JP2012082553A - Waste paper recycling treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste paper recycling treatment apparatus that can prevent a precipitation of fibers in a tank in a simple apparatus constitution.SOLUTION: There is provided a waste paper recycling treatment apparatus that has a processing part for each treatment step, and a plurality of processing parts constitute a waste paper recycling treatment system. In the apparatus, a white water tank part 70 and a drain water treatment tank part 60 that form the processing parts are provided with circulation water passages from their tanks to the processing parts to which water is fed, and water receiving passages from the processing parts in which water is received to their tanks. Either the white water tank part 70 has return water passages 715 and 720 which are branched from the circulation water passages 711 and 712 to its tank, or the drain water treatment tank part 60 has a return water passage 605 which is branched from the circulation water passage 600 to its tank.

Description

  The present invention relates to a used paper recycling apparatus that can be installed in an office or the like where waste paper is generated to recycle the paper, and more particularly relates to a technique for stirring the inside of a tank of a processing unit.

2. Description of the Related Art Conventionally, a papermaking method for recycling used paper such as used newspaper in a general papermaking factory includes processing steps of a used paper pulp process, a paper making process, and a finishing process.
In the waste paper pulp process, waste paper, which is the raw material in the pulper, is dissolved in water, and metal, film, adhesive resin, and printing ink (dye type, pigment type) that are foreign matters other than paper fibers using mechanical power and chemicals. ), Separating and removing the copy toner and the like, and then bleaching, dehydrating and drying to obtain waste paper pulp.

  In the paper making process, the product paper is processed through the wire part, press part, dryer part, calendar part, and coater part of the paper machine. In the wire part, the prepared (regenerated) pulp is placed on a paper making net (wire) and dehydrated to make paper, and in the press part, the moisture in the wet paper containing a large amount of moisture from the wire part is removed. In the dryer part, the paper is dried through a dryer heated with steam, in the calendar part, the paper surface is smoothed between the rolls, and in the coater part, the base paper is coated with paint.

  In the finishing process, in the super calender part, the micro unevenness of the paper surface coated by the coater part is smoothed to give gloss, and in the cutter and winder part, it is cut into a predetermined product size or wound on a roll.

  A small papermaking machine has a processing unit provided for each processing step, and a plurality of processing units constitute a used paper recycling processing system. The processing unit includes a pulper unit that disaggregates regenerated raw materials to prepare regenerated pulp, a storage tank unit that stores regenerated pulp, a deinking unit that deinks regenerated pulp to prepare deinked pulp, and deinked pulp. There are a paper making section for making wet paper, a dehydrating and drying section for dehydrating and drying wet paper, a white water tank section for storing white water discharged from the paper making section, and a waste water treatment tank section for treating waste water. White water or waste water flows into the white water tank unit and the waste water treatment tank unit through the water receiving path from the water receiving target processing unit.

  Patent Document 1 describes a cleaning method and system for a used paper recycling apparatus. This is to wash the pulp manufacturing section and the pulp concentration adjusting section by circulating white water dehydrated and collected in the paper making section as washing water to the pulp manufacturing section and the pulp concentration adjusting section.

JP2008-184699

  By the way, the white water tank unit and the waste water treatment tank unit store white water discharged from the paper making unit and deinked waste water discharged from the deinking unit in their own tanks. The fiber settles during storage in the tank.

  For this reason, if only the supernatant water staying in the tank of the white water tank section or the wastewater treatment tank section is reused, the fibers will remain in the tank, and if the precipitated fibers are discharged together, the pump or valve may be clogged. Therefore, it is necessary to periodically remove the fibers.

In order to prevent the precipitation of the fibers, it is necessary to provide a stirring device. However, providing a stirrer having a waterproof property causes complication of the apparatus and an increase in cost.
The present invention has been made to solve the above-described problems, and an object thereof is to provide a used paper recycling apparatus capable of preventing the precipitation of fibers in a tank with a simple apparatus configuration.

  In order to solve the above problems, a used paper recycling processing apparatus of the present invention has a plurality of processing units provided for each processing step, and the used paper recycling processing apparatus includes a plurality of processing units to constitute a used paper recycling processing system. The white water tank part and the waste water treatment tank part are provided with a circulating water path from the own tank to the water supply target processing part and a water receiving path from the water receiving target processing part to the own tank. And at least one of the wastewater treatment tank sections has a return water path that branches from the circulating water path and reaches the tank of its own.

In the used paper recycling apparatus of the present invention, the circulating water path has a pump, and the return water path has a valve.
In the used paper recycling apparatus of the present invention, the return water returning from the return water path to the tank serves as a stirring means for stirring the inside of the tank.

  As described above, according to the present invention, the white water tank unit and the waste water treatment tank unit supply white water or waste water as reused water from its own tank to the water supply target treatment unit through the circulation water path. At this time, part of the white water or drainage returns to the tank as return water through the return water path, and the return water flowing into the tank agitates the white water or drainage in the tank to prevent fiber precipitation. Since the water flow of the return water flowing into the tank depends on the discharge pressure of the pump in the circulating water path, a reliable stirring force can be realized. Stirring can be performed at any time by opening and closing the valve of the return water path.

The block diagram which shows the used paper reproduction | regeneration processing apparatus in embodiment of this invention Schematic diagram showing a used paper recycling apparatus in the same embodiment Schematic showing the filtration dehydration apparatus in the same embodiment The top view which shows the filtration dehydration apparatus in the embodiment

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2, the used paper recycling processing apparatus has a plurality of processing units constituting a used paper recycling processing system. The processing unit includes a pulper unit 10, a storage tank unit 20, a deinking unit 30, and a paper making unit. 40, a dehydration drying unit 50, a wastewater treatment tank unit 60, and a white water tank unit 70.

  The pulper unit 10 separates a piece of paper to prepare a pulp suspension containing regenerated pulp, and includes a pulper tank 11 and a stirring device 12 provided inside the pulper tank 11. The pulper unit 10 is connected to the storage tank unit 20 via a first recycled pulp supply system 102 having a first tube pump 101.

  The storage tank unit 20 includes a storage tank 21 that stores the pulp suspension obtained in the pulper unit 10, and a stirring device 22 disposed inside the storage tank 21, and a second tube pump 201. 2 is connected to the deinking unit 30 via the recycled pulp supply system 202.

  The deinking unit 30 prepares deinked pulp by deinking the pulp suspension sent from the storage tank unit 20. The deinking tank 31 forms a meandering flow path, and the lower part of the deinking tank 31. A diffuser (not shown) that discharges a large number of air bubbles and a bubble receiving tank 32 surrounding the deinking tank 31 are provided. The deinking unit 30 is connected to the paper making unit 40 via a deinking pulp supply system 302 having a third tube pump 301.

  The paper making unit 40 makes wet paper from the deinked pulp suspension, and includes a paper making wire 42 composed of a mesh belt wound around a plurality of rollers 41, and a deinked pulp suspension. A head box 43 for supplying the liquid onto the papermaking wire 42 is provided.

  The dehydrating and drying unit 50 includes a dehydrating unit 51 that dehydrates the wet paper and a drying unit 55 that dries the dehydrated wet paper. The dewatering unit 51 includes a felt water absorbing belt 53 wound around a plurality of rollers 52. The wet paper is transferred from the paper making wire 42 to the water absorbing belt 53, and the water absorbing belt 53 absorbs and dehydrates the wet paper. The drying unit 55 includes a drying roller 56 having a built-in heating device and a metal conveying belt 58 wound around a plurality of rollers 57.

  The waste water treatment tank unit 60 processes the deinking waste liquid flowing from the deinking unit 30, and includes a filtration dehydration device 61, a filtration treatment device 62, a waste water circulation tank 63, and a waste bin 64.

The filter dehydrator 61 removes fibers and toner with a filter (mesh belt), and a deinking waste liquid system 303 is connected to the foam receiving tank 32. Details thereof will be described later.
The filtration processing device 62 includes a flocculation process step, neutralizes by adding chemicals, and treats the water quality so that it can be drained to the sewage pipes of public sewage. A coagulation stirrer 66 is provided.

  The rotation speed of the stirring blades of the agglomeration stirrer 66 is set to such an extent that the drainage is not bubbled, that is, to the extent that cavitation does not occur. The stirring blade is provided near the water surface, and as a result, the precipitate is not entangled with the stirring blade.

  The agglomeration treatment tank 65 is connected to the filtration dehydrator 61 via an agglomeration waste liquid supply system 652 having an electric ball valve 651, and an agglomeration treatment discharge system 654 having an agglomeration treatment discharge valve 653 is connected to the agglomeration treatment tank 65. Yes.

  The wastewater treatment tank unit 60 includes a first drainage return system 600 that forms a circulation water path from a drainage circulation tank 63 that is a self tank to a deinking unit 30 that is a treatment target for water supply, and a treatment unit that is a target for receiving water. The deinking tank 31 of the deinking unit 30, the deinking drainage system 304 and the filtering drainage system 305 that are connected to the drainage circulation tank 63, which is its own tank, from the filtration dehydrator 61 are connected to each other. The ink drainage system 304 has a deinking drainage valve 306.

  The first drainage return system 600 has a drainage pump 602 and a drainage first valve 603, the tip is connected to the shower head 307 of the deinking unit 30, and from the first drainage return system 600 downstream of the drainage pump 602. A branched second drainage return system 601 is connected to the filtration apparatus 62 via a drainage second valve 604. The first drainage return system 600 has a drainage return system 605 branched from the first drainage return system 600 downstream of the drainage pump 602 and connected to the drainage circulation tank 63 via the drainage third valve 606 as a return water path. A wire cleaning water system 607 branched from the drain return system 605 on the upstream side of the third drain valve 606 is connected to the filtration dehydrator 61 via the fourth drain valve 608. The wire cleaning water system 607 supplies cleaning water for the mesh belt 612 described later.

  The filtration apparatus 62 has a flocculant tank 660 for storing the flocculant, and the flocculant tank 660 is connected to the flocculant treatment tank 65 via a flocculant supply system 662 having a flocculant supply pump 661, and the second A turbidity measuring device 663 such as a permeation sensor interposed in the drainage return system 601 is connected to the coagulant supply pump 661.

  The white water tank unit 70 includes a first white water return system 711 and a second white water return system 712 that form a circulating water path from the white water tank 701 as its own tank to the pulper unit 10 and the deinking unit 30 as processing units to be supplied with water. Are connected to each other to form a water receiving path from the paper making unit 40 and the dehydrating / drying unit 50, which are water receiving target processing units, to the white water tank 701, which is its own tank, and a first white water drainage system 401 that collects by natural fall A second white water drainage system 501 is connected.

  The first white water return system 711 includes a white water first pump 713 and a white water first valve 714, and a first white water return system 715 branched on the downstream side of the white water first pump 713 returns via the white water second valve 716. The water path is connected to the white water tank 701.

  A second white water return system 712 that supplies dilution water 717 to the deinking unit 30 includes a white water second pump 718 and a white water third valve 719, and a second recycled pulp supply system 202 downstream of the second tube pump 201. The second white water return system 720 that branches to the downstream side of the white water second pump 718 is connected to the white water tank 701 via the white water fourth valve 721 as a return water path and downstream of the white water second pump 718. A third white water return system 722 that branches on the side is connected to the deinking unit 30 via a white water fifth valve 723.

  A water supply system 80 for supplying clean water is downstream of the main valve 81, a pulper water supply system 801 connected to the pulper unit 10, a papermaking unit water supply system 802 connected to the papermaking unit 40, and a dehydration connected to the dehydration drying unit 50. Branching to the drying unit water supply system 803, the pulper water supply system 801 further branches to a storage tank water supply system 804 connected to the storage tank unit 20.

  The pulper water supply system 801 has a first water supply valve 805 and a second water supply valve 806 to supply disaggregation water and maintenance water. The storage tank water supply system 804 is provided between the first valve 805 and the second valve 806. Branching from the pulper water supply system 801 has a third water supply valve 807 to supply maintenance water, and the papermaking unit water supply system 802 has a fourth water supply valve 808 to supply water for cleaning the papermaking wire 42. The dehydrating and drying unit water supply system 803 has a fifth water supply valve 809 and supplies water for acclimation and cleaning of the water absorption belt 53. A first white water return system 711 is connected to the pulper water supply system 801 between a water supply first valve 805 and a water supply second valve 806.

  The overflow detection tank 91 is connected to a pulper overflow system 911 of the pulper tank 11, a storage tank overflow system 912 of the storage tank 21, and a filtration processing device overflow system 913 of the filtration processing device 62.

  As shown in FIG. 3 to FIG. 4, the filtration and dehydration device 61 disposed above the drainage circulation tank 63 includes an endless mesh belt 612 spanned by a plurality of rotating rollers 611. In the upper part, the deinking waste liquid supply unit 613 connected to the deinking waste liquid system 303 and the aggregation waste liquid supply system 652, the pressing roller 614 disposed to face one of the plurality of rotating rollers 611, and the pressing roller 614 are brought into contact with each other. The water that is in contact with the transfer roller 615, the scraper 616 that is in sliding contact with the outer peripheral surface of the transfer roller 615, and the rotating roller 611 that faces the pressing roller 614 at a predetermined pressure, and is absorbed by a water absorbing member (not shown) of the rotating roller 611 A squeezing roller 610 is provided.

  The pressing roller 614 is biased at both ends by a spring (not shown) toward the rotating roller 611, and even if it is a thick waste fiber layer that occurs in normal operation, the thin waste fiber that occurs during maintenance of the deinking tank 31 Even a layer can be reliably dehydrated. When the urging force by the spring does not act, the squeezing roller 614 cannot be retracted when the layer is a thick waste fiber layer, so that clogging may occur.

  A filter scraping unit 617 is provided above the mesh belt 612 and downstream of the deinking waste liquid supply unit 613 in the traveling direction of the mesh belt 612. The filter cake scraping part 617 contacts the upper surface of the mesh belt 612 and scrapes the filter cake by a predetermined amount, and scrapes the rotary shaft 618 and the two scrapers projecting from the outer peripheral surface of the rotary shaft 618. The blade 619 and a scraping drive unit 620 that rotationally drives the rotary shaft 618 are provided.

  The two scraping blades 619 are provided radially from the rotation shaft 618, and each scraping blade 619 is formed in a substantially rectangular thin plate shape and has a bent portion 621, the tip portion of which is made of PET, PP, PE, or the like. The scraper blades 619 come into contact with the upper surface of the mesh belt 612 at a predetermined rotational speed and contact pressure as it rotates, such as synthetic resin or a metal thin plate such as aluminum or stainless steel.

  The scraping blade 619 has a bent portion 621 so that the tip edge line is arranged at a twisted position with respect to the axis of the rotation shaft 618. Thus, by providing an angle between the leading edge line of the scraping blade 619 and the axis of the rotation shaft 618, the scraping blade 619 does not contact the mesh belt 612 at a time, and the scraping blade 619 It abuts on the mesh belt 612 on one end side, and then gradually abuts on the mesh belt 612 toward the other end side. As a result, the rubbing sound between the scraping blades 619 and the mesh belt 612 is reduced, and the scraping blades 619 that are bent due to the contact with the mesh belt 612 gradually move away from the mesh belt 612, and the scraping blades 619. Since bending is not released at a stretch, water splashing can be suppressed.

  The mesh belt 612 has a mesh capable of filtering waste paper pulp contained in the deinking waste liquid, the mesh is in the range of 10 mesh to 50 mesh, and preferably 20 mesh to 30 mesh. By making the mesh 10 mesh or more, it is possible to reduce the amount of used paper pulp that passes through the mesh, and by making it 50 mesh or less it is difficult for clogging of the mesh due to waste paper pulp and the like to improve filtration efficiency. it can.

  The squeezing roller 614 holds the mesh belt 612 between the opposing rotating rollers 611 to filter the deinking waste liquid with the mesh belt 612 and squeezes the residue remaining on the mesh belt 612. The drainage produced by the pressing is absorbed by a water absorbing member (not shown) of the rotating roller 611 facing the pressing roller 614. The wastewater absorbed by the water absorbing member is squeezed out of the water absorbing member under the pressing force of the squeezing roller 610 and flows into the drainage circulation tank 63 through the filtered drainage system 305. The outer peripheral surface of the squeezing roller 614 has a smooth shape with less irregularities than the surface of the mesh belt 612, so that the filter cake is transferred from the mesh belt 612 to the squeezing roller 614 when the filter cake on the mesh belt 612 is pressed. To do.

Then, the filter cake transferred to the pressing roller 614 is further transferred to the transfer roller 615, and the filter cake is peeled off from the transfer roller 615 by the scraper 616 and discharged to the trash box 64.
During maintenance of the deinking tank 31, the amount of wastewater flowing into the filtration and dehydrating device 61 through the deinking waste liquid system 303 is increased, so that the conveying speed of the mesh belt 612 is made faster than normal and the processing capacity is improved.

  The pulper unit 10 separates the paper pieces to prepare a pulp suspension containing the regenerated pulp, and supplies the pulp suspension to the storage tank unit 20 through the first regenerated pulp supply system 102 by the first tube pump. The storage tank unit 20 supplies the pulp suspension stored in the storage tank 21 to the deinking unit 30 through the second recycled pulp supply system 202 by the second tube pump 201 while stirring the pulp suspension with the stirring device 22.

  The deinking unit 30 prepares deinked pulp by deinking the pulp suspension in a deinking tank 31 having a meandering flow path, and the deinked pulp is passed through the deinked pulp supply system 302 by the third tube pump 301. The paper is supplied to the paper making unit 40.

  The paper making unit 40 supplies deinked pulp from the head box 43 onto the paper making wire 42 to make wet paper. The dehydrating unit 51 of the dehydrating and drying unit 50 transfers wet paper from the paper making wire 42 to the water absorbing belt 53 to absorb and dehydrate, and the drying unit 55 transfers wet paper from the water absorbing belt 53 to the conveying belt 58 to heat the drying roller 56. Dry on equipment.

  The wastewater treatment tank unit 60 removes fibers, ink, and toner in the deinking waste liquid flowing from the deinking unit 30 with the mesh belt 612 of the filtration dewatering device 61, and performs the aggregation treatment with the filtration processing device 62. The coagulation waste liquid in the coagulation treatment tank 65 is supplied to the filtration dehydrator 61 through the coagulation waste liquid supply system 652.

  In the wastewater treatment tank 60, the deinking waste liquid flows from the deinking tank 31 through the deinking drainage system 304 into the drainage circulation tank 63, and the filtered wastewater flows from the filtration dehydrator 61 through the filtering drainage system 305. Further, the waste water is supplied from the waste water circulation tank 63 to the shower head 307 of the deinking unit 30 through the first waste water return system 600 or the waste water is supplied to the filtration device 62 through the second waste water return system 601.

  A part of the drainage returns to the drainage circulation tank 63 through the drainage return system 605, and the return water flowing into the tank stirs the drainage in the tank and prevents the precipitation of the fibers. Since the water flow of the return water flowing into the tank depends on the discharge pressure of the drainage pump 602, a reliable stirring force can be realized. Moreover, stirring can be performed at any time by opening and closing the drainage third valve 606.

  The filtration processing device 62 detects the turbidity of the wastewater flowing into the flocculation treatment tank 65 by the turbidity measuring device 663 and controls the flocculant supply pump 661 according to the detected turbidity of the wastewater from the flocculant tank 660. The amount of the flocculant supplied to the flocculation treatment tank 65 is adjusted. The flocculant is added in a state where the waste water is stirred by the flocculent stirring device 66 to advance the flocculence reaction. Thereafter, the agglomeration stirrer 66 is reversely rotated for a certain period of time and then stopped to precipitate the agglomerated dust (fibers).

  In the white water tank unit 70, white water flows from the paper making unit 40 through the first white water drainage system 401, and white water flows from the dehydration drying unit 50 through the second white water drainage system 501. Further, white water is supplied from the white water tank 701 to the pulper unit 10 through the first white water return system 711, and white water is supplied to the deinking unit 30 through the second white water return system 712.

  A part of the white water returns to the white water tank 701 through the first white water return system 715 and the second white water return system 720, and the return water flowing into the tank stirs the waste water in the tank and prevents the precipitation of fibers. . Since the water flow of the return water flowing into the tank depends on the discharge pressures of the white water first pump 713 and the white water second pump 718, a reliable stirring force can be realized. Moreover, stirring can be performed at any time by opening and closing the white water second valve 716 and the white water fourth valve 721.

  In the above-described embodiment, the first white water return system and the second white water return system are provided as the white water return water path. However, only one of the white water return systems may be provided. In the above-described embodiment, the drainage return system 605 has the drainage third valve 606, the first whitewater return system 715 has the whitewater second valve 716, and the second whitewater return system 720 has the whitewater fourth valve 721. However, it is not always necessary to provide a valve in each return system. When each return system is not provided with a valve, the return water flows into the tank through each return system only when the drain pump 602, the white water first pump 713, and the white water second pump 718 of each return system are operated. When the pump 602, the white water first pump 713, and the white water second pump 718 are not operated, the return water does not flow into the tank.

  In each return system, it is preferable that an inlet of return water in each tank is opened downward or sideways in the vicinity of the bottom surface of the tank. When the inlet is provided downward, the return water that has flowed first hits the bottom surface of the tank, then flows sideways, that is, near the bottom surface of the tank along the bottom surface, and the return water that flows near the bottom surface of the tank hits the side surface of the tank. The flow changes upward, and then the return water changes sideways near the surface of the water, and finally the return water changes downward toward the inlet, creating a convection swirling up and down in the tank.

  When the inflow port is provided sideways, the returned return water flows in the vicinity of the tank bottom surface along the tank bottom surface, first hits the tank side surface, and then changes the flow upward along the tank side surface. After that, convection flowing along the tank shape is generated in the same manner as when the inflow port is provided downward.

  Thus, by providing the inflow port downward or sideways in the vicinity of the bottom surface of the tank, convection can be generated and the waste water in the tank can be agitated. Although it is possible to provide the return water inlet upward in the vicinity of the bottom of the tank, if the discharge pressure of the return water flowing in is strong, there is a risk that it will be ejected higher than the water surface. Such considerations are necessary.

DESCRIPTION OF SYMBOLS 10 Pulper part 11 Pulper tank 12 Stirrer 20 Storage tank part 21 Storage tank 22 Stirrer 30 Deinking part 31 Deinking tank 32 Foam receiving tank 40 Paper making part 41 Roller 42 Paper making wire 43 Head box 50 Dehydration drying part 51 Dehydration part 55 Drying section 52 Roller 53 Water absorption belt 56 Drying roller 57 Roller 58 Conveying belt 60 Wastewater treatment tank section 61 Filtration dewatering apparatus 62 Filtration processing apparatus 63 Wastewater circulation tank 64 Recycle bin 65 Coagulation treatment tank 66 Coagulation stirring apparatus 70 White water tank section 80 Water supply system 81 Original valve 91 Overflow detection tank 101 First tube pump 102 First recycled pulp supply system 201 Second tube pump 202 Second recycled pulp supply system 301 Third tube pump 302 Deinked pulp supply system 303 Deinked waste liquid system 304 Deinked drainage Series 305 Filtration drainage system 06 Deinking drain valve 307 Shower head 401 First white water drain system 501 Second white water drain system 600 First drain return system 601 Second drain return system 602 Drain pump 603 Drain first valve 604 Drain second valve 605 Drain return system 606 Drainage third valve 607 Wire cleaning water system 608 Drainage fourth valve 610 Squeezing roller 611 Rotating roller 612 Mesh belt 613 Deinking waste liquid supply unit 614 Squeezing roller 615 Transfer roller 616 Scraper 617 Filtering scraping unit 618 Rotating shaft 619 Scraping Blade 620 scraping drive unit 651 electric ball valve 652 coagulation waste liquid supply system 653 coagulation treatment discharge valve 654 coagulation treatment discharge system 660 coagulant supply pump 662 coagulant supply system 663 turbidity measuring device 701 white water tank 711 first White water return system 712 Second white water return system 713 White water 1 pump 714 white water first valve 715 first white water return system 716 white water second valve 717 dilution water 718 white water second pump 719 white water third valve 720 second white water return system 721 white water fourth valve 722 third white water return system 723 white water Fifth valve 801 Pulper water supply system 802 Papermaking unit water supply system 803 Dehydration drying unit water supply system 804 Storage tank water supply system 805 Water supply first valve 806 Water supply second valve 807 Water supply third valve 808 Water supply fourth valve 809 Water supply fifth valve 911 Pulper Overflow system 912 Storage tank overflow system 913 Filtration processing equipment overflow system

Claims (3)

  In the used paper recycling processing equipment, which has a plurality of processing units provided for each processing process and constitutes a used paper recycling processing system with a plurality of processing units, the white water tank unit and the waste water processing tank unit constituting the processing unit are separated from their own tanks. Provided with a circulating water path leading to the water supply target processing section and a water receiving path from the water receiving target processing section to its own tank, at least one of the white water tank section and the waste water treatment tank section branches off from the circulating water path And having a return water path leading to its own tank.   The used paper recycling apparatus according to claim 1, wherein the circulating water path has a pump, and the return water path has a valve.   3. The used paper recycling apparatus according to claim 1, wherein the return water returning from the return water path to the tank serves as a stirring means for stirring the inside of the tank.

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