid such as water or alcohol, and an alkali such as sodium hydroxide may coexist in this fluid.

  A heating means 8 formed by a heater, a heat medium jacket or the like is provided on the outer periphery of the decomposition tank 1 of the present embodiment, and a temperature detector 9 formed by a temperature sensor or the like is provided by being inserted into the decomposition tank 1. ing. The decomposition tank 1 is provided with a pressure detecting means 10 formed by a pressure gauge for measuring the internal pressure. In the plastic decomposition process, the temperature detector 9 and the pressure detection means 10 detect the temperature and pressure of the decomposition tank 1, and the heating means 8 heats the decomposition tank 1 to detect the temperature. The heating means 8 is controlled based on the pressure to perform heating at the optimum temperature. The pressure detecting means 10 detects the internal pressure of the decomposition tank 1 even when air is supplied from the air supply port 6, and closes the air supply valve 61 based on the detected pressure to stop the supply of air. Like to do.

  The decomposition tank 1 of the present embodiment is provided with a stirring device 20 for mixing the plastic and solvent supplied to the decomposition tank 1. The agitation device 20 has a rotating shaft 201 and an agitating blade 202 attached to the rotating shaft 201. By rotating the rotating shaft 201 with a motor provided in the upper part of the decomposition tank 1, the plastic decomposition process is performed. In, the plastic and solvent in the decomposition tank 1 are stirred and mixed. When the cleaning liquid 100 is supplied into the decomposition tank 1, the rotating shaft 201 of the stirring device 20 is driven to rotate by a motor, so that the solid content adhering to the inner wall of the decomposition tank 1 can be effectively removed and the cleaning liquid is washed. The solid content that has been peeled off and settled at the bottom of the decomposition tank 1 is stirred so that it does not remain in the decomposition tank 1 when the cleaning liquid 100 is discharged.

  In the decomposition tank 1 of the present embodiment, a safety valve line 30 constituted by piping is formed, and a safety valve 301 is provided in the middle of the safety valve line 30. The safety valve 301 is a valve having a safety mechanism for preventing damage to the decomposition tank 1 due to an abnormal increase in internal pressure under high temperature and high pressure during plastic decomposition.

  In the present embodiment, the cleaning liquid 100 cannot be supplied from the cleaning liquid supply port 5 in a state where the decomposition tank 1 is sealed. For this reason, a separate on-off valve may be provided and opened to open the decomposition tank 1 to the outside and supply the cleaning liquid 100. However, the safety valve 301 is opened to open the decomposition tank 1 to the outside and the cleaning liquid is supplied. 100 may be supplied. After supplying the cleaning liquid 100 into the decomposition tank 1, the safety valve 301 is closed and air is supplied from the air supply port 6 to increase the internal pressure of the decomposition tank 1 to a predetermined pressure.

  In the present embodiment, a weight detector 40 such as a load cell is provided in the decomposition tank 1 so that the weight of the plastic, the cleaning liquid 100 and the solvent supplied to the decomposition tank 1 can be detected and weight management can be performed. . For example, a predetermined amount of the cleaning liquid 100 is supplied to clean the inside of the decomposition tank 1, and the amount of the cleaning liquid 100 is detected by the weight of the cleaning liquid 100 supplied into the decomposition tank 1, and the supply is performed when the predetermined weight is reached. I try to stop. The amount of the cleaning liquid 100 may be managed by providing a flow meter in the pipe and measuring the integrated flow rate.

  In the disassembling apparatus having the above configuration, the cleaning process is performed as follows. In addition, this washing process shall be performed in a state where the plastic decomposition process is completed in the decomposition tank 1 and the decomposition solution is discharged from the decomposition tank 1.

  First, the discharge on-off valve 31 is closed, the cleaning liquid supply valve 51, the supply valve 21 and the safety valve 301 are opened, and the cleaning liquid 100 is supplied from the cleaning liquid supply port 5 to the decomposition tank 1. By supplying the cleaning liquid 100 to the decomposition tank 1, the inside of the raw material supply pipe 2 and the inside of the decomposition tank 1 are cleaned. The weight of the cleaning liquid 100 supplied to the decomposition tank 1 is detected by the weight detector 40. When a predetermined amount is reached, the cleaning liquid supply valve 51 is closed to stop the supply of the cleaning liquid 100. The cleaning liquid 100 supplied to the decomposition tank 1 is stirred by the stirring device 20 to remove the solid content adhering to the inner wall of the decomposition tank 1, but at this time, the solid content separated by the cleaning does not settle to the bottom of the decomposition tank 1. To stir. Next, the safety valve 301 is closed, the air supply valve 61 is opened, and air is supplied from the air supply port 6 to increase the internal pressure of the decomposition tank 1. When the internal pressure of the decomposition tank 1 is detected by the pressure detection means 10 and reaches a predetermined pressure, the air supply valve 61 is closed to stop the supply of air. Next, the discharge on-off valve 31 is opened, and the cleaning liquid 100 pressurized by the internal pressure of the decomposition tank 1 is discharged from the decomposition tank 1 through the discharge pipe 3 to the outside. As a result, the solid content adhering to the inside of the discharge pipe 3 is removed by washing.

  As described above, in this embodiment, the raw material supply pipe 2 is cleaned together with the inside of the decomposition tank 1 and the inside of the discharge pipe 3.

  In the above embodiment, the cleaning liquid supply port 5 and the solvent supply port 72 are provided separately. For example, when the same type of cleaning liquid 100 is used as the solvent, the solvent is supplied from the cleaning liquid supply port 5 to the decomposition tank 1. The plastic may be decomposed. In this case, there is no need to provide the solvent supply line 7 having the solvent supply port 72 as a separate body from the cleaning liquid supply port 5, and the structure can be simplified and reduced in size, and the decomposition apparatus can be manufactured at low cost. There is.

  In this embodiment, the plastic is supplied to the decomposition tank 1 through the raw material supply line 2 and the solvent is supplied into the decomposition tank 1 through the solvent supply line 7. However, both the plastic and the solvent are supplied to the raw material supply line. 2 may be supplied to the decomposition tank 1. Also in this case, there is no need to provide the solvent supply pipe 7 as a separate body, and there is an advantage that the structure can be simplified and the size can be reduced, and the decomposition apparatus can be manufactured at low cost.

  FIG. 2 is a schematic configuration diagram showing another embodiment of the plastic disassembling apparatus according to the present invention. In addition, the same code | symbol is attached | subjected about the part same as the part shown in FIG. 1, and description is abbreviate | omitted.

  During the plastic decomposition process in the decomposition tank 1, solid content may adhere to the inside of the safety valve line 30 due to the spray of the decomposition liquid. In this embodiment, the solid content adhering to the inside of the safety valve conduit 30 is washed away. Specifically, a pipe having the cleaning liquid supply port 5 is connected to the secondary side of the safety valve 301 in the safety valve line 30. In such a decomposition apparatus, when the cleaning liquid 100 is supplied from the cleaning liquid supply port 5, it reaches the decomposition tank 1 from the secondary side of the safety valve 301 through the safety valve line 30, so that the inside of the safety valve line 30 including the safety valve 301 is cleaned. Thus, the safety valve line 30 can be prevented from being blocked and safety can be ensured.

  2, the air supply port 6 is provided in the raw material supply pipe 2 in the same manner as the decomposition device in FIG. 1, but air is supplied to the secondary side of the safety valve 301 together with the cleaning liquid supply port 5. A mouth 6 may be provided.

  FIG. 3 is a schematic configuration diagram showing still another embodiment of the plastic disassembling apparatus according to the present invention. In addition, the same code | symbol is attached | subjected about the part same as the part shown in FIG. 1, and description is abbreviate | omitted.

  In the present embodiment, the pipe having the cleaning liquid supply port 5 branches into two and extends into the decomposition tank 1, and an injection nozzle 52 is provided at each tip. The spray nozzle 52 is, for example, a spray nozzle or a nozzle that sprays in the form of a shower, and changes the flow rate, spray pressure, spray form, and the like to clean a specific part inside the decomposition tank 1 and strip off the attached solid content. Play. Solid content mainly composed of inorganic substances easily adheres to the draft surface of the decomposition solution in the decomposition tank 1, and depending on the degree of adhesion, depending on the case, the heating performance of the decomposition tank 1 may decrease. As a result, the decomposition efficiency also decreases. The decomposition apparatus of the present embodiment is effective for removing the solid content attached to such a part, and can maintain the decomposition efficiency of the decomposition tank 1.

  FIG. 4 is a schematic configuration diagram showing still another embodiment of the plastic disassembling apparatus according to the present invention. In addition, the same code | symbol is attached | subjected about the part same as the part shown in FIG. 1, and description is abbreviate | omitted.

  When the plastic decomposition process is completed in the decomposition tank 1, the decomposition liquid is recovered from the bottom of the decomposition tank 1 to the decomposition liquid storage tank 50 through the discharge pipe 3 by opening the discharge on-off valve 31, as shown in FIG. Is done. In the present embodiment, a waste liquid storage tank 60 for storing the cleaning liquid 100 discharged from the decomposition tank 1 is provided on the outlet side of the discharge pipe 3 separately from the decomposition liquid storage tank 50 of the decomposition liquid. Although the decomposition liquid storage tank 50 is provided on the upstream side of the drainage liquid storage tank 60, the decomposition liquid storage tank 50 may be provided on the downstream side of the drainage liquid storage tank 60, and the positional relationship is not particularly limited. The decomposition liquid storage tank 50 and the drainage liquid storage tank 60 are respectively provided with a decomposition liquid opening / closing valve 501 and a drainage opening / closing valve 601 on the inlet side thereof. By opening this, the decomposition solution and the cleaning solution 100 are collected in the decomposition solution storage tank 50 and the drainage storage tank 60, respectively. For example, when the plastic decomposition process is completed and the decomposition liquid is discharged from the decomposition tank 1, the drainage on-off valve 601 is closed, the decomposition liquid on-off valve 501 is opened, and the decomposition liquid is collected in the decomposition liquid storage tank 50. Thus, when cleaning of the inside of the decomposition tank 1 is completed and the cleaning liquid 100 is discharged from the decomposition tank 1, conversely, the decomposition liquid on-off valve 501 is closed and the drain on-off valve 601 is opened to discharge the cleaning liquid 100. It collects in the storage tank 60.

  Thus, in this embodiment, since the decomposition liquid and the cleaning liquid 100 are collected separately, each can be reused. For example, the recovered cleaning liquid 100 can be used again as a solvent for decomposing the cleaning liquid 100 and plastic.

  FIG. 5 is a schematic configuration diagram showing still another embodiment of the plastic disassembling apparatus according to the present invention. In addition, the same code | symbol is attached | subjected about the part same as the part shown in FIG. 1 and FIG. 4, and description is abbreviate | omitted.

  In the present embodiment, a solid content separation device 70 such as filtration is provided on the outlet side of the decomposition liquid storage tank 50 and the drainage liquid storage tank 60. For example, the cleaning liquid 100 stored in the drainage storage tank 60 contains solids removed by cleaning of the raw material supply pipe 2, the decomposition tank 1, the safety valve pipe 30, the discharge pipe 3, and the like. By passing the cleaning liquid 100 containing such a solid content through the solid content separation device 70, the solid content can be separated from the cleaning liquid 100 and the filtrate can be recovered. Since the decomposed liquid also contains undecomposed or undissolved solid content, the filtrate can be collected by separating the solid content from the decomposed liquid by passing the decomposed liquid through the solid content separation device 70.

  The solid content separator 70 includes a decomposition liquid filtrate storage tank 80 that collects the filtrate of the decomposition liquid stored in the decomposition liquid storage tank 50, and a drainage filtrate storage tank 90 that collects the filtrate of the cleaning liquid 100 stored in the drainage storage tank 60. And pipes leading to are connected. The cracked filtrate storage tank 80 and the drained filtrate storage tank 90 are respectively provided with a cracked filtrate on-off valve 801 and a drained filtrate on-off valve 901 on the inlet side. By opening this, the decomposed filtrate and the washing filtrate are recovered in the decomposed filtrate storage tank 80 and the drained filtrate storage tank 90, respectively. For example, when the decomposition liquid is discharged from the decomposition liquid storage tank 50, the drainage filtrate on-off valve 901 is closed, the decomposition liquid filtrate on-off valve 801 is opened, and the decomposition liquid filtrate is recovered in the decomposition liquid filtrate storage tank 80. When the cleaning liquid 100 is discharged from the drainage storage tank 60, the decomposition liquid filtrate on / off valve 801 is closed, and the drainage filtrate on / off valve 901 is opened to collect the cleaning liquid filtrate in the drainage filtrate storage tank 90.

  As described above, in the present embodiment, since the decomposition solution filtrate and the washing solution filtrate are separately collected, each can be reused. For example, the collected washing liquid filtrate can be used again as a solvent for decomposing the washing liquid 100 and plastic.

  FIG. 6 is a schematic configuration diagram showing still another embodiment of the plastic disassembling apparatus according to the present invention. In addition, the same code | symbol is attached | subjected about the part same as the part shown in FIG. 1 and FIG. 4, and description is abbreviate | omitted.

  When the plastic decomposition liquid is discharged from the decomposition tank 1, the clogging of the discharge pipe 3 is suppressed by pumping and discharging the slurry-like decomposition liquid by high pressure discharge. There is a case where a part of the discharge pipe 3 remains without being completely removed and adheres to the wall surface of the discharge pipe 3. When the discharge on-off valve 31 is opened in this state and the cleaning liquid 100 is discharged from the decomposition tank 1, only the cleaning liquid 100 passes through the discharge pipe 3 vigorously, and the deposits (solid content) on the wall surface of the discharge pipe 3. May remain as it is.

  Therefore, in the present embodiment, the cleaning liquid supply port 5 ′ is provided in the discharge pipe 3. Specifically, a pipe having a cleaning liquid supply port 5 ′ is connected to a pipe constituting the discharge pipe 3, and the connection position is downstream of the discharge on-off valve 31 and the decomposition liquid on-off valve of the decomposition liquid storage tank 50. 501 and upstream side of the drainage on-off valve 601 of the drainage storage tank 60. The pipe having the cleaning liquid supply port 5 ′ is provided with a cleaning liquid supply valve 51 ′, which is opened and the cleaning liquid 100 is introduced into the discharge pipe 3 from the cleaning liquid supply port 5 ′ by a high-pressure pump or the like. ing.

  In performing the cleaning process with the plastic decomposing apparatus of the present embodiment, first, the discharge on-off valve 31, the decomposition liquid on-off valve 501, and the drainage on-off valve 601 are closed, and the cleaning liquid supply valve 51, the supply valve 21, and the safety valve 301 are closed. And the cleaning liquid 100 is supplied to the decomposition tank 1 from the cleaning liquid supply port 5. When the cleaning liquid 100 in the decomposition tank 1 reaches a predetermined amount, the cleaning liquid supply valve 51 is closed to stop the supply of the cleaning liquid 100, and the cleaning liquid 100 in the decomposition tank 1 is stirred by the stirring device 20 to the inner wall of the decomposition tank 1. Remove attached solids. Next, the safety valve 301 is closed, the air supply valve 61 is opened, air is supplied from the air supply port 6 to increase the internal pressure of the decomposition tank 1 to a predetermined pressure, and then the air supply valve 61 is closed to supply air. To stop. Meanwhile, the cleaning liquid supply valve 51 'is opened, and a predetermined amount of the cleaning liquid 100 is supplied from the cleaning liquid supply port 5' to the discharge pipe 3 by a timer or an integrated flow meter. At this time, since the discharge on-off valve 31, the decomposition liquid on-off valve 501 and the drainage on-off valve 601 are closed, the cleaning liquid 100 supplied to the discharge pipe 3 from the cleaning liquid supply port 5 ′ is separated from the discharge on-off valve 31 and the decomposition liquid. It collects between the on-off valve 501 and the drainage on-off valve 601. Here, it is not necessary to completely fill the inside of the discharge pipe 3 with the cleaning liquid 100. For example, it may be about 70% of its volume. After the cleaning liquid 100 is stored in the discharge pipe 3, the cleaning liquid supply valve 51 'is closed to stop the supply of the cleaning liquid 100. Next, the discharge on / off valve 31 and the drain on / off valve 601 are opened, and the cleaning liquid 100 pressurized by the internal pressure of the decomposition tank 1 is discharged from the decomposition tank 1 through the discharge pipe 3 into the discharge pipe 3. The stored cleaning liquid 100 is extruded, and the adhered flow on the wall surface in the discharge pipe 3 is removed and discharged by the extrusion flow. This ensures the cleaning of the discharge line 3. Moreover, in this embodiment, the deposits on the wall surface of the discharge pipe 3 can be effectively removed without supplying a large amount of the cleaning liquid 100 into the decomposition tank 1. The supply amount and discharge amount of the supplied cleaning liquid 100 as a whole can be suppressed.

  In the above embodiment, the discharge on / off valve 31, the decomposition liquid on / off valve 501 and the drain on / off valve 601 are closed and the cleaning liquid 100 is supplied to the discharge pipe 3 from the cleaning liquid supply port 5 ′. When supplying the cleaning liquid 100 from the port 5 ′ to the discharge pipe 3, the decomposition liquid on / off valve 501 and the drain liquid on / off valve 601 are closed and the discharge on / off valve 31 is opened to clean the cleaning liquid in the direction opposite to the method of discharging the decomposition liquid. 100 may flow through the discharge line 3. In this case, in order to broaden the range of cleaning in the discharge pipe 3 by the cleaning liquid 100, the connection position of the pipe having the cleaning liquid supply port 5 ′ and the pipe constituting the discharge pipe 3 is further set to the decomposition liquid on-off valve 501. It is desirable to set to the side or the drainage on-off valve 601 side. In general, since the piping constituting the discharge pipe 3 has a valve, a bent portion, and the like and is the portion most likely to be clogged, it is discharged by flowing the cleaning liquid 100 in the direction opposite to the method of discharging the decomposition liquid. The inside of the pipe line 3 can be effectively cleaned. After supplying the cleaning liquid 100 from the cleaning liquid supply port 5 ′ to the discharge pipe 3 and storing the cleaning liquid 100 in the decomposition tank 1, the cleaning liquid supply valve 51 ′ is closed to stop the supply of the cleaning liquid 100. Next, the cleaning liquid supply valve 51 is opened, the cleaning liquid 100 is supplied from the cleaning liquid supply port 5 and the cleaning liquid 100 is further stored in the decomposition tank 1, and then air is supplied from the air supply port 6 in the same manner as in the above embodiment. Then, the internal pressure of the decomposition tank 1 is increased to a predetermined pressure, and the cleaning liquid 100 is discharged from the decomposition tank 1 through the discharge pipe 3. Here, depending on the amount of the cleaning liquid 100 in the decomposition tank 1 supplied from the cleaning liquid supply port 5 ′ and the degree of contamination inside the raw material supply pipe 2, the decomposition is performed without supplying the cleaning liquid 100 from the cleaning liquid supply port 5. The internal pressure of the tank 1 may be increased to a predetermined pressure and the cleaning liquid 100 may be discharged from the decomposition tank 1 through the discharge pipe 3.

  FIG. 7 is a schematic configuration diagram showing still another embodiment of the plastic disassembling apparatus according to the present invention. In addition, the same code | symbol is attached | subjected about the part same as the part shown in FIG.1, FIG4 and FIG.6, and description is abbreviate | omitted.

  In the present embodiment, the cleaning liquid supply port 5 ′ is provided in the discharge pipe 3 in the same manner as the plastic decomposing apparatus shown in FIG. 6, and the pipe having the cleaning liquid supply port 5 ′ is used as the pipe constituting the discharge pipe 3. Although connected, the connection position is closer to the decomposition tank 1, for example, upstream of the discharge on-off valve 31.

  Also in the plastic decomposing apparatus of the present embodiment, the cleaning liquid 100 is introduced into the discharge pipe 3 from the cleaning liquid supply port 5 ′ in the same manner as the plastic decomposing apparatus in FIG. 6 so that the discharge pipe 3 is filled with the cleaning liquid 100. However, it is not necessary to fill the entire discharge pipe 3, and for example, a part where a large amount of solid matter is expected to remain, such as a lower part of a vertical pipe or a throttle part, is included. do it. Therefore, when introducing the cleaning liquid 100 from the cleaning liquid supply port 5 ′ into the discharge pipe 3, the discharge on-off valve 31 is closed and the cleaning liquid 100 is poured into the discharge pipe 3 upstream of the discharge on-off valve 31. Alternatively, the discharge on-off valve 31 is opened and the decomposition liquid on-off valve 501 and the drain on-off valve 601 are closed, and the discharge pipe 3 on the upstream side of the decomposition liquid on-off valve 501 and the drain on-off valve 601 The opening and closing valve provided in the middle of the discharge pipe 3 may be appropriately opened and closed so that the inside of the discharge pipe 3 is filled with the cleaning liquid 100. Further, when the inside of the discharge pipe 3 is filled with the cleaning liquid 100, it is desirable to eliminate the gas phase as much as possible and to keep it full.

  When the cleaning liquid 100 is introduced into the discharge pipe 3, the solid matter remaining in the discharge pipe 3 is moved by the liquid flow of the cleaning liquid 100 introduced from the cleaning liquid supply port 5 ′, and the solids are folded over. Therefore, it is desirable to adjust the supply flow rate of the cleaning liquid 100 from the cleaning liquid supply port 5 ′ so that the solid matter does not move. Specifically, when the solid is an FRP piece having a piece of about 10 mm, the settling speed of the solid is about 0.1 m / s, and therefore a speed lower than the settling speed, for example, 1 of the settling speed of the solid. If the cleaning liquid 100 is introduced from the cleaning liquid supply port 5 ′ at a flow rate of about / 10, that is, a flow rate of about 0.01 m / s, the movement of the solid matter is hardly observed.

  In performing the cleaning process, after the cleaning liquid 100 is introduced into the discharge pipe 3 as described above, the cleaning liquid 100 is pumped and discharged from the decomposition tank 1 in the same manner as in the plastic decomposition apparatus of FIG. The cleaning liquid 100 filling the pipeline 3 is pushed out and discharged. As a result, since solids in the discharge pipe 3 are discharged without being folded, blockage in the discharge pipe 3 can be prevented.

DESCRIPTION OF SYMBOLS 1 Decomposition tank 2 Raw material supply line 21 Supply valve 3 Discharge line 31 Discharge on-off valve 4 Cleaning device 5, 5 'Cleaning liquid supply port 51, 51' Cleaning liquid supply valve 52 Injection nozzle 6 Air supply port 61 Air supply valve 30 Safety valve Pipe 301 Safety valve 50 Decomposition liquid storage tank 501 Decomposition liquid opening / closing valve 60 Waste liquid storage tank 601 Drainage opening / closing valve 70 Solid content separation device 80 Decomposition liquid filtrate storage tank 801 Decomposition liquid filtrate opening / closing valve 90 Drainage filtrate storage tank 901 Drainage filtrate opening / closing valve 100 Cleaning liquid

Claims (13)

A decomposition tank for decomposing plastic with a solvent in a supercritical or subcritical state is provided, a raw material supply line for supplying the plastic to the decomposition tank, and a discharge line for taking out the decomposition solution of the plastic decomposed in the decomposition tank And after the plastic is decomposed in a state in which the on-off valve is closed in the disassembly device in which the on-off valve is formed in the discharge pipe, the on-off valve is opened and the decomposition liquid is taken out from the decomposition tank. A method of supplying a cleaning liquid and cleaning a decomposition tank and a discharge pipe,
After removing the decomposition liquid from the decomposition tank, the cleaning valve is supplied to the decomposition tank with the on-off valve closed, and the inside of the decomposition tank is washed with the cleaning liquid while storing the cleaning liquid in the decomposition tank. After supplying air to the decomposition tank until the pressure exceeds the atmospheric pressure, open the on-off valve and discharge the cleaning liquid in the decomposition tank to the discharge line by the internal pressure of the decomposition tank to clean the inside of the discharge line A method for cleaning a plastic disassembling apparatus.   2. The method for cleaning a plastic decomposing apparatus according to claim 1, wherein the cleaning liquid is supplied to the decomposition tank from the raw material supply pipe.   2. The method for cleaning a plastic decomposing apparatus according to claim 1, wherein the cleaning liquid is supplied to the decomposition tank from the secondary side of the safety valve of the decomposition tank.   Before discharging the cleaning liquid in the decomposition tank to the discharge pipe by the internal pressure of the decomposition tank, supply the cleaning liquid to the discharge pipe in addition to the decomposition tank and store the cleaning liquid in the discharge pipe in advance. The method for cleaning a plastic disassembling apparatus according to any one of claims 1 to 3.   5. The method for cleaning a plastic decomposing apparatus according to claim 4, wherein the cleaning liquid is supplied from the downstream side to the upstream side of the discharge pipe and the cleaning liquid is stored in the discharge pipe.   The supply of air to the decomposition tank is performed until the internal pressure of the decomposition tank reaches a pressure in the range of 150 to 500 kPa, and the plastic decomposition apparatus according to any one of claims 1 to 5, Method. A decomposition tank for decomposing plastic with a solvent in a supercritical or subcritical state is provided, a raw material supply line for supplying the plastic to the decomposition tank, and a discharge line for taking out the decomposition solution of the plastic decomposed in the decomposition tank In the plastic decomposing apparatus in which
A cleaning device for cleaning the inside of the decomposition tank and the inside of the discharge pipe with a cleaning liquid, a cleaning liquid detection means for detecting the amount of cleaning liquid in the decomposition tank, a pressure detection means for detecting the internal pressure in the decomposition tank, and a cleaning liquid for the discharge pipe Means for controlling the inflow of
The cleaning apparatus has a first cleaning liquid supply means for supplying a cleaning liquid to the decomposition tank and an air supply means for supplying air to the decomposition tank. The first cleaning liquid supply means is a cleaning liquid detected by the cleaning liquid detection means. The air supply means supplies the predetermined amount of cleaning liquid based on the amount, and the air supply means is based on the internal pressure in the decomposition tank detected by the pressure detection means in a state where the predetermined amount of cleaning liquid is supplied in the decomposition tank. Air is supplied so that the internal pressure in the decomposition tank exceeds the atmospheric pressure ,
The means for controlling the flow of the cleaning liquid into the discharge pipe is such that the on-off valve provided in the discharge pipe has an internal pressure exceeding the atmospheric pressure in a state where a predetermined amount of the cleaning liquid is supplied into the decomposition tank. During the supply of air from the air supply means to the decomposition tank so as to become pressure , it is closed, and after the internal pressure in the decomposition tank reaches a pressure exceeding the atmospheric pressure , it is opened and pressurized in the decomposition tank The plastic disassembling apparatus is controlled so that the cleaned cleaning liquid is discharged into a discharge pipe.   8. The plastic decomposing apparatus according to claim 7, wherein the cleaning liquid supply port of the first cleaning liquid supply means in the cleaning apparatus is provided in the raw material supply pipe.   8. The plastic decomposition apparatus according to claim 7, wherein the cleaning liquid supply port of the first cleaning liquid supply means in the cleaning apparatus is provided on the secondary side of the safety valve of the decomposition tank.   8. A spray nozzle is provided at a tip of a pipe extending from the cleaning liquid supply port of the first cleaning liquid supply means in the cleaning apparatus into the decomposition tank, and a specific portion inside the decomposition tank is cleaned by spraying the cleaning liquid. The plastic disassembling apparatus described in 1.   11. The plastic according to claim 7, further comprising a drain storage tank on an outlet side of the discharge pipe, and storing the cleaning liquid discharged from the decomposition tank in a reusable manner. Disassembly equipment.   It has a solid content separation device that separates the solid content from the decomposition solution at the subsequent stage of the decomposition tank, and the cleaning liquid stored in the drainage storage tank is passed through the solid content separation device to separate the solid content from the cleaning liquid, 12. The plastic decomposing apparatus according to claim 11, wherein the cleaning liquid from which the solid content has been removed is reusable as a solvent or a cleaning liquid. Furthermore, the cleaning device includes a second cleaning liquid supply unit that supplies the cleaning liquid to the discharge pipe line.
The second cleaning liquid supply means supplies a predetermined amount of cleaning liquid according to the volume of the discharge conduit,
The means for controlling the inflow of the cleaning liquid into the discharge pipe has a large internal pressure in the decomposition tank due to the supply of air from the air supply means when the open / close valve is supplied with a predetermined amount of cleaning liquid in the decomposition tank. After reaching a pressure exceeding the atmospheric pressure and a predetermined amount of cleaning liquid is supplied from the second cleaning liquid supply means to the discharge pipe, it is opened, and the cleaning liquid in the discharge pipe is pressurized in the decomposition tank. It is controlled so that it may be discharged | emitted with a washing | cleaning liquid, The plastics decomposition | disassembly apparatus as described in any one of Claim 7 to 12 characterized by the above-mentioned.

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