JP2021100738A - Waste material disposal system - Google Patents

Abstract

To stir fragments of processed objects without causing entangling.SOLUTION: A waste material disposal system 10 includes: a process tank 39 which may house fragments F of disposable diapers D each having polymers P in a water absorption state and a process liquid T for reducing water holding capacities of the polymers P; and a stirring member 48 having a disc-like body part 51 and a rib 52 protruding from a surface of the body part 51 and extending from a rotation center of the body part 51 in a radial direction, the stirring member 48 provided in the process tank 39.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to a sewage treatment apparatus.

Patent Document 1 discloses a disposal facility for disposing of disposable diapers. After crushing the disposable diaper, this disposal facility separates water from the polymer of the disposable diaper and recovers the pulp component and the polymer contained in the disposable diaper. In the step of separating water from the polymer, crushed pieces of disposable diapers, water and a decomposition agent are mixed and stirred in a polymer decomposition tank.

Japanese Unexamined Patent Publication No. 2000-84533

When the paper diaper is crushed into strips, when the crushed pieces of the paper diaper are stirred by a propeller-shaped stirring member, the strip-shaped crushed pieces are entangled with the propeller and the stirring becomes insufficient. Insufficient agitation also results in inadequate polymer decomposition treatment.

The present disclosure has been made in view of the above-mentioned conventional circumstances, and it is an object to be solved to stir without entwining the crushed fragments of the object to be treated.

The sewage treatment apparatus of the present disclosure includes a treatment tank capable of accommodating crushed pieces of an object to be treated having a water-absorbing polymer, a treatment liquid for reducing the water retention capacity of the polymer, a disk-shaped main body portion, and the main body portion. It has a rib protruding from the surface of the main body and extending in the radial direction from the rotation center of the main body, and includes a stirring member provided in the processing tank for rotation.

Configuration diagram of the sewage treatment device of the first embodiment Top view of deodorizer XX-ray cross-sectional view of FIG. Cross-sectional view of the water separation treatment device YY line cross-sectional view of FIG. Flow chart of control leading to the start of crushing process Flow chart of water separation treatment process and dehydration process Graph showing the change in polymer particle size in the water separation treatment process Graph showing the time course of the opening of the on-off valve

<Embodiment 1>
Hereinafter, the first embodiment embodying the sewage treatment apparatus 10 of the present disclosure will be described with reference to FIGS. 1 to 9. In the following description, with respect to the vertical direction, the directions appearing in FIGS. 1 and 5 are defined as upward and downward as they are. Regarding the left-right direction, the directions appearing in FIGS. 1 to 4 are defined as left and right as they are. Regarding the front-back orientation, the downward direction in FIGS. 2 and 4 and the right side in FIG. 5 are defined as forward.

The sewage treatment device 10 is a device that performs a treatment for discarding the used disposable diaper D as an object to be treated. The sewage treatment device 10 is installed in a nursing care facility or the like where a plurality of used disposable diapers D are generated irregularly with a time lag.

The disposable diaper D to be treated contains a super absorbent polymer (SAP, superabsorbent polymer, hereinafter simply referred to as polymer P) or pulp contained in a sheet material S such as a non-woven fabric. The sheet material S has a surface layer material made of a non-woven fabric made of polypropylene or the like and a waterproof material made of a resin material such as polyethylene. Pulp or polymer P is sandwiched between the surface layer material and the waterproof material. Pulp and polymer P have a water absorption performance of absorbing water from filth such as human waste and a water retention performance of keeping the water absorbed. The sheet material S contains a resin material such as polyethylene having a specific gravity smaller than that of water. The particle size of the polymer P before absorbing water is 150 to 600 μm. The polymer P that has absorbed water swells into a gel, and the particle size of the polymer P in the water-absorbing state is 600 μm to 4 mm.

The treatment of the used disposable diaper D is performed through a crushing step of crushing the disposable diaper D, a water separation treatment step of separating water from the polymer P in a water-absorbing state, and a dehydration step. In the dehydration step, the waste liquid such as water separated from the treatment liquid T and the polymer P used in the water separation treatment step is separated from the solid matter such as the sheet material S and the polymer P.

The water separation treatment step is performed by using a water separation agent R that lowers the water retention performance of the polymer P that has absorbed water. Specifically, the crushed piece F of the disposable diaper D is immersed in the treatment liquid T in which the water separating agent R is dissolved in water. The crushed piece F contains a water-absorbing polymer P. As an example of the water separating agent R, calcium chloride containing a divalent metal ion is used in this embodiment. By reacting the water separating agent R with the polymer P, the water is separated from the polymer P that has absorbed the water. The polymer P from which the water has been separated loses its water absorption performance and becomes an irreversible state in which it cannot absorb the water again. Even if the used disposable diaper D contains a polymer P that has not absorbed water, the water absorption performance of the polymer P is lost.

As shown in FIG. 1, the sewage treatment device 10 includes a multifunctional treatment device 11 and a dehydration device 60. The multifunctional processing device 11 includes a charging unit 12, a crushing device 25, a water separation treatment device 38, and a control unit 58. The multifunctional processing device 11 has a vertically long box-shaped housing 13 shared by the charging unit 12, the crushing device 25, and the water separation treatment device 38. A crushing device 25 is arranged below the charging unit 12, a water separation treatment device 38 is arranged below the crushing device 25, and a dehydration device 60 is arranged below the water separation treatment device 38.

The loading portion 12 has a box shape with an open lower surface. The inside of the loading unit 12 is a loading space 14 into which the used disposable diaper D is loaded. In the first embodiment, the charging unit 12 is provided with a first charging port 15 and a second charging port 17. The charging unit 12 may be provided with only one of the first charging port 15 and the second charging port 17. The first input port 15 is formed on the right wall portion constituting the housing 13. The first loading port 15 is provided with a first lid 16 that can be opened and closed from the outside of the loading portion 12. The first lid 16 has a central axis 16A extending in the horizontal direction (that is, in the front-rear direction) along the lower edge of the first lid 16. The central shaft 16A is supported by the housing 13. The first lid 16 rotates outward around the central axis 16A so that its posture can be changed between the standing state V and the lying state L.

A closing portion 22 is provided in the loading portion 12 so as to cover the first loading port 15 from the inside. The closing portion 22 is made of, for example, a flexible rubber or synthetic resin formed in a flat plate shape. A plurality of slits are formed in the closed portion 22 from slightly below the upper end of the closed portion 22 to the lower end. A plurality of rectangular portions 22A whose upper end portions are connected to each other are formed in the closed portion 22 by slits. The closing portion 22 is attached to the loading portion 12 so that the upper end portion thereof is along the upper end edge of the first loading port 15. For example, when the disposable diaper D is thrown into the throwing section 12 from the first throwing port 15, each rectangular portion 22A of the closing section 22 is pushed out into the throwing section 12. When the paper diaper D has been thrown into the throwing section 12, each rectangular section 22A returns to its original posture so as to close the first throwing port 15.

The used disposable diaper D generated on the floor where the sewage treatment device 10 is installed can be thrown into the throwing space 14 from the first throwing port 15. At this time, the first lid 16 is manually changed from the standing state V to the lying state L, and the first input port 15 is opened. The user loads the disposable diaper D into the loading section 12 via the first loading port 15 and the closing section 22. At this time, the first lid 16 is maintained in the prone state L in its own posture. Therefore, the first lid 16 can prevent moisture and the like adhering to the inner surface (that is, the surface located in the charging portion 12 in the standing state V) from flowing to the floor. The disposable diaper D is charged into the charging unit 12 along the inner surface of the first lid 16. Therefore, when the disposable diaper D is loaded from the first loading port 15, the posture of the disposable diaper D with respect to the crushing device 25 is likely to be stable. After loading the disposable diaper D, the user manually changes the first lid 16 from the lying state L to the standing state V, and closes the first loading port 15.

The second input port 17 is formed on the left wall portion of the wall portion constituting the housing 13, which is different from the first input port 15. The second input port 17 is provided with a second lid 18 that opens into the input space 14. The downstream end of the shooter 19 is connected to the second input port 17. The upstream end of the shooter 19 functions as a dumping port (not shown) provided on the upper floor above the floor where the sewage treatment device 10 is installed. The used disposable diaper D generated on the upper floor is thrown into the shooter 19 from the dumping port. The disposable diaper D thrown into the shooter 19 passes through the shooter 19 and pushes and moves the second lid 18 to be accommodated in the throwing space 14 from the second throwing port 17. When the disposable diaper D passes through the second input port 17, the second lid 18 closes the second input port 17 by its own weight.

The loading unit 12 is provided with a loading sensor 20 that detects that the disposable diaper D has been loaded into the loading space 14 from the first loading port 15 and the second loading port 17. The throw-in sensor 20 transmits a detection signal to the control unit 58 each time one paper diaper D is thrown in. An operation unit (not shown) is electrically connected to the control unit 58. A user who uses the sewage treatment device 10 can start or stop the operation of the sewage treatment device 10 by operating this operation unit.

A deodorizing device 21 is provided on the upper surface of the charging unit 12. As shown in FIG. 2, the first opening 12A, the second opening 12B, and the third opening 12C are formed on the upper surface of the charging portion 12. The third opening 12C is arranged along the right side edge portion of the upper surface of the loading portion 12 close to the first loading port 15 in the left-right direction. The first opening 12A and the second opening 12B are arranged along the left side edge portion of the upper surface of the loading portion 12 away from the first loading port 15 with the third opening 12C sandwiched in the left-right direction. There is.

As shown in FIG. 2, the deodorizing device 21 includes a first deodorizing device 21A and a second deodorizing device 21B. The first deodorizing device 21A and the second deodorizing device 21B are arranged side by side in the left-right direction on the upper surface of the charging unit 12. Specifically, the second deodorizing device 21B is arranged along the right side edge portion of the upper surface of the charging portion 12 close to the first charging port 15 in the left-right direction. The first deodorizing device 21A is arranged along the left side edge portion of the upper surface of the charging section 12 away from the first loading port 15 with the second deodorizing device 21B sandwiched in the left-right direction. The first deodorizing device 21A has a case 21C, an intake unit 21D, and a deodorizing unit main body 21E. The case 21C has a box shape with the upper end closed and the lower end open. The case 21C is attached so that the lower end is in contact with the upper surface of the charging portion 12. The case 21C communicates the first opening 12A and the second opening 12B of the charging portion 12.

For the intake unit 21D, for example, a known axial flow fan or the like is used. The intake unit 21D takes in air from the lower surface and blows air from the upper surface. The intake unit 21D is electrically connected to the control unit 58. The intake portion 21D is attached to the upper surface of the input portion 12 so as to cover the first opening 12A with the lower surface. The intake unit 21D is located inside the case 21C. The intake unit 21D takes in air from the input unit 12 through the first opening 12A.

For the deodorizing unit main body 21E, for example, a so-called deodorizing filter formed of a non-woven fabric or the like to which activated carbon is attached is used. The deodorizing section main body 21E is arranged so that the air blown from the upper surface (that is, the blowing surface) of the intake section 21D is blown to the front side surface of the deodorizing section main body 21E. Specifically, the deodorizing portion main body 21E is arranged in the case 21C so as to partition the side through which the first opening 12A communicates and the side through which the second opening 12B communicates. The intake unit 21D sucks the air in the charging unit 12 from the lower surface and blows the air from the upper surface toward the deodorizing unit main body 21E. The deodorizing unit main body 21E deodorizes the air blown from the upper surface of the intake unit 21D. The deodorized air is returned to the inlet 12 through the second opening 12B. The second opening 12B is a circulation port for returning the air deodorized by the first deodorizing device 21A into the input unit 12. The first deodorizing device 21A circulates air in the front-rear direction mainly in the left region in the charging unit 12 to deodorize.

The second deodorizing device 21B has a case 21F, an intake unit 21G, and a deodorizing unit main body 21H. The case 21F has a box shape in which the upper surface is closed and the lower surface and a part of the rear surface are open. The case 21F is attached so that the lower surface is in contact with the upper surface of the charging portion 12. The rear surface of the case 21F is open. The case 21F is arranged on the upper surface of the charging portion 12 so that the lower surface of the case 21F overlaps the third opening 12C of the charging portion 12.

Similar to the intake unit 21D, a known axial flow fan or the like is used for the intake unit 21G. The intake unit 21G takes in air from the lower surface and blows air from the upper surface. The intake unit 21G is electrically connected to the control unit 58. The intake portion 21G is attached to the upper surface of the input portion 12 so as to cover the third opening 12C on the lower surface of the intake portion 21G. The intake unit 21G is located in the case 21F. The intake unit 21G takes in air from the input unit 12 via the third opening 12C.

Similar to the deodorizing section main body 21E, a so-called deodorizing filter made of, for example, a non-woven fabric to which activated carbon is attached is used for the deodorizing section main body 21H. The deodorizing portion main body 21H is arranged so as to close the open rear surface of the case 21F. The air blown from the upper surface (that is, the blowing surface) of the intake section 21G is blown onto the front surface of the deodorizing section main body 21H. The deodorizing unit main body 21H discharges the deodorized air from the rear surface to the outside. At this time, the air Ex discharged to the outside is discharged toward the rear direction different from the right side where the first input port 15 is formed. As a result, the deodorized air is not discharged toward the user at a position facing the first input port 15, so that the sewage treatment device 10 can make it difficult for the user to feel the odor. The intake unit 21G sucks the air in the charging unit 12 from the lower surface and blows air from the upper surface toward the deodorizing unit main body 21H. That is, the second deodorizing device 21B takes in the odor generated from the disposable diaper D charged into the charging unit 12 from the right side of the charging unit 12 to deodorize it, and discharges the deodorized air to the outside.

The crushing device 25 is a device for crushing the disposable diaper D, which is the object to be crushed, which has been charged into the charging unit 12. The crushing device 25 includes a peripheral wall portion 26, a pair of left and right crushing members 28, and a first water supply portion 34. The peripheral wall portion 26 constitutes the housing 13 and is connected to the lower end of the wall portion of the loading portion 12. Inside the crushing device 25, a crushing space 27 surrounded by a peripheral wall portion 26 is formed. The crushing space 27 communicates with the input space 14. A pair of crushing members 28 are housed in the crushing space 27.

The pair of crushing members 28 have a cylindrical shape with the axes oriented in the front-rear direction as a whole. Each crushing member 28 has a rotating shaft 30 that is rotationally driven by a crushing motor 29. The drive of the crushing motor 29 is controlled by the control unit 58. The pair of crushing members 28 are arranged so that the axes of the rotating shaft 30 are arranged side by side at the same height. A plurality of shearing blades 31 are formed on the outer periphery of each crushing member 28. One shearing blade 31 has a disk shape concentric with the rotating shaft 30. The maximum outer diameter of the shearing blade 31 is larger than the outer diameter of the rotating shaft 30. The plurality of shearing blades 31 are arranged at regular intervals in the axial direction of the rotating shaft 30. The axial width dimension of one shear blade 31 is the same as or slightly smaller than the distance between adjacent shear blades 31.

The outer peripheral surface of each shearing blade 31 has a serrated shape in which a plurality of protrusions 32 are arranged at a constant pitch in the circumferential direction. The protruding direction of the protrusion 32 is an oblique direction with respect to the radial direction of the shear blade 31. The protrusion 32 projects so as to face forward in the rotational direction of the protrusion 32. A recess 33 is formed between the protrusions 32 adjacent to each other in the circumferential direction on the outer circumference of the shearing blade 31. The plurality of recesses 33 are arranged on the outer periphery of the shear blade 31 at intervals in the circumferential direction. The shapes of the protrusions 32 and the recesses 33 of one shearing blade 31 are symmetrical with the shapes of the protrusions 32 and the recesses 33 of the other shearing blade 31.

As shown in FIG. 3, the plurality of shearing blades 31 formed on one crushing member 28 and the plurality of shearing blades 31 formed on the other crushing member 28 alternately alternate in the axial direction of the rotating shaft 30. They are arranged side by side. In the front view shown in FIG. 1 when the sewage treatment device 10 is viewed from the front, the rotation direction of one crushing member 28 and the rotation direction of the other crushing member 28 are opposite to each other. In the region where one shear blade 31 and the other shear blade 31 overlap in the axial direction, both one shear blade 31 and the other shear blade 31 are displaced downward as the crushing member 28 rotates.

The minimum required clearance between the shear blades 31 adjacent to each other in the axial direction is such that the crushing members 28 can rotate smoothly without interfering with each other and the crushed piece F of the disposable diaper D does not get caught between the shear blades 31. Is vacant. The clearance between the shear blades 31 is, for example, 40 μm or more. There is a minimum necessary clearance between the outer circumference of the shear blade 31 of one crushing member 28 and the outer peripheral surface of the rotating shaft 30 of the other crushing member 28 so as not to hinder the rotation of both crushing members 28. There is. The clearance between the shear blade 31 and the rotating shaft 30 is, for example, 100 μm or more.

Of the shear blades 31, the portions on the opposite side of the shear blades 31 that are alternately arranged in the axial direction are displaced upward as the crushing member 28 rotates. The portion of the shear blade 31 that moves upward is arranged along the inner surface of the peripheral wall portion 26. The shearing blade 31 can rotate smoothly between the shearing blade 31 and the peripheral wall portion 26 without interfering with the peripheral wall portion 26, and the crushed piece F of the disposable diaper D does not enter between the shearing blade 31 and the peripheral wall portion 26. The minimum required clearance is available. The clearance between the shear blade 31 and the peripheral wall portion 26 is, for example, 100 μm or more.

The maximum outer diameter of one crushing member 28 and the maximum outer diameter of the other crushing member 28 have the same dimensions. The maximum outer diameter of the crushing member 28 is 120 mm, and the rotation speed of the crushing member 28 is 9 rpm. Therefore, the outer circumference of the crushing member 28, that is, the peripheral speed of the shearing blade 31 is 0.057 m / s. The outer circumference of the crushing member 28, that is, the peripheral speed of the shearing blade 31 is preferably 0.1 m / s or less. The width dimension of one shearing blade 31, that is, the axial dimension of the rotating shaft 30, is 6 mm or more and 30 mm or less. The width dimension of the shearing blade 31 is preferably larger than 4 mm, which is the particle size of the polymer P in the water-absorbing state.

The first water supply portion 34 is arranged at a position above the crushing member 28 in the peripheral wall portion 26. Water is discharged into the crushing space 27 from the first nozzle 35 of the first water supply unit 34. The water discharged from the first nozzle 35 falls on the crushing member 28 from above. The water poured onto the crushing member 28 passes through the gap between the shearing blades 31, the gap between the shearing blade 31 and the rotating shaft 30, and the gap between the shearing blade 31 and the peripheral wall portion 26, and is below the crushing member 28. Flow down to. The water supply operation of the first water supply unit 34 is controlled by the control unit 58.

The water separation treatment device 38 includes a treatment tank 39, a stirring member 48, a second water supply unit 54, and a water separation agent supply unit 56. The treatment tank 39 has a box shape, and the right side region of the upper surface of the treatment tank 39 is open. The inside of the treatment tank 39 is a treatment space for performing water separation treatment. The open right side region of the upper surface portion of the treatment tank 39 is connected to the upper end of the peripheral wall portion 26 of the crushing device 25. The crushing space 27 and the space inside the processing tank 39 communicate with each other vertically.

The bottom surface 41 of the treatment tank 39 is composed of a first inclined surface 42 formed of a flat surface and a second inclined surface 43 also formed of a flat surface. The bottom surface 41 of the treatment tank 39 is bent in a valley shape at the boundary line 44 between the first inclined surface 42 and the second inclined surface 43. The first inclined surface 42 constitutes an area on the front side of the bottom surface 41. The first inclined surface 42 is arranged below the opening region on the upper surface of the treatment tank 39, that is, below the pair of crushing members 28. The second inclined surface 43 constitutes a region on the rear side of the bottom surface 41. The second inclined surface 43 is arranged in a region displaced rearward with respect to the pair of crushing members 28.

As shown in FIG. 5, the lower end edge of the first inclined surface 42 in the left-right direction and the lower end edge of the second inclined surface 43 in the left-right direction are connected at an obtuse angle. The first inclined surface 42 is inclined so as to descend toward the rear and is inclined so as to descend toward the left. The second inclined surface 43 is inclined so as to be lowered toward the front and is inclined so as to be lowered toward the left. The boundary line 44 between the first inclined surface 42 and the second inclined surface 43 is inclined in the downward direction toward the discharge port 47 described later. The front-rear dimension of the first inclined surface 42 is larger than the front-rear dimension of the second inclined surface 43. As shown in FIG. 5, in the side view, the inclination angle β of the second inclined surface 43 with respect to the horizontal plane H is larger than the inclination angle α of the first inclined surface 42 with respect to the horizontal plane H. The inclination angle α of the first inclined surface 42 is 15 °. The inclination angle β of the second inclined surface 43 is 45 ° or less.

A circular discharge port 47 is formed on the left side wall portion 46 constituting the treatment tank 39. After the water separation treatment is completed in the treatment tank 39, the crushed pieces F, the polymer P, and the treatment liquid T in the treatment tank 39 are discharged from the discharge port 47 and sent to the dehydrator 60 through the discharge passage 64. The crushed piece F also includes lightweight shards such as a resin material having a specific gravity smaller than that of water among the sheet material S. The height dimension of the opening region of the discharge port 47, that is, the diameter dimension of the discharge port 47 is 50 mm or more. This dimension setting is based on the assumption that the maximum width dimension of the crushed piece F sheared by the shear blade 31 is about 30 mm.

The discharge port 47 opens to the right toward the inside of the treatment tank 39, and opens at the lowest position of the bottom surface 41. Specifically, the discharge port 47 is a lower end position on the left edge portion of the first inclined surface 42 and the second inclined surface 43, and is opened at a position corresponding to the boundary line 44 in the front-rear direction. Therefore, the bottom surface 41 of the treatment tank 39 is inclined so as to have a downward slope toward the discharge port 47.

The lowermost end of the discharge port 47 is located at a height close to the lowermost end of the bottom surface 41 of the processing tank 39. The maximum depth of the treatment tank 39 is the height dimension from the lowermost end (that is, the left end) of the boundary line 44 of the bottom surface 41 of the treatment tank 39 to the upper end of the treatment tank 39 (that is, the lower end of the crushing device 25). is there. The maximum depth of the treatment tank 39 is within three times the height from the bottom surface 41 of the treatment tank 39 to the uppermost end of the discharge port 47. The maximum depth of the treatment liquid T that can be stored in the treatment tank 39 is the height dimension from the bottom surface 41 to the maximum liquid level. The maximum depth of the treatment tank 39 is the same as the maximum liquid level. According to this dimensional setting, the water level of the treatment liquid T stored in the treatment tank 39 can be made relatively low, and the area of the liquid surface of the treatment liquid T can be secured widely. In the first embodiment, the left-right dimension and the front-rear dimension of the processing tank 39 are larger than the maximum depth dimension of the processing tank 39.

A stirring member 48 is provided on the bottom surface 41. As shown in FIG. 4, when the water separation treatment device 38 is viewed from above, the stirring member 48 is arranged only in the range corresponding to the first inclined surface 42 of the bottom surface 41. In the front-rear direction, the stirring member 48 is arranged at a position biased toward the rear side of the center of the first inclined surface 42, that is, the side closer to the discharge port 47 and the boundary line 44. In the left-right direction, the stirring member 48 is arranged at a position biased to the left side of the center of the first inclined surface 42, that is, to the side closer to the discharge port 47. As shown in FIG. 1, the stirring member 48 is rotationally driven by a stirring motor 50 having a drive shaft 49 in the vertical direction.

The stirring member 48 has a main body 51 having a disk shape concentric with the drive shaft 49, and a plurality of ribs 52 that rotate integrally with the main body 51. The main body 51 is parallel to the first inclined surface 42. There is a clearance between the lower surface of the main body 51 and the first inclined surface 42 so that the stirring member 48 can rotate smoothly and the crushed piece F of the disposable diaper D is not caught. The clearance between the stirring member 48 and the first inclined surface 42 is about 10 mm. The plurality of ribs 52 project from the surface of the main body 51 and extend in the radial direction from the rotation center of the main body 51. The plurality of ribs 52 are arranged radially on the upper surface of the main body 51.

The drive of the stirring motor 50 is controlled by the control unit 58. In the water separation process, the stirring member 48 is rotationally driven by the control unit 58 alternately in the forward direction and the reverse direction. The forward direction is the counterclockwise direction in FIG. 4, and the reverse direction is the clockwise direction in FIG. After the water separation treatment, the crushed piece F containing the polymer P in the treatment tank 39 and the treatment liquid T are discharged from the discharge port 47. In a plan view, the streamline 47L of the discharge stream at the discharge port 47 is in a direction perpendicular to the left side wall portion 46 in which the discharge port 47 is formed, and is in a direction parallel to the boundary line 44. Of the tangents in contact with the outer peripheral edge of the stirring member 48, the tangent perpendicular to the left wall portion 46 is parallel to the streamline 47L of the discharge flow. In other words, among the tangent lines tangent to the outer peripheral edge of the stirring member 48, the discharge port 47 exists on an extension of the tangent line parallel to the boundary line 44. Therefore, among the flows generated by the rotation of the stirring member 48 at the time of discharge, the streamline 48L of the flow toward the discharge port 47 is close to the streamline 47L of the discharge flow at the discharge port 47 in parallel.

During the water separation treatment, the rotation angle in one positive direction is 60 °. The rotation angle in the reverse direction once is 45 °, which is smaller than the rotation angle in the forward direction. In both the forward direction and the reverse direction, the rotation angle at one time is preferably 10 ° or more and 120 ° or less. The outer diameter of the stirring member 48 is 120 mm. The time required for one rotation in the forward direction is 0.3 seconds, and the time required for one rotation in the reverse direction is 0.2 seconds. The peripheral speed of the outer circumference of the stirring member 48 is 200 mm / s. The peripheral speed of the outer circumference of the stirring member 48 during the water separation treatment can be adjusted in the range of 100 to 500 mm / s. After the water separation treatment is completed and the water supply to the treatment tank 39 is started, the crushed piece F and the treatment liquid T in the treatment tank 39 are discharged, and the solid matter of the crushed piece F is recovered from the dehydrator 60. Until then, the peripheral speed of the outer circumference of the stirring member 48 is adjusted to 600 mm / s or more.

The second water supply unit 54 has a second nozzle 55 attached to the treatment tank 39. The second nozzle 55 faces the inside of the processing tank 39. The second nozzle 55 is arranged so as to discharge water toward the discharge port 47. The discharge and stop of water from the second nozzle 55 are controlled by the control unit 58. A water release agent supply unit 56 is attached to the treatment tank 39. The water release agent supply unit 56 supplies the above-mentioned water release agent R in a predetermined amount into the treatment tank 39. The supply operation and supply amount of the water release agent R are controlled by the control unit 58.

A discharge path 64 is provided between the treatment tank 39 and the dehydrator 60. The upstream end of the discharge path 64 is connected to the discharge port 47, and the downstream end of the discharge path 64 is connected to the dehydrator 60. The discharge path 64 has a form in which a downward slope is formed from the upstream end to the downstream end in the entire region from the upstream end to the downstream end. The crushed pieces F, the treatment liquid T, and the like in the treatment tank 39 flow downstream in the discharge path 64 due to their own weight and the water pressure of the treatment liquid T in the treatment tank 39.

An on-off valve 65 for opening and closing the discharge path 64 is provided in the middle of the discharge path 64. As the on-off valve 65, for example, an electric ball valve is used. When the on-off valve 65 is opened, the crushed pieces F and the processing liquid T in the processing tank 39 flow into the dehydrator 61 through the discharge port 47 and the discharge path 64. When the on-off valve 65 is closed, the crushed pieces F and the treatment liquid T in the treatment tank 39 are not discharged to the dehydrator 61 and remain in the treatment tank 39. As will be described in detail later, the opening / closing operation of the on-off valve 65 is controlled by the control unit 58.

The dehydrating device 60 includes a dehydrating machine 61, an inflow section 62, an outflow section 63, and a water collecting section 69. The inflow portion 62 is arranged at the left end portion of the dehydrator 61, and has a form in which the inflow portion 62 protrudes upward from the dehydrator 61 in a tubular shape. The downstream end of the discharge path 64 is connected to the upper end of the inflow portion 62. The crushed piece F and the treatment liquid T of the treatment tank 39 are transferred into the dehydrator 61 by passing through the discharge port 47, the discharge passage 64, the on-off valve 65, and the inflow portion 62. The inflow section 62 communicates with the discharge port 47 of the treatment tank 39 via the discharge path 64. The outflow portion 63 is arranged at the right end portion of the dehydrator 61, and has a form in which the outflow portion 63 projects downward from the dehydrator 61 in a tubular shape. A collection port 71 that opens downward is formed at the lower end of the outflow portion 63.

The dehydrator 60 is arranged directly below the processing tank 39. The inflow portion 62 is arranged at the left end portion of the dehydrator 60. The discharge port 47 is arranged at the left end of the treatment tank 39. Therefore, the length of the discharge path 64 of the first embodiment is the shortest path as compared with the case where either the discharge port 47 or the inflow portion 62 is arranged at a position opposite to that of the present embodiment. It has become. Since the discharge path 64 is a path for sending the crushed piece F and the treatment liquid T to the dehydrator 60 by its own weight and the water pressure of the treatment liquid T in the treatment tank 39, the short path length means that the crushed piece F in the discharge path 64. Means that it is hard to get clogged.

A dehydration filter 66 and a screw 67 as a transfer member are housed in the dehydrator 61. The dehydration filter 66 has a cylindrical shape with the axis directed to the left and right. The mesh size of the dehydration filter 66 is, for example, 300 μm. The size of this eye is smaller than the particle size of the polymer P in the water-separated state after the water is separated from the water-absorbing state. The internal space of the dehydration filter 66 is a transfer space 66S for transferring the crushed piece F. The upstream end of the transfer space 66S communicates with the lower end of the inflow portion 62, and the downstream end of the transfer space 66S communicates with the upper end of the outflow portion 63.

The screw 67 has a shaft portion 67A and a feed plate 67B that spirally protrudes from the outer circumference of the shaft portion 67A. The screw 67 is coaxially housed in the dehydration filter 66 and is rotationally driven by the dehydration motor 68. The operation of the dehydration motor 68 is controlled by the control unit 58. The screw 67 rotates in the direction of transferring the crushed piece F and the treatment liquid T transferred from the inflow section 62 into the transfer space 66S to the outflow section 63. The crushed piece F that does not pass through the mesh of the dehydration filter 66 is carried to the downstream end of the transfer space 66S by the feed plate 67B of the screw 67, falls in the outflow portion 63, and is collected from the collection port 71.

A water collecting portion 69 is formed in a region of the lower surface portion of the dehydrator 61 corresponding to the dehydration filter 66. In the transfer direction by the screw 67, the water collecting portion 69 opens upward toward the transfer space 66S over the entire range from the upstream end to the downstream end of the transfer path by the screw 67, that is, the transfer space 66S. A drainage port 70 is formed at the lowest position of the water collecting portion 69. In the process in which the screw 67 transfers the crushed piece F and the treatment liquid T in the transfer space 66S, the waste liquid containing the treatment liquid T flows down to the outside of the transfer space 66S through the mesh of the dehydration filter 66. The waste liquid that has flowed out of the transfer space 66S is collected by the water collecting unit 69 and discharged from the drain port 70 to sewage or the like via a drain pipe (not shown).

The axis of the screw 67 is the same as the axis of the dehydrator 61, and is parallel to the transfer direction by the screw 67. In a plan view (not shown), the axis of the screw 67 is parallel to the boundary line 44 of the processing tank 39. As shown in FIG. 1, in the side view, the axis of the screw 67 is inclined with respect to the horizontal direction. Specifically, the axis of the screw 67 is inclined so that the downstream end in the transfer direction is higher than the upstream end in the transfer direction among both ends of the screw 67 in the transfer direction. Therefore, as compared with the case where the axis of the screw 67 is horizontal, the height difference between the collection port 71 protruding downward from the downstream end in the transfer direction of the dehydrator 61 and the lower end of the upstream end in the transfer direction of the dehydrator 61 is smaller. ing. The direction in which the screw 67 transfers the crushed piece F in the transfer space 66S is a direction in which the crushed piece F is lifted against gravity.

The treatment tank 39 is arranged above the dehydrator 60. The boundary line 44 of the bottom surface 41 of the treatment tank 39 is inclined so as to descend from the downstream end side to the upstream end side in the transfer direction of the screw 67. As shown in FIG. 1, when the sewage treatment device 10 is viewed from the front, the direction of inclination of the bottom surface 41 of the treatment tank 39 and the direction of inclination of the top surface of the dehydrator 61 are the same. As a result, the vertical dead space between the bottom surface 41 of the processing tank 39 and the top surface of the dehydrator 61 is narrowed.

The control unit 58 controls the timing of starting the water separation process according to the amount of the disposable diaper D charged into the charging unit 12 and the elapsed time after the feeding of the disposable diaper D. The control unit 58 controls the water separation treatment time in the water separation treatment device 38 and the timing of transferring the crushed piece F and the treatment liquid T after the water separation treatment to the dehydration device 60.

The sewage treatment device 10 can efficiently treat a plurality of used disposable diapers D that are generated irregularly with a time lag. The process will be described below. First, the processing amount setting unit 72, the standby time setting unit 73, and the stirring setting unit 75 make settings. In the processing amount setting unit 72, the number of paper diapers D, which is a condition for starting the water separation treatment, is set as the processing number. In the present embodiment, the set processing number is a number corresponding to the maximum processing capacity of the sewage treatment apparatus 10, but an arbitrary number can be set. Further, the number of setting processes is not limited to a plurality, and may be one. The set number of processing is input from the processing amount setting unit 72 to the control unit 58 as the number of disposable diapers D to be processed in one water separation treatment step.

The standby time setting unit 73 sets the standby time, which is a condition for starting the water separation process. This waiting time is the longest time that can be waited from the time when the disposable diaper D is first put into the charging unit 12 after the end of the previous water separation treatment until the crushing treatment is started. In the stirring setting unit 75, conditions related to the rotational operation of the stirring member 48 are set. Specifically, the time for the stirring member 48 to continue the rotational operation, the rotation angle of the stirring member 48 in the forward direction and the reverse direction, and the rotation speed of the stirring member 48 are set. The conditions related to the rotational operation of the stirring member 48 set by the stirring setting unit 75 are input to the control unit 58.

Next, among the processing steps of the disposable diaper D, the control step executed by the control unit 58 before the crushing process starts will be described with reference to the flowchart of FIG. When the first used disposable diaper D is charged into the charging space 14 from either the first charging port 15 or the second charging port 17 after the previous water separation treatment is completed, a detection signal is sent from the charging sensor 20. It is input to the control unit 58. When the control unit 58 first detects that the used disposable diaper D has been thrown into the throwing space 14 (step S10), the control unit 58 activates the timer 74 (step S11). When the used disposable diaper D is first charged into the charging space 14 after the previous water separation treatment is completed, the deodorizing device 21 starts operation.

The control unit 58 compares whether or not the number of inserted disposable diapers D has reached the same number as the set number of processed diapers D at predetermined time intervals (step S12). When the number of disposable diapers D to be loaded reaches the set number of processes, the control unit 58 starts the crushing process (step S13). When the number of disposable diapers D has not reached the set number of processes, the control unit 58 determines the waiting time set by the standby time setting unit 73 after the first disposable diaper D is loaded after the previous water separation process is completed. It is determined whether or not the elapse has passed (step S14). If the countdown of the timer 74 is not completed, it is determined that the waiting time has not elapsed. When the control unit 58 determines in step S14 that the waiting time has not elapsed, the control unit 58 again determines whether or not the number of inserted disposable diapers D has reached the same number as the set number of processes (step S12). When the control unit 58 determines that the number of input of the disposable diapers D in step S12 has reached the set number of processes, the control unit 58 starts the crushing process (step S13).

In step S14, when the countdown of the timer 74 is completed, the control unit 58 determines that the waiting time has elapsed since the disposable diaper D was first inserted. When the waiting time has elapsed, the control unit 58 starts the crushing process even if the number of disposable diapers D put in is less than the set number of processes (step S13). Even when the number of set processes is a plurality and the number of disposable disposable diapers D is only one, the control unit 58 starts the crushing process when the waiting time elapses. In the crushing process, the control unit 58 activates the crushing motor 29. Immediately after the thrown-in paper diaper D is thrown in, it is crushed by a pair of shearing blades 31 to form strip-shaped crushed pieces F and fall into the processing tank 39. The crushed piece F after crushing contains the polymer P in the water supply state.

The crushing member 28 may continue to rotate at all times, or may be rotated only while the disposable diaper D is crushed. The amount of water supplied from the first water supply unit 34 is only the amount required for crushing and separating water from one disposable diaper D. While the maximum particle size of the water-absorbing polymer P is about 4 mm, the width dimension of the shearing blade 31 of the crushing member 28 is 6 mm or more, so that the water-absorbing polymer P may be sheared by the shearing blade 31. Absent. Since the peripheral speed of the outer circumference of the shearing blade 31 is as low as 0.1 m / s or less, crushing of the polymer P in the water-absorbing state can be avoided even by setting the speed. Since the width dimension of the shearing blade 31 is 30 mm or less, the sheet material S of the disposable diaper D can be finely sheared into strips. Since the crushed crushed piece F is hooked on the protrusion 32 on the outer periphery of the shearing blade 31 and fits into the recess 33, it can be reliably dropped into the processing tank 39 below the crushing member 28.

The control of the water separation treatment and the dehydration treatment by the control unit 58 will be described with reference to the flowchart of FIG. The control unit 58 starts the rotation of the stirring member 48 (step S20). Next, the water separating agent R made of calcium chloride is charged into the treatment tank 39, and water supply from the first water supply unit 34 is started (step S21). It is preferable that the water release agent R and the water supply from the first water supply unit 34 are started at the same time, but the water release agent R and the water supply from the first water supply unit 34 may be started at different times. The water supplied from the first water supply unit 34 cleans the crushing member 28 and flows down into the treatment tank 39. After the predetermined amount of water is supplied, the water supply from the first water supply unit 34 is stopped (step S22).

The amount of the water separating agent R added is controlled by the control unit 58 so as to be an appropriate amount based on the number of disposable diapers D to be treated for water separation, that is, the mass. When the water separating agent R is dissolved in the water supplied into the treatment tank 39, it becomes the treatment liquid T for the water separation treatment. In the first embodiment, the water separating agent R and water are separately supplied to the treatment tank 39, but the treatment liquid T in which the water separating agent R is dissolved in water in advance may be supplied to the treatment tank 39. The water separation treatment is a treatment in which the water retention performance of the polymer P of the crushed piece F immersed in the treatment liquid T is lowered by the water release agent R in the water separation liquid, and water is separated from the polymer P. The reaction rate of the water separation treatment increases as the amount of the water separation agent R increases, that is, as the concentration of the treatment liquid T increases.

As shown in FIG. 8, as the water separation treatment time elapses, the particle size of the water-absorbing polymer P gradually decreases, and the mass of the polymer P becomes lighter. The mass and particle size of the polymer P are typical parameters indicating the water absorption state of the polymer P. The particle size of the polymer P before water absorption is about 400 μm as shown by the reference numeral Ga in FIG. 8, and the mass is about 0.02 mg. The particle size of the water-absorbing polymer P is about 1400 μm as shown by the reference numeral Gb in FIG. 8, and the mass is about 0.8 mg. When the treatment liquid T is a solution having calcium chloride as a water separating agent R and having a concentration of 1%, the particle size of the polymer P is reduced to about 600 μm and the mass of the polymer P is 0 when 250 seconds have passed from the start of the water separation treatment. Lightens to .06 mg. After 300 seconds have passed from the start of the water separation treatment, the particle size and mass of the polymer P remain constant.

The stirring member 48 alternately repeats the operation of rotating in the forward direction, which is the counterclockwise direction in FIG. 4, and the operation of rotating in the opposite direction. Therefore, even if the crushed pieces F are piled up on the stirring member 48 at the start of rotation of the stirring member 48, the crushed pieces F are broken and crushed by moving the stirring member 48 in both forward and reverse directions. One piece F is dispersed in the treatment liquid T. Since the peripheral speed of the outer circumference of the stirring member 48 is slower than 500 mm / s, the crushed piece F and the treatment liquid T are not radially bounced off.

The rotation angle of the stirring member 48 in the forward direction is 60 °, while the rotation angle of the stirring member 48 in the reverse direction is 45 °. The stirring member 48 rotates intermittently in the forward direction due to the difference in the forward and reverse rotation angles. Due to the intermittent rotation operation of the stirring member 48 in the positive direction, the processing liquid T and the crushed piece F flow as a spiral rectification as a whole in the region of the processing tank 39 far from the stirring member 48. Turbulence occurs in the vicinity of the stirring member 48, and the treatment liquid T and the crushed piece F move finely. Due to these movements, the water separating agent R comes into contact with the polymer P and the water separating treatment proceeds.

The control unit 58 determines whether or not a predetermined water separation treatment time has elapsed since the water separation treatment time started (step S23). When the predetermined water separation treatment time has elapsed, the water separation treatment is completed. The predetermined water separation treatment time is shorter than the time required for the water to be completely separated from the polymer P. The particle size and mass of the polymer P at the time when the water separation treatment time has elapsed are larger than the particle size and mass of the polymer P when the water separation is completely performed.

When the water separation treatment is completed, the control unit 58 starts water supply from the first water supply unit 34 and the second water supply unit 54 to the treatment tank 39 (step S24). Since the concentration of the treatment liquid T in the treatment tank 39 is lowered by this water supply, the progress of the water separation treatment by the water release agent R is stopped. During this time, the polymer P is in an irreversible state. When the water supply to the treatment tank 39 progresses to a certain extent, the water supply to the treatment tank 39 is stopped (step S25). After that, the control unit 58 rotates the stirring member 48 in the forward direction to start the rotation of the screw 67 (step S26), and then opens the on-off valve 65 (step S27).

When the on-off valve 65 is opened, the processing liquid T and the crushed piece F in the processing tank 39 are discharged from the discharge port 47. In the process of discharging the treatment liquid T and the crushed piece F from the discharge port 47, the stirring member 48 continues to rotate in the forward direction. Since the viscosity of the treatment liquid T is lowered by the water supply from the first water supply unit 34 and the second water supply unit 54, the flow resistance is small and the discharge from the discharge port 47 is smoothly performed. The direction of the discharge flow at the discharge port 47 is parallel to the boundary line 44 between the first inclined surface 42 and the second inclined surface 43. Of the vortex flow generated by the stirring member 48, a part of the flow in the region tangent to the boundary line 44 is parallel to the boundary line 44 and heads toward the discharge port 47. Therefore, the flow velocity of the discharge flow at the discharge port 47 is increased. Further, when the on-off valve 65 is opened, water is temporarily supplied from the second nozzle 55 of the second water supply unit 54 toward the discharge port 47 (step S28). This water supply increases the flow velocity of the discharge flow from the discharge port 47.

In the process in which the treatment liquid T and the crushed piece F in the treatment tank 39 are discharged through the discharge path 64, the control unit 58 controls the opening / closing operation of the on-off valve 65 and the water supply operation of the second water supply unit 54. An example of the control mode will be described with reference to the graph of FIG. The horizontal axis of the graph represents the elapsed time in seconds since the opening of the on-off valve 65 was started. The polygonal line Gc represents a change in the opening degree of the on-off valve 65. The opening degree of the on-off valve 65 is shown with the opening degree when fully opened as 6 on the vertical axis on the right side of the graph. The vertically long bar represents the flow rate of the discharge flow when the opening degree of the on-off valve 65 is increased. The flow rate value is shown on the left vertical axis, and the unit is liter. The polygonal line Gd represents the cumulative flow rate of the discharge path 64 after the on-off valve 65 is opened.

The control unit 58 changes the opening degree of the on-off valve 65 with time in the discharge process in the discharge path 64. Within 10 seconds after starting the opening of the on-off valve 65, the opening of the on-off valve 65 is increased to about 60% of the fully opened state. During this time, the flow rate in the discharge path 64 increases, and the crushed piece F and the treatment liquid T flow out to the dehydrator 60 side. After that, in 10 seconds, the opening is narrowed down to a state close to fully closed. When the opening degree is reduced, the flow rate in the discharge path 64 is reduced to a value close to zero. After maintaining the state in which the opening degree is narrowed for 10 seconds, the opening degree is increased to 60% of the fully opened state to increase the flow rate in the discharge path 64.

After that, the opening degree is reduced again in 10 seconds, and the closed state is maintained for 10 seconds. After that, the opening degree of the on-off valve 65 is fully opened within 10 seconds. In the fully open state, the flow rate of the discharge path 64 is higher than when the opening degree is about 60%. Further, in the fully open state, water is discharged from the second nozzle 55 of the second water supply unit 54 toward the discharge port 47. As a result, the flow velocity in the discharge path 64 becomes high. After fully opening, the opening is narrowed down to near fully closed over 10 seconds. After that, the operation of opening the opening to about 60% as described above is performed twice, and then the operation of fully opening the opening is repeated once.

When the opening and closing of the on-off valve 65 is repeatedly increased and decreased, the maximum peak of the opening of the on-off valve 65 is repeated a plurality of times. In this process, the opening at the maximum peak time accompanied by the discharge of water from the second water supply unit 54 is fully open. On the other hand, the maximum peak opening without water discharge from the second water supply unit 54 is about 60%, which is smaller than the peak opening with water supply from the second water supply unit 54. .. Therefore, the fluctuation range of the flow velocity in the discharge path 64 becomes large. By repeating the increase and decrease of the opening degree of the on-off valve 65 in this way, the flow of the crushed piece F and the processing liquid T in the discharge path 64 becomes a turbulent state. In a turbulent state, the crushed pieces F are less likely to be entangled with each other in the discharge path 64, and the crushed pieces F are less likely to concentrate at the entrance of the on-off valve 65. Therefore, there is no possibility that the crushed piece F will be clogged in the on-off valve 65. Further, since the opening degree of the on-off valve 65 is not fully closed, there is no possibility that the strip-shaped component of the disposable diaper D is caught in the on-off valve 65 and clogged.

The treatment liquid T and the crushed piece F discharged from the discharge port 47 are transferred into the dehydrator 61 through the discharge path 64. In the dehydrator 61, the crushed piece F containing the treatment liquid T is pushed by the feed plate 67B of the screw 67 and compressed in the axial direction, so that the water in the crushed piece F seeps out. The exuded water passes through the eyes of the dehydration filter 66 and is discharged from the drain port 70. The crushed piece F containing the polymer P pushed by the screw 67 is recovered from the recovery port 71.

In the dehydration filter 66, since a part of the polymer P comes into contact with the inner peripheral surface of the dehydration filter 66, there is a concern that it may pass through the eyes of the dehydration filter 66. However, in the crushing device 25, the peripheral speed of the shear blade 31 is set to a low speed of 0.1 m / s, and the width dimension of the shear blade 31 is set to 6 mm or more, which is larger than the particle size of the polymer P in the water absorbing state. Therefore, the polymer P in the water-absorbing state falls into the treatment tank 39 of the water separation treatment device 38 as large particles without being sheared. Further, in the water separation treatment apparatus 38, the water separation treatment is completed before the water is completely separated from the polymer P, so that the particle size of the polymer P is maintained in a state having a certain size. Therefore, there is no possibility that the polymer P will pass through the eyes of the dehydration filter 66.

When the collection of the crushed piece F from the collection port 71 is completed (step S29), the control unit 58 stops the rotation of the stirring member 48 (step S30) and stops the rotation of the screw 67 (step S31). The deodorizing device 21 also stops operating. With the above, the water separation treatment and the dehydration treatment are completed. After the collection of the crushed piece F is completed from the collection port 71, the user operates the operation unit to stop the rotation of the stirring member 48, the rotation of the screw 67, and the operation of the deodorizing device 21. May be good.

The crushing device 25 has a housing 13 into which the paper diaper D as a material to be crushed containing the water-absorbing polymer P is put, and a crushing member 28 housed in the housing 13 for crushing the paper diaper D. The moving speed of the crushing member 28 is 0.1 m / s or less. When the disposable diaper D is crushed by the shearing blade 31 moving at a speed of 0.1 m / s or less, the water-absorbing polymer P contained in the disposable diaper D passes through the crushing device 25 with almost no crushing. Therefore, after the crushing treatment, the polymer P can be recovered by the dehydration filter 66 in the dehydrator 60.

The crushing member 28 can rotate about the rotation shaft 30. A shear blade 31 is formed on the outer circumference of the crushing member 28. The moving speed of the crushing member 28 is the peripheral speed of the tooth tip of the shearing blade 31 when the crushing member 28 is rotated. The peripheral speed of the tooth tip of the shear blade 31 is 0.1 m / s or less. Since the disposable diaper D is sent in the rotational direction of the crushing member 28 while being crushed by the shearing blade 31, the disposable diaper D is more likely to pass through the crushing member 28 than the one in which the shearing blade 31 reciprocates in parallel.

The two rotating shafts 30 are arranged parallel to each other. The object to be crushed is crushed between the shearing blade 31 of one rotating shaft 30 and the shearing blade 31 of the other rotating shaft 30. Since the paper diaper D is caught between the two shear blades 31, the paper diaper D can be reliably crushed. Since the shearing blade 31 of one rotating shaft 30 and the shearing blade 31 of the other rotating shaft 30 are arranged so as to be aligned in the axial direction of the rotating shaft 30, the paper diaper D is surely placed between the two shearing blades 31. Can be crushed.

The rotation directions of the two rotation shafts 30 are opposite to each other. The proximity portion of the shear blade 31 of one rotating shaft 30 and the shear blade 31 of the other rotating shaft 30 moves in the same direction as each other, that is, downward. The crushed piece F of the disposable diaper D can surely pass through the crushing device 25 by being fed by the two shear blades 31. The shear blade 31 has a recess 33 in which the outer peripheral surface of the shear blade 31 is recessed. The crushed piece F of the disposable diaper D after shearing can surely pass through the crushing device 25 by being caught in the recess 33.

The plurality of shear blades 31 are arranged adjacent to each other in a direction intersecting the moving direction of the shear blade 31, that is, in the axial direction of the rotation shaft 30. The width dimension of the shear blades 31 in the alignment direction is 6 mm or more. Since the maximum outer diameter of the water-absorbing polymer P is about 4 mm, it is possible to prevent the polymer P from being crushed by the shear blade 31. The plurality of shearing blades 31 are arranged adjacent to each other in a direction intersecting the moving direction of the shearing blades 31, and the width dimension in the arrangement direction of the shearing blades 31 is 30 mm or less. When the disposable diaper D contains the sheet material S, the crushed pieces F of the sheet material S can be made finer, so that the crushed pieces F can be easily processed.

The sewage treatment device 10 includes a charging unit 12, a crushing device 25, and a control unit 58. A disposable diaper D containing a water-absorbing polymer P is charged into the charging unit 12. The crushing device 25 performs a process of crushing the inserted disposable diaper D. The control unit 58 starts the crushing process of the crushing device 25 on condition that the amount of the disposable diaper D charged into the charging unit 12 reaches a predetermined amount. A plurality of disposable diapers D loaded into the loading unit 12 with a time lag can be crushed together. Therefore, regarding the processing of the disposable diaper D that is loaded later, it is not necessary to wait until the crushing treatment of the disposable disposable diaper D that is loaded earlier is completed, so that the efficiency of the crushing treatment is high.

The predetermined amount at which the control unit 58 starts the crushing process is an amount corresponding to the maximum processing capacity of the water separation treatment device 38. Since the treatment capacity of the water separation treatment device 38 can be maximized, the number of times of water separation treatment can be reduced. The sewage treatment device 10 includes a treatment amount setting unit 72 capable of changing a predetermined amount. Since the amount of the disposable diaper D to be subjected to the water separation treatment at one time can be appropriately set according to the frequency of feeding the disposable diaper D and the like, the efficiency of the water separation treatment can be improved.

The sewage treatment device 10 is installed in a large building such as a nursing care facility or a building with multiple floors. Since the charging unit 12 has a first charging port 15 and a second charging port 17, the number of charging units 12 can be reduced. Since the disposable diapers D thrown in from the plurality of inlets are subjected to the water separation treatment in the common water separation treatment device 38, the number of the water separation treatment devices 38 can be reduced.

The control unit 58 starts the crushing process of the crushing device 25 on condition that a predetermined waiting time has elapsed from the first charging of the object to be processed after the water separation process is completed. Even if the amount of the disposable diaper D charged into the charging unit 12 has not reached a predetermined amount, the crushing process is started when a predetermined waiting time elapses after the first disposable diaper D is charged after the crushing process. Since there is no possibility that the disposable diaper D is left for a long time without being separated from water, it is possible to avoid an unpleasant situation caused by the odor of the disposable diaper D.

The sewage treatment device 10 includes a standby time setting unit 73 capable of changing a predetermined standby time. The waiting time of the unprocessed disposable diaper D can be appropriately set according to the frequency of inserting the disposable disposable diaper D and the like. It is possible to avoid an unpleasant situation caused by the odor of the untreated disposable diaper D without reducing the efficiency of the water separation treatment.

The water separation treatment device 38 of the sewage treatment device 10 includes a treatment tank 39 and a stirring member 48 rotatably provided in the treatment tank 39. The treatment tank 39 can accommodate a crushed piece F of a disposable diaper D having a water-absorbing polymer P and a treatment liquid T that reduces the water retention capacity of the polymer P. The stirring member 48 has a disk-shaped main body 51 and ribs 52 protruding from the surface of the main body 51. The rib 52 extends in the radial direction from the center of rotation of the main body 51.

The crushed disposable diaper D put into the treatment tank 39 is stirred together with the treatment liquid T by the stirring member 48. By stirring, the water retention capacity of the polymer P is reduced by the treatment liquid T, and the water retained in the polymer P is separated from the polymer P. Since the stirring member 48 has a shape in which ribs 52 in the radial direction are projected from the surface of the rotating disk-shaped main body 51, even if the crushed piece F of the disposable diaper D is strip-shaped, the crushed piece F is the stirring member 48. There is no risk of getting entangled in.

The stirring member 48 is arranged on the bottom surface 41 of the processing tank 39 and can rotate about the drive shaft 49 in the vertical direction. The rib 52 projects from the upper surface of the main body 51. Since the height dimension of the stirring member 48 is small, the stirring member 48 exhibits a sufficient stirring function even if the amount of the crushed piece F and the processing liquid T charged into the processing tank 39 is small.

Since the stirring member 48 can rotate in both the forward and reverse directions, the stirring member 48 exhibits a sufficient stirring function even if the crushed pieces F of the disposable diaper D are piled up on the upper surface of the stirring member 48. Can be done. Since the rotation angle of the stirring member 48 in the forward direction and the rotation angle in the opposite direction is 10 ° or more and 120 ° or less, it is possible to prevent the crushed piece F of the disposable diaper D from being entangled with the stirring member 48.

Since the stirring member 48 can rotate alternately in the forward direction and the reverse direction, it is possible to prevent the crushed piece F of the disposable diaper D from being caught by the stirring member 48. The rotation angle of the stirring member 48 in the forward direction is larger than the rotation angle of the stirring member 48 in the reverse direction. Even if the rotation direction of the stirring member 48 is alternately switched between the forward direction and the reverse direction, the rotation operation of the stirring member 48 proceeds in the forward direction. The crushed piece F and the treatment liquid T in the treatment tank 39 are stirred so as to rotate in one direction as a whole. The rotation time of the stirring member 48 in the forward direction is longer than the rotation time of the stirring member 48 in the reverse direction. The difference in rotation time between the forward direction and the reverse direction can prevent the crushed piece F of the disposable diaper D from being entangled with the stirring member 48.

The peripheral speed of the outer circumference of the stirring member 48 is 100 to 500 mm / s. Due to this peripheral speed, the stirring member 48 can exhibit a sufficient stirring function. At this peripheral speed, there is no possibility that the crushed piece F and the processing liquid T are bounced off by the rotation of the stirring member 48.

The treatment tank 39 has a discharge port 47 for discharging the crushed pieces F and the treatment liquid T in the treatment tank 39. Of the flows generated by the rotation of the stirring member 48 when discharging from the discharge port 47, the streamline 48L of the flow toward the discharge port 47 is substantially parallel to the streamline 47L of the discharge flow at the discharge port 47. It overlaps with the streamline 47L of the discharge stream at the discharge port 47. The crushed piece F and the treatment liquid T can be effectively discharged.

The discharge port 47 is opened so as to face the peripheral edge of the bottom surface 41 of the treatment tank 39. The stirring member 48 is arranged at a position closer to the discharge port 47 than the center on the bottom surface 41 of the processing tank 39. Since the flow generated by the stirring member 48 flows strongly into the discharge port 47, it is possible to prevent the disposable diaper D from being clogged in the discharge port 47.

The bottom surface 41 of the processing tank 39 includes a first inclined surface 42 that supports the stirring member 48, and a second inclined surface 43 that is connected to the boundary line 44 that is the lowermost edge of the first inclined surface 42. .. The inclination angle α of the first inclined surface 42 with respect to the horizontal plane H is smaller than the inclination angle β of the second inclined surface 43 with respect to the horizontal plane H. Even if the amount of the treatment liquid T is small, the stirring member 48 can be immersed in the treatment liquid T. Even if the crushed piece F of the disposable diaper D is placed on the second inclined surface 43, the crushed piece F slides down to the first inclined surface 42 side due to the inclination of the second inclined surface 43.

The sewage treatment device 10 has a discharge port 47 for discharging the crushed pieces F and the treatment liquid T in the treatment tank 39, and a first water supply unit 34 and a second water supply unit 54. The first water supply unit 34 and the second water absorption unit supply water to the treatment tank 39 when discharging from the discharge port 47. When water is supplied from the first water supply unit 34 and the second water supply unit 54 to the treatment tank 39, the concentration of the treatment liquid T decreases, so that the flow velocity of the discharge flow at the discharge port 47 increases, and the discharge efficiency improves. Since the second water supply unit 54 has a second nozzle 55 that discharges water toward the discharge port 47, the discharge efficiency is further improved.

The sewage treatment device 10 includes a water separation treatment device 38, a dehydration device 60, and a control unit 58. The water separation treatment device 38 performs a water separation treatment for separating water from the water-absorbing polymer P by a treatment liquid T that reduces the water retention capacity of the polymer P. The dehydrating device 60 separates the treatment liquid T and the polymer P transferred from the water separation treatment device 38 by the dehydration filter 66. An on-off valve 65 is provided in the discharge path 64 for transferring the treatment liquid T and the polymer P in the water separation treatment device 38 to the dehydration device 60. The control unit 58 opens the on-off valve 65 after supplying water to reduce the concentration of the treatment liquid T. The control unit 58 opens the on-off valve 65 in a state where the polymer P immersed in the treatment liquid T has a larger representative parameter indicating the degree of water absorption than the polymer P before water absorption, and the polymer in the water separation treatment device 38. Control for transferring P to the dehydrator 60 is performed.

A representative parameter indicating the degree of water absorption includes the mass of the polymer P in the water absorption state. Since the polymer P during the water separation treatment is transferred to the dehydrator 60 in a state heavier than the polymer P before water absorption, the polymer P shifts to the water separation treatment step using a filter in a state having a relatively large particle size. Therefore, the polymer P can be easily recovered by the filter.

A representative parameter indicating the degree of water absorption includes the particle size of the polymer P in the water absorption state. The control unit 58 transfers the polymer P in the water separation treatment device 38 to the dehydration device 60 in a state where the particle size of the polymer P immersed in the treatment liquid T is larger than the particle size of the polymer P before water absorption. According to this configuration, the polymer P during the water separation treatment is transferred to the dehydrator 60 in a state where the particle size is larger than that of the polymer P before water absorption, so that the polymer P can be easily recovered by the filter.

The control unit 58 transfers the polymer P in the water separation treatment device 38 to the dehydration device 60 based on the elapsed time of the water separation treatment. During the water separation treatment, the amount of water separated from the polymer P increases with the passage of time, and the particle size of the polymer P decreases. Since the particle size of the polymer P can be estimated based on the elapsed time of the water separation treatment, the dehydration treatment can be started without checking the mass and the particle size of the polymer P.

The water separation treatment device 38 includes a treatment tank 39 that stores the polymer P and the treatment liquid T and performs water separation treatment, and a first water supply unit 34 and a second water supply unit 54. The first water supply unit 34 and the second water supply unit 54 supply water to the treatment tank 39 before the polymer P and the treatment liquid T that have been separated from each other are transferred to the dehydrator 60. After the water separation treatment is completed, the concentration of the treatment liquid T is diluted by the supply of water from the first water supply unit 34 and the second water supply unit 54. As a result, the progress of water separation from the polymer P is suppressed, and the particle size of the polymer P in the dehydration step can be kept large. Since the viscosity of the treatment liquid T is lowered, the transfer from the water separation treatment device 38 to the dehydration device 60 can be smoothly performed.

The crushing device 25 includes a first lid 16 that closes the first input port 15 in the upright state V and opens it in the lying state L. The first lid 16 changes into an upright state V and a prone state L around a central axis 16A extending laterally along the lower end edge of the first lid 16. In the crushing device 25, since the first input port 15 is covered by the first lid 16, odor is suppressed from leaking to the outside, and when the first lid 16 is in the inverted state L, it adheres to the inner surface of the first lid 16. It is possible to prevent the water from falling onto the floor surface or the like.

The crushing device 25 includes a deodorizing device 21 that deodorizes the odor generated based on the put-in disposable diaper D. The crushing device 25 can weaken the odor by deodorizing the odor in the charging unit 12. As a result, even when the first inlet 15 is opened, the odor flowing from the first inlet 15 to the outside can be weakened.

The deodorizing device 21 of the crushing device 25 is arranged above the charging section 12. The odor generated based on the disposable diaper D tends to rise upward. The crushing device 25 can surely catch the odor rising upward at the upper part of the charging unit 12 and deodorize it.

The deodorizing device 21 has a first deodorizing device 21A that returns the air after deodorizing the odor generated based on the charged disposable diaper D to the charging unit 12. Therefore, the crushing device 1 can repeatedly deodorize the air in the charging section 12 by the first deodorizing device 21A, and more reliably weaken the odor in the charging section 12.

The charging unit 12 of the crushing device 25 is formed with a second opening 12B for returning air into the charging unit 12. The second opening 12B is provided at a position away from the side surface where the first charging port 15 is provided in the upper part of the charging portion 12. Therefore, the air deodorized by the first deodorizing device 21A is returned to the charging unit 12 at a position away from the first charging port 15. As a result, the flow of air from the first inlet 15 to the outside can be suppressed, so that the odor can be suppressed from leaking to the outside from the first inlet 15.

The deodorizing device 21 has a second deodorizing device 21B. The second deodorizing device 21B discharges the air after deodorizing the odor generated based on the disposable diaper D charged into the charging unit 12 to the outside. Therefore, the pressure inside the charging unit 12 can be set to negative. As a result, even when the first inlet 15 is open, it is possible to prevent the odor from leaking to the outside from the first inlet 15.

The sewage treatment device 10 includes a treatment tank 39 in which a crushed piece F of a disposable diaper D having a water-absorbing polymer P as an object to be treated and a treatment liquid T for reducing the water retention capacity of the polymer P are housed. A discharge port 47 for discharging the crushed pieces F and the treatment liquid T in the treatment tank 39 is open on the side surface of the treatment tank 39. Since the discharge port 47 is opened not on the bottom surface 41 of the treatment tank 39 but on the side surface of the treatment tank 39, the lightweight debris having a specific gravity smaller than that of the treatment liquid T among the crushed pieces F is treated in the treatment tank 39. While the liquid T remains, it is discharged together with the treatment liquid T from the discharge port 47. The crushed piece F of the disposable diaper D in the processing tank 39 can be discharged without remaining on the bottom surface 41 of the processing tank 39.

The height dimension from the bottom surface 41 of the treatment tank 39 to the liquid level at the time of maximum storage of the treatment liquid T is within three times the height from the bottom surface 41 of the treatment tank 39 to the uppermost end of the discharge port 47. According to this dimensional setting, the water level of the treatment liquid T stored in the treatment tank 39 can be made relatively low, and the area of the liquid level of the treatment liquid T can be secured widely. Therefore, the liquid level of the treatment liquid T can be secured. It is possible to reduce the uneven distribution of lightweight debris floating on the surface. This makes it possible to prevent lightweight debris from remaining on the bottom surface 41 of the processing tank 39.

Since the width dimension of one shearing blade 31 is 30 mm or less, the width dimension of the crushed piece F sheared by the shearing blade 31 is about 30 mm at the maximum. Focusing on this point, the height dimension of the opening region of the discharge port 47 was set to 50 mm or more. With this dimensional setting, lightweight debris can be reliably discharged from the discharge port 47 to the outside of the processing tank 39.

A stirring member 48 is rotatably provided on the bottom surface 41 of the processing tank 39. Of the flows generated by the rotation of the stirring member 48 during discharge from the discharge port 47, the streamline 48L of the flow toward the discharge port 47 is substantially parallel to the streamline 47L of the discharge flow at the discharge port 47, or is a flow. It overlaps with line 47L. According to this configuration, lightweight debris can be reliably discharged from the discharge port 47.

Since the stirring member 48 is arranged at a position closer to the discharge port 47 than the center on the bottom surface 41 of the processing tank 39, the flow generated by the stirring member 48 flows strongly into the discharge port 47. As a result, the lightweight debris can be reliably discharged from the discharge port 47.

Since the bottom surface 41 of the treatment tank 39 is inclined so as to have a downward slope toward the discharge port 47, lightweight debris can be reliably discharged from the discharge port 47. The treatment tank 39 has a second nozzle 55 that discharges water toward the discharge port 47. The water discharged from the second nozzle 55 increases the flow velocity of the discharge flow at the discharge port 47, so that lightweight debris can be reliably discharged.

The sewage treatment device 10 has a treatment tank 39 and a dehydration device 60. The treatment tank 39 contains a crushed piece F of a disposable diaper D as an object to be treated containing the polymer P in a water-absorbing state, and a treatment liquid T that reduces the water retention capacity of the polymer P. The dehydrating device 60 separates the crushed piece F discharged from the processing tank 39 and the processing liquid T while moving them sideways, that is, in the left-right direction by a screw 67 as a transfer member. At the downstream end of the screw 67 in the transfer direction, the dehydrated crushed piece F is collected from the downward collection port 71.

The dehydrator 60 is arranged in an inclined form so that the downstream end in the transfer direction of the screw 67 is higher than the upstream end in the transfer direction. According to this configuration, the height difference between the position of the downward collection port 71 and the position of the upstream end of the dehydrating device 60 in the transfer direction becomes small, so that the dehydrating device 60 can be installed at a low position as a whole. As a result, the height of the sewage treatment device 10 can be reduced.

The direction in which the crushed piece F is transferred by the transfer member in the dehydrating device 60 is the direction in which the crushed piece F is lifted against gravity. Therefore, as the transfer member, a screw 67 having a spiral feed plate 67B formed on the outer circumference of the rotating shaft portion 67A was used. The crushed piece F is surely sent to the collection port 71 while being raised by the spiral feeding plate 67B.

The treatment tank 39 is arranged above the dehydrator 60, and the bottom surface 41 of the treatment tank 39 is inclined so as to descend from the downstream end side to the upstream end side in the transfer direction of the screw 67. When the sewage treatment device 10 is viewed from the front, the direction of inclination of the bottom surface 41 of the treatment tank 39 and the direction of inclination of the dehydration device 60 are the same. As a result, the dead space in the vertical direction between the bottom surface 41 of the treatment tank 39 and the top surface of the dehydration device 60 is narrowed, so that the height of the entire sewage treatment device 10 can be reduced accordingly.

The dehydrating device 60 has a water collecting unit 69 that receives waste liquid such as a treatment liquid T that has flowed down in the process of transferring the crushed piece F by the screw 67. The water collecting portion 69 is provided so as to open at least toward the upstream end in the transfer direction in the transfer path by the screw 67. As a result, the waste liquid such as the treatment liquid T that has flowed down is collected in the water collecting section 69 without remaining in the middle of the transfer path by the screw 67.

The sewage treatment device 10 includes a treatment tank 39, a discharge path 64, an on-off valve 65, and a control unit 58. The treatment tank 39 contains a crushed piece F of a disposable diaper D containing a water-absorbing polymer P and a treatment liquid T that reduces the water retention capacity of the polymer P. The discharge path 64 is a path for discharging the crushed pieces F and the treatment liquid T in the treatment tank 39 to the outside of the treatment tank 39. The on-off valve 65 is provided in the middle of the discharge path 64. The control unit 58 changes the opening degree of the on-off valve 65 with time in the discharge process in the discharge path 64. Since the opening degree of the on-off valve 65 fluctuates with time, the flow velocity in the discharge path 64 changes with time, so that it is possible to prevent the on-off valve 65 from being clogged with the crushed pieces F.

The control unit 58 controls the on-off valve 65 so that it does not fully close at the minimum opening. Since the on-off valve 65 is not fully closed, there is no possibility that the crushed piece F will be clogged on the upstream side of the on-off valve 65 in the discharge path 64.

The treatment tank 39 includes a discharge port 47 that communicates with the discharge port 64, and a second water supply unit 54 that discharges water toward the discharge port 47. The discharge of water in the second water supply unit 54 is controlled by the control unit 58 in the discharge process in the discharge path 64. If water is discharged from the second water supply unit 54 toward the discharge port 47 during the discharge of the crushed piece F and the treatment liquid T, the flow velocity in the discharge path 64 increases, so that the discharge efficiency is improved.

The second water supply unit 54 is controlled by the control unit 58 so as to discharge water when the opening degree of the on-off valve 65 increases. If water is discharged from the second water supply unit 54 when the opening degree of the on-off valve 65 is increased, the flow velocity in the discharge path 64 is increased, so that the discharge efficiency is improved. The opening degree of the on-off valve 65 is controlled by the control unit 58 so that the on-off valve 65 is fully opened when water is discharged from the second water supply unit 54. Since the water is discharged with the on-off valve 65 fully opened, the flow rate in the discharge path 64 can be significantly increased.

In the process in which the maximum peak of the opening is repeated a plurality of times as the opening of the on-off valve 65 increases or decreases, the opening of the on-off valve 65 is the opening at the maximum peak accompanied by the discharge of water from the second water supply unit 54. Is controlled by the control unit 58 so as to be larger than the opening degree at the maximum peak without discharging water from the second water supply unit 54. Since the maximum peak value of the opening degree of the on-off valve 65 is different between when water is discharged and when water is not discharged, the fluctuation range of the flow velocity in the discharge path 64 becomes large. As a result, entanglement of the crushed pieces F and concentration of the crushed pieces F at the inlet of the on-off valve 65 are less likely to occur, so that clogging of the on-off valve 65 can be prevented more reliably.

<Other Embodiments>
The present disclosure is not limited to the embodiments described by the above description and drawings, and for example, the following embodiments are also included in the technical scope of the present disclosure.
The stirring member may be arranged on the side surface of the processing tank and rotate about a lateral drive shaft.
The rotation operation of the stirring member may be performed in only one direction.
The rotation form of the stirring member is not limited to alternating rotation in the forward direction and the reverse direction, and may be a combination of the normal direction and a plurality of intermittent rotations in the reverse direction.
The forward rotation angle of the stirring member may be less than 10 ° or greater than 120 °.
The rotation angle of the stirring member in the opposite direction may be less than 10 ° and may be larger than 120 °.
The rotation angle of the stirring member in the forward direction and the reverse direction may be the same.
The rotation time of the stirring member in the forward direction and the reverse direction may be the same length.
The peripheral speed of the outer circumference of the stirring member may be less than 100 mm / s and may be faster than 500 mm / s.
The streamline of the flow generated by the stirring member toward the discharge port at the time of discharge from the discharge port may be in a direction intersecting the streamline of the discharge flow at the discharge port.
The discharge port may be open to the bottom surface of the treatment tank.
The stirring member may be arranged in the center of the bottom surface of the processing tank.
The bottom surface of the treatment tank may be formed of a single plane having a constant inclination angle with respect to the horizontal plane.
The nozzle of the water supply unit may discharge water in a direction different from that of the discharge port.
The object to be treated is not limited to disposable diapers, but may be a sanitary napkin, a pet sheet, or the like containing a super absorbent polymer.
The water separating agent may be a treatment agent containing calcium acetate, another chemical containing a divalent metal salt such as Ca or Mg, a water-soluble alkaline earth metal salt of magnesium chloride or magnesium nitrate, or the like.

10 ... Sewage treatment device, 34 ... 1st water supply unit (water supply unit), 39 ... Treatment tank, 41 ... Bottom surface of treatment tank, 42 ... 1st inclined surface, 43 ... 2nd inclined surface, 44 ... Boundary line (1st) The lowermost edge of the inclined surface), 47 ... Discharge port, 47L ... Discharge flow streamline, 48 ... Stirring member, 48L ... Flow line toward the discharge port, 49 ... Drive shaft, 51 ... Main body, 52 ... Rib , 54 ... 2nd water supply section (water supply section), 55 ... 2nd nozzle (nozzle), D ... paper diaper (object to be treated), F ... crushed piece, H ... horizontal plane, P ... polymer, T ... treatment liquid, α ... The inclination angle of the first inclined surface with respect to the horizontal plane, β ...

Claims (14)

A treatment tank capable of accommodating crushed pieces of an object to be treated having a water-absorbing polymer and a treatment liquid for reducing the water retention capacity of the polymer.
A filth treatment including a disk-shaped main body portion, a rib that protrudes from the surface of the main body portion and extends in the radial direction from the rotation center of the main body portion, and a stirring member provided in the processing tank for rotation. apparatus. The stirring member is arranged on the bottom surface of the processing tank and can rotate about a drive shaft in the vertical direction.
The sewage treatment device according to claim 1, wherein the ribs protrude from the upper surface of the main body. The sewage treatment device according to claim 2, wherein the stirring member can rotate in both the forward direction and the reverse direction. The sewage treatment apparatus according to claim 3, wherein the rotation angle of the stirring member in the forward direction is 10 ° or more and 120 ° or less. The sewage treatment apparatus according to any one of claims 3 and 4, wherein the rotation angle of the stirring member in the reverse direction is 10 ° or more and 120 ° or less. The sewage treatment apparatus according to any one of claims 3 to 5, wherein the stirring member can rotate alternately in the forward direction and the reverse direction. The sewage treatment apparatus according to claim 6, wherein the rotation angle of the stirring member in the forward direction is larger than the rotation angle of the stirring member in the reverse direction. The sewage treatment apparatus according to any one of claims 6 and 7, wherein the rotation time of the stirring member in the forward direction is longer than the rotation time of the stirring member in the reverse direction. The sewage treatment apparatus according to any one of claims 2 to 8, wherein the peripheral speed of the outer circumference of the stirring member is 100 to 500 mm / s. The treatment tank has a discharge port for discharging the crushed pieces and the treatment liquid in the treatment tank.
Claims 2 to 2, wherein the streamline of the flow toward the discharge port among the flows generated by the rotation of the stirring member at the time of discharge is substantially parallel to or overlaps with the streamline of the discharge flow at the discharge port. The sewage treatment apparatus according to any one of 9. The discharge port is open so as to face the peripheral edge of the bottom surface of the treatment tank.
The sewage treatment apparatus according to claim 10, wherein the stirring member is arranged at a position closer to the discharge port than the center of the bottom surface of the treatment tank. The bottom surface of the processing tank is configured to include a first inclined surface that supports the stirring member and a second inclined surface that is continuous with the lowermost edge of the first inclined surface.
The sewage treatment apparatus according to any one of claims 2 to 11, wherein the inclination angle of the first inclined surface with respect to the horizontal plane is smaller than the inclination angle of the second inclined surface with respect to the horizontal plane. A discharge port for discharging the crushed fragments and the treatment liquid in the treatment tank, and
The sewage treatment apparatus according to any one of claims 1 to 12, further comprising a water supply unit that supplies water to the treatment tank when discharging from the discharge port. The sewage treatment device according to claim 13, wherein the water supply unit has a nozzle for discharging water toward the discharge port.

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