Decolorization device, decolorization system, and decolorization method

Abstract

The present invention efficiently performs decolorization treatment. A decolorization device 1 comprises a treatment tank 2, a drum 30 and a rotation support mechanism 35 for the drum 30, and a tank part 5. The treatment tank 2 can receive a plurality of workpieces and stores a decolorization liquid Q. The drum 30 provided in the treatment tank 2 is rotated by the rotation support mechanism 35, and the decolorization liquid Q stored in the treatment tank 2 is thereby agitated. The tank part 5 stores the decolorization liquid Q and is connected to the treatment tank 2 via a flow passage 6. The tank part 5 has a first tank 51 and a second tank 52. The flow path 6 has a supply path 61 for the decolorization liquid Q that connects the first tank 51 and the second tank 52 to the treatment tank 2 directly or via another tank, and a discharge path 62 for the decolorization liquid Q that connects the treatment tank 2 to the first tank 51.

Description

Decolorization Device, Decolorization System, and Decolorization Method

[0001] The present invention relates to a decolorization device, a decolorization system, and a decolorization method.

[0002] For a workpiece containing fibers such as polyester, dyes can be sublimated and transferred for dyeing. A technique has been proposed to make the workpiece recyclable by decolorizing the dyed workpiece (for example, Patent Document 1). For example, after immersing the workpiece in a decolorizing solution and heating it, the workpiece is pressed against an absorber. As a result, the dye moves from the workpiece to the absorber, enabling the decolorization of the workpiece.

[0003] Japanese Patent Application Laid-Open No. 2007-224128

[0004] However, when decolorizing the workpieces one by one as in Patent Document 1, the process takes time and may affect the efficiency of the decolorization process.

[0005] There is a need to decolorize the workpieces in batches to improve the efficiency of the decolorization process.

[0006] A decolorization device according to an aspect of the present invention is: (1) a decolorization device for decolorizing a workpiece containing fibers dyed or colored with a dye, which can accommodate a plurality of the workpieces, a treatment tank for storing a decolorizing solution, a stirring unit for stirring the decolorizing solution stored in the treatment tank, and a tank unit for storing the decolorizing solution and connected to the treatment tank via a flow path. The tank unit has a first tank and a second tank, and the flow path has a supply path for the decolorizing solution connecting the first tank and the second tank to the treatment tank directly or via another tank, and a discharge path for the decolorizing solution connecting the treatment tank to the first tank.

[0007] (2) In the decolorization device of (1) above, the tank unit has a third tank, the discharge path connects the treatment tank to the third tank, and a separation unit is provided for separating the dye from the decolorizing solution stored in the third tank and supplying it to the second tank.

[0008] (3) In the decolorization apparatus of (1) or (2) above, the tank section has a heating section for heating the stored decolorization liquid and a fourth tank connected to the second tank, and the supply passage connects the fourth tank to the processing tank.

[0009] (4) In any of the decolorization apparatuses described in (1) to (3) above, at least one of the first tank and the second tank has a heating section for heating the decolorization liquid, a cooling device for cooling the decolorization liquid that has been heated and turned into fumes in at least one of the first tank and the second tank, and a return channel for supplying the decolorization liquid cooled by the cooling device to the second tank.

[0010] (5) In any of the decolorization apparatuses described in (4) above, the processing tank has a heating section for heating the decolorization liquid, and comprises a tank section, a cooling device for cooling the decolorization liquid which has been heated in the processing tank and turned into a fume, a return channel for supplying the decolorization liquid cooled by the cooling device to a second tank, and a reduced pressure tank provided in the return channel.

[0011] (6) In any of the decolorization apparatuses described in (1) to (5) above, the processing tank has a drying section for drying the workpiece.

[0012] (7) In any of the decolorization apparatuses described in (1) to (6) above, the tank section is located below the processing tank, and the supply passage is provided with a pump that sucks up the decolorization liquid stored in the tank section and supplies it to the processing tank.

[0013] (8) In the decolorization apparatus of (7) above, the discharge passage is provided as a branch passage of the supply passage and comprises a first branch passage connecting the upstream side of the pump and the treatment tank of the supply passage, and a second branch passage connecting the downstream side of the pump and the tank section.

[0014] A decolorization system in one aspect of the present invention is a decolorization system comprising: (9) a decolorization device for decolorizing a workpiece containing fibers dyed or colored with a dye; and a control device for controlling the decolorization device, wherein the decolorization device comprises: a processing tank into which a plurality of the workpieces can be loaded and for storing a decolorization liquid; a stirring unit for stirring the decolorization liquid stored in the processing tank; and a tank section for storing the decolorization liquid and connected to the processing tank via a flow passage, wherein the tank section has a first tank and a second tank; the flow passage has a supply passage for the decolorization liquid connecting the first tank and the second tank to the processing tank directly or via another tank; and a discharge passage for the decolorization liquid connecting the processing tank to the first tank; and the control device provides the decolorization device with a first decolorization process, which involves supplying the decolorization liquid from the first tank to the processing tank into which the workpieces are loaded, and stirring the decolorization liquid with the stirring unit. The system is configured to perform a first discharge process, which involves discharging the decolorizing liquid used in the first decolorizing process from the processing tank; a second decolorizing process, which involves supplying the decolorizing liquid from the second tank to the processing tank and stirring the decolorizing liquid with the stirring unit; and a second discharge process, which involves discharging the decolorizing liquid used in the second decolorizing process from the processing tank to the first tank.

[0015] (10) In the decolorization system of (9) above, the tank section has a third tank, the discharge passage connects the processing tank to the third tank, the decolorization device includes a separation section that separates the dye from the decolorization liquid stored in the third tank and supplies it to the second tank, and the control device causes the decolorization device to discharge the decolorization liquid from the processing tank to the third tank in the first discharge process.

[0016] (11) In the decolorization system of (9) or (10) above, the tank section has a fourth tank which is connected to the second tank and is provided with a heating section for heating the decolorization liquid, the supply passage connects the fourth tank to the processing tank, and the control device causes the decolorization device to supply the decolorization liquid from the second tank to the fourth tank during the first decolorization process, heat the decolorization liquid in the fourth tank, and supply the heated decolorization liquid from the fourth tank to the processing tank during the second decolorization process.

[0017] (12) In any of the decolorization systems described in (9) to (10), the second tank has a heating section for heating the decolorizing liquid, and the control device causes the decolorization apparatus to heat the decolorizing liquid in the second tank during the first decolorization process, and to supply the heated decolorizing liquid from the second tank to the processing tank during the second decolorization process.

[0018] (13) In any of the decolorization systems described in (9) to (12), the treatment tank has a drying section for drying the workpiece, and the control device causes the decolorization device to perform a drying process in which the drying section dries the workpiece in the treatment tank after the second discharge process.

[0019] A decolorization method in one aspect of the present invention is (14) a decolorization method in a decolorization apparatus for decolorizing a workpiece containing fibers dyed or colored with a dye, the decolorization apparatus comprising: a processing tank into which a plurality of the workpieces can be loaded and for storing a decolorizing liquid; a stirring unit for stirring the decolorizing liquid stored in the processing tank; a tank section for storing the decolorizing liquid and connected to the processing tank via a flow passage, the tank section having a first tank and a second tank, the flow passage having a supply passage for the decolorizing liquid connecting the first tank and the second tank to the processing tank directly or via another tank, and a discharge passage for the decolorizing liquid connecting the processing tank to the first tank, a first decolorization process comprising: supplying the decolorizing liquid from the first tank to the processing tank into which the workpieces have been loaded and stirring the decolorizing liquid with the stirring unit; and a first discharge process for discharging the decolorizing liquid used in the first decolorization process from the processing tank. The process includes a second decolorization process in which the decolorizing liquid is supplied from the second tank to the processing tank and stirred by the stirring unit, and a second discharge process in which the decolorizing liquid used in the second decolorization process is discharged from the processing tank to the first tank.

[0020] According to the present invention, the efficiency of the decolorization process can be increased by decolorizing the workpieces in batches.

[0021] This is a schematic diagram showing the configuration of a decolorizing apparatus and decolorizing system according to an embodiment. This is a schematic cross-sectional view along line A-A in Figure 1. This is a diagram showing the configuration of the tank section and how it is connected to the processing tank. This is a chart showing an example of the processing flow of the decolorizing apparatus in chronological order. This is a diagram showing the configuration of the decolorizing apparatus according to Modification 1. (a) is a diagram showing the flow of decolorizing liquid in the supply path A when supplying decolorizing liquid to the processing tank, and (b) is a diagram showing the flow of decolorizing liquid in the discharge path when discharging decolorizing liquid from the processing tank. This is a chart showing an example of the processing flow of the decolorizing apparatus according to Modification 1 in chronological order.

[0022] Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a schematic diagram showing the configuration of a decolorizing apparatus and decolorizing system according to an embodiment. Figure 2 is a schematic diagram of a cross-section along line A-A in Figure 1. In the following description, the positional relationships will be described with reference to the X, Y, and Z directions shown in Figure 1. The Z direction is the direction along the vertical line (direction of gravity) in the installed state of the decolorizing apparatus, and is the up and down direction on the plane of the paper in Figure 1. The X and Y directions are the directions along the horizontal direction, and are perpendicular to the Z direction. In this embodiment, the width direction of the decolorizing apparatus (left and right direction in Figure 1) will be described as the X direction, and the front and rear direction of the decolorizing apparatus (left and right direction in Figure 2) will be described as the Y direction. Furthermore, one side in the X direction (left side in Figure 1) will be described as the X1 side, and the other side (right side in Figure 1) will be described as the X2 side. Note that in the following description, when we say "along the X, Y, or Z direction", we are not limited to cases where it is perfectly parallel to the X, Y, or Z direction, but also include cases where it is slightly inclined with respect to the X, Y, or Z direction.

[0023] The decolorization apparatus 1 according to this embodiment decolorizes a workpiece containing fibers dyed or colored with a sublimable dye (dye) using a decolorization solution. The decolorization system 10 includes the decolorization apparatus 1 and a control device 80 that controls the decolorization apparatus 1. <Workpiece> The workpiece contains fibers that can be dyed or colored with a sublimable dye. The fibers are, for example, polyester fibers or nylon fibers. The workpiece may also include, for example, knits or fabrics formed from polyester yarn, nylon yarn, polyester blended yarn, or nylon blended yarn. Examples of fibers to be blended with polyester or nylon include cotton, polyurethane, rayon, linen, etc., and blends of polyester and nylon are also included. The blending ratio of polyester or nylon to other yarns (polyester or nylon: other yarns to be blended) can be set to any ratio in the range of, for example, 50:50 to 90:10. The workpiece can be any article that uses the above-mentioned fibers in at least part of it. The work can include, for example, clothing such as T-shirts, fabric accessories such as bags and scarves, decorative panels, advertising banners, tapestries, etc.

[0024] <Sublimation Dyes> Sublimation dyes are not limited to any specific type, as long as the pigment they contain can be incorporated into the gaps between the molecular chains of polyester or nylon fibers to dye or color the fibers. Sublimation dyes are especially preferred if they are dyes that are sublimable, such as sublimation dyes or disperse dyes. Examples of dyeing methods using sublimation dyes include sublimation transfer printing, direct sublimation printing, exhaust dyeing, or thermosol dyeing.

[0025] <Decolorizing Solution> The decolorizing solution is heated and used in the decolorizing apparatus 1. The decolorizing solution is not limited to any particular type, as long as it (i) has a boiling point that exceeds the heating temperature in the decolorizing apparatus 1, (ii) can move sublimable dyes into the decolorizing solution, and (iii) does not have a significant adverse effect on the workpiece. Adverse effects to be avoided on the workpiece include, for example, changes in the color of the fibers themselves that make up the workpiece, deterioration of the texture of the fibers, and shrinkage of the fibers.

[0026] Examples of organic solvents include dimethyl succinate (boiling point: 200°C), dimethyl glutarate (boiling point: 214°C), dimethyl adipate (boiling point: 245°C), ethyl acetate dioxol (boiling point: 218°C), 3-methoxy-N,N-dimethylpropanamide (boiling point: 215°C), benzyl benzoate (boiling point: 325°C), diethylene glycol (boiling point: 245°C), trichloroethane (boiling point: 74°C), dimethyl sulfoxide (boiling point: 189°C), acetone (boiling point: 56°C), methyl ethyl ketone (boiling point: 80°C), and propylene glycol monomethyl ether acetate (boiling point: 146°C). The decolorizing solution may also be prepared by diluting these components with water or other organic solvents. Additives such as surfactants and fluorescent whitening agents may also be added.

[0027] <Processing Flow in the Decolorizing Apparatus> In this embodiment, as an example of processing by the decolorizing apparatus 1, the following will be described: (i) decolorization treatment (first decolorization treatment), (ii) rinsing treatment (second decolorization treatment), and (iii) drying treatment. (i) In the decolorization treatment, the sublimable dye is extracted and separated from the gaps in the fibers of the workpiece. (ii) In the rinsing treatment, the workpiece from which the sublimable dye has been separated is rinsed. (iii) In the drying treatment, the decolorizing liquid absorbed by the workpiece is dried.

[0028] (i) Decolorization process In the decolorization process, the workpiece dyed or colored with a sublimable dye is immersed in a decolorization solution Q heated to a temperature of T1 or higher and agitated. This widens the gaps between the fibers in the workpiece, and the sublimable dye that was held in the fibers escapes from the gaps between the fibers and moves into the decolorization solution Q.

[0029] The temperature T1 should preferably be above the temperature at which the gaps between the molecular chains of the fibers contained in the workpiece loosen, making it easier for the sublimable dye to escape (hereinafter referred to as the "fiber opening temperature"). For example, the temperature T1 of the decolorizing solution Q should be above the glass transition temperature of the polyester or nylon fibers contained in the workpiece. Furthermore, if the workpiece is dyed by exhaust dyeing, it is desirable that the temperature T1 of the decolorizing solution Q be above the dyeing temperature of the workpiece. In particular, if the workpiece contains polyester fibers, the temperature T1 of the decolorizing solution Q can be 110°C or higher, 115°C or higher, 120°C or higher, 125°C or higher, or 130°C or higher. Furthermore, if the workpiece contains nylon fibers, the temperature T1 of the decolorizing solution Q can be 70°C or higher, 80°C or higher, 90°C or higher, or 100°C or higher. Furthermore, it is desirable that the temperature T1 of the decolorizing solution Q be lower than the boiling point of the decolorizing solution Q.

[0030] (ii) Rinsing Treatment In the rinsing treatment, the decolorized workpiece is immersed in a decolorizing solution Q heated to a temperature T2 lower than temperature T1 and agitated. Some of the sublimable dye that escaped from the gaps in the workpiece during the decolorization treatment remains on the surface of the workpiece. During the rinsing treatment, the remaining sublimable dye moves into the decolorizing solution. In addition, by immersing the workpiece in a decolorizing solution at a temperature T2 lower than temperature T1, the temperature of the workpiece decreases, the gaps between the fibers of the workpiece narrow again, and the re-entry of sublimable dye into the gaps between the fibers is reduced. It is desirable that the temperature T2 of the decolorizing solution in the rinsing treatment be, for example, 140°C or higher. This allows for further decolorization of parts that were not completely decolorized during the decolorization treatment, and prevents the dirty decolorizing solution Q adhering to the workpiece from soaking into the workpiece again, thereby increasing the efficiency of rinsing.

[0031] (iii) Drying process: In the drying process, the rinsed workpiece is heated to evaporate any remaining decolorizing solution within the workpiece. This completes the decolorization of the workpiece, making it reusable.

[0032] <Outline Configuration of the Decolorization Apparatus> As shown in Figure 1, the decolorization apparatus 1 includes a processing tank 2. In this embodiment, the decolorization apparatus 1 can perform the decolorization process, rinsing process, and drying process described above in a single processing tank 2 in a continuous manner. Furthermore, the processing tank 2 can accommodate multiple workpieces, and the decolorization of workpieces can be performed in batches. The decolorization apparatus 1 also includes a tank section 5 for storing the decolorization liquid Q used in the processing tank 2.

[0033] The processing tank 2 is housed inside a highly airtight case 4, and is designed to reduce leakage of the decolorizing liquid Q that is heated and vaporized in the processing tank 2. In Figure 1, the front part 45 of the case 4 (see Figure 2) is omitted, and the processing tank 2 housed inside the case 4 is shown exposed. The case 4 is supported by a frame 49 and is positioned at a distance in the Z direction from the mounting surface FS. The tank section 5 is located in the space below the case 4.

[0034] Case 4 has a bottom portion 41 and an upper portion 42 that extend along the X and Y directions. Case 4 also has a side portion 43 on the X1 side (left side in the figure) and a side portion 44 on the X2 side that connect the ends of the bottom portion 41 and the upper portion 42 in the X direction. The side portions 43 and 44 extend along the Y and Z directions. As shown in Figure 2, Case 4 also has a front portion 45 that connects the front ends of the bottom portion 41 and the upper portion 42 in the Y direction, and a rear portion 46 that connects the rear ends. The front portion 45 and the rear portion 46 extend along the X and Z directions. Here, the front portion 45 is inclined towards the rear in the Y direction as it moves from the bottom to the top in the Z direction. The user loads and retrieves workpieces into and out of the processing tank 2 from the front of the decolorization device 1. Because the front portion 45 is inclined, the user can load and retrieve workpieces without bending down too much. A door 47, which can be opened toward the front, is provided in the center of the front section 45. By opening the door 47, the inside and outside of the case 4 are connected.

[0035] As shown in Figures 1 and 2, the processing tank 2 is box-shaped. In Figure 1, the position of the drum 30 inside the processing tank 2 and the liquid level of the decolorizing solution Q are shown by dashed lines. The processing tank 2 is positioned at a distance in the Z direction from the bottom surface 41 of the case 4 by a support portion 48 located on the bottom surface 41 of the case 4. As shown in Figure 1, the processing tank 2 has a bottom wall portion 21 and an upper wall portion 22 that extend along the X and Y directions. The processing tank 2 has a side wall portion 23 that connects the X1 side end of the bottom wall portion 21 and the upper wall portion 22 in the X direction, and a side wall portion 24 that connects the X2 side end. The side wall portions 23 and 24 extend along the Y and Z directions. Also, as shown in Figure 2, the processing tank 2 has a front wall portion 26 that connects the front end of the bottom wall portion 21 and the upper wall portion 22 in the Y direction, and a rear wall portion 27 that connects the rear end. The front wall portion 26 and the rear wall portion 27 extend along the X and Z directions, respectively.

[0036] The processing tank 2 is positioned at an incline. Specifically, the processing tank 2 is inclined so that it is located downward in the Z direction as it moves from the front wall portion 26 to the rear wall portion 27. The front portion 45 of the case 4 is at an inclination angle that matches the processing tank 2. The front wall portion 26 is located near the front portion 45 of the case 4. The front wall portion 26 is provided with a door portion 28 that can be opened toward the front. The door portion 28 is located in an area that overlaps with the door portion 47 of the case 4 when viewed from the Y direction. The door portion 28 can be provided in a size smaller than the door portion 47, for example. When the user puts a workpiece to be decolorized into the processing tank 2, or when retrieving a decolorized workpiece from the processing tank 2, the user opens the door portion 47 of the case 4 and the door portion 28 of the processing tank 2. When the user operates the decolorization device 1 to decolorize a workpiece, the user closes the door portion 47 and the door portion 28. By providing a double-door structure for the case 4 and the processing tank 2, the airtightness of the processing tank 2 can be improved. Alternatively, instead of providing door sections 28 and 47 on the front wall 26 and the front section 45 respectively, a single integrated door section may be provided.

[0037] The processing tank 2 is connected via a flow passage 6 to a tank section 5 (see Figure 1) located in the space below the case 4. Figure 3 shows the configuration of the tank section 5 and how it is connected to the processing tank 2. As shown in Figure 3, the decolorizing liquid Q is supplied from the tank section 5 to the inside of the processing tank 2 via the flow passage 6. The decolorizing liquid Q used in the processing tank 2 is discharged to the tank section 5 via the flow passage 6. The detailed configuration of the tank section 5 will be described later. As shown in Figure 2, the decolorizing liquid Q supplied from the tank section 5 is stored in the processing tank 2. As mentioned above, the processing tank 2 is arranged at an incline, so the water level of the decolorizing liquid Q becomes deeper towards the rear of the processing tank 2. A heating device 71 (heating section), such as an IH, is provided on the bottom wall 21 of the processing tank 2. By operating the heating device 71, the decolorizing liquid Q stored in the processing tank 2 is heated.

[0038] A drum 30 is placed inside the processing tank 2. The drum 30 is cylindrical in shape and has openings 32 and 33 at both ends. The outer circumferential surface 31 of the drum 30 is positioned along the Y direction inside the processing tank 2. The openings 32 and 33 at both ends of the drum 30 are positioned towards the front and rear in the Y direction, respectively. The outer circumferential surface 31 of the drum 30 is positioned at intervals from the upper wall 22 and the bottom wall 21 of the processing tank 2. The drum 30 is positioned so that its central axis C is inclined along the inclination angle of the processing tank 2. That is, the central axis C of the drum 30 is inclined to be located downward in the Z direction as it moves from the front opening 32 to the rear opening 33.

[0039] The drum 30 is supported by a rotation support mechanism 35 so as to be rotatable around a central axis C. The outer circumferential surface 31 of the drum 30 is provided with a plurality of holes 34 that penetrate radially through the central axis C. The decolorizing liquid Q stored at the bottom of the processing tank 2 passes through the holes 34 and is also stored inside the drum 30.

[0040] When viewed from the Y direction, the front opening 32 of the drum 30 overlaps at least partially with the door 47 of the case 4 and the door 28 of the processing tank 2. This allows the user to open the doors 47 and 28 and load workpieces into the interior surrounded by the outer circumferential surface 31 of the drum 30. Workpieces loaded into the drum 30 are immersed in the decolorizing liquid Q. By rotating the drum 30 with the rotation support mechanism 35, the workpieces are agitated in the decolorizing liquid Q. In other words, the drum 30 and the rotation support mechanism 35 function as agitation units. The processing tank 2 and the drum 30 are set to a size that can accommodate multiple workpieces.

[0041] A blower duct 72 is attached to the upper wall 22 of the processing tank 2. The blower duct 72 supplies air from a fan (not shown) into the processing tank 2 during the drying process. A heat source 73, such as an electric heating element, is located inside the blower duct 72. When the heat source 73 is driven, the air from the fan is heated by the heat source 73 and supplied to the processing tank 2 as warm air. When the heat source 73 is not driven, the air from the fan is supplied to the processing tank 2 as cold air. The blower duct 72 and the heating device 71 of the processing tank 2 described above function as a drying unit that dries the workpieces contained in the processing tank 2 during the drying process.

[0042] An exhaust duct 74 is attached to the rear wall 27 of the processing tank 2. As shown in Figure 3, the exhaust duct 74 is connected to a cooling device 75. The cooling device 75 can be, for example, a cooling fan, a condenser, an intercooler, etc. The cooling device 75 can be, for example, placed inside the case 4 (see Figure 2). The cooling device 75 is connected to an external tank 76 located outside the case 4. In the processing tank 2, when the decolorizing liquid Q is heated, air containing fumes F from the decolorizing liquid Q is generated. The fumes F from the decolorizing liquid Q contained in the air are exhausted outside the processing tank 2 via the exhaust duct 74 and are cooled by the cooling device 75, returning to a liquid state. The decolorizing liquid Q that has returned to a liquid state is stored in the external tank 76. The decolorizing liquid Q stored in the external tank 76 can be reused for decolorizing treatment of the decolorizing liquid Q.

[0043] As shown in FIG. 3, the tank section 5 includes a plurality of tanks capable of storing the decoloring liquid Q. The tank section 5 includes, as an example, four tanks: a first tank 51, a second tank 52, a third tank 53, and a fourth tank 54. The first tank 51 stores the decoloring liquid Q used for the decoloring treatment. The decoloring liquid Q used for the rinsing treatment is discharged from the treatment tank 2 to the first tank 51. The second tank 52 stores the decoloring liquid Q used for the rinsing treatment. The second tank 52 stores a new decoloring liquid Q or a regenerated decoloring liquid Q. The third tank 53 stores the decoloring liquid Q discharged from the treatment tank 2 after the decoloring treatment and to be regenerated. The fourth tank 54 is connected to the second tank 52 by a supply line 68. By opening the valve V2 provided in the supply line 68, the decoloring liquid Q is supplied from the second tank 52 to the fourth tank 54. During the decoloring treatment, the decoloring liquid Q used for the rinsing treatment is supplied from the second tank 52 to the fourth tank 54. The fourth tank 54 preheats the decoloring liquid Q used for the next rinsing treatment during the decoloring treatment.

[0044] The flow passage 6 connecting the treatment tank 2 and the tank section 5 includes a supply line 61 for supplying the decoloring liquid Q from the tank section 5 to the treatment tank 2 and a discharge line 62 for discharging the decoloring liquid Q from the treatment tank 2 to the tank section 5. The supply line 61 connects the first tank 51 and the fourth tank 54 to the treatment tank 2. By opening and closing the valves V1 and V3 provided in the supply line 61, the tank for supplying the decoloring liquid Q can be switched between the first tank 51 and the fourth tank 54. A pump P is provided in the supply line 61. The pump P is arranged such that the suction port Pa is on the side of the first tank 51 and the fourth tank 54, and the discharge port Pb is on the side of the treatment tank 2. The pump P sucks the decoloring liquid Q stored in the first tank 51 or the fourth tank 54 and discharges it toward the treatment tank 2.

[0045] The discharge passage 62 connects the processing tank 2 to the first tank 51 and the third tank 53. By opening and closing valves V4 and V5 provided in the supply passage 61, the tank from which the decolorizing liquid Q is discharged can be switched to the first tank 51 or the third tank 53. The tank section 5 is located below the case 4 that houses the processing tank 2, as described above (see Figure 1). That is, the liquid level of the decolorizing liquid Q stored in the processing tank 2 is located above the liquid level of the decolorizing liquid Q stored in the first tank 51 to the fourth tank 54 of the tank section 5 in the Z direction. As a result, it is possible to discharge the decolorizing liquid Q from the processing tank 2 to the first tank 51 or the third tank 53 using the difference in water head, even without providing a pump in the discharge passage 62. Alternatively, a pump may be provided in the discharge passage 62 to allow the decolorizing liquid Q to be discharged more quickly.

[0046] The third tank 53 and the fourth tank 54 are provided with heating devices 531 and 541 (heating sections) for heating the decolorizing liquid Q stored therein. In the third tank 53 and the fourth tank 54, similar to the treatment tank 2, the decolorizing liquid Q is heated and evaporated, generating air containing fumes F from the decolorizing liquid Q. The fumes F from the decolorizing liquid Q generated in the third tank 53 and the fourth tank 54 are recovered by a cooling device 56 via a recovery duct 55. The cooling device 56 can be, for example, a cooling fan, a condenser, an intercooler, etc. The fumes F from the decolorizing liquid Q are cooled by the cooling device 56 and return to a liquid state. The decolorizing liquid Q, now back into a liquid state, is supplied to the second tank 52 via a return channel 57. The cooling device 56 can be located inside or outside the case 4. Note that the cooling device 56 may be provided separately from the cooling device 75 described above, or they may be the same.

[0047] The decolorizing liquid Q stored in the third tank 53 is used in the rinsing process and the decolorizing process, and a large amount of sublimable dye is dissolved therein. When the decolorizing liquid Q in the third tank 53 is heated to become fumes F, the sublimable dye is separated from the decolorizing liquid Q. By returning the fumes F of the decolorizing liquid Q from which the sublimable dye has been separated to a liquid state with the cooling device 56, the decolorizing liquid Q can be regenerated. That is, the heating device 531 and the cooling device 56 of the third tank 53 function as a separating unit that separates the sublimable dye from the decolorizing liquid Q stored in the third tank 53.

[0048] As shown in FIG. 1, outside the case 4, the electrical components 8 of the decolorizing device 1 are arranged. The electrical components 8 include, for example, electrical equipment that supplies power to the decolorizing device 1 and electronic equipment that functions as a control device 80 of the decolorizing device 1. By arranging the electrical components 8 separately from the processing tank 2 and the tank unit 5 in which the decolorizing liquid Q is stored, contact between the decolorizing liquid Q and the electrical components 8 can be avoided. The control device 80 is electrically connected to each part of the decolorizing device 1 via wiring (not shown). The control device 80 can be composed of an electronic device including a processor such as a CPU (Central Processing Unit), a storage device such as a ROM (Read Only Memory), a RAM (Random Access Memory), a HDD (Hard Disk Drive), a SSD (Solid State Drive), an input device such as a keyboard, a mouse, a touch panel, a physical switch, and a display device such as a display. The control device 80 controls the operation of the decolorizing device 1 by executing a program stored in the storage device.

[0049] In this embodiment, decolorization, rinsing, and drying are performed consecutively in a single processing tank 2. As described above, in the decolorization and rinsing processes, the workpiece is immersed in heated decolorizing solution Q and agitated. This loosens the gaps in the molecular chains of the fibers contained in the workpiece, and the pigment of the sublimable dye held in the fibers moves to the decolorizing solution Q, thereby decolorizing the workpiece. That is, the decolorizing solution Q used in the decolorization or rinsing process contains the sublimable dye separated from the workpiece. Here, in the rinsing process performed after the decolorization process, it is desirable to use a new decolorizing solution Q or a regenerated decolorizing solution Q. This reduces the adhesion of the sublimable dye dissolved in the decolorizing solution Q to the surface of the workpiece. On the other hand, in the decolorization process performed before the rinsing process, a decolorizing solution Q in which some of the dye has dissolved can also be used.

[0050] In this embodiment, the decolorization apparatus 1 uses either new or recycled decolorization solution Q during the rinsing process. In the decolorization process performed before the rinsing process, the decolorization apparatus 1 uses the decolorization solution Q used in the rinsing process. The decolorization apparatus 1 then recycles the decolorization solution Q used in the decolorization process and reuses it in the rinsing process. To enable this operation, the decolorization apparatus 1 is equipped with multiple tanks (first tank 51 to fourth tank 54) in the tank section 5. The control device 80 of the decolorization system 10 (see Figure 1) controls the supply and discharge of decolorization solution Q between the processing tank 2 of the decolorization apparatus 1 and the first tank 51 to fourth tank 54.

[0051] Figure 4 is a time-series chart showing an example of the processing flow of the decolorization apparatus 1. Figure 4 shows a time chart starting from the point when the user places the workpiece to be decolorized into the processing tank 2 and inputs a processing start instruction to the control device 80 (see Figure 1). The control device 80 controls the decolorization apparatus 1 to perform the processing shown in Figure 4. At the start of processing by the decolorization apparatus 1, decolorization liquid Q is stored in at least the first tank 51 and the second tank 52. In addition, new decolorization liquid Q or recycled decolorization liquid Q is stored in the second tank 52. The decolorization liquid Q stored in the first tank 51 is new decolorization liquid Q, recycled decolorization liquid Q, or decolorization liquid Q used in the rinsing process.

[0052] As shown in Figure 4, the decolorization device 1 opens valve V1 of the supply passage 61 and drives pump P to supply decolorizing liquid Q in amount A1 from the first tank 51 to the processing tank 2 (step S01). Amount A1 can be the amount of decolorizing liquid Q used in the decolorization process. When decolorizing liquid Q is supplied into the processing tank 2, the workpieces placed in the processing tank 2 are immersed in the decolorizing liquid Q. In parallel with step S01, the decolorization device 1 opens valve V2 of the supply passage 68 and supplies decolorizing liquid Q in amount A2 from the second tank 52 to the fourth tank 54 (step S02). Amount A2 can be determined by taking into account the amount A3 of decolorizing liquid Q used in the rinsing process. For example, amount A2 can be the amount A3 of decolorizing liquid Q used in the rinsing process plus the amount evaporated due to heating in the fourth tank 54.

[0053] Once the decolorization device 1 has finished supplying the decolorization liquid Q to the processing tank 2, it activates the heating device 71 (see Figure 2) of the processing tank 2 to heat the decolorization liquid Q (step S03). The decolorization device 1 heats the decolorization liquid Q until its temperature reaches temperature T1 or higher. In parallel with step S03, the decolorization device 1 activates the heating device 541 (see Figure 3) of the fourth tank 54 to preheat the decolorization liquid Q used for rinsing (step S04, heating treatment). The decolorization device 1 heats the decolorization liquid Q until its temperature reaches temperature T2 or higher.

[0054] The decolorization device 1 performs the decolorization process (step S05) once the heating of the decolorization liquid Q stored in the processing tank 2 is complete. Specifically, the decolorization device 1 rotates the drum 30 (see Figure 2) in the processing tank 2 using the rotating support mechanism 35 to agitate the workpiece. When the workpiece is heated, the gaps between the fibers contained in the workpiece widen. Also, when the workpiece is agitated, the sublimable dye that was held in the fibers escapes from the gaps between the fibers and moves more easily into the decolorization liquid Q.

[0055] When the decolorization process is complete, the decolorization device 1 opens the valve V5 of the discharge passage 62 and discharges the decolorization liquid Q from the processing tank 2 to the third tank 53 (step S06, first discharge process). When the decolorization liquid Q is discharged to the third tank 53, the decolorization device 1 performs a regeneration process on the decolorization liquid Q (step S07). The regeneration process in step S07 is performed in parallel with the processing in the processing tank 2 from step S08 onwards. The decolorization device 1 operates the heating device 531 (see Figure 3) of the third tank 53 to heat the decolorization liquid Q. When the heated decolorization liquid Q becomes fumes F, the sublimable dyes dissolved in the decolorization liquid Q are separated. The decolorization liquid Q that has become fumes F is cooled by the cooling device 56 and returns to a liquid state. The decolorization liquid Q that has returned to a liquid state is sequentially supplied to the second tank 52 via the reflux passage 57. Sublimable dyes remaining in the third tank 53 can be removed, for example, by washing the third tank 53.

[0056] The decolorizing device 1 opens the valve V3 of the supply passage 61 and drives the pump P to supply a decolorizing liquid Q in quantity A3 from the fourth tank 54 to the processing tank 2 (step S08). Once the supply of decolorizing liquid Q is complete, the control device 80 causes the decolorizing device 1 to perform a rinsing process (step S09). Specifically, the control device 80 rotates the drum 30 (see Figure 2) in the processing tank 2 using the rotation support mechanism 35 to agitate the workpiece. Sublimable dyes that have escaped from the gaps in the workpiece during the decolorizing process and remain on the surface of the workpiece move into the decolorizing liquid Q. In addition, by immersing the workpiece in the decolorizing liquid Q at a temperature T2 lower than the temperature T1 during the decolorizing process, the temperature of the workpiece decreases, the gaps between the fibers of the workpiece narrow again, and the re-entry of sublimable dyes into the gaps between the fibers is reduced.

[0057] Here, the decolorizing solution Q used for rinsing is preheated in the fourth tank 54 during the decolorizing process. Therefore, the decolorizing device 1 can quickly start the rinsing process without having to perform the heating process in the treatment tank 2.

[0058] When the rinsing process is complete, the decolorization device 1 opens the valve V4 of the discharge passage 62 and discharges the used decolorization liquid Q from the processing tank 2 to the first tank 51 (step S10, second discharge process). The decolorization liquid Q discharged to the first tank 51 is used in the next decolorization process. When the decolorization device 1 has finished discharging the decolorization liquid Q from the processing tank 2, it performs a drying process on the workpiece (step S11). The decolorization device 1 heats the processing tank 2 by operating the heating device 71 (see Figure 2) of the processing tank 2. The decolorization device 1 also drives the heat source 73 of the air supply duct 72 and supplies hot air into the processing tank 2 to dry the workpiece.

[0059] Once the drying process is complete, the decolorization device 1 performs a cooling process on the workpiece (step S12). The decolorization device 1 stops the heating device 71 (see Figure 2) and the heat source 73 of the air supply duct 72. As a result, cold air is supplied into the processing tank 2, and the workpiece is cooled. Once the cooling process is complete, the user retrieves the workpiece from the processing tank 2.

[0060] As described above, the decolorization apparatus 1 and decolorization system 10 described in the embodiment have, for example, the following configuration: (1) The decolorization apparatus 1 decolorizes a workpiece containing fibers dyed or colored with a sublimable dye. The decolorization apparatus 1 comprises a processing tank 2, a drum 30 and a rotation support mechanism 35 (agitation section) for the drum 30, and a tank section 5. The processing tank 2 can accommodate multiple workpieces and stores the decolorization liquid Q. The drum 30 provided in the processing tank 2 is rotated by the rotation support mechanism 35 to agitate the decolorization liquid Q stored in the processing tank 2. The tank section 5 stores the decolorization liquid Q and is connected to the processing tank 2 via a flow passage 6. The tank section 5 has a first tank 51 and a second tank 52. The flow passage 6 includes a supply passage 61 for the decolorizing liquid Q that connects the first tank 51 and the second tank 52 to the treatment tank 2 directly or via other tanks, and a discharge passage 62 for the decolorizing liquid Q that connects the treatment tank 2 to the first tank 51.

[0061] (9) The decolorization system 10 comprises a decolorization device 1 and a control device 80 that controls the decolorization device 1. The control device 80 causes the decolorization device 1 to perform a decolorization process (first decolorization process, step S05), a first discharge process (step S06), a rinsing process (second decolorization process, step S09), and a second discharge process (step S10). In the decolorization process, the decolorization device 1 supplies decolorizing liquid Q from the first tank 51 to the processing tank 2 into which the workpiece is placed, and agitates the decolorizing liquid Q by rotating the drum 30 with the rotation support mechanism 35. In the first discharge process, the decolorization device 1 discharges the decolorizing liquid Q used in the decolorization process from the processing tank 2. In the rinsing process, the decolorizing device 1 supplies decolorizing liquid Q from the second tank 52 to the treatment tank 2 via the fourth tank 54, and agitates the decolorizing liquid Q by rotating the drum 30 with the rotation support mechanism 35. In the second discharge process, the decolorizing device 1 discharges the decolorizing liquid Q used in the rinsing process from the treatment tank 2 to the first tank 51.

[0062] The decolorization apparatus 1 and decolorization system 10 of this embodiment can decolorize workpieces in batches, thereby increasing the efficiency of the decolorization process. The decolorization apparatus 1 comprises a processing tank 2 into which multiple workpieces can be fed, and two tanks (a first tank 51 and a second tank 52) connected to the processing tank 2 via a flow passage 6. By exchanging the decolorization liquid Q between the processing tank 2 and the two tanks 51 and 52, the decolorization apparatus 1 can continuously perform decolorization and rinsing processes on many workpieces in a single processing tank 2. In this way, the decolorization apparatus 1 has a compact configuration and can decolorize workpieces in batches.

[0063] Furthermore, the decolorization device 1 can, for example, use the decolorizing liquid Q from the first tank 51 for the decolorization process and the decolorizing liquid Q from the second tank 52 for the rinsing process. The decolorization device 1 discharges the decolorizing liquid Q used in the rinsing process from the processing tank 2 to the first tank 51. The decolorization device 1 can reuse the decolorizing liquid Q used in the rinsing process in the next decolorization process. The decolorization device 1 does not need to replace all of the decolorizing liquid Q between the decolorization process and the rinsing process. The decolorization device 1 can reduce the amount of decolorizing liquid Q used, thereby reducing the cost and environmental burden associated with the decolorizing liquid Q.

[0064] (2) The tank section 5 has a third tank 53. The discharge passage 62 connects the processing tank 2 to the third tank 53. The decolorization device 1 includes a heating device 531 provided in the third tank 53 and a cooling device 56 connected to the third tank 53. The heating device 531 and the cooling device 56 function as a separation unit. The heating device 531 heats and evaporates the decolorization liquid Q stored in the third tank 53, thereby separating the sublimable dye. The cooling device 56 cools the fumes F of the decolorization liquid Q back into liquid for regeneration and supplies it to the second tank 52.

[0065] (10) The control device 80 causes the decolorizing device 1 to discharge the decolorizing liquid Q from the processing tank 2 to the third tank 53 in the first discharge process.

[0066] The decolorization apparatus 1 discharges the decolorization liquid Q used in the decolorization process into the third tank 53. The decolorization liquid Q discharged into the third tank 53 has the sublimable dye separated by the heating device 531 and the cooling device 56, and is regenerated and returned to the second tank 52. By regenerating and repeatedly using the decolorization liquid Q, the cost and environmental burden associated with the decolorization liquid Q can be reduced. In this embodiment, the method for separating the sublimable dye from the decolorization liquid Q is not limited to this configuration. For example, the third tank 53 may be provided with a filter or the like for separating the sublimable dye from the decolorization liquid Q.

[0067] (3) The tank section 5 includes a fourth tank 54. The fourth tank 54 is equipped with a heating device 541 (heating section) for heating the stored decolorizing liquid Q and is connected to the second tank 52 via a supply passage 68. The supply passage 61 of the flow passage 6 connects the fourth tank 54 to the processing tank 2.

[0068] (11) The control device 80 causes the decolorizing device 1 to supply decolorizing liquid Q from the second tank 52 to the fourth tank 54 during the first decolorizing process, to heat the decolorizing liquid Q in the fourth tank 54, and to supply the heated decolorizing liquid Q from the fourth tank 54 to the processing tank 2 during the second decolorizing process.

[0069] Although heating the decolorizing solution Q takes time, preheating the decolorizing solution Q used in the rinsing process in the fourth tank 54 during the decolorizing process allows the rinsing process to start quickly after the decolorizing process. In addition, only an amount A2 of decolorizing solution Q, taking into account the amount A3 required for the rinsing process, is transferred from the second tank 52 to the fourth tank 54 and heated. This reduces the amount of electricity required to heat the decolorizing solution Q.

[0070] (I) The processing tank 2 is equipped with a heating device 71 (heating unit) capable of heating the decolorizing liquid Q. The control device 80 instructs the decolorizing device 1 to heat the decolorizing liquid Q supplied from the first tank 51 in the processing tank 2 during the decolorizing process.

[0071] During the first step, the decolorization process, the decolorizing liquid Q supplied from the first tank 51 is directly heated in the processing tank 2. If the decolorizing liquid Q were heated in the first tank 51, its temperature might decrease as it flows through the supply passage 61. However, by directly heating it in the processing tank 2, the temperature drop of the decolorizing liquid Q can be reduced. Furthermore, by keeping the heating device 71 in the processing tank 2 running during the decolorization and rinsing processes, the temperature of the decolorizing liquid Q can be maintained.

[0072] (6) The processing tank 2 includes, as a drying section for drying the workpiece after the second discharge treatment, a heating device 71 and an air supply duct 72 equipped with a heat source 73. When the heat source 73 is driven, the air from the air supply duct 72 is heated by the heat source 73 and supplied as warm air to the inside of the processing tank 2.

[0073] (13) The control device 80 causes the decolorization device 1 to perform a drying process (step S11) after the second discharge process. In the drying process, the decolorization device 1 heats the processing tank 2 with the heating device 71 and supplies hot air into the processing tank 2 from the air supply duct 72 to dry the workpiece.

[0074] The decolorization apparatus 1 of this embodiment can complete the decolorization, rinsing, and drying processes for many workpieces within a single processing tank 2, thereby improving the processing efficiency of workpiece batches.

[0075] (7) The tank section 5 is located below the processing tank 2. The supply passage 61 is equipped with a pump P that sucks up the decolorizing liquid Q stored in the tank section 5 and supplies it to the processing tank 2.

[0076] Since the tank section 5 is positioned below the processing tank 2, the liquid levels in the first tank 51 to the fourth tank 54 are lower than the liquid level in the processing tank 2. This allows the decolorizing liquid Q to be discharged from the processing tank 2 to the tank section 5 using the difference in water head, thus eliminating the need for the pump P in the discharge passage 62. This reduces the installation cost and space required for the pump P. Alternatively, a pump P may be provided in the discharge passage 62 to allow for faster discharge of the decolorizing liquid Q.

[0077] <Modification 1> Figure 5 is a diagram showing the configuration of a decolorization apparatus and decolorization system according to Modification 1. In Modification 1, the same reference numerals are used for components that are the same as in the embodiment, and detailed explanations are omitted. As shown in Figure 5, in the decolorization apparatus 1A of Modification 1, the tank section 5A comprises three tanks: a first tank 51A, a second tank 52A, and a third tank 53A. That is, in Modification 1, the fourth tank 54 (see Figure 3) of the embodiment is omitted. Similar to the embodiment, the first tank 51A stores the decolorization liquid Q used for the decolorization process. The decolorization liquid Q used for rinsing is discharged from the processing tank 2 into the first tank 51A. The second tank 52A stores the decolorization liquid Q used for rinsing. The second tank 52A stores new decolorization liquid Q or regenerated decolorization liquid Q. The third tank 53A stores the decolorization liquid Q that is discharged from the processing tank 2 after the decolorization process and regenerated. In Modification 1, heating devices 511 and 521 are provided not only in the third tank 53A, but also in the first tank 51A and the second tank 52A.

[0078] In the embodiment, an example was described in which the decolorizing liquid Q supplied from the first tank 51 is heated in the processing tank 2 to perform the decolorization treatment (see Figure 4, step S03). In Modification 1, the decolorizing liquid Q can be heated in the first tank 51A before being supplied to the processing tank 2. Also, in the embodiment, the decolorizing liquid Q from the second tank 52 was transferred to the fourth tank 54 for heating, but in Modification 1, the second tank 52A heats the decolorizing liquid Q and supplies it directly to the processing tank 2.

[0079] The flow passage 6A connecting the processing tank 2 and the tank section 5A includes a supply passage 61A for supplying decolorizing liquid Q from the tank section 5A to the processing tank 2, and a discharge passage 62A for discharging the decolorizing liquid Q from the processing tank 2 to the tank section 5A. In the modified example 1, the supply passage 61A connects the first tank 51A and the second tank 52A to the processing tank 2. The supply passage 61A is provided with a pump P, similar to the embodiment. The pump P has an inlet Pa on the side of the first tank 51A and the second tank 52A, and a discharge port Pb on the side of the processing tank 2.

[0080] The supply path 61A is equipped with valves V2 and V6 for switching the connection between the pump P and the first tank 51A and the second tank 52A. By opening and closing valves V2 and V6, the tank supplying the decolorizing liquid Q to the processing tank 2 can be switched to either the first tank 51A or the second tank 52A. Valve V7 is provided between the pump P and the processing tank 2 in the supply path 61A.

[0081] In the first modified example, the discharge passage 62A is provided by branching off from the supply passage 61A, which is equipped with a pump P. The discharge passage 62A includes a first branch passage 621 and a second branch passage 622. The first branch passage 621 connects the upstream side of the pump P in the supply passage 61A to the treatment tank 2. Specifically, the first branch passage 621 branches off from the junction J1 between the suction port Pa of the pump P and valves V2 and V6 in the supply passage 61A and connects to the treatment tank 2. Valve V8 is provided in the first branch passage 621.

[0082] The second branch line 622 connects the downstream side of the pump P in the supply line 61A to the tank section 5A. Specifically, the second branch line 622 branches off from the junction J2 between the discharge port Pb of the pump P and the valve V7 in the supply line 61A and connects to the first tank 51A and the third tank 53A. The second branch line 622 is equipped with valves V4 and V5 that switch the connection between the processing tank 2 and the first tank 51A and the third tank 53A. By opening and closing valves V4 and V5, the tank from which the decolorizing liquid Q is discharged from the processing tank 2 can be switched to either the first tank 51A or the third tank 53A.

[0083] As described above, in Modification 1, by providing the discharge passage 62A as a branch of the supply passage 61A, the decolorizing liquid Q can be discharged from the processing tank 2 to the tank section 5A using the pump P in the supply passage 61A. By using the pump P, the discharge time of the decolorizing liquid Q can be shortened compared to the case where the decolorizing liquid Q is discharged only by the pressure due to the difference in water head between the processing tank 2 and the tank section 5A. Now, with reference to Figure 6, the flow of the decolorizing liquid Q in Modification 1 will be specifically explained. Figure 6(a) shows the flow of the decolorizing liquid Q in the supply passage 61A when supplying the decolorizing liquid Q to the processing tank 2, and Figure 6(b) shows the flow of the decolorizing liquid Q in the discharge passage 62A when discharging the decolorizing liquid Q from the processing tank 2. Note that Figure 6 illustrates the flow of the decolorizing liquid Q between the processing tank 2 and the first tank 51A. Also, in Figure 6, closed valves are hatched to distinguish between open and closed valves. Furthermore, the dashed lines indicate the portion where the flow of the decolorizing solution Q is blocked by opening and closing the valve.

[0084] In Modification 1, similar to the embodiment, the control device 80 controls the opening and closing of valves and the driving of pump P. As shown in Figure 6(a), when supplying decolorizing liquid Q from the first tank 51A to the processing tank 2, the control device 80 (see Figure 1) opens valves V2 and V7 and closes the other valves. By closing valves V4 and V8, the flow of decolorizing liquid Q in the discharge passage 62A is blocked. When the control device 80 drives pump P, the decolorizing liquid Q stored in the first tank 51A is drawn into pump P, flows through supply passage 61A, and is supplied to the processing tank 2. Although not shown, when supplying decolorizing liquid Q from the second tank 52A (see Figure 5) to the processing tank 2, the control device 80 opens valves V6 and V7 and closes the other valves. When the control device 80 drives pump P, the decolorizing liquid Q stored in the second tank 52A is drawn into pump P, flows through supply passage 61A, and is supplied to the processing tank 2.

[0085] As shown in Figure 6(b), when discharging the decolorizing liquid Q from the processing tank 2 to the first tank 51A, the control device 80 opens valves V4 and V8 and closes the other valves. Closing valve V2 blocks the flow of the decolorizing liquid Q in the supply passage 61A between the junction J1 and the first tank. Closing valve V7 also blocks the flow of the decolorizing liquid Q in the supply passage 61A between the processing tank 2 and the junction J2. When the control device 80 drives the pump P, the decolorizing liquid Q stored in the processing tank 2 flows through the first branch passage 621, enters the supply passage 61A from the junction J1, and is drawn into the pump P. The decolorizing liquid Q discharged from the pump P enters the second branch passage 622 from the junction J2 and is discharged into the first tank 51A.

[0086] Although not shown in the diagram, when discharging the decolorizing liquid Q from the processing tank 2 to the third tank 53A (see Figure 5), the control device 80 opens valves V5 and V8 and closes the other valves. When the control device 80 drives the pump P, the decolorizing liquid Q stored in the processing tank 2 flows through the first branch line 621 and enters the supply line 61A from the junction J1, and is drawn into the pump P. The decolorizing liquid Q discharged from the pump P enters the second branch line 622 from the junction J2 and is discharged into the third tank 53A.

[0087] In this modified example 1, by configuring the discharge channel 62A as a branch of the supply channel 61A, the decolorizing liquid Q can be discharged from the treatment tank 2 using the pump P of the supply channel 61A without having to install a separate pump in the discharge channel 62A.

[0088] As shown in Figure 5, in Modification 1, in addition to the third tank 53A, the first tank 51A and the second tank 52A are connected to the cooling device 56A via the recovery duct 55A. Fumes F generated when the decolorizing liquid Q is heated in the first tank 51A to the third tank 53A are recovered to the cooling device 56A via the recovery duct 55A.

[0089] In the embodiment (see Figure 3), a cooling device 75 is provided in the exhaust duct 74 of the processing tank 2, and the fumes F generated in the processing tank 2 are cooled by the cooling device 75 before being discharged to the external tank 76. As shown in Figure 5, in Modification 1, the exhaust duct 74A is connected to the cooling device 56A together with the recovery duct 55A. That is, in Modification 1, both the fumes F generated in the processing tank 2 and the fumes F generated in the first tank 51A to the third tank 53A are recovered by the cooling device 56A.

[0090] The cooling device 56A cools the fumes F in the decolorizing liquid Q and returns them to a liquid state. The decolorizing liquid Q, now back into a liquid, is supplied to the second tank 52A via the reflux channel 57A. In Modification 1, a vacuum tank 58 is provided in the reflux channel 57A. The vacuum tank 58 is a tank that can be evacuated by a vacuum ejector (not shown). In Modification 1, the fumes F generated in the first tank 51A, the second tank 52A, the third tank 53A, and the processing tank 2 are collected in the cooling device 56A, resulting in a larger amount of fumes F compared to the embodiment. Therefore, there is a possibility that fumes F that are not sufficiently cooled and do not return to a liquid state may be generated in the cooling device 56A.

[0091] Therefore, by providing a vacuum tank 58 as a buffer in the reflux channel 57A, even if the decolorizing liquid Q does not completely return to liquid in the cooling device 56A, it is temporarily stored in the vacuum tank 58, where it is sufficiently cooled and becomes easier to return to liquid. When the vacuum tank 58 is evacuated by the vacuum ejector, the inside of the processing tank 2 connected to the vacuum tank 58 via the reflux channel 57A and exhaust duct 74A is also depressurized. As a result, the boiling point of the decolorizing liquid Q in the processing tank 2 is lowered, making it easier to evaporate even at low temperatures. For example, by depressurizing the vacuum tank 58 during the drying process, the decolorizing liquid Q remaining in the processing tank 2 evaporates quickly and is easily recovered by the cooling device 56A.

[0092] Figure 7 is a time-series chart showing an example of the processing flow of the decolorization apparatus 1A according to Modification 1. Note that the processing content of each step is the same as in the embodiment, so it will be explained in a simplified manner. In Figure 7, the time chart is shown from the point when the user places the workpiece to be decolorized into the processing tank 2 and operates the control device 80 (see Figure 1) to input the instruction to start processing. The control device 80 controls the decolorization apparatus 1A to perform the processing shown in Figure 7. As shown in Figure 7, the decolorization apparatus 1A operates the heating device 511 (see Figure 5) of the first tank 51A to heat the decolorization liquid Q (step S21). The decolorization apparatus 1A heats the decolorization liquid Q until the temperature is T1 or higher. In parallel with step S21, the decolorization apparatus 1A heats the decolorization liquid Q in the second tank 52A (step S22). The decolorization apparatus 1A heats the decolorization liquid Q until the temperature is T2 or higher. Once the decolorization device 1A has finished heating the decolorization solution Q, it opens valves V2 and V7 and drives pump P to supply an amount A1 of decolorization solution Q from the first tank 51A to the processing tank 2 (step S23). Once the decolorization device 1A has finished supplying the decolorization solution Q to the processing tank 2, it performs the decolorization process (step S24).

[0093] When the decolorization process is complete, the decolorization device 1A opens valves V5 and V8 and drives pump P to discharge the decolorizing liquid Q from the processing tank 2 to the third tank 53A (step S25, first discharge process). When the decolorizing liquid Q is discharged to the third tank 53A, the decolorization device 1A operates the heating device 531 of the third tank 53A to perform a regeneration process in which the sublimable dye is separated from the used decolorizing liquid Q and regenerated (step S26). The decolorization device 1A opens valves V6 and V7 and drives pump P to supply an amount A3 of decolorizing liquid Q from the second tank 52A to the processing tank 2 (step S27). When the supply of decolorizing liquid Q is complete, the decolorization device 1A performs a rinsing process (step S28). When the rinsing process is complete, the decolorizing device 1A opens valves V4 and V8 and drives pump P to discharge the used decolorizing liquid Q from the processing tank 2 to the first tank 51A (step S29, second discharge process). The decolorizing liquid Q discharged to the first tank 51A can be used for the next decolorizing process. In modified example 1, pump P is used to discharge the decolorizing liquid Q in both the first and second discharge processes. Although schematically illustrated in the drawing, the time required for the first and second discharge processes is shorter compared to the case where pump P is not used.

[0094] Once the decolorization device 1A has finished discharging the decolorization liquid Q from the processing tank 2, it performs drying and cooling treatment on the workpiece (steps S30, S31). After the cooling treatment is complete, the user retrieves the workpiece from the processing tank 2. The user can also place the next workpiece into the processing tank 2 after retrieving the previous one and decolorize it continuously.

[0095] When multiple processes are performed consecutively in the decolorization apparatus 1A, the heating devices 511, 521, and 531 of the first tank 51A to the third tank 53A may be kept running continuously. In this case, for the second and subsequent processing of workpieces, the decolorization liquid Q in the first tank 51A is already heated when the user puts the workpiece into the processing tank 2. Therefore, the heating process in step S21 can be omitted or shortened. As a result, the time T1 from when the user puts the workpiece into the processing tank 2 until the decolorization process begins can be shortened compared to the first time for the second and subsequent processing.

[0096] As described above, the decolorization apparatus 1A and decolorization system 10A according to Modification 1 have, for example, the following configuration: (4) The first tank 51A and the second tank 52A may have heating devices 511, 521 (heating sections) for heating the decolorization liquid Q. The decolorization apparatus 1A may include a cooling device 56A for cooling the decolorization liquid Q that has been heated in the first tank 51A and the second tank 52A and turned into fumes F, and a return channel 57A for supplying the decolorization liquid Q cooled by the cooling device 56A to the second tank 52A.

[0097] (12) The control device 80 causes the decolorizing device 1A to heat the decolorizing liquid Q in the second tank 52A during the first decolorizing process (step S24), and to supply the heated decolorizing liquid Q from the second tank 52A to the processing tank 2 during the second decolorizing process (step S28).

[0098] In the decolorization apparatus 1A of the modified example 1, heating devices 511 and 521 can also be provided in the first tank 51A and the second tank 52A. The decolorization apparatus 1A can, for example, supply a decolorizing liquid Q that has been preheated in the first tank 51A to the processing tank 2 during the decolorization process. When processing workpieces continuously, etc., by keeping the decolorizing liquid Q constantly heated in the first tank 51A, the time from when the user puts the workpiece into the processing tank 2 until the decolorization process begins can be shortened.

[0099] Furthermore, the decolorization device 1A can, for example, heat the decolorization liquid Q for rinsing in the second tank 52A during the decolorization process. This allows the decolorization liquid Q to be directly supplied from the second tank 52A to the processing tank 2 during the rinsing process. In the decolorization device 1A of Modification 1, the fourth heating tank 54 (see Figure 3) can be omitted, making it suitable for cases where the installation space for the decolorization device 1A is limited. Depending on the installation space and installation costs of the decolorization device 1A, the heating device may be provided in only one of the first tank 51A or the second tank 52A.

[0100] (II) The decolorization apparatus 1A is equipped with a cooling device 56A. The cooling device 56A cools the fumes F generated when the decolorization liquid Q is heated in the processing tank 2 and the tank section 5A, returns them to liquid form, and supplies them to the second tank 52A.

[0101] By cooling the fumes F of the decolorizing liquid Q contained in the exhaust from the treatment tank 2 and tank section 5A back into liquid, the exhaust from the treatment tank 2 and tank section 5A can be safely released into the atmosphere, thereby reducing the environmental burden. Furthermore, in the modified example 1, the decolorizing liquid Q, which has been returned to liquid by the cooling device 56A, is supplied directly to the second tank 52A. Since the work of supplying the decolorizing liquid Q stored in the external tank 76 (see Figure 3) to the second tank 52A is unnecessary, the cost of the decolorizing liquid Q can be reduced, and the workload of the user can be reduced.

[0102] (5) The processing tank 2 has a heating device 71 (heating section) for heating the decolorizing liquid Q. The decolorizing device 1A includes a tank section 5, a cooling device 56A for cooling the decolorizing liquid Q which has been heated in the processing tank 2 and turned into fume F, and a return channel 57A for supplying the decolorizing liquid Q cooled by the cooling device 56A to the second tank 52A. The decolorizing device 1A also includes a reduced pressure tank 58 provided in the return channel 57A. The reduced pressure tank 58 can be depressurized with a vacuum ejector or the like.

[0103] In Modification 1, the fumes F generated in the first tank 51A to the third tank 53A of the tank section 5A and in the processing tank 2 are supplied to the cooling device 56A. If the processing volume in the cooling device 56A increases, there is a possibility that fumes F will not be sufficiently cooled in the cooling device 56A and will not return to liquid. In Modification 1, a vacuum tank 58 is provided between the cooling device 56A and the second tank 52A. Fumes F that did not return to liquid in the cooling device 56A will also be more likely to return to liquid as their temperature drops in the vacuum tank 58 before reaching the second tank 52A. In addition, for example, during the drying process, reducing the pressure in the vacuum tank 58 lowers the boiling point of the decolorizing liquid Q in the processing tank 2, making it easier to evaporate, thus allowing the workpiece to be dried quickly.

[0104] (8) The discharge passage 62A may be provided as a branch of the supply passage 61A. The discharge passage 62A includes a first branch passage 621 and a second branch passage 622. The first branch passage 621 connects the upstream side of the pump P in the supply passage 61A to the treatment tank 2. The second branch passage 622 connects the downstream side of the pump P in the supply passage 61A to the tank section 5A.

[0105] In the decolorization apparatus 1A, the supply of decolorizing liquid Q from the tank section 5A (first tank 51A or second tank 52A) to the processing tank 2 and the discharge of decolorizing liquid Q from the processing tank 2 to the tank section 5A (first tank 51A or third tank 53A) can be switched by opening and closing valves V2, V6, V7, V4, V5, and V8 provided in the supply passage 61A and the discharge passage 62A. The decolorizing liquid Q discharged from the processing tank 2 to the tank section 5A flows from the first branch passage 621 through the pump P to the second branch passage 622. This allows the decolorizing liquid Q to be discharged using the pump P in the supply passage 61A without providing another pump P in the discharge passage 62A. In other words, in the modified example 1, the installation cost and installation space of the pump P can be reduced while the decolorizing liquid Q can be discharged quickly, thereby improving the processing efficiency of the workpiece.

[0106] The effects described in Embodiment and Modification 1 also apply to the decolorization method performed in the decolorization apparatus 1, 1A and the decolorization systems 10, 10A. The present invention is not limited to the embodiments and modifications described above, and can be modified as appropriate within the scope of the technical idea of ​​the present invention. Furthermore, all of the configurations of the modifications may be applied to the embodiments, or only some of them may be applied to the embodiments.

[0107] 1, 1A: Decolorization device 2: Processing tank 5, 5A: Tank section 10, 10A: Decolorization system 30: Drum (agitation section) 35: Support rotation mechanism (agitation section) 71: Heating device (drying section) 72: Air duct (drying section) 51, 51A: First tank 52, 52A: Second tank 53, 53A: Third tank 54: Fourth tank 61, 61A: Supply path 62, 62A: Discharge path 531: Heating device (separation section) 56, 56A: Cooling device (separation section) 80: Control device 621: First branch path 622: Second branch path

Claims

1. A decolorizing apparatus for decolorizing a workpiece containing fibers dyed or colored with a dye, comprising: a processing tank capable of accepting a plurality of the workpieces and storing a decolorizing liquid; a stirring unit for stirring the decolorizing liquid stored in the processing tank; and a tank section for storing the decolorizing liquid and connected to the processing tank via a flow passage, wherein the tank section comprises a first tank and a second tank, and the flow passage comprises a supply passage for the decolorizing liquid connecting the first tank and the second tank to the processing tank directly or via another tank, and a discharge passage for the decolorizing liquid connecting the processing tank to the first tank.

2. The decolorization apparatus according to claim 1, wherein the tank section has a third tank, and the discharge passage has a separation section that connects the processing tank to the third tank and separates the dye from the decolorizing liquid stored in the third tank and supplies it to the second tank.

3. The decolorization apparatus according to claim 1 or 2, wherein the tank section has a heating section for heating the stored decolorizing liquid and a fourth tank connected to the second tank, and the supply passage connects the fourth tank to the processing tank.

4. The decolorization apparatus according to claim 1 or 2, wherein at least one of the first tank and the second tank has a heating section for heating the decolorizing liquid, a cooling device for cooling the decolorizing liquid that has been heated and turned into fumes in at least one of the first tank and the second tank, and a return channel for supplying the decolorizing liquid cooled by the cooling device to the second tank.

5. The decolorization apparatus according to claim 4, wherein the processing tank has a heating section for heating the decolorizing liquid, and comprises a tank section, a cooling device for cooling the decolorizing liquid which has been heated in the processing tank and turned into a fumes, a return channel for supplying the decolorizing liquid cooled by the cooling device to the second tank, and a reduced pressure tank provided in the return channel.

6. The decolorization apparatus according to claim 1 or 2, characterized in that the processing tank has a drying section for drying the workpiece.

7. The decolorization apparatus according to claim 1 or 2, characterized in that the tank section is provided below the processing tank, and the supply passage is provided with a pump that sucks up the decolorizing liquid stored in the tank section and supplies it to the processing tank.

8. The decolorization apparatus according to claim 7, wherein the discharge passage is provided as a branch passage of the supply passage and comprises a first branch passage connecting the upstream side of the pump and the treatment tank of the supply passage, and a second branch passage connecting the downstream side of the pump and the tank section.

9. A decolorization system comprising: a decolorization device for decolorizing a workpiece containing fibers dyed or colored with a dye; and a control device for controlling the decolorization device, wherein the decolorization device comprises: a processing tank into which a plurality of the workpieces can be loaded and for storing a decolorization liquid; a stirring unit for stirring the decolorization liquid stored in the processing tank; and a tank section for storing the decolorization liquid and connected to the processing tank via a flow passage, wherein the tank section has a first tank and a second tank; the flow passage has a supply passage for the decolorization liquid connecting the first tank and the second tank to the processing tank directly or via another tank; and a discharge passage for the decolorization liquid connecting the processing tank to the first tank; and the control device provides the decolorization device with: a first decolorization process of supplying the decolorization liquid from the first tank to the processing tank into which the workpieces are loaded and stirring the decolorization liquid with the stirring unit; and a first discharge process of discharging the decolorization liquid used in the first decolorization process from the processing tank. A decolorization system characterized by performing a second decolorization process in which the decolorizing liquid is supplied from the second tank to the processing tank and the decolorizing liquid is stirred by the stirring unit, and a second discharge process in which the decolorizing liquid used in the second decolorization process is discharged from the processing tank to the first tank.

10. The decolorization system according to claim 9, wherein the tank section has a third tank, the discharge passage connects the processing tank to the third tank, the decolorization device includes a separation section that separates the dye from the decolorization liquid stored in the third tank and supplies it to the second tank, and the control device causes the decolorization device to discharge the decolorization liquid from the processing tank to the third tank in the first discharge process.

11. The decolorization system according to claim 9 or 10, wherein the tank section has a fourth tank connected to the second tank and is provided with a heating section for heating the decolorizing liquid, the supply path connects the fourth tank to the processing tank, and the control device causes the decolorizing device to supply the decolorizing liquid from the second tank to the fourth tank during the first decolorization process, heat the decolorizing liquid in the fourth tank, and supply the heated decolorizing liquid from the fourth tank to the processing tank during the second decolorization process.

12. The decolorization system according to claim 9 or 10, wherein the second tank has a heating section for heating the decolorizing liquid, and the control device causes the decolorizing apparatus to heat the decolorizing liquid in the second tank during the first decolorization process, and to supply the heated decolorizing liquid from the second tank to the processing tank during the second decolorization process.

13. The decolorization system according to claim 9 or 10, wherein the processing tank has a drying section for drying the workpiece, and the control device causes the decolorization device to perform a drying process in which the drying section dries the workpiece in the processing tank after the second discharge process.

14. A decolorization method in a decolorization apparatus for decolorizing a workpiece containing fibers dyed or colored with a dye, wherein the decolorization apparatus comprises: a processing tank into which a plurality of the workpieces can be loaded and for storing a decolorization liquid; a stirring unit for stirring the decolorization liquid stored in the processing tank; and a tank section for storing the decolorization liquid and connected to the processing tank via a flow passage, wherein the tank section has a first tank and a second tank, and the flow passage has a supply passage for the decolorization liquid connecting the first tank and the second tank to the processing tank directly or via another tank, and a discharge passage for the decolorization liquid connecting the processing tank to the first tank, wherein the decolorization method comprises: a first decolorization process in which the decolorization liquid is supplied from the first tank to the processing tank into which the workpieces are loaded and the decolorization liquid is stirred by the stirring unit; and a first discharge process in which the decolorization liquid used in the first decolorization process is discharged from the processing tank. A decolorization method characterized by comprising: a second decolorization process in which the decolorizing liquid is supplied from the second tank to the processing tank and the decolorizing liquid is stirred by the stirring unit; and a second discharge process in which the decolorizing liquid used in the second decolorization process is discharged from the processing tank to the first tank.

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