Cleaning apparatus, separation system and cleaning method

Abstract

This invention can reliably remove foreign matter. It comprises: a storage container for storing a filter with cured polyester and impurities attached to it; a first fluid supply section for supplying a first fluid that removes the cured polyester from the filter to the storage container; and a second fluid supply section for supplying a second fluid that removes impurities from the filter to the storage container after the first fluid supply section supplies the first fluid to the storage container.

Description

Technical Field

[0001] This invention relates to a cleaning device, a separation system, and a cleaning method. Prior Technology

[0002] For example, for the purpose of recycling polyester, there are known techniques for separating impurities from polyester. Patent Document 1 describes a process in which polyethylene terephthalate (PET) waste is fed into ethylene glycol (EG) for depolymerization to obtain bis(β-hydroxyethyl) terephthalate (BHET); and foreign matter other than PET is removed by a filter during or after the depolymerization reaction. [Previous Technical Documents] [Patent Literature]

[0003] [Patent Document 1] Japanese Patent No. 4065659 Summary of the Invention

[0004] [The problem that the invention aims to solve] However, when foreign matter clogs the filter of the filter press during the depolymerization reaction of PET, the depolymerization reaction needs to be stopped, and it is difficult to reliably remove foreign matter.

[0005] The present invention was made to solve the above-mentioned problems, and its purpose is to provide a cleaning device, separation system and cleaning method that can reliably remove foreign matter. [Methods used to solve problems]

[0006] To solve the above-mentioned problems and achieve the objective, the cleaning apparatus of the present invention comprises: a storage container for storing a filter with cured polyester and impurities attached thereto; a first fluid supply unit for supplying a first fluid that removes the cured polyester from the filter to the storage container; and a second fluid supply unit for supplying a second fluid that removes the impurities from the filter to the storage container after the first fluid supply unit supplies the first fluid to the storage container.

[0007] To solve the above-mentioned problems and achieve the objective, the separation system of the present invention comprises: a separation system body for monomerizing polyester contained in polyester raw materials to generate monomers; and the aforementioned cleaning device for cleaning the aforementioned filter of the separation system body.

[0008] To solve the above-mentioned problems and achieve the objective, the cleaning method of the present invention is a cleaning method for cleaning a filter with adhered solidified polyester and impurities, comprising: a step of placing the filter in a storage container; a step of supplying a first fluid, which removes the solidified polyester from the filter, to the storage container; and a step of supplying a second fluid, which removes the impurities from the filter, to the storage container after the first fluid supply unit supplies the first fluid to the storage container. [Invention Benefits]

[0009] According to the present invention, foreign matter can be removed reliably. Simple Explanation of the Diagram

[0010] [Figure 1] is a schematic diagram of the polyester recycling steps in this embodiment. [Figure 2] is a schematic diagram of the separation system in the first implementation. [Figure 3] is a schematic diagram showing the composition of the filter mechanism. [Figure 4] is a schematic top view of the filter. [Figure 5] is a schematic diagram of the cleaning device in the first embodiment. [Figure 6] is a diagram illustrating the control of the cleaning device in the first embodiment. [Figure 7] is a partial schematic diagram of the separation system in the second embodiment. [Figure 8] is a schematic diagram of a washing device in another example. [Figure 9] is a schematic diagram of a washing device in a modified example of another example. Implementation

[0011] The following detailed description of suitable embodiments of the present invention is based on the accompanying drawings. Furthermore, the present invention is not limited to these embodiments; when multiple embodiments exist, it also includes embodiments constructed by combining various embodiments.

[0012] (First Implementation Form) (Recycling Steps) Figure 1 is a schematic diagram of the polyester recycling steps in this embodiment. In this embodiment, the polyester raw material Pm is depolymerized to monomerize, and the monomer is polymerized again to recover (recycle) the polyester raw material Pm. Specifically, as shown in Figure 1, the polyester raw material Pm is sheeted (step S100), the sheeted polyester raw material Pm is dissolved in carboxylic acid-derived monomer D to generate a polyester solution (step S101), foreign matter is removed from the solution (step S102), the solution with foreign matter removed is mixed with reaction solvent M and depolymerized (step S103), the monomers of the depolymerized polyester are purified (separated) to generate carboxylic acid-derived monomer D and alcohol monomer E (step S104), monomer D is hydrolyzed to separate reaction solvent M (step S106), monomer F generated from the hydrolysis of monomer D is polymerized with monomer E (step S108), thereby regenerating the polyester raw material Pm. The recycling step of the separation system 1 in this embodiment can omit the sheeting step S100, or skip the repolymerization process up to step S108, and only perform the recycling processes of monomers D and E shown in steps S102 and S104, and monomer F shown in step S106.

[0013] (Polyester raw materials) In this embodiment, the polyester raw material Pm, which is the target of depolymerization, is a substance containing polyester. The polyester raw material Pm is not particularly limited, and examples include waste products of polyethylene terephthalate (PET), polyethylene butylene terephthalate (PEBT), polybutylene terephthalate (PBT), polycyclohexanedimethyl terephthalate (PCT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), and polycarbonate (PC). The polyester raw material Pm is not limited to containing only polyester components; it may also contain components other than polyester (impurities). Examples of components other than polyester contained in polyester raw material Pm include: plastics other than polyester such as polyethylene, polystyrene, polypropylene, and polyvinyl chloride; metals; dyes; pigments; and polymerization catalysts. Clothing woven from polyester and other components into fibers can also be exemplified as polyester raw material Pm. Hereinafter, components other than polyester contained in polyester raw material Pm will be referred to as impurities R.

[0014] (Reaction solvent) The reaction solvent M is a solvent that reacts with the polyester, causing the polyester to depolymerize. The reaction solvent M can be at least one of, for example, methanol, ethanol, water, and ethylene glycol.

[0015] (Carboxylic acid derivative monomers) The carboxylic acid-derived monomer D is generated by the depolymerization of polyester and is a monomer with a carboxyl group. Monomer D can be, for example, dimethyl carboxylate or diethyl carboxylate. More preferably, monomer D is a monomer of terephthalic acid, such as dimethyl terephthalate (DMT).

[0016] (Monomers of alcohol components) The monomer E of the alcohol component is a monomer of the alcohol component generated by the depolymerization reaction of polyester. Monomer E can be, for example, a dihydroxy compound (divalent alcohol), and more specifically, ethylene glycol (EG).

[0017] The following explanation uses PET as the polyester, methanol as the reaction solvent, D as the monomer, and EG as the monomer.

[0018] (Separation System) Figure 2 is a schematic diagram of the separation system of the first embodiment. The separation system 1 of the first embodiment is a system for monomerizing the polyester raw material Pm to generate monomers D and E. As shown in Figure 1, the separation system 1 includes: a raw material storage section 10, a dissolving section 12, a solid-liquid separation section 13, a storage section 20, a removal section 26, a reaction solvent storage section 14, a reaction section 16, a separation section 18, a control section 30, and a washing device 100. The washing device 100 can be arranged in different locations or in the same location as the other components of the separation system 1, namely the raw material storage section 10, the dissolving section 12, the solid-liquid separation section 13, the storage section 20, the removal section 26, the reaction solvent storage section 14, the reaction section 16, the separation section 18, and the control section 30.

[0019] (Raw Material Storage Section) The raw material storage section 10 is a tank for introducing and storing polyester raw material Pm. In this embodiment, the raw material storage section 10 stores sheet-like polyester raw material Pm, but the shape or size of the polyester raw material Pm can be arbitrary. The raw material storage section 10 is connected to the dissolving section 12 through an inlet pipe 10a. The polyester raw material Pm in the raw material storage section 10 is supplied to the dissolving section 12 through the inlet pipe 10a. The inlet pipe 10a is provided with an adjustment section 10b for adjusting the amount of polyester raw material Pm supplied from the raw material storage section 10 to the dissolving section 12. The adjustment section 10b is, for example, an on / off valve. When open, it supplies polyester raw material Pm from the raw material storage section 10 to the dissolving section 12; when closed, it stops the supply of polyester raw material Pm from the raw material storage section 10 to the dissolving section 12. However, the adjustment section 10b is not limited to an on / off valve and can be any mechanism capable of adjusting the supply of polyester raw material Pm to the dissolving section 12. Alternatively, the polyester raw material Pm can be supplied directly to the dissolving section 12 without going through the raw material storage section 10, the inlet pipe 10a, or the adjustment section 10b.

[0020] (Dissolution section) The dissolution section 12 is a tank for storing the dissolving solution Pd. The dissolving solution Pd is a solution generated by mixing polyester raw material Pm with monomer D. Here, the polyester contained in polyester raw material Pm dissolves in monomer D, but the components other than polyester contained in polyester raw material Pm, i.e., impurities R, do not dissolve in monomer D and remain. Therefore, the dissolving solution Pd can be said to contain a polyester solution P from polyester raw material Pm dissolved in monomer D, as well as impurities R contained in polyester raw material Pm.

[0021] Monomer D and polyester raw material Pm are supplied to the dissolving section 12. Within the dissolving section 12, the polyester contained in the polyester raw material Pm dissolves in monomer D, while impurity R remains undissolved in monomer D, generating a solution Pd containing polyester solution P and impurity R. This dissolution of polyester in monomer D reduces viscosity and improves flowability, allowing the polyester to be easily discharged to the reaction section 16. The polyester solution P is not limited to complete dissolution of polyester in monomer D; at least a portion of the polyester may remain undissolved in monomer D. Furthermore, when the polyester raw material Pm contains components other than polyester that are soluble in monomer D, the polyester solution P may also contain those components dissolved in monomer D.

[0022] In this embodiment, the dissolving section 12 is provided with a heating section 12A. The heating section 12A heats the monomer D and polyester raw material Pm supplied to the dissolving section 12 to a predetermined temperature by heating the interior of the dissolving section 12. The predetermined temperature is the temperature at which the polyester can dissolve in the monomer D. Heating at this predetermined temperature allows the polyester contained in the polyester raw material Pm to dissolve appropriately in the monomer D. The predetermined temperature is preferably 140°C to 300°C, more preferably 160°C to 280°C, and even more preferably 190°C to 250°C. The impurity R also contains components that melt upon heating to the predetermined temperature (the temperature at which the polyester can dissolve in the monomer D). Therefore, when the impurity R contains components that melt upon heating to the predetermined temperature, a portion of it is in a molten state and contained in the solution Pd. In this embodiment, the heating section 12A is provided in the dissolving section 12, but the location of the heating section 12A is not limited to this and can be arbitrary.

[0023] (Solid-Liquid Separation Section) A solid-liquid separation section 13 is disposed in the dissolving section 12. The solid-liquid separation section 13 captures solid impurities R contained in the dissolved liquid Pd stored in the dissolving section 12, separating the solid impurities R from the dissolved liquid Pd. The solid-liquid separation section 13 is a mesh filter through which liquid passes and solids are captured. In this embodiment, the solid-liquid separation section 13 is shaped like an open container and is disposed with a predetermined interval between its sides and bottom relative to the dissolving section 12. The solid-liquid separation section 13 is disposed downstream of the inlet pipe 10a and the supply pipe for the supplied monomer D, and upstream of the inlet pipe 12a that supplies the dissolved liquid Pd to the downstream storage section 20 from the dissolving section 12. The dissolved liquid Pd flowing from the dissolving section 12 into the inlet pipe 12a passes through the solid-liquid separation section 13. In this way, the solid-liquid separation section 13 captures solids larger than the opening diameter of the mesh. Preferably, the opening diameter of the mesh in the solid-liquid separation section 13 is set to 1 mm or more and 50 mm or less.

[0024] The solid-liquid separation unit 13 in this embodiment uses a mesh filter for filtration, but it is not limited to this. The solid-liquid separation unit 13 can also separate impurities R from the solution Pd by centrifugation. In this centrifugation, the interior of the stirring and dissolving unit 12 is surrounded by a predetermined axis, moving the impurities to the radially outer side of the rotating axis. The solid-liquid separation unit 13 is only required to separate solid impurities of a predetermined size or larger from the solution Pd, and is not limited to filtration or centrifugation.

[0025] The foreign matter recovery unit 50 recovers solid impurities captured by the solid-liquid separation unit 13. The foreign matter recovery unit 50, for example, moves the filter of the solid-liquid separation unit 13 to recover the attached impurities. Alternatively, the solid-liquid separation unit 13 may also be equipped with a pressing device that pushes the impurities attached to the mesh filter against the filter, squeezing out the dissolved liquid Pd contained in the impurities. Before recovering the impurities, the foreign matter recovery unit 50 squeezes out the dissolved liquid using the pressing device, which can leave more dissolved liquid Pd in ​​the separation system 1. When the solid-liquid separation unit 13 performs separation by centrifugation, the foreign matter recovery unit 50 recovers the impurities from the area where impurities are stored during centrifugation.

[0026] (Storage Department) The storage section 20 is a tank for storing the dissolved solution Pd. The storage section 20 is connected to the dissolving section 12 via an inlet pipe 12a. The dissolved solution Pd in ​​the dissolving section 12 is supplied to the storage section 20 via the inlet pipe 12a. The inlet pipe 12a is provided with an adjustment section 12a1 for adjusting the amount of dissolved solution Pd supplied from the dissolving section 12 to the storage section 20. The adjustment section 12a1 is, for example, an on / off valve. When open, it supplies the dissolved solution Pd in ​​the dissolving section 12 to the storage section 20. When closed, it stops the supply of dissolved solution Pd from the dissolving section 12 to the storage section 20. However, the adjustment section 12a1 is not limited to an on / off valve and can be any mechanism capable of adjusting the supply of dissolved solution Pd to the storage section 20. In this embodiment, the storage section 20 is connected to the dissolving section 12 via the inlet pipe 12a, but a temporary storage section for temporarily storing the dissolved solution Pd can also be provided between the dissolving section 12 and the storage section 20.

[0027] In the storage section 20, the dissolved liquid Pd separates into polyester solution P and impurity R by gravity. Here, the impurity R separated in the storage section 20 is the impurity that was not recovered in the solid-liquid separation section 13 and moved to the storage section 20 along with the dissolved liquid Pd. In this embodiment, the dissolved liquid Pd stored in the storage section 20 is allowed to stand, and then separated into polyester solution P and impurity R by gravity.

[0028] In this embodiment, the solution Pd stored in the storage section 20 separates into a layer of first impurity R1, a layer of polyester solution P, and a layer of second impurity R2 by gravity. The layer of first impurity R1 forms vertically below the layer of polyester solution P. That is, the first impurity R1 is the impurity R that is insoluble in monomer D and has a specific gravity greater than that of polyester solution P. The first impurity R1 settles in the polyester solution P within the storage section 20, forming the layer of first impurity R1. On the other hand, the layer of second impurity R2 forms vertically above the layer of polyester solution P. That is, the second impurity R2 is the impurity R that is insoluble in monomer D and has a specific gravity less than that of polyester solution P. The second impurity R2 floats to the surface in the polyester solution P within the storage section 20, forming the layer of second impurity R2.

[0029] Furthermore, the dissolved liquid Pd in ​​the storage section 20 is maintained above a predetermined temperature (the temperature at which the polyester can dissolve in monomer D). The first impurity R1 and the second impurity R2 are components of impurity R that melt when heated to the predetermined temperature, and therefore also exist in a molten state in the storage section 20. The first impurity R1 and the second impurity R2 are, for example, plastics other than polyester (polyethylene, polystyrene, polypropylene, polyvinyl chloride, etc.).

[0030] In this embodiment, the polyester solution P contains a third impurity R3. The third impurity R3 is a component of impurity R that is insoluble in monomer D and does not melt at a predetermined temperature (the temperature at which the polyester can dissolve in monomer D). That is, the third impurity R3 does not separate from the polyester solution P even by gravity separation and exists in the polyester solution P in a non-melting solid state. In this embodiment, the third impurity R3 is dispersed in the polyester solution P. The third impurity R3 may be, for example, a dye, pigment, or polymerization catalyst.

[0031] The storage section 20 is connected to a discharge pipe 20a. The discharge pipe 20a is a pipe used to discharge the first impurity R1 separated into the lower layer of the polyester solution P from the storage section 20. The discharge pipe 20a is connected to the position where the layer of the first impurity R1 is formed in the storage section 20, and in this embodiment, it is connected to the bottom of the storage section 20. The discharge pipe 20a is provided with a first discharge section 22a. The first discharge section 22a is a mechanism for discharging the first impurity R1 from the storage section 20, and in this embodiment, it is a pump.

[0032] The storage section 20 is connected to a discharge pipe 20b. The discharge pipe 20b is a pipe used to discharge the second impurity R2 separated to the upper layer of the polyester solution P from the storage section 20. The discharge pipe 20b is connected to the position where the layer of the second impurity R2 is formed in the storage section 20, and is connected above the discharge pipe 20a in the vertical direction. The storage section 20 is equipped with second discharge sections 22b1 and 22b2 to discharge the second impurity R2 from the storage section 20. The second discharge section 22b1 is a skimmer provided at the liquid surface of the polyester solution P to recover (skim off) the second impurity R2 floating on the liquid surface of the polyester solution P. The second discharge section 22b2 is provided at the discharge pipe 20b, and is a mechanism for discharging the second impurity R2 recovered by the second discharge section 22b1 through the discharge pipe 20b. In this embodiment, it is a pump. Thus, in this embodiment, a second discharge section 22b1 and 22b2 are provided as the mechanism for discharging the second impurity R2. However, the configuration of the second discharge section for discharging the second impurity R2 is not limited to this and can be arbitrary.

[0033] The first impurity R1 and the second impurity R2 separated from the polyester solution P in the storage section 20 are discharged to the outside of the storage section 20 via the first discharge section 22a and the second discharge sections 22b1 and 22b2. In this way, the first impurity R1 and the second impurity R2 are removed from the polyester solution P. Hereinafter, the first discharge section 22a and the second discharge sections 22b1 and 22b2 will not be distinguished and will be referred to as discharge section 22. In the above description, impurity R contains the first impurity R1, which has a higher specific gravity than the polyester solution P, and the second impurity R2, which has a lower specific gravity than the polyester solution P. However, this is not a limitation; impurity R may contain only one of the first impurity R1 and the second impurity R2.

[0034] The storage section 20 is connected to an inlet pipe 20c. The inlet pipe 20c is a pipe used to discharge the polyester solution P separated from the impurity R from the storage section 20. The inlet pipe 20c is connected at the position where the layer of polyester solution P is formed in the storage section 20. In this embodiment, it is connected between the discharge pipe 20a and the discharge pipe 20b in the vertical direction. The inlet pipe 20c is provided with a discharge section 24. The discharge section 24 is a mechanism for discharging the polyester solution P from the storage section 20. In this embodiment, it is a pump. In this embodiment, the inlet pipe 20c includes an inlet pipe 20c1 connecting the storage section 20 and the filter 26a (described later), an inlet pipe 20c2 connecting the filter 26a and the adsorption tower 26b (described later), and an inlet pipe 20c3 connecting the adsorption tower 26b and the reaction section 16.

[0035] (Excluding the part) The removal unit 26 is a mechanism for removing the third impurity R3 contained in the polyester solution P from the polyester solution P. The removal unit 26 is connected to the storage unit 20 and removes the present third impurity R3 from the polyester solution P discharged from the storage unit 20. In this embodiment, the removal unit 26 is provided with a filter 26a and an adsorption tower 26b.

[0036] (Filter machine) The filter 26a is connected to the storage section 20 via the inlet pipe 20c1. In the filter 26a, the polyester solution P discharged from the storage section 20 is introduced through the inlet pipe 20c1. The filter 26a uses a filter to capture the solid components contained in the third impurity R3 of the polyester solution P. The structure of the filter 26a will be described later.

[0037] (Adsorption tower) Adsorption tower 26b is connected to filter 26a via inlet pipe 20c2. In adsorption tower 26b, polyester solution P (the polyester solution P after solid components are captured by filter 26a) discharged from filter 26a is introduced through inlet pipe 20c2. Adsorption tower 26b has a collection section for capturing the third impurity R3 contained in polyester solution P. The collection section of adsorption tower 26b can be an adsorbent for adsorbing the third impurity R3 contained in polyester solution P, or it can be a filtration section for capturing the third impurity by filtration. That is, adsorption tower 26b can capture the third impurity R3 by at least one of adsorption or filtration. The adsorbent collected in adsorption tower 26b is preferably capable of adsorbing the molecular skeleton of the third impurity R3 (e.g., quinone group, azo group, heterocyclic ring, benzene ring). The adsorbent is preferably, for example, activated carbon.

[0038] The adsorption tower 26b is connected to the reaction section 16 (described later) through the inlet pipe 20c3. That is, the polyester solution P after the third impurity is removed in the adsorption tower 26b is introduced into the reaction section 16 through the inlet pipe 20c3.

[0039] Thus, the polyester solution P, which is discharged from the storage section 20 to the inlet pipe 20c1, is introduced into the filter 26a, where at least a portion of the third impurity R3 contained in the polyester solution P is captured by the filter 26a. The third impurity R3 captured by the filter 26a is discharged to the outside through the outlet pipe 26a1 connected to the filter 26a. In the example of Figure 2, the outlet pipe 26a1 merges with the outlet pipe 20a, but it may not merge with the outlet pipe 20a. The polyester solution P, with at least a portion of the third impurity R3 removed by the filter 26a, is discharged from the filter 26a and introduced into the adsorption tower 26b. In the adsorption tower 26b, the third impurity R3 remaining in the polyester solution P is adsorbed or filtered by the adsorption tower 26b and removed from the polyester solution P. The third impurity R3 adsorbed or filtered by the adsorption tower 26b is, for example, a dye or a polymerization catalyst. The polyester solution P, from which the third impurity R3 is removed by the adsorption tower 26b, is led out from the adsorption tower 26b and introduced into the reaction section 16 through the inlet pipe 20c.

[0040] Thus, in this embodiment, as a mechanism for removing the third impurity R3 from the polyester solution P, a filter 26a and an adsorption tower 26b are provided, but the configuration of the removal unit 26 for discharging the third impurity R3 is not limited to this and can be arbitrary.

[0041] (Reaction solvent storage section) The reaction solvent storage section 14 is a tank for introducing and storing the reaction solvent M. The reaction solvent storage section 14 is connected to the reaction section 16 via an inlet pipe 14a. The reaction solvent M in the reaction solvent storage section 14 is supplied to the reaction section 16 through the inlet pipe 14a. More specifically, the inlet pipe 14a is provided with a heating and pressurizing section 14b for pressurizing and heating the reaction solvent M. The heating and pressurizing section 14b pressurizes and heats the reaction solvent M, making it into a supercritical or subcritical state (pressurized gas or pressurized liquid). The reaction section 16 is supplied with the supercritical or subcritical (pressurized gas or pressurized liquid) reaction solvent M.

[0042] (Reaction Section) The reaction section 16 is a container for introducing the polyester solution P, which has been separated from impurities R, and the reaction solvent M into the storage section 20, to depolymerize the polyester in the polyester solution P. The reaction section 16 includes a first reaction section 16A and a second reaction section 16B. Hereinafter, the direction from the first reaction section 16A toward the second reaction section 16B within the reaction section 16 is designated as direction Y1, and the direction opposite to direction Y1 (from the second reaction section 16B toward the first reaction section 16A) is designated as direction Y2. In this embodiment, direction Y2 is the direction of gravity (vertically downward).

[0043] (First Reaction Section) A first reaction section 16A is formed within the reaction section 16. In this embodiment, the first reaction section 16A can be considered as a location within the reaction section 16 filled with a filler material. The filler material used in the first reaction section 16A can be any known material used in gas-liquid or liquid-liquid contact devices, such as the same filler material used in contact devices for contacting heavy oil with water to extract the active ingredient. Specific examples of filler materials include: tubes made of SUS, Raschig rings, Berl saddles, Terralet rings, and balls.

[0044] The first reaction section 16A is connected to an inlet tube 20c. More specifically, the inlet tube 20c connects the first reaction section 16A to the polyester solution P from the storage section 20, which is the inlet port 16C. The inlet port 16C is connected to the surface 16A1 of the first reaction section 16A on the first direction Y1 side. The inlet tube 20c is connected to the surface 16A1 such that the inlet port 16C opens towards the second direction Y2 side, which is opposite to the first direction Y1. Thus, in this embodiment, the inlet port 16C, which opens towards the second direction Y2 side, is connected to the surface 16A1 of the first reaction section 16A, but it is not limited to this. For example, the inlet port 16C may not be directly connected to the first reaction section 16A, and the inlet port 16C, which opens towards the second direction Y2 side, may also be connected to the reaction section 16 further towards the first direction Y1 side than the surface 16A1 of the first reaction section 16A.

[0045] The reaction section 16 is connected to an inlet pipe 14a. More specifically, the inlet pipe 14a connects the reaction section 16 to the inlet section 16, which is the opening of the reaction solvent M in the reaction solvent storage section 14, i.e., the inlet port 16D. The inlet port 16D is connected to the surface 16A2, which is closer to the second direction Y2 side than the second direction D2 side of the first reaction section 16A. The inlet pipe 14a is connected to the surface 16A2, which is closer to the second direction Y2 side, so that the inlet port 16D opens towards the first direction Y1 side or from the side towards the center side. Thus, in this embodiment, the inlet port 16D, which opens towards the first direction Y1 side or from the side towards the center side, is connected to the surface 16A2, which is closer to the second direction Y2 side than the surface 16A2 of the first reaction section 16A, but it is not limited to this. For example, the inlet port 16D can also be directly connected to the first reaction section 16A, or it can be connected to the surface 16A2 of the first reaction section 16A.

[0046] Thus, in this embodiment, the inlet 16C for introducing the polyester solution P opens towards the second direction Y2, and the inlet 16D for introducing the reaction solvent M opens towards the first direction Y1 or from the side towards the center. Therefore, the polyester solution P and the reaction solvent M are introduced into the first reaction section 16A in mutually opposing directions.

[0047] Polyester solution P introduced into the first reaction section 16A through inlet 16C moves towards the second direction Y2 on the surface of the filler material of the first reaction section 16A. Meanwhile, a supercritical or subcritical (pressurized gas or pressurized liquid) reaction solvent M introduced through inlet 16D moves towards the first direction Y1 within the first reaction section 16A. In the first reaction section 16A, the supercritical or subcritical (pressurized gas or pressurized liquid) reaction solvent M comes into contact with the polyester solution P. The polyester in the polyester solution P is depolymerized (reduced in molecular weight) by the reaction solvent M, and the depolymerized polyester is extracted by the supercritical or subcritical (pressurized gas or pressurized liquid) reaction solvent M. Hereinafter, the depolymerized polyester in the first reaction section 16A is referred to as the first depolymerized polyester P1, and the mixture of the first depolymerized polyester P1 and the reaction solvent M (the reaction solvent M that extracts the first depolymerized polyester P1) is referred to as the first solvent M1. The first solvent M1 containing the first depolymerized polyester P1 moves toward the first direction Y1 side of the first reaction section 16A and is discharged to the first direction Y1 side of the first reaction section 16A.

[0048] The first depolymerized polyester P1 contains: monomers D and E generated by the depolymerization of polyester in polyester solution P; monomer D originally mixed in polyester solution P; and oligomers generated by the depolymerization of polyester. Here, oligomers refer to carboxylic acid derivatives or alcohol components derived from polyester depolymerization, even though they are not monomerized (oligomers with a molecular weight smaller than that of polyester).

[0049] (Second Reaction Section) The second reaction section 16B is formed within the reaction section 16, and is formed at the location where the first solvent M1 is discharged from the first reaction section 16A. In this embodiment, the first solvent M1 is discharged to the first direction Y1 side, so the second reaction section 16B can be considered as the space formed on the first direction Y1 side of the first reaction section 16A.

[0050] In the second reaction section 16B, the first depolymerized polyester P1 contained in the first solvent M1 is further depolymerized (reduced in molecular weight) by the reaction solvent M contained in the first solvent M1. Hereinafter, the first depolymerized polyester P1 further depolymerized in the second reaction section 16B will be referred to as the second depolymerized polyester P2, and the mixture of the second depolymerized polyester P2 and the reaction solvent M (the reaction solvent M that dissolves the second depolymerized polyester P2) will be referred to as the second solvent M2. The second reaction section 16B is connected to an outlet pipe 16a. More specifically, the second reaction section 16B is connected to an outlet pipe 16a with an opening, namely an outlet port 16E, through which the second solvent M2 is discharged from the second reaction section 16B. The second solvent M2 containing the second depolymerized polyester P2 in the second reaction section 16B is discharged from the outlet port 16E through the outlet pipe 16a to the outside of the second reaction section 16B.

[0051] In addition, the second depolymerized polyester P2 contains: monomers D and E from the first depolymerized polyester P1; monomers D and E generated by the depolymerization of the oligomers in the first depolymerized polyester P1; and oligomers generated by the depolymerization of the first depolymerized polyester P1.

[0052] A discharge pipe 16b is connected to the bottom of the reaction section 16. More specifically, the outlet 16F is the opening through which the discharge pipe 16b discharges the non-extractable material (described later) from the reaction section 16. The non-extractable material containing impurities such as metal compounds not extracted by the reaction solvent M, and undecomposed polyester residue not extracted by the reaction solvent M, is discharged from the outlet 16F. That is, the non-extractable material at the bottom of the reaction section 16 is discharged from the outlet 16F through the discharge pipe 16b to the outside of the reaction section 16. The non-extractable material discharged from the outlet 16F can be considered as the component in the polyester solution P that was not used as the second solvent M2 (the reaction solvent M that dissolves the second depolymerized polyester P2) and was not discharged to the separation section 18, but remains in the first reaction section 16A and the second reaction section 16B.

[0053] Additionally, the reaction section 16 may also include a heating section for heating the interior of the reaction section 16 and a pressurizing section for maintaining the pressure inside the reaction section 16 at a predetermined value or higher. The temperature inside the reaction section 16 is preferably set to 250°C or higher and 400°C or lower, more preferably 250°C or higher and 350°C or lower. Furthermore, the pressure inside the reaction section 16 is preferably 1 MPa or higher and 30 MPa or lower, more preferably 6 MPa or higher and 25 MPa or lower. The pressurizing section and the heating section can be controlled by the control section 30.

[0054] (Separation section) Separation section 18 introduces a second solvent M2 containing the second depolymerized polyester P2, separating the second solvent M2 into reaction solvent M, carboxylic acid-derived monomer D contained in the second depolymerized polyester P2, alcohol monomer E contained in the second depolymerized polyester P2, and residual substances. The residual substances are components in the second solvent M2 other than reaction solvent M, monomer D, and monomer E, and include oligomers.

[0055] In this embodiment, the separation section 18 has a first separation section 18A, a second separation section 18B, and a third separation section 18C.

[0056] The first separation section 18A is a separation tower connected to the outlet pipe 16a. In the first separation section 18A, a second solvent M2 containing the second depolymerized polyester P2 is introduced through the outlet pipe 16a. The first separation section 18A separates the second solvent M2 into a low-boiling-point component and a high-boiling-point component (with a higher boiling point than the low-boiling-point component). For example, in the first separation section 18A, the second solvent M2 can be set to a predetermined temperature, resulting in a gaseous component as the low-boiling-point component and a liquid component as the high-boiling-point component. The first separation section 18A is connected to outlet pipes 18Aa and 18Ab. The low-boiling-point component is discharged from outlet pipe 18Aa, and the high-boiling-point component is discharged from outlet pipe 18Ab.

[0057] The second separation section 18B is a separation tower connected to the first separation section 18A via an outlet pipe 18Aa. In the second separation section 18B, low-boiling-point components are introduced through the outlet pipe 18Aa. The second separation section 18B separates the low-boiling-point components into reaction solvent M and monomer E. The second separation section 18B is connected to outlet pipes 18Ba and 18Bb. Reaction solvent M is discharged from outlet pipe 18Ba, and monomer E is discharged from outlet pipe 18Bb. Outlet pipe 18Ba is connected to the second separation section 18B and the reaction solvent storage section 14. Therefore, the reaction solvent M discharged from the second separation section 18B returns to the reaction solvent storage section 14 and is reused in the depolymerization of the polyester.

[0058] The third separation section 18C is a separation tower connected to the first separation section 18A via an outlet pipe 18Ab. In the third separation section 18C, high-boiling-point components are introduced through the outlet pipe 18Ab. The third separation section 18C separates the high-boiling-point components into residues with even higher boiling points, low-boiling-point components containing the reaction solvent M and monomer E, and monomer D. The third separation section 18C is connected to outlet pipes 18Ca, 18Cb, and 18Cc. Outlet pipe 18Ca is connected to the second separation section 18B. The low-boiling-point components separated in the third separation section 18C are exported to the second separation section 18B through outlet pipe 18Ca. Additionally, monomer D separated in the third separation section 18C is exported through outlet pipe 18Cb, and the residues separated in the third separation section 18C are exported through outlet pipe 18Cc.

[0059] The third separation section 18C is connected to an inlet pipe 18Cd. The inlet pipe 18Cd is also connected to the dissolution section 12, through which monomer D supplied from the third separation section 18C is introduced into the dissolution section 12. In the example of Figure 2, the inlet pipe 18Cd branches off from the outlet pipe 18Cb. The inlet pipe 18Cd is provided with an adjustment section 18Ce for adjusting the amount of monomer D supplied from the third separation section 18C to the dissolution section 12. The adjustment section 18Ce is, for example, an on / off valve, which, when open, supplies monomer D to the dissolution section 12, and when closed, stops the supply of monomer D to the dissolution section 12. However, the adjustment section 18Ce is not limited to an on / off valve and can be any mechanism capable of adjusting the supply of monomer D to the dissolution section 12. In this embodiment, the adjustment section 18Ce is located at the branch point of the inlet pipe 18Cd from the outlet pipe 18Cb, but its location is not limited to this and can be arbitrary. Alternatively, the inlet tube 18Cd may not be connected to the outlet tube 18Cb, but may be directly connected to the third separation section 18C. Alternatively, for example, the outlet tube 18Cb may also be provided with a storage section (trough) for storing monomer D, and the inlet tube 18Cd may be connected to the storage section.

[0060] Furthermore, the outlet tube 18Cc can also be connected to the dissolution section 12 to introduce at least a portion of the residual material into the dissolution section 12. By introducing the residual material into the dissolution section 12, the oligomers contained in the residual material can be depolymerized again in the reaction section 16, thereby increasing the monomer yield.

[0061] (Control Department) The control unit 30 is a control device for the separation system 1. The control unit 30 controls the adjustment unit 10b to control the amount of polyester raw material Pm supplied from the raw material storage unit 10 to the dissolving unit 12. The control unit 30 controls the foreign matter recovery unit 50 to recover impurities captured by the solid-liquid separation unit 13. Furthermore, when the solid-liquid separation unit 13 is equipped with a drive unit, the control unit 30 controls the operation of the solid-liquid separation unit 13. The control unit 30 controls the adjustment unit 12a1 to control the amount of dissolved liquid Pd supplied from the dissolving unit 12 to the storage unit 20. The control unit 30 controls the discharge unit 22 to discharge impurities R separated from the polyester solution P in the storage unit 20. The control unit 30 controls the outlet unit 24 to outlet the polyester solution P separated from impurities R in the storage unit 20, and controls the amount of polyester solution P introduced into the reaction unit 16. The control unit 30 controls the heating and pressurizing unit 14b to make the reaction solvent M into a supercritical or subcritical state (pressurized gas or pressurized liquid), and controls the supply amount of the supercritical or subcritical (pressurized gas or pressurized liquid) reaction solvent M to the reaction unit 16. The control unit 30 controls the adjusting unit 18Ce to control the supply amount of monomer D to the dissolving unit 12.

[0062] In this embodiment, the control unit 30 is a computer, such as a processor containing a CPU (Central Processing Unit) and other computing circuits, and a memory unit containing various information such as the calculation content or program of the memory processor. The control unit 30 executes the control of the discrete system 1 by reading the program from the memory unit.

[0063] However, the separation system 1 is not limited to automatic control by the control unit 30; for example, at least part of the processing can also be controlled by the operator.

[0064] (Operation of the separation system) Next, the operation of separation system 1 will be explained. Control unit 30 controls adjustment units 10b and 18Ce to introduce polyester raw material Pm and monomer D into dissolution unit 12, where polyester raw material Pm and monomer D are mixed to generate a solution Pd. Control unit 30 controls adjustment unit 12a1 to introduce the solution Pd generated in dissolution unit 12 into storage unit 20. Separation system 1 removes impurities R from the solution Pd supplied from dissolution unit 12 to storage unit 20 via solid-liquid separation unit 13. The solution Pd introduced into storage unit 20 is allowed to stand for a predetermined time, and then separated by gravity into a layer of first impurity R1, a layer of polyester solution P, and a layer of second impurity R2. The method of allowing the solution Pd to stand can be arbitrary.

[0065] The control unit 30 controls the discharge unit 22 to discharge the first impurity R1 and the second impurity R2 from the storage unit 20, and simultaneously controls the outlet unit 24 to outlet the polyester solution P from the storage unit 20. The polyester solution P outletped from the storage unit 20 is then de-impaired by the removal unit 26 to remove the third impurity R3, and introduced into the first reaction unit 16A. The control unit 30 controls the heating and pressurizing unit 14b to supply the reaction solvent M, which is in a supercritical or subcritical state (pressurized gas or pressurized liquid), to the reaction unit 16. Preferably, the control unit 30 sets the reaction solvent M to a temperature of 250°C or higher to 400°C or lower, and more preferably to a temperature of 250°C or higher to 350°C or lower. Preferably, the control unit 30 sets the reaction solvent M to a pressure of 1 MPa or higher to 30 MPa or lower, and more preferably to a pressure of 6 MPa or higher to 25 MPa or lower.

[0066] Thus, by supplying polyester solution P and reaction solvent M to reaction section 16, in the first reaction section 16A, the polyester contained in polyester solution P depolymerizes to generate a first depolymerized polyester P1. Then, in the second reaction section 16B, the first depolymerized polyester P1 further depolymerizes to generate a second solvent M2, which is a mixture of a second depolymerized polyester P2 and reaction solvent M. The second solvent M2 is separated into reaction solvent M, monomer D, monomer E, and residual substances in the first separation section 18A, the second separation section 18B, and the third separation section 18C. In this way, monomers D and E are recovered from polyester raw material Pm, and by polymerizing them, polyester can be regenerated.

[0067] (Components of a filter) Next, the configuration of filter 26a will be described using a full-volume filtration method. In this embodiment, filter 26a is not limited to a full-volume filtration method; for example, a cross-flow method may also be used. Furthermore, in this embodiment, filter 26a is arranged vertically, but it may also be arranged horizontally. In this case, the polyester solution P in filter 26a flows horizontally. Figure 3 is a schematic diagram showing the configuration of the filter. Figure 4 is a schematic top view of the filter. Filter 26a includes a receiving container 40 and a filter 47.

[0068] (Storage container) The storage container 40 is a container for storing the filter 47. The storage container 40 has a lid 41, a storage part 43, and a compartment member 45.

[0069] The storage section 43 is a container with a bottom and sides, and an open top, for storing the filter 47. A flange 43a is formed at the upper end of the storage section 43. An opening 43b for fluid passage is formed on the upper surface (bottom) of the storage section 43 in the Y direction. The upper end of the storage section 43 is not limited to a flange shape. For example, the flange 43a can be any shape capable of fixing the cover 41 to the storage section 43.

[0070] The cover 41 closes the top of the receiving part 43. The cover 41 is fixed to the receiving part 43. The cover 41 is connected to an inlet tube 20c1 for supplying polyester solution P. The cover 41 supplies the polyester solution P to the receiving part 43. The cover 41 has a flange 41a at its upper end and a flange 41b at its lower end.

[0071] (Partition components) A partition member 45 is disposed in the storage section 43. The partition member 45 supports a plurality of filters 47 disposed in the storage section 43. The partition member 45 is fixed to the cover 41 side of the storage section 43. Except for the connection portion with the filter 47, the partition member 45 is a liquid-impermeable structure. The partition member 45 separates the space surrounded by the storage section 43 and the cover 41 into a first space 42 on the cover 41 side and a second space 44 on the bottom side of the storage section 43.

[0072] (Filter) Filter 47 is a cylindrical component extending along the Y direction (vertical direction) and disposed inside the receiving container 40. A plurality of filters 47 are arranged side-by-side in the receiving container 40. In this embodiment, filter 47 is a porous ceramic filter. Polyester solution P flowing into the first space 42 through filter 47 is discharged into the second space 44 via the side and bottom surfaces. Impurities are filtered out from polyester solution P as it passes through filter 47. Polyester solution P flows through filter 47, and components contained in polyester solution P adhere to it. Specifically, a portion of the polyester and a third impurity R3 contained in polyester solution P adhere to filter 47. Filter 47 captures the third impurity R3 contained in polyester solution P. Specifically, filter 47 captures large-diameter polymeric catalysts or solid inorganic substances contained in the third impurity R3. Thus, a portion of the impurities contained in the third impurity R3 are captured, and the polyester solution P after capturing a portion of the impurities is introduced into the adsorption tower.

[0073] The number and arrangement of filters 47 are not limited to the example in Figure 4, and can be arbitrary. Similarly, the number and arrangement of flow holes 47a are also not limited to the example in Figure 4, and can be arbitrary. Furthermore, the structure of filters 47 is not limited to a porous structure, and can also be any structure such as a mesh structure or a net. Additionally, filters 47 are not limited to ceramic filters.

[0074] The housing 48 is detachably disposed inside the receiving section 43 and supports the filter 47. The housing 48 can also be connected to the partition member 45. The housing 48 only needs to be able to fix the filter 47 relative to the receiving section 43, and has a structure that allows the polyester solution P of the receiving section 43 to pass through, for example, a structure with an opening.

[0075] The polyester solution P flowing in the filter 26a is discharged to the outside through the filter 47 housed in the housing container 40. Specifically, the polyester solution P flowing in the filter 26a flows through the first space 42 of the cover 41 and toward the opening 43b formed in the housing 43 to be discharged to the adsorption tower 26b.

[0076] (Washing device) Figure 5 is a schematic diagram of the cleaning apparatus according to the first embodiment. The cleaning apparatus 100 cleans the filter 26a. The cleaning apparatus 100 includes a storage container 60, a supply unit 70, and a control unit 80. The cleaning apparatus 100 houses the filter 47 in the storage container 60 and supplies cleaning liquid C to the filter from the supply unit 70 to clean the filter 47 in the storage container 60. In the example shown in Figure 5, the cleaning apparatus 100 is configured such that the cleaning liquid C flows vertically in the storage container 60, but it can also be configured such that the cleaning liquid C flows horizontally. In this case, it is preferable to house the filter 47 horizontally. The structure, installation direction, and flow direction of the cleaning liquid C of the filter 47 are not particularly limited as long as it can filter the cleaning liquid C.

[0077] (Storage container) The storage container 60 is a container for storing the filter 47. The filter 47, which is to be cleaned, is used in the filter machine 26a and is adhered with cured polyester and impurities. The storage container 60 stores the filter 47 along the Y direction. The storage container 60 stores multiple filters 47. The storage container 60 may also store the filter 47 together with the housing 48 containing the filter 47. Alternatively, the storage container 60 may store only one filter 47. The storage container 60 has a cover 61, a storage section 63, and a compartment member 65. The storage container 60 is connected to an outlet pipe 67 and a supply section 70.

[0078] The storage section 63 is a container with a bottom and sides, used to store the filter 47, which is to be cleaned. The storage section 63 is connected to the supply section 70, which supplies the cleaning solution to the filter 47, via a supply pipe 77. Additionally, the storage section 63 is connected to an outlet pipe 67 through which the cleaning solution AC flows after the filter 47 has been cleaned. A differential pressure gauge 66 is connected to the storage section 63. A flange 63a is formed at the upper end of the storage section 63.

[0079] The cover 61 is a structure that closes the upper part of the storage part 63 and is fixed to the storage part 63 in a state that allows the upper part of the storage part 63 to be opened and closed. The cover 61 has a flange 61b formed at its lower end.

[0080] A partition member 65 is disposed in the storage section 63. The partition member 65 supports the filter 47, which is disposed in the storage section 63 and is intended for cleaning. The partition member 65 is fixed to the cover 61 side of the storage section 63. Except for the connection portion with the filter 47, the partition member 65 is a liquid-impermeable structure. The partition member 65 separates the space surrounded by the storage section 63 and the cover 61 into a first space 62 on the cover 61 side and a second space 64 on the bottom side of the storage section 63.

[0081] Differential pressure gauge 66 measures the differential pressure of filter 47. One end of differential pressure gauge 66 is connected to the first space 62, and the other end is connected to the second space 64. Differential pressure gauge 66 measures the differential pressure during the cleaning process of filter 47. Specifically, differential pressure gauge 66 measures the pressure difference between the upstream and downstream of filter 47, specifically the pressure difference between the first space 62 and the second space 64. When the opening of filter 47 is blocked, pressure loss occurs. Therefore, the pressure difference measured by differential pressure gauge 66 is larger than when the opening of filter 47 is not blocked. Therefore, the pressure difference measured by differential pressure gauge 66 decreases as filter 47 is cleaned, decreasing from the beginning of cleaning towards the end of cleaning.

[0082] The outlet pipe 67 is connected to the receiving container 60. The outlet pipe 67 is connected to the first space of the receiving container 60. The cleaning solution AC after the filter 47 is cleaned flows through the outlet pipe 67. The outlet pipe 67 discharges the fluid that has removed the substances adhering to the filter 47 from the receiving container 60 to the outside.

[0083] (Supply Department) The supply unit 70 is connected to the storage container 60 via a supply pipe 77. Here, one end of the supply pipe 77 is connected to the first fluid supply unit 71, the second fluid supply unit 72, and the third fluid supply unit 73, and the other end is connected to the second space of the storage container 60. One end of the supply pipe 77 is a branch pipe, and the other end is a main pipe. Each branch pipe of the supply pipe 77 is connected to the first fluid supply unit 71, the second fluid supply unit 72, and the third fluid supply unit 73. The main pipe of the supply pipe 77 is connected to the storage container 60. The supply pipe 77 can also be separately piped to various parts of the supply unit 70 and the storage container. A pump 78 is located on the supply pipe 77. The pump 78 is located at a non-branching position (main pipe) of the supply pipe 77. The pump 78 delivers the cleaning solution C flowing in the supply pipe 77 to the storage container 60.

[0084] The supply unit 70 includes a first fluid supply unit 71, a second fluid supply unit 72, and a third fluid supply unit 73. The supply unit 70 sequentially supplies first fluid C1, second fluid C2, and third fluid C3 to the receiving container 60 through supply pipes 77 from the first fluid supply unit 71, the second fluid supply unit 72, and the third fluid supply unit 73, respectively. Hereinafter, without distinguishing between the first fluid C1, the second fluid C2, and the third fluid C3, they will be appropriately referred to as cleaning solution C.

[0085] The first fluid C1 is a liquid that removes the cured polyester from the filter 47. The first fluid C1 is a liquid that dissolves the polyester. In this embodiment, the first fluid C1 is a cleaning solution with triethylene glycol as its main component. The first fluid C1 can be any liquid as long as it can remove the cured polyester.

[0086] The second fluid C2 is an acidic or alkaline liquid. The second fluid C2 is the cleaning solution used by the first fluid C1 to remove the cured polyester from the filter 47, thus removing impurities adhering to the filter 47. The second fluid C2 removes impurities by washing or dissolving them. The type of the second fluid C2 depends on the equipment used with the filter 47.

[0087] The third fluid C3 is the liquid used after the second fluid C2 removes the adhering impurities from the filter 47. The third fluid C3 is the washing liquid used to clean the filter 47 after removing impurities from the filter 47. In this embodiment, the third fluid C3 is ion-exchanged water.

[0088] The first fluid supply unit 71 includes a first fluid supply tank 71a and a first fluid adjustment unit 71b. The first fluid supply tank 71a is connected to the receiving container 60 through a supply pipe 77. The first fluid supply tank 71a stores the first fluid C1. The first fluid adjustment unit 71b is provided on the supply pipe 77. The first fluid adjustment unit 71b is a valve that controls the flow rate of the first fluid C1. The first fluid adjustment unit 71b is, for example, an on / off valve. When the first fluid C1 is supplied, it is in an open state, allowing the first fluid C1 in the first fluid supply tank 71a to be supplied to the receiving container 60. When the first fluid C1 is not supplied, it is in a closed state, stopping the supply of the first fluid C1 in the first fluid supply tank 71a to the receiving container 60. However, the first fluid adjustment unit 71b is not limited to an on / off valve and can be any mechanism capable of adjusting the supply of the first fluid C1 to the receiving container 60. The first fluid supply unit 71 supplies the first fluid C1 to the receiving container 60. The first fluid supply unit 71 supplies the first fluid C1 to the storage container 60 to backwash the filter 47 stored in the storage container 60. The first fluid supply unit 71 supplies the first fluid C1 to the storage container 60 to remove the cured polyester adhering to the filter 47 stored in the storage container 60.

[0089] The second fluid supply unit 72 includes a second fluid supply tank 72a and a second fluid adjustment unit 72b. The second fluid supply tank 72a is connected to the receiving container 60 through a supply pipe 77. The second fluid supply tank 72a stores the second fluid C2. The second fluid adjustment unit 72b is provided on the supply pipe 77. The second fluid adjustment unit 72b is a valve that adjusts the flow rate of the second fluid C2. The second fluid adjustment unit 72b is, for example, an on / off valve. When the second fluid C2 is supplied, it is in an open state, allowing the second fluid C2 in the second fluid supply tank 72a to be supplied to the receiving container 60. When the second fluid C2 is not supplied, it is in a closed state, stopping the supply of the second fluid C2 in the second fluid supply tank 72a to the receiving container 60. However, the second fluid adjustment unit 72b is not limited to an on / off valve and can be any mechanism capable of adjusting the supply of the second fluid C2 to the receiving container 60. After the first fluid supply unit 71 supplies the first fluid C1 to the receiving container 60, the second fluid supply unit 72 supplies the second fluid C2 to the receiving container 60. The second fluid supply unit 72 supplies the second fluid C2 to the receiving container 60 to backwash the filter 47 stored in the receiving container 60. The second fluid supply unit 72 supplies the second fluid C2 to the receiving container 60 to remove impurities attached to the filter 47 stored in the receiving container 60.

[0090] The third fluid supply unit 73 includes a third fluid supply tank 73a and a third fluid adjustment unit 73b. The third fluid supply tank 73a is connected to the receiving container 60 through a supply pipe 77. The third fluid supply tank 73a stores the third fluid C3. The third fluid adjustment unit 73b is provided on the supply pipe 77. The third fluid adjustment unit 73b is a valve that adjusts the flow rate of the third fluid C3. The third fluid adjustment unit 73b is, for example, an on / off valve. When the third fluid C3 is supplied, it is in an open state, allowing the third fluid C3 in the third fluid supply tank 73a to be supplied to the receiving container 60. When the third fluid C3 is not supplied, it is in a closed state, stopping the supply of the third fluid C3 in the third fluid supply tank 73a to the receiving container 60. However, the third fluid adjustment unit 73b is not limited to an on / off valve and can be any mechanism capable of adjusting the supply of the third fluid C3 to the receiving container 60. After the second fluid supply unit 72 supplies the second fluid C2 to the receiving container 60, the third fluid supply unit 73 supplies the third fluid C3 to the receiving container 60. The third fluid supply unit 73 supplies the third fluid C3 to the storage container 60 to backwash the filter 47 stored in the storage container 60. The third fluid supply unit 73 supplies the third fluid C3 to the storage container to remove the second fluid C2 adhering to the filter 47.

[0091] (Control Department) The control unit 80 is a control device for the cleaning apparatus 100. The control unit 80 controls the first fluid adjustment unit 71b to control the amount of first fluid C1 supplied from the first fluid supply tank 71a to the receiving container 60. The control unit 80 controls the second fluid adjustment unit 72b to control the amount of second fluid C2 supplied from the second fluid supply tank 72a to the receiving container 60. The control unit 80 controls the third fluid adjustment unit 73b to control the amount of third fluid C3 supplied from the third fluid supply tank 73a to the receiving container 60. For example, the control unit 80 obtains the value shown by the differential pressure gauge 66 and controls the flow rate of the cleaning liquid C.

[0092] In this embodiment, the control unit 80 is a computer, such as a memory unit containing a processor including a CPU and other computing circuits, and various information such as the calculation content or program of the memory processor. The control unit 80 executes the control of the cleaning device 100 by reading the program from the memory unit.

[0093] However, the washing device 100 is not limited to automatic control by the control unit 80; for example, at least part of the processing can also be controlled by the operator.

[0094] (Reverse rinsing) Next, the backwashing process will be explained. In this embodiment, the supply unit 70 supplies the cleaning liquid C to the outer peripheral surface (second space 64) of the filter 47 housed in the storage container 60. The supply unit 70 causes the cleaning liquid C supplied to the storage container 60 to flow into the filter 47. The supply unit 70 backwashes the filter 47 by the cleaning liquid C flowing from the bottom surface (Y2 direction side) to the top surface (Y1 direction side) of the filter 47 within the storage container 60. The cleaning liquid C flowing from the bottom surface of the filter 47 to the top surface is directed towards the Y1 direction (first space 62) of the partition member 65 due to the pressure difference between the first space 62 and the second space 64, and is discharged from the outlet pipe 67 as the cleaning liquid AC after cleaning the filter 47.

[0095] Figure 6 illustrates the control of the cleaning device in the first embodiment. The horizontal axis of Figure 6 represents time, and the vertical axis represents differential pressure. Line L represents the change in differential pressure of filter 47. That is, in line L, the differential pressure of filter 47 decreases simultaneously with the start of backwashing. In other words, the differential pressure decreases when the cured polyester or impurities adhering to filter 47 are removed (the mesh is cleared of blockage).

[0096] In the control unit 80, a predetermined differential pressure is preset for each cleaning fluid C. For example, in Figure 6, the predetermined differential pressure for the first fluid C1 is differential pressure P1, and the differential pressure for the second fluid C2 is differential pressure P2. The differential pressures P1 and P2 can be set within a range. In this embodiment, the range of differential pressure P1 is 0.10 MPa to 0.15 MPa, and the range of differential pressure P2 is 0.05 MPa to 0.08 MPa. The ranges of differential pressures P1 and P2 are not limited to the above ranges and can be set arbitrarily.

[0097] During a first period t1 from time T0 to the first time sequence T1, the control unit 80 controls the first fluid supply unit 71 to supply the first fluid C1 to the receiving container 60. The first time sequence T1 is the time when the differential pressure of the filter 47 shown by the differential pressure gauge 66 becomes differential pressure P1. Furthermore, the control unit 80 also controls the first fluid supply unit 71 during a second period t2 from the first time sequence T1 to the second time sequence T2, during which the first fluid supply unit 71 supplies the first fluid C1 to the receiving container 60. The second period t2 is the residence time of the first fluid C1 in the receiving container 60. That is, the backwashing of the filter 47 with the first fluid C1 occurs from time T0 to the second time sequence T2. By setting the residence time, the cured polyester adhering to the filter 47 can be more effectively removed.

[0098] The control unit 80 switches the fluid supplied to the receiving container 60 from the first fluid C1 to the second fluid C2. During the third period t3 from the second time sequence T2 to the third time sequence T3, the control unit 80 controls the second fluid supply unit 72 to supply the second fluid C2 to the receiving container 60. The third time sequence T3 is the time when the differential pressure of the filter 47 shown by the differential pressure gauge 66 becomes the differential pressure P2. In addition, the control unit 80 also controls the second fluid supply unit 72 during the fourth period t4 from the third time sequence T3 to the fourth time sequence T4, and the second fluid supply unit 72 supplies the second fluid C2 to the receiving container 60. The fourth period t4 is the residence time of the second fluid C2 in the receiving container 60. That is, the backwashing of the filter 47 with the second fluid C2 is from the second time sequence T2 to the fourth time sequence T4. By setting the residence time, impurities attached to the filter 47 (captured by the filter 47) can be removed more effectively.

[0099] During the fifth period t5, from the fourth time sequence T4 to the fifth time sequence T5, the control unit 80 controls the third fluid supply unit 73 to supply the third fluid C3 to the receiving container 60 until it is full. After the receiving container 60 is filled with the third fluid C3, the control unit 80 stops supplying the third fluid C3 during the fifth period t5, which is later than the fourth time sequence T4. The fifth period t5 is the residence time of the third fluid C3 in the receiving container 60. By setting the residence time, the filter 47 can be properly cleaned.

[0100] In this embodiment, the residence time of the first fluid C1, the second fluid C2, and the third fluid C3 in the receiving container 60 is n times the time required to fill the capacity of the receiving container 60. More specifically, when the receiving container 60 (second space 64) is supplied with cleaning liquid C, and the receiving container 60 (second space 64) is filled to its capacity in X time, the residence time of the cleaning liquid C is nX time. In this embodiment, the residence time of the first fluid C1, the second fluid C2, and the third fluid C3 in the receiving container 60 is preferably 3 times the time required to fill the capacity, i.e., 3X time. The residence time can be arbitrarily determined.

[0101] (Effect) Over time, the filter openings of a filter press become clogged due to the adhesion of polyester or impurities contained in the polyester solution P flowing through the filter (mesh clogging). When the filter openings are clogged, the impurity collection performance decreases. Therefore, the impurities collected by the filter press should be directed to an adsorption tower for collection by the adsorbent. Filters with reduced impurity collection performance are discarded and replaced with new ones, or the filters are cleaned to remove impurities. However, filter replacement costs increase, or the temperature of the filter decreases during cleaning, causing the polyester adhering to the filter to solidify and making it impossible to remove impurities. In addition, when the collection performance of the filter press decreases, the amount of adsorbent required for impurity collection by the adsorbent in the adsorption tower increases.

[0102] In contrast, the cleaning apparatus 100 includes a receiving container 60, a first fluid supply unit 71, and a second fluid supply unit 72. A first fluid C1 is supplied to the receiving container 60 from the first fluid supply unit 71, and a second fluid C2 is supplied to the receiving container 60 from the second fluid supply unit 72. When the filter 47 is received from the filter 26a into the receiving container 60, the polyester adhering to the filter 47 cures. In this embodiment, the first fluid C1 and the second fluid C2 are different liquids. Therefore, when the first fluid supply unit 71 supplies the first fluid C1 to the receiving container 60, it can remove the cured polyester from the filter 47 received in the receiving container 60. Furthermore, after the first fluid supply unit 71 supplies the first fluid C1 to the receiving container 60, the second fluid supply unit 72 supplies the second fluid C2 to the receiving container 60, thus also removing impurities adhering to the filter 47. Therefore, foreign matter can be removed reliably. Furthermore, by capturing large-particle impurities (polymerization catalyst) in filter 26a, the amount of polymerization catalyst or solid inorganic matter adsorbed by the adsorbent in adsorption tower 26b can be reduced, thus extending the service life of the adsorbent. In other words, the necessary amount of adsorbent in adsorption tower 26b can be reduced.

[0103] (Second Implementation Form) Next, the second embodiment will be described. In the second embodiment, the separation system 1A differs from the first embodiment in that it includes a built-in cleaning device 100A. Specifically, the integration of the storage container 60 of the cleaning device 100 and the storage container 40 of the separation system 1A differs from the first embodiment. Details common to the first embodiment in the second embodiment will be omitted.

[0104] Figure 7 is a partial schematic diagram of the separation system of the second embodiment. As shown in Figure 7, the separation system 1A of the second embodiment includes a washing device 100A.

[0105] In separation system 1A, the washing device 100A is connected to the receiving container 40 of the filter 26aA. Specifically, in separation system 1A, the outlet pipe 67 is connected to the inlet pipe 20c1 connected to the filter 26aA. In separation system 1A, the supply unit 70 is connected to the inlet pipe 20c2 connected to the filter 26aA. The supply unit 70 is the same as in the first embodiment, so its description is omitted.

[0106] The structure and function of filter 26aA are the same as those of filter 26a, so the description is omitted. In filter 26aA, the inlet pipe 20c2 branches off, and the supply pipe 77 is connected to the inlet pipe 20c2. Additionally, in filter 26A, the inlet pipe 20c1 branches off and is connected to the outlet pipe 67. That is, the supply pipe 77 merges into the inlet pipe 20c2, and the outlet pipe 67 merges into the inlet pipe 20c1.

[0107] The inlet pipe 20c1 is provided with an adjustment section 90. The adjustment section 90 is a valve that allows the polyester solution P to flow. The adjustment section 90 is, for example, an on / off valve. When the polyester solution P flows in the inlet pipe 20c1, it is in an open state, allowing the polyester solution P to be supplied from the storage section 20 to the receiving container 40. When the filter 26a is being cleaned, it is in a closed state, stopping the supply of polyester solution P from the storage section 20 to the receiving container 40. However, the adjustment section 90 is not limited to an on / off valve and can be any mechanism capable of supplying polyester solution P to the receiving container 40.

[0108] The inlet pipe 20c2 is equipped with an adjustment section 92. The adjustment section 92 is identical to the adjustment section 90; it is open when the polyester solution P flows in the inlet pipe 20c2, supplying the polyester solution P flowing in the filter 26a to the adsorption tower 26b; and it is closed when the filter 26a is being cleaned, stopping the supply of the polyester solution P flowing in the filter 26a to the adsorption tower 26b. However, the adjustment section 92 is not limited to an on / off valve and can be any mechanism capable of supplying the polyester solution P to the adsorption tower 26b.

[0109] The outlet pipe 67 is equipped with an adjustment section 94. The adjustment section 94 is a valve for discharging the cleaning solution AC from the filter 47 after cleaning. The adjustment section 94 is, for example, an on / off valve, which is open when the filter 26aA is being cleaned, allowing the cleaning solution AC from the filter 26aA to be discharged to the outside, and closed when the filter 26aA is not being cleaned, preventing the polyester solution P from being discharged to the outside. The adjustment section 94 is not limited to an on / off valve, and can be any mechanism that allows the cleaning solution AC from the filter 26aA to be discharged to the outside while preventing the polyester solution P from being discharged to the outside.

[0110] Differential pressure gauge 66A measures the differential pressure of filter 47. One end of differential pressure gauge 66A is connected to the first space 42, and the other end is connected to the second space 44. Differential pressure gauge 66A measures the differential pressure during the cleaning of filter 47. Differential pressure gauge 66A measures the pressure difference upstream and downstream of filter 47, specifically the pressure difference between the first space 62 and the second space 64. When the opening of filter 47 is blocked, pressure loss occurs. Therefore, the pressure difference measured by differential pressure gauge 66A is larger than when the opening of filter 47 is not blocked. Therefore, the pressure difference measured by differential pressure gauge 66A decreases as filter 47 is cleaned, decreasing from the beginning of cleaning towards the end of cleaning.

[0111] Polyester solution P from storage section 20 is supplied to filter 26aA. Polyester solution P flows to filter 47 and second space 44 housed in storage container 40. Impurities in polyester solution P passing through filter 26aA are captured by filter 47 and introduced into adsorption tower 26b. Additionally, during backwashing of filter 47, filter 26aA supplies washing liquid C from supply section 70. Washing liquid C flows to filter 47 and second space 44 housed in storage container 40. Washing liquid C flows from the outer periphery of filter 47 through the interior of filter 47 in the Y1 direction. The washing liquid AC after washing filter 47 is discharged to the outside through outlet pipe 67.

[0112] The control unit 30A controls the adjustment units 90, 92, and 94. The control unit 30A controls the opening and closing of the adjustment units 90, 92, and 94 based on the flow of the polyester solution P and the flow of the cleaning solution C. This allows the supply unit 70 to direct the cleaning solution C in the appropriate direction when cleaning the filter 47. For example, it can prevent the cleaning solution C from flowing into the inlet pipe 20c2 and into pipe 26b. Furthermore, for example, when the polyester solution P flows into pipe 20c1, it can prevent the polyester solution P from flowing into the outlet pipe 67.

[0113] Additionally, the control unit 30A can obtain the value shown by the differential pressure gauge 66A and notify a management terminal (not shown) of the timing for cleaning the filter 47. When the time for cleaning the filter 47 is reached, the control unit 30A can automatically switch the operating mode to cleaning mode, control the opening and closing state of the adjusting unit (opening and closing valve), and clean the filter 47. The control unit 30A can be equipped with a display unit to display the timing of filter cleaning and can also notify the operator's portable terminal. Furthermore, the operation mode switching of the control unit 30A can also be performed by the operator.

[0114] (Effect) In the second embodiment, the separation system includes a cleaning device. Also in the second embodiment, the first fluid C1 and the second fluid C2 are different liquids. The first fluid supply unit 71 supplies the first fluid C1 to the receiving container 60, removing the cured polyester from the filter 47 stored in the receiving container 60. Furthermore, after the first fluid supply unit 71 supplies the first fluid C1 to the receiving container 60, the second fluid supply unit 72 supplies the second fluid C2 to the receiving container 60. This also removes impurities adhering to the filter 47. Therefore, foreign matter can be removed reliably.

[0115] Furthermore, in the second embodiment, the filter is equipped with a differential pressure gauge. Therefore, the control unit can obtain the value shown by the differential pressure gauge and can notify the filter cleaning sequence. Thus, the operator can know the filter cleaning sequence in advance.

[0116] In the second embodiment, the washing device 100A may be installed before the adsorption tower 26b of the separation system 1A. For example, the washing device 100A may be installed between the storage section 20 of the separation system 1A and the adsorption tower 26b.

[0117] (Other examples) Next, other examples will be described. In these other examples, the point where the heating element 102 is connected to the storage container 60 differs from that in the first embodiment. Details common to the first embodiment in these other examples will be omitted.

[0118] Figure 8 is a schematic diagram of another example of a washing device. As shown in Figure 8, the washing device 100B of another example includes a storage container 60B, a supply unit 70B, a control unit 80, and a heating unit 102.

[0119] The storage container 60B is a container for storing the filter 47. The filter 47, which is to be cleaned, is used in the filter machine 26a and is covered with cured polyester and impurities. The storage container 60B stores the filter 47 along the Y direction. The storage container 60B stores multiple filters 47. The storage container 60B may also store the filter 47 together with the housing 48 containing the filter 47. Alternatively, the storage container 60B may store only one filter 47. The storage container 60B has a cover 61, a storage section 63, and a partition member 65. The storage container 60B is connected to an outlet pipe 67 and a supply section 70B. The storage container 60B is connected to a heating section 102.

[0120] The heating element 102 is connected to the storage container 60B. The heating element 102 heats the filter 47 stored in the storage container 60B to a predetermined temperature by heating the interior of the storage container 60B. The predetermined temperature is the temperature at which the cured polyester attached to the filter 47 can dissolve. Heating at this predetermined temperature melts the cured polyester. The predetermined temperature is preferably between 140°C and 300°C, more preferably between 160°C and 280°C, and even more preferably between 190°C and 250°C.

[0121] The supply unit 70B includes a first fluid supply unit 71B, a second fluid supply unit 72, and a third fluid supply unit 73. The second and third fluid supply units are the same as in the first embodiment, so their description is omitted.

[0122] The first fluid supply unit 71B includes a first fluid supply tank 71aB and a first fluid adjustment unit 71bB. The first fluid supply tank 71aB is connected to the receiving container 60B through a supply pipe 77. The first fluid supply tank 71aB stores the first fluid C1. The first fluid adjustment unit 71bB is provided on the supply pipe 77. The first fluid adjustment unit 71bB is a valve that controls the flow rate of the first fluid C1. The first fluid adjustment unit 71bB is, for example, an on / off valve. When the first fluid C1 is supplied, it is in an open state, allowing the first fluid C1 in the first fluid supply tank 71aB to be supplied to the receiving container 60B. When the first fluid C1 is not supplied, it is in a closed state, stopping the supply of the first fluid C1 in the first fluid supply tank 71aB to the receiving container 60B. However, the first fluid adjustment unit 71bB is not limited to an on / off valve and can be any mechanism capable of adjusting the supply of the first fluid C1 to the receiving container 60B. The first fluid supply unit 71B supplies the first fluid C1 to the receiving container 60B. The first fluid supply unit 71B supplies the first fluid C1 to the receiving container 60B to backwash the filter 47 stored in the receiving container 60B. The first fluid supply unit 71B supplies the first fluid C1 to the receiving container 60B to remove the cured polyester adhering to the filter 47 stored in the receiving container 60B.

[0123] (Other variations of the example) Next, a modified example of another example will be described. In the modified example of the washing device 100C, the heating unit 102 is connected to the first fluid supply unit 71C.

[0124] In other examples, the heating element 102 is located in the receiving container 60B, but it is not limited to this and may also be located in the supply unit 70C. Figure 9 is a schematic diagram of a modified example of the cleaning device. In this case, as shown in Figure 9, the heating element 102 is located in the first fluid supply unit 71C. Specifically, the heating element 102 is located in the first fluid supply tank 71aC, and by heating the inside of the first fluid supply tank 71aC, the first fluid C1 in the first fluid supply tank 71aC is heated to a predetermined temperature. The predetermined temperature is the temperature at which the cured polyester attached to the filter 47 can dissolve. The first fluid adjustment unit 71bC supplies the first fluid C1 heated by the heating element 102 to the receiving container 60. By heating the first fluid C1 to the predetermined temperature, the cured polyester attached to the filter can be dissolved.

[0125] (Effect) In other examples, the washing device is equipped with a heating element. In this case, the cured polyester adhering to the filter can be dissolved by heating, and the cured polyester can be removed from the filter.

[0126] In other examples, the first fluid C1 is not a liquid whose main component is triethylene glycol.

[0127] (Effects of the invention) The first embodiment of the cleaning apparatus of the present invention comprises: a storage container 60 for storing a filter 47 to which cured polyester and impurities are attached; a first fluid supply section 71 for supplying a first fluid C1 to remove the cured polyester from the filter 47 to the storage container 60; and a second fluid supply section 72 for supplying a second fluid C2 to remove impurities from the filter 47 to the storage container 60 after the first fluid supply section 71 supplies the first fluid C1 to the storage container 60.

[0128] According to the present invention, the first fluid supply unit supplies a first fluid to the receiving container, thereby removing the cured polyester from the filter. Furthermore, after the first fluid supply unit supplies the first fluid to the receiving container, the second fluid supply unit supplies a second fluid to the receiving container. This also removes impurities adhering to the filter. Therefore, foreign matter can be removed reliably.

[0129] The second-state cleaning device of the present invention is the same as the first-state cleaning device, wherein the first fluid supply unit 71 backwashes the filter 47 with a first fluid C1 in the receiving container 60, and the second fluid supply unit 72 backwashes the filter 47 with a second fluid C2 in the receiving container 60. This removes the cured polyester and impurities adhering to the filter.

[0130] The cleaning device of the third state of the present invention is a cleaning device of the first state or the second state, wherein the first fluid C1 is a liquid that dissolves polyester. This allows for the removal of cured polyester adhering to the filter.

[0131] The fourth-state cleaning device of the present invention is a cleaning device for any of the first to third states, and further includes a heating unit for a heated filter 47, wherein a first fluid supply unit 71 supplies a first fluid C1 to the heated filter 47. This allows for the removal of cured polyester and impurities adhering to the filter.

[0132] The fifth type of cleaning device of the present invention is a cleaning device for any of the first to fourth types of samples, and further includes a heating unit for heating a first fluid C1, and a first fluid supply unit 71 supplies the heated first fluid C1. This enables the removal of cured polyester and impurities adhering to the filter.

[0133] The cleaning device of the sixth state of the present invention is a cleaning device for any one of the first to fifth states, wherein the second fluid C2 is an acidic or alkaline liquid. This allows for the removal of impurities adhering to the filter.

[0134] The seventh-state cleaning device of the present invention is a cleaning device for any of the first to sixth states, and further includes a third fluid supply unit 73 that supplies the third fluid C3 of the cleaning filter 47 to the storage container 60 after the second fluid supply unit 72 supplies the second fluid C2 to the storage container 60. This allows the second fluid to remove impurities adhering to the cleaning filter.

[0135] The washing device of the eighth state of the present invention is the washing device of the seventh state, wherein the third fluid C3 is ion-exchanged water. This allows the second fluid, which removes impurities adhering to the filter, from the washing process.

[0136] The separation system for the ninth state sample of the present invention comprises: a separation system body for monomerizing polyester monomer contained in polyester raw material Pm to generate monomer; and a washing device for washing any one of the first to eighth state samples of the filter 47 of the separation system body.

[0137] According to the present invention, the first fluid supply unit supplies a first fluid to the receiving container, thereby removing the cured polyester from the filter. Furthermore, after the first fluid supply unit supplies the first fluid to the receiving container, the second fluid supply unit supplies a second fluid to the receiving container. This also removes impurities adhering to the filter. Therefore, foreign matter can be removed reliably.

[0138] The tenth aspect of the present invention is a cleaning method for cleaning a filter that is coated with cured polyester and impurities, comprising: a step of placing the filter 47 in a receiving container 60; a step of supplying a first fluid C1, which removes the cured polyester from the filter 47, to the receiving container 60; and a step of supplying a second fluid C2, which removes impurities from the filter 47, to the receiving container 60 after supplying the first fluid C1 to the receiving container 60.

[0139] According to the present invention, the first fluid supply unit supplies a first fluid to the receiving container, thereby removing the cured polyester from the filter. Furthermore, after the first fluid supply unit supplies the first fluid to the receiving container, the second fluid supply unit supplies a second fluid to the receiving container. This also removes impurities adhering to the filter. Therefore, foreign matter can be removed reliably.

[0140] While the embodiments of the present invention have been described above, the embodiments are not limited to these embodiments. Furthermore, the aforementioned constituent elements include those readily conceived by those skilled in the art, those that are substantially the same, and those of equivalent scope. Moreover, the aforementioned constituent elements can be appropriately combined. Furthermore, various omissions, substitutions, or modifications of the constituent elements can be made without departing from the spirit of the aforementioned embodiments.

[0141] 1: Separation System 12: Dissolution section 13: Solid-liquid separation section 14: Reaction solvent storage section 16: Reaction Section 18: Separation section 20: Storage Department 22: Discharge section 26: Remove part 26a: Filter machine 26b: Adsorption tower 30, 30A, 80: Control Unit 40, 60: Storage containers 41,61: cover 42,62: First Space 43,63: Storage Department 44,64: Second Space 45, 65: Partition components 47: Filter 48: Cover 66: Differential pressure gauge 70: Supply Department 71: First Fluid Supply Department 72: Second Fluid Supply Department 73: Third Fluid Supply Department 100, 100A, 100B, 100C: Washing devices 102: Heating section C1: First fluid C2: Second fluid C3: Third Fluid D, E: Monomers M: Reaction solvent P: Polyester solution Pd: Dissolution Pm: Polyester raw material R: Impurities R1: First impurity R2: Second impurity R3: Third impurity

Claims

1. A cleaning apparatus comprising: a storage container for storing a filter having cured polyester and impurities attached thereto; a first fluid supply section for supplying a first fluid that removes the cured polyester from the filter to the storage container; and a second fluid supply section for supplying a second fluid that removes the impurities from the filter to the storage container after the first fluid supply section supplies the first fluid to the storage container.

2. The cleaning apparatus as described in claim 1, wherein the first fluid supply unit backwashes the filter in the aforementioned storage container using the first fluid; and the second fluid supply unit backwashes the filter in the aforementioned storage container using the second fluid.

3. The cleaning apparatus as described in claim 1 or 2, wherein the aforementioned first fluid is a liquid that dissolves the aforementioned polyester.

4. The cleaning apparatus described in claim 1 or 2 further includes a heating unit for heating the aforementioned filter; the aforementioned first fluid supply unit supplies the aforementioned first fluid to the heated aforementioned filter.

5. The cleaning apparatus described in claim 1 or 2 further includes a heating unit for heating the aforementioned first fluid; the aforementioned first fluid supply unit supplies the heated first fluid.

6. The cleaning apparatus as described in claim 1 or 2, wherein the aforementioned second fluid is an acidic or alkaline liquid.

7. The cleaning apparatus described in claim 1 or 2 is further equipped with a third fluid supply unit that supplies a third fluid for cleaning the filter to the aforementioned storage container after the aforementioned second fluid supply unit supplies the aforementioned second fluid to the aforementioned storage container.

8. The cleaning apparatus as described in claim 7, wherein the aforementioned third fluid is ion-exchanged water.

9. A separation system comprising: a separation system body for monomerizing polyester contained in a polyester raw material to generate monomers; and a cleaning device as described in claim 1 or 2 for cleaning the aforementioned filter of the separation system body.

10. A cleaning method for cleaning a filter with adhered cured polyester and impurities, comprising: a step of placing the filter in a receiving container; a step of supplying a first fluid, which removes the cured polyester from the filter, to the receiving container; and a step of supplying a second fluid, which removes the impurities from the filter, to the receiving container after supplying the first fluid to the receiving container.

Images