Separator

Abstract

To improve solid / liquid separation efficiency.SOLUTION: A separation device 1 comprises: a casing 10 provided with an object feed port 11C, an object discharge port 11A, and a separated liquid discharge port 11B; a screw shaft 20 provided inside the casing 10; a first screw blade 30 having a first surface 30a and a second surface 30b; a second screw blade 40 spirally extending from a first end 40A to a second end 40B and having a third surface 40a and a fourth surface 40b; and a cover 50. The cover 50 faces an outer peripheral surface of the screw shaft 20 and spirally extends to cover a first space S1 between the first surface 30a and the fourth surface 40b at least from the first end 40A to the second end 40B.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a separation device.

Background Art

[0002] As described in Patent Document 1, there is known a separation device that rotates a screw provided with two screw blades to convey and squeeze sludge. This separation device forms a first space and a second space sandwiched between two screw blades inside a casing provided with a sludge inlet on the side surface. This separation device dehydrates and discharges raw sludge in the first space, and discharges the separated liquid generated by dehydration from the first space to the second space through the gap between the outer periphery of the screw blade and the inner periphery of the casing.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a separation device, it is more preferable to improve the solid-liquid separation efficiency.

[0005] The present invention has been made in view of the above, and an object thereof is to provide a separation device capable of improving the solid-liquid separation efficiency.

Means for Solving the Problems

[0006] To solve the above-described problems and achieve the object, the separation device of the present disclosure includes a casing provided with an object inlet into which an object is introduced, an object outlet from which the dehydrated object is discharged, and a separation liquid outlet from which the separation liquid from the object is discharged, a screw shaft provided inside the casing, a first screw blade that spirally extends on the outer peripheral surface of the screw shaft and has a first surface and a second surface on the back side of the first surface, and a second screw blade that spirally extends on the outer peripheral surface of the screw shaft from a first end to a second end and has a third surface that faces the first surface of the first screw blade at a predetermined interval and a fourth surface on the back side of the third surface, and a cover portion. The casing has the object outlet on the side in a first direction along the rotation axis of the screw shaft with respect to the object inlet, and has the separation liquid outlet on the side in a second direction opposite to the first direction along the rotation axis with respect to the object inlet. The cover portion faces the outer peripheral surface of the screw shaft and spirally extends, covering at least the first space between the first surface and the third surface from the first end to the second end.

Advantages of the Invention

[0007] According to the present invention, the solid-liquid separation efficiency can be improved.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0009] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited by the embodiments described below.

[0010] (Overall Configuration of the Separation Device) FIG. 1 is a partial cross-sectional view of the separation device according to the present embodiment. FIG. 2 is a schematic enlarged cross-sectional view of the separation device according to the present embodiment. As shown in FIG. 1, the separation device 1 according to the present embodiment is a screw type separation device, and includes a casing 10, a screw shaft 20, a first screw blade 30, a second screw blade 40, a cover portion 50, a partition portion 60, a charging portion 70, a discharge pump 71, an inclination adjustment portion 72, and a control portion 73. The separation device 1 dehydrates the object A0 introduced into the casing 10 from the object inlet 11C described later, and discharges the concentrated object A after dehydration from the object outlet 11A described later. Then, the separation device 1 discharges the separation liquid B separated from the object A0 by dehydration from the separation liquid outlet 11B described later. The object A0 is the object before being dehydrated by the separation device 1, and in the present embodiment, it is sludge such as sewage or industrial wastewater with a high water content. The object A0 may be sludge in which a flocculant is added and the solid components are flocculated, or sludge that is not flocculated without the addition of a flocculant.

[0011] Hereinafter, the direction parallel to the ground surface G0, that is, the horizontal direction, is defined as the direction X. And one direction of the direction X is defined as the direction X1, and the other direction of the direction X, that is, the direction opposite to the X1 direction, is defined as the X2 direction. Also, the direction orthogonal to the ground surface G0, that is, the vertical direction, is defined as the direction Z. And the direction upward in the vertical direction, which is one direction of the direction Z, is defined as the Z1 direction, and the direction downward in the vertical direction, which is the other direction of the direction Z, is defined as the Z2 direction.

[0012] (Casing) The casing 10 is a frustum-shaped member that extends from one end 10A to the other end 10B located on the Z1-direction side of the end 10A along the extending direction E that is axial, and a space is provided inside. The extending direction E is along the direction Z, and the casing 10 extends vertically. However, the casing 10 is not limited to extending vertically and may extend obliquely with respect to the horizontal direction. In this case, it is preferable to set the inclination angle of the casing 10 such that the angles of the screw blades (the first screw blade 30 and the second screw blade 40) described later are inclined to such an extent that an object does not accumulate on the surface of the screw blade. The inclination angle of the casing 10 with respect to the horizontal direction (the angle formed by the extending direction E and the X direction) is preferably, for example, 30 degrees or more and 90 degrees or less, and more preferably 90 degrees. Hereinafter, among the directions along the extending direction E, the direction from the end 10B side toward the end 10A side is defined as the first direction E1, and the direction opposite to the first direction E1, that is, the direction from the end 10A side toward the end 10B side is defined as the second direction E2.

[0013] An object inlet 11C is open on the side surface (outer peripheral surface) of the intermediate portion 10C of the casing 10, an object discharge port 11A is open on the Z2-direction side (the first direction E1 side) of the object inlet 11C, and a separation liquid discharge port 11B is open on the Z1-direction side (the second direction E2 side) of the object inlet 11C. In the present embodiment, the object discharge port 11A is open at the end 10A of the casing 10, and the separation liquid discharge port 11B is open at the end 10B of the casing 10. The intermediate portion 10C is located at the center of the casing 10 along the extending direction E, but may be at any position between the end 10A and the end 10B along the extending direction E. A plurality of separation liquid discharge ports 11B may be provided at the end 10B of the casing 10. When a plurality of separation liquid discharge ports 11B are provided, by the casing 10 extending vertically and the end 10B (the end surface on the second direction E2 side) of the casing 10 extending in the horizontal direction (the direction orthogonal to the extending direction E of the casing 10), each separation liquid discharge port 11B can be positioned at the same height, and the separation liquid can be appropriately discharged from the separation liquid discharge port 11B, which is preferable.

[0014] Except for the object inlet 11C, the object outlet 11A, and the separation liquid outlet 11B, the casing 10 has no holes formed to communicate the inside and the outside, but openings may be formed otherwise. However, it can be said that the casing 10 is not structured to have a large number of openings formed throughout the area, unlike screens such as meshes and punching plates.

[0015] As the casing 10 goes in the first direction E1 (the object outlet 11A side), the cross-sectional area of the internal space when viewed in the extending direction E becomes smaller. In the present embodiment, the casing 10 has a hollow truncated cone shape with a diameter that becomes smaller as it goes in the first direction E1. By narrowing the object outlet side, it becomes easier to concentrate the objects. However, the shape of the casing 10 is not limited to this and is arbitrary. For example, it may be a cylindrical shape with a constant diameter.

[0016] (Screw shaft) The screw shaft 20 has a cylindrical shape and is provided inside the casing 10 and extends along the extending direction E along the rotation axis of the screw shaft 20. At least one of one end 20A or the other end 20B of the screw shaft 20 is connected to a motor (not shown in either case) that is axially supported by a bearing. When this motor is driven by the control unit 73, the screw shaft 20 rotates in the rotation direction R with the extending direction E as the axis center. In the present embodiment, the rotation direction R is counterclockwise when viewed from the end 20B side, but it is not limited thereto.

[0017] (First screw blade) The first screw blade 30 is provided so as to extend spirally on the outer peripheral surface of the screw shaft 20 from one end 30A to the other end 30B inside the casing 10 in the second direction E2. The end 30A is the end on the object discharge port 11A side and is located between the object inlet 11C and the object discharge port 11A in the extending direction E. The end 30B is the end on the separation liquid discharge port 11B side and is located between the object inlet 11C and the separation liquid discharge port 11B in the extending direction E. The first screw blade 30 has a first surface 30a on one side (lower side in the vertical direction) facing the object discharge port 11A side (the first direction E1 side) and a second surface 30b on the other side (upper side in the vertical direction) facing the separation liquid discharge port 11B side (the second direction E2 side) (the surface on the back side of the first surface 30a). A virtual straight line passing through the first screw blade 30 along the extending direction E will alternately intersect the first surface 30a and the second surface 30b as it advances in the extending direction E.

[0018] The first screw blade 30 is wound in a direction opposite to the rotation direction R from the end 30B toward the end 30A. That is, when the rotation direction R is counterclockwise as viewed from the end 20B side, the first screw blade 30 is provided in a so-called Z-wound (right-handed) spiral. Conversely, when the rotation direction R is clockwise as viewed from the end 20B side, the first screw blade 30 is provided in a so-called S-wound (left-handed) spiral. The first screw blade 30 rotates as the screw shaft 20 rotates. The inclination angle of the first screw blade 30 is preferably inclined to such an extent that the object does not accumulate on the surface and slides down, and may be, for example, 30 degrees or more. Note that the inclination angle of the first screw blade 30 refers to the angle formed by a line connecting the inner peripheral portion to the outer peripheral portion of the first screw blade 30 toward the radially outer side with the axis direction being the central axis AX of the screw shaft 20 and a line along the radial direction.

[0019] The outer peripheral portion 30c of the first screw blade 30 does not contact the inner peripheral surface 10a of the casing 10, and a gap H is formed between the outer peripheral portion 30c and the inner peripheral surface 10a. The gap H may be formed to be large enough for the object A to be concentrated to pass through. The width of the gap H (the distance between the outer peripheral portion 30c and the inner peripheral surface 10a) is, for example, 5 mm or more or 10 mm or more, but is not limited thereto and may be any size.

[0020] (Second Screw Blade) The second screw blade 40 extends spirally along the outer peripheral surface of the screw shaft 20 along the extending direction E inside the casing 10. The second screw blade 40 is provided at a position shifted from the first screw blade 30 by a predetermined interval along the extending direction E, and is wound in the same winding direction as the first screw blade 30. The second screw blade 40 also rotates as the screw shaft 20 rotates. The second screw blade 40 has a third surface 40a (a surface facing the second surface 30b of the first screw blade 30 with a predetermined interval) on one side (the lower side in the vertical direction) facing the object discharge port 11A side (the first direction E1 side), and a fourth surface 40b (a surface on the back side of the third surface 40a) on the other side (the upper side in the vertical direction) facing the separation liquid discharge port 11B side (the second direction E2 side). A virtual straight line passing through the second screw blade 40 along the extending direction E alternately intersects the third surface 40a and the fourth surface 40b as it advances in the extending direction E. The inclination angle of the second screw blade 40 may be, for example, 30 degrees or more. Note that the inclination angle of the second screw blade 40 refers to the angle formed by a line connecting from the inner peripheral portion to the outer peripheral portion of the second screw blade 40 toward the outer side in the radial direction with respect to the central axis AX of the screw shaft 20 as the axial direction and a line along the radial direction.

[0021] The second screw blade 40 extends spirally from a first end 40A which is one end to a second end 40B which is the other end. The first end 40A is the end on the object discharge port 11A side, and is located between the object inlet 11C and the object discharge port 11A in the extending direction E. The first end 40A is located on the separation liquid discharge port 11B side (the second direction E2 side) rather than the end 30A of the first screw blade 30 in the extending direction E. The second end 40B is the end on the separation liquid discharge port 11B side, and is located between the object inlet 11C and the separation liquid discharge port 11B in the extending direction E. In the present embodiment, the second end 40B is at the same position as the end 30B of the first screw blade 30 in the extending direction E, and the second ends 40B and 30B are connected to a partition portion 60 described later.

[0022] The outer peripheral portion 40c of the second screw blade 40 does not contact the inner peripheral surface 10a of the casing 10, and a gap H is formed between the outer peripheral portion 40c and the inner peripheral surface 10a.

[0023] Here, the first screw blade 30 and the second screw blade 40 of the present embodiment are in a shape that extends spirally and has a smooth curved shape. However, the first screw blade 30 and the second screw blade 40 do not have to have a smooth curved structure, and for example, a simple structure combining flat plates may be used, or any structure that forms two water channels (a first space S1 and a second space S2 described later) may be used.

[0024] (Conveyance promotion section and object conveyance section) Since the first screw blade 30 and the second screw blade 40 are provided in the above positions, in the section from the first end 40A to the second end 40B of the second screw blade 40 (hereinafter, this section is referred to as a conveyance promotion section K1), both the first screw blade 30 and the second screw blade 40 are provided. Further, in the section from the first end 40A of the second screw blade 40 to the end 30A of the first screw blade 30 (hereinafter, this section is referred to as an object conveyance section K2), the first screw blade 30 is provided and the second screw blade 40 is not provided.

[0025] The conveyance promotion section K1 is a double screw section where the first screw blade 30 and the second screw blade 40 are provided. The conveyance promotion section K1 is set so as to overlap the object input port 11C in at least a part of the section when viewed from the radial direction centered on the central axis AX.

[0026] In the conveyance promotion section K1, a first space S1 through which the separation liquid B is conveyed and a second space S2 through which the object A0 and the object to be concentrated A are conveyed are formed. The first space S1 is the space between the first surface 30a of the first screw blade 30 and the fourth surface 40b of the second screw blade 40 facing the first surface 30a. The first surface 30a faces the separation liquid discharge port 11B side (the second direction E2 side) of the first space S1, and the fourth surface 40b faces the object discharge port 11A side (the first direction E1 side) of the first space S1. The second space S2 is the space between the second surface 30b of the first screw blade 30 and the third surface 40a of the second screw blade 40 facing the second surface 30b. The second surface 30b faces the object discharge port 11A side (the first direction E1 side) of the second space S2, and the third surface 40a faces the separation liquid discharge port 11B side (the second direction E2 side) of the second space S2.

[0027] The distance in the extending direction E between the first surface 30a of the first screw blade 30 and the fourth surface 40b of the second screw blade 40 facing the first surface 30a (that is, the length of the first space S1 in the extending direction) is preferably shorter than the distance in the extending direction E between the second surface 30b of the first screw blade 30 and the third surface 40a of the second screw blade 40 facing the second surface 30b (that is, the length of the second space S2 in the extending direction E). Therefore, in the present embodiment, the volume of the first space S1 is smaller than the volume of the second space S2. However, it is not limited thereto, and the volume of the first space S1 may be the same as or larger than the volume of the second space S2.

[0028] The object conveyance section K2 is the section on the object discharge port 11A side rather than the conveyance promotion section K1. In the present embodiment, the object conveyance section K2 is a single screw section where the first screw blade 30 is provided and the second screw blade 40 is not provided. However, for example, when the end 30A of the first screw blade 30 and the first end 40A of the second screw blade 40 are at the same position, it becomes a section where neither the first screw blade 30 nor the second screw blade 40 is provided.

[0029] In the object conveyance section K2, a third space S3 for conveying the object A0 and the object to be concentrated A is formed. The third space S3 communicates with the object discharge port 11A on the second direction E2 side and communicates with the first space S1 and the third space S3 of the conveyance promotion section K1 on the first direction E1 side. The opening that communicates the first space S1 and the third space S3 is hereinafter referred to as the lower opening OP2. The lower opening OP2 can be said to be an opening provided at the first end 40A of the second screw blade 40. The size and shape of the lower opening OP2 are arbitrary. For example, no baffle (partition wall) is provided between the first space S1 and the third space S3, and the lower opening OP2 may be formed by the entire area between the first space S1 and the third space S3 (the area where the first space S1 communicates with the third space S3) being open. Also, for example, a baffle (partition wall) is provided between the first space S1 and the third space S3, and the lower opening OP2 may be formed by a through hole that communicates the first space S1 and the third space S3 opening in the baffle.

[0030] (Cover part) The cover portion 50 is a cover that faces the outer peripheral surface of the screw shaft 20 and extends spirally along the extending direction E. The cover portion 50 is a cover that covers the radially outer side of the first space S1 when the central axis AX is the axial direction, and covers the entire area of the surface on the radially outer side of the first space S1. As shown in FIG. 1, the cover portion 50 covers the first space S1 over at least the entire area of the conveyance promotion section K1, that is, from at least the first end 40A to the second end 40B of the second screw blade 40. In the example of FIG. 1, the end portion of the cover portion 50 on the first direction E1 side is at the same position as the first end 40A in the extending direction E, and the end portion of the cover portion 50 on the second direction E2 side is at the same position as the second end 40B in the extending direction E. However, the fact that the cover portion 50 covers the first space S1 from at least the first end 40A to the second end 40B does not necessarily mean that the end portion of the cover portion 50 on the first direction E1 side and the end portion on the second direction E2 side are exactly at the same positions as the first end 40A and the second end 40B in the extending direction E. For example, the end portion of the cover portion 50 on the first direction E1 side may be located on the first direction E1 side of the first end 40A, or the end portion of the cover portion 50 on the second direction E2 side may extend to the second direction E2 side of the second end 40B. Also, for example, the end portion of the cover portion 50 on the first direction E1 side may be located on the second direction E2 side of the first end 40A by a predetermined distance, or the end portion of the cover portion 50 on the second direction E2 side may be located on the first direction E1 side of the second end 40B by a predetermined distance. The predetermined distance here may be the length within the range where the effects of the present embodiment are exhibited, and may be, for example, 5% or less of the total length of the screw shaft 20 in the extending direction E. The cover portion 50 extends spirally along the outer periphery of the first space S1.

[0031] As shown in Fig. 2, the cover portion 50 is provided from the outer peripheral portion 30c of the first screw blade 30 to the outer peripheral portion 40c of the second screw blade 40 adjacent thereto in the extending direction E with respect to the outer peripheral portion 30c on the second direction E2 side (Z1 direction side) of the object inlet 11C, and the second screw blade 40 and the cover portion 50 are connected. Therefore, on the second direction E2 side (Z1 direction side) of the object inlet 11C, the first space S1 is a space surrounded by the first surface 30a of the first screw blade 30, the fourth surface 40b of the second screw blade 40, the outer peripheral surface of the screw shaft 20, and the inner peripheral surface 50a of the cover portion 50, and does not communicate with the second space S2 adjacent thereto in the extending direction E. Even at the same position as the object inlet 11C in the extending direction E (Z direction), it is preferable that the cover portion 50 is provided from the outer peripheral portion 30c of the first screw blade 30 to the outer peripheral portion 40c of the second screw blade 40, and the first space S1 and the second space S2 do not communicate with each other.

[0032] As shown in Fig. 2, on the first direction E1 side (Z2 direction side) of the object inlet 11C, the cover portion 50 extends from the outer peripheral portion 30c of the first screw blade 30 toward the outer peripheral portion 40c of the second screw blade 40 adjacent thereto in the extending direction E with respect to the outer peripheral portion 30c, but does not contact the outer peripheral portion 40c, and a gap OP1 is formed therebetween. It can also be said that the gap OP1 is formed between the inner peripheral surface 50a of the cover portion 50 and the outer peripheral portion 40c of the second screw blade 40. The first space S1 communicates with the second space S2 adjacent thereto on the first direction E1 side (Z2 direction side) of the object inlet 11C through this gap OP1 (that is, the portion on the first direction E1 side of the first space S1 and the portion on the second direction E2 side of the second space S2 communicate with each other). On the first direction E1 side of the object inlet 11C, since the outer peripheral portion 40c of the second screw blade 40 extends spirally without contacting the inner peripheral surface 50a of the cover portion 50, it can be said that the gap OP1 also extends spirally between the outer peripheral portion 40c and the inner peripheral surface 50a.

[0033] The width of the gap OP1 (the distance between the outer peripheral portion 40c and the inner peripheral surface 50a) may be formed to be large enough for the object A to be concentrated to pass through. For example, the width of the gap OP1 may be 20% or more and 30% or more of the width of the first screw blade 30 (the distance from the inner peripheral portion to the outer peripheral portion 30c of the first screw blade 30). Also, for example, it may be 5 mm or more and 30 mm or less in length, but it is not limited thereto and may be any length. If the width of the gap OP1 is too small, the flow rate of the separated liquid flowing into the second space S2 through the gap OP1 may increase and the solid-liquid separation efficiency may decrease. Even if the width of the gap OP1 is too large, there is no problem with the solid-liquid separation efficiency. However, if the width of the gap OP1 is too large, the width of the second screw blade 40 will be shortened, which may affect the function of the second screw blade 40. On the other hand, by setting the width of the gap OP1 within the above range, an increase in the flow rate of the separated liquid and an increase in the inflow amount of the object A to be concentrated are suppressed, and a decrease in the solid-liquid separation efficiency is suppressed, while sufficiently maintaining the width of the second screw blade 40 (for example, about 70% or more of the portion without the gap OP1), so that the function of the second screw blade 40 can be appropriately maintained.

[0034] As described above, in the present embodiment, due to the gap OP1 between the outer peripheral portion 40c and the inner peripheral surface 50a, the first space S1 and the second space S2 adjacent to the first space S1 on the first direction E1 side are communicated with each other on the first direction E1 side of the object inlet 11C. However, the first space S1 and the second space S2 are not limited to being communicated with each other through the gap OP1. For example, on the first direction E1 side of the object inlet 11C, an opening penetrating from the third surface 40a to the fourth surface 40b may be formed in the second screw blade 40, and the first space S1 and the second space S2 may be communicated with each other through the opening.

[0035] (Partition portion) As shown in FIG. 1, the partition portion 60 is a plate-like member connected to the second end 40B of the second screw blade 40. The partition portion 60 partitions the space inside the casing 10 on the object input port 11C side of the partition portion 60 and the space on the separation liquid discharge port 11B side of the partition portion 60. Specifically, the surface 60a on the first direction E1 side of the partition portion 60 is connected to the end 30B of the first screw blade 30, the second end 40B of the second screw blade 40, and the end on the second direction E2 side of the cover portion 50. The partition portion 60 partitions the second space S2 on the object input port 11C side of the partition portion 60 and the fourth space S4 which is the space on the separation liquid discharge port 11B side of the partition portion 60.

[0036] An upper opening OP3 that communicates the first space S1 and the fourth space S4 is formed in the partition portion 60. The upper opening OP3 is formed from a location surrounded by the end 30B of the first screw blade 30, the second end 40B of the second screw blade 40, and the end on the second direction E2 side of the cover portion 50 on the surface 60a of the partition portion 60 to the surface 60b on the second direction E2 side of the partition portion 60.

[0037] The outer peripheral portion of the partition part 60 does not contact the inner peripheral surface 10a of the casing 10, and a gap Ha is formed between the outer peripheral portion of the partition part 60 and the inner peripheral surface 10a of the casing 10. The second space S2 and the fourth space S4 communicate with each other through this gap Ha. The upper opening OP3 preferably has an opening area larger than that of the gap Ha. Since the discharge amount of the separation liquid depends on the size of the upper opening OP3, by making the upper opening OP3 larger than the gap Ha, the discharge amount of the separation liquid can be improved, and the outflow of solid components from the gap Ha to the fourth space S4 (the side of the separation liquid discharge port 11B) can be suppressed, thereby improving the solid-liquid separation efficiency. The upper opening OP3 preferably has the same opening area as the lower opening OP2, and the lower opening OP2 also preferably has an opening area larger than that of the gap Ha. The width of the gap Ha (the distance between the outer peripheral portion of the partition part 60 and the inner peripheral surface 10a of the casing 10) is preferably smaller than the width of the gap OP1, and preferably smaller than the gap H between the first screw blade 30 and the second screw blade 40. Since the partition part 60 also rotates as the screw shaft 20 rotates, the width of the gap Ha is preferably small enough not to interfere with the rotation of the partition part 60, and for example, it may be about 1 mm or more and 2 mm or less.

[0038] The input part 70 is connected to the object input port 11C and is a device for controlling the input amount of the object A0 into the casing 10. The input part 70 is, for example, an on-off valve or a pump for transporting the object A0.

[0039] The discharge pump 71 is a pump connected to the object discharge port 11A. When stopped, the discharge pump 71 blocks the concentrated object A that has moved to the end 10A of the casing 10. Also, when driven, the discharge pump 71 sucks to forcibly discharge the concentrated object A in the casing 10 from the object discharge port 11A. However, the discharge pump 71 is not an essential component, and for example, it may be discharged by gravity.

[0040] The inclination adjustment part 72 is attached to the casing 10 and changes the inclination angle of the casing 10. However, the inclination adjustment part 72 is not an essential component, and the inclination angle may be constant.

[0041] The control unit 73 is a control device that controls the operation of the separation device 1. The control unit 73 controls at least one of the rotation of the screw shaft 20 by a motor, the input amount of the object A0 by the input unit 70, the operation of the discharge pump 71, that is, the discharge amount of the object A to be concentrated in the casing 10, and the inclination angle by the inclination adjustment unit 72. The control unit 73 is, for example, a computer having an arithmetic unit, that is, a CPU (Central Processing Unit), and controls the operation of the separation device 1 by the arithmetic operation of the CPU.

[0042] (Operation of the separation device) Next, the operation of the separation device 1 configured as described above and the behavior of the object will be described. The control unit 73 controls the input unit 70 to input the object A0 into the casing 10 from the object input port 11C. Since the position of the object input port 11C overlaps with the conveyance acceleration section K1, the object A0 from the object input port 11C is blocked by the cover section 50 provided over the entire conveyance acceleration section K1, and the inflow into the first space S1 is suppressed, and it flows into the second space S2. The control unit 73 rotates the screw shaft 20. The object A0 introduced into the second space S2 moves toward the first direction E1 while the liquid component is separated by the frictional force between gravity and the second surface 30b of the first screw blade 30 due to rotation, and flows into the third space S3 that communicates with the second space S2 through the second space S2. The solid component of the object A0 that has flowed into the third space S3 is discharged to the outside of the casing 10 from the object discharge port 11A as the object A to be concentrated from which the liquid component has been separated by the discharge pump 71 driven by the control unit 73. In the present embodiment, since the gap H between the first screw blade 30 and the second screw blade 40 and the inner peripheral surface 10a of the casing 10 is relatively large, a part of the object A0 settles toward the third space S3 by gravity through the gap H.

[0043] In the second space S2, the object A0 sinks toward the first direction E1 side (vertically downward side), that is, toward the second surface 30b side of the first screw blade 30, due to gravity. From the object A0, the separation liquid B as supernatant is separated toward the second direction E2 side (vertically upward side) of the object A0. The separation liquid B separated in the second space S2 flows into the first space S1 from the gap OP1 on the first direction E1 side (vertically upward side) of the second space S2. The separation liquid B separated from the object A0 in the third space S3 flows into the first space S1 from the lower opening OP2 that communicates the third space S3 and the first space S1. The separation liquid B that has flowed into the first space S1 from the second space S2 and the third space S3 moves spirally toward the second direction E2 side in the first space S1, flows into the fourth space S4 from the upper opening OP3, and is discharged to the outside of the casing 10 from the separation liquid discharge port 11B. On the second direction E2 side (vertically upward side) from the object input port 11C, since the gap OP1 is not formed and the first space S1 and the second space S2 do not communicate, the separation liquid B in the first space S1 is suppressed from flowing out into the second space S2.

[0044] Note that due to the flow toward the second direction E2 side in the first space S1, the object A0, which is a solid component, may also enter the first space S1 from the third space S3 through the lower opening OP2. However, since the flow of the object A0 toward the first direction E1 side due to gravity and the rotation of the screw shaft 20 is strong and the lower opening OP2 and the upper opening OP3 are larger than the gap Ha, the object A0 is pushed out toward the first direction E1 side and is suppressed from being discharged from the separation liquid discharge port 11B together with the separation liquid B. Since the object A0, which is a solid component, thus moves toward the first direction E1 side, the separation liquid B can easily flow toward the second direction E2 side, and the separation liquid B can easily flow into the first space S1 from the gap OP1.

[0045] (Configuration 1 of the present embodiment) As described above, the separation device 1 according to the present embodiment includes a casing 10, a screw shaft 20 provided inside the casing 10, a first screw blade 30, a second screw blade 40, and a cover portion 50. The casing 10 is provided with an object inlet 11C into which the object A0 is introduced, an object outlet 11A from which the dehydrated object A0 is discharged, and a separation liquid outlet 11BA from which the separation liquid B from the object A0 is discharged. The first screw blade 30 extends spirally on the outer peripheral surface of the screw shaft 20 and has a first surface 30a and a second surface 30b on the back side of the first surface 30a. The second screw blade 40 extends spirally on the outer peripheral surface of the screw shaft 20 from a first end 40A to a second end 40B and has a third surface 40a facing the second surface 30b at a predetermined interval and a fourth surface 40b on the back side of the third surface 40a. The casing 10 has the object outlet 11A on the first direction E1 side along the rotation axis of the screw shaft 20 with respect to the object inlet 11C, and has the separation liquid outlet 11B on the second direction E2 side opposite to the first direction E1 with respect to the object inlet 11C. The cover portion 50 faces the outer peripheral surface of the screw shaft 20 and extends spirally, covering at least the first space S between the first surface 30a and the fourth surface 40b from the first end 40A to the second end 40B.

[0046] (Effect by Configuration 1) In the separation device 1 according to the present embodiment, since the separation liquid outlet 11B is on the second direction E2 (vertically upward) side and the object outlet 11A is on the first direction E1 (vertically downward) side, the object A0 can be gravity-settled. By providing the cover portion 50 from the first end 40A to the second end 40B, the inflow of the object A0 into the first space S1 can be preferably suppressed. According to the separation device 1 according to the present embodiment, while gravity-settling the object A0 in the space vertically below the first space S1 partitioned by the cover portion 50, the separation liquid can be moved to the separation liquid outlet 11B side in the first space S1 formed vertically above the space for gravity-settling the object A0. Thereby, in order to gravity-settle the object A0 while suppressing the inflow of the object A0 into the first space S1, the solid-liquid separation efficiency can be appropriately improved.

[0047] Further, in the present embodiment, in order to cause the object A0 to settle by gravity, it is possible to suppress the object A0 from reaching the separation liquid discharge port 11B side through the gap H between the first screw blade 30 and the second screw blade 40 and the inner peripheral surface 10a of the casing 10. As a result, it is not necessary to make the gap H small so that the object A0 does not pass through. Therefore, it is possible to suppress the complication of the manufacturing process due to reducing the gap H and facilitate the manufacturing. By widening the gap H, it is also possible to suppress the flow velocity of the solid components flowing through the gap H from becoming too high and improve the solid-liquid separation efficiency by gravity sedimentation.

[0048] (Configuration 2 and Effect of the Present Embodiment) The separation device 1 according to the present embodiment preferably also has a configuration 2 described below. In configuration 2, a gap OP1 that communicates the first space S1 and the second space S2 is formed in the second screw blade 40 on the side of the first direction E1 (vertically downward) with respect to the object inlet 11C. A cover portion 50 that covers the first space S1 is formed from the first end 40A to the second end 40B of the second screw blade 40. A gap OP1 is formed on the side of the first direction E1 (downward) with respect to the object inlet 11C, and no gap is formed on the side of the second direction E2 (upward) with respect to the object inlet 11C. Therefore, while suppressing the inflow of the object A0 into the first space S1 by the cover portion 50, it is possible to allow the separation liquid B separated from the object A0 to flow into the first space S1 from the gap OP1, thereby improving the solid-liquid separation efficiency.

[0049] (Configuration 3 and Effect of the Present Embodiment) The separation device 1 according to the present embodiment preferably also has a configuration 3 described below. In configuration 3, a lower opening OP2 is formed at the first end 40A on the side of the first direction E1 (vertically lower side) of the second screw blade 40. The lower opening OP2 communicates the first space S1 and a space (third space S3) vertically below the first space S1. According to the configuration 3 of the present embodiment, by forming the lower opening OP2, it is possible to appropriately allow B to flow from the third space S3 into the first space S1 and more appropriately improve the solid-liquid separation efficiency.

[0050] (Configuration 4 and Effects of this Embodiment) The separation device 1 according to this embodiment preferably also has Configuration 4 described below. In Configuration 4, the second end 40B of the second screw blade 40 on the second direction E2 side (upper vertical direction) is located at a position between the object inlet CA and the separation liquid discharge port 11B. A partition wall portion 60 is provided at the second end 40B of the second screw blade 40 to partition the space on the object inlet 11C side and the space on the separation liquid discharge port 11B side (the fourth space S4) in the casing 10. An upper opening OP3 is formed in the partition wall portion 60 to communicate the space on the separation liquid discharge port 11B side (the fourth space S4) and the first space S1 in the casing 10. According to Configuration 4 of this embodiment, by providing the partition wall portion 60 where the upper opening OP3 is formed, while suppressing the inflow of solid components into the fourth space S4, the separation liquid B in the first space S1 can be appropriately discharged from the separation liquid discharge port 11B.

[0051] (Configuration 5 and Effects of this Embodiment) The separation device 1 according to this embodiment preferably also has Configuration 5 described below. In Configuration 5, the cross-sectional area of the space in the casing 10 becomes smaller as it goes toward the object discharge port 11A side. By making the object discharge port 11A side of the casing 10 smaller, the space where the object A0 accumulates is narrowed, and the dehydration efficiency of the object A0 can be improved.

[0052] The embodiments of the present invention have been described above, but the embodiments are not limited by the contents of these embodiments and the like. In addition, the above-described components include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those within the so-called equivalent range. Furthermore, the above-described components can be combined as appropriate. For example, for the separation device 1 according to this embodiment, only any one of the above-described Configurations 2 to 5 or any combination of two or more thereof may be used. Furthermore, various omissions, substitutions, or changes of the components can be made without departing from the gist of the above-described embodiments and the like.

Explanation of Reference Numerals

[0053] 1 Separation device 10 Casing 11A Object discharge port 11B Separation liquid discharge port 11C Object inlet 20 Screw shaft 30 First screw blade 30a, 30b, 40a, 40b Surfaces 40 Second screw blade 40A, 40B Ends 50 Cover part 60 Partition part OP1 Gap OP2 Lower opening OP3 Upper opening S1 First space S2 Second space

Claims

1. A casing having an object inlet into which an object is inserted, an object outlet through which the dehydrated object is discharged, and a separation liquid outlet through which the separation liquid from the object is discharged, A screw shaft provided inside the casing, A first screw blade that extends spirally on the outer peripheral surface of the screw shaft and has a first surface and a second surface on the back side of the first surface, On the outer peripheral surface of the screw shaft, a second screw blade that extends spirally from a first end to a second end and has a third surface that faces the second surface of the first screw blade at a predetermined interval and a fourth surface on the back side of the third surface, A cover portion, and The casing, Has the object outlet on the side in the first direction along the rotation axis of the screw shaft with reference to the object inlet, Has the separation liquid outlet on the side in the second direction opposite to the first direction along the rotation axis with reference to the object inlet, The cover portion faces the outer peripheral surface of the screw shaft and extends spirally, covering at least the first space between the first surface and the fourth surface from the first end to the second end. A separation device.

2. A second space is formed between the second surface and the third surface, On the first direction side of the object inlet, a gap is formed in the second screw blade to communicate the first space and the second space, On the second direction side of the object inlet, the second screw blade and the cover portion are connected. The separation device according to claim 1.

3. A lower opening is formed at the first end on the first direction side of the second screw blade, and the lower opening communicates the first space and the space on the first direction side of the first space. The separation device according to claim 1 or claim 2.

4. The second end on the second direction side of the second screw blade is located between the object inlet and the separation liquid outlet, A partition portion is provided at the second end of the second screw blade to partition the space on the object inlet side and the space on the separation liquid outlet side in the casing, An upper opening is formed in the partition portion to communicate the space on the separation liquid outlet side and the first space in the casing. The separation device according to any one of claims 1 to 3.

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