JP2021084060A - Driving method of solid-liquid separator - Google Patents

Abstract

To provide a driving method of a solid-liquid separator that enables the solid-liquid separator to be downsized.SOLUTION: A driving method of a solid-liquid separator 1, which comprises a concentrating container 3 that receives liquid mixed with sand; a concentrated liquid tank 4 that stores concentrated liquid having concentrations of sand increased; a carrier device 5 extending obliquely upward; and a liquid feeding pipe 6 whose inflow port 611 is connected to the concentrating container 3 and whose outflow port 62 is arranged lower than the inflow port 611, and drives the carrier device 5 at a predetermined driving speed so that the sand in the concentrated liquid is carried out, which includes: a filling step of filling the liquid feeding pipe 6 with sewage by rising liquid level in the concentrated liquid tank 4 while driving the carrier device 5 at a driving speed lower than the predetermined driving speed; a liquid feeding step of feeding sewage in the concentrated liquid stored in the concentrated liquid tank 4 through the liquid feeding pipe 6 to the outside of the concentrated liquid tank 4 by utilizing a potential energy of the sewage to lower the liquid level in the concentrated liquid tank 4; and a carrying step of carrying the sand by driving the carrier device 5 at the predetermined driving speed after the liquid feeding step.SELECTED DRAWING: Figure 4

Description

The present invention relates to a method for driving a solid-liquid separator that separates a liquid from a mixed liquid mixed with a solid.

The sewage treatment facility is provided with a sand basin for removing sand from sewage and a settling basin for removing sludge from sewage. In the sand basin, the sand contained in the sewage that has flowed in is collected in the sand collection pit at the bottom of the pond, and then the sand-mixed water mixed with the collected sand is sucked up by a sand pump and a solid liquid provided on the ground. Transferred to a separator. This solid-liquid separator receives the transferred sand-mixed water, separates sand and sewage from the sand-mixed water, and returns the sewage to the sand basin. In the settling basin, after the sludge contained in the received sewage is collected in the sludge pit at the bottom of the pond, the sludge mixed water mixed with the sludge collected in the sludge pit is provided above the settling basin by a sludge pump. It is transferred to the solid-liquid separator. The solid-liquid separator provided above the settling basin also accepts the transferred sludge-mixed water, separates the sewage from the sludge-mixed water, and returns it to the settling basin. Further, other than the sewage treatment facility, a solid-liquid separation device for separating a liquid from a mixed liquid in which a solid is mixed in the liquid is used. Such solid-liquid separation devices include, for example, one that separates water and metal powder from factory wastewater, and one that separates earth and sand that has flowed into a reservoir such as a dam lake from water. Hereinafter, sand and sludge and residue contained in sewage, metal powder contained in industrial wastewater, and earth and sand flowing into a reservoir together with water may be collectively referred to as solid. In addition, liquids mixed with solids may be collectively referred to as mixed liquids.

As this solid-liquid separation device, a device including a concentrating container, a concentrating liquid tank, and a transport device is known (see, for example, Patent Document 1 and the like). The concentrating container of Patent Document 1 is arranged above the concentrating liquid tank, and is connected to a sand-lifting pump and a sand-lifting pipe arranged in a sand basin. The concentrating container receives the sand-mixed water transferred from the sand basin by the sand-lifting pump, and discharges the concentrated liquid in which the concentration of sand in the sewage is higher than that of the sand-mixed water from the discharge port provided in the concentrating container. The concentrating liquid tank receives and stores the concentrated liquid discharged from the concentrating container. The transport device is connected to the lower end portion of the concentrating liquid tank, and extends diagonally upward from the connected portion. The sand that has settled at the lower end of the concentrate tank is transported while being drained diagonally upward by this transport device and sent to the outside of the concentrate tank.

Japanese Unexamined Patent Publication No. 2012-21483

The transport device of the solid-liquid separation device disclosed in Patent Document 1 has a transport path extending from the lower end portion of the concentrate tank to a considerably higher position than the concentrate tank. The transport device transports sand while draining water in a portion of the transport path located above the water surface of the concentrating liquid tank. By lengthening the transport distance while draining the water in the transport device, it is possible to prevent the sewage in the concentrate stored in the concentrate tank from being sent to the outside of the concentrate tank together with the sand. However, there is a problem that the transport path of the transport device becomes long by lengthening the transport distance while draining water, and as a result, the solid-liquid separation device becomes large.

In view of the above circumstances, an object of the present invention is to provide a method for driving a solid-liquid separation device that can realize miniaturization of the solid-liquid separation device.

The driving method of the solid-liquid separator of the present invention that solves the above object is a concentrating container that accepts a mixed liquid in which a solid is mixed in a liquid and discharges a concentrated liquid in which the concentration of the solid with respect to the liquid is increased from a discharge port. The concentrating liquid tank in which the discharge port is arranged in the tank and stores the concentrated liquid obtained in the concentrating container and the lower end portion of the transport path extending diagonally upward are connected to the bottom of the concentrating liquid tank. A transport device in which the upper end portion of the transport path is arranged above the discharge port and an inflow port are connected to the concentrating container, and the outlet is located outside the concentrating liquid tank and below the inflow port. A liquid feeding tube is provided, and the solid in the concentrated liquid is collected at the lower end portion, and the transport device is driven at a predetermined driving speed to transport the solid diagonally upward along the transport path. It is a method of driving a solid-liquid separation device that sends the liquid in the mixed liquid received by the concentrating container to the outside of the concentrating liquid tank through the liquid feeding pipe.
With the transport device stopped or driven at a driving speed slower than the predetermined driving speed, the liquid level of the concentrating liquid tank is raised above the discharge port, and the concentrating container is inside the liquid feeding pipe. The filling step of filling with the liquid in the received mixed liquid, and
The liquid in the concentrated liquid stored in the concentrated liquid tank is sent to the outside of the concentrated liquid tank through the liquid feeding pipe by utilizing the position energy of the liquid in the concentrated liquid, and the liquid in the concentrated liquid tank is sent. The liquid feeding process that lowers the surface and
It is characterized by having a transporting step of lowering the liquid level of the concentrated liquid tank by the liquid feeding step, driving the transporting device at the predetermined driving speed, and transporting the solid collected at the lower end portion. ..

According to the driving method of the solid-liquid separation device, the transport device is driven after the liquid level of the concentrated liquid tank is lowered, so that the transport path in the transport device can be shortened. As a result, the solid-liquid separation device can be miniaturized. Further, in the liquid feeding step, since the liquid is sent to the outside of the concentrated liquid tank by utilizing the potential energy of the liquid in the concentrated liquid, it is not necessary to provide a device such as a pump in the solid-liquid separation device. Can also lower the liquid level of the concentrated liquid tank.

In the driving method of this solid-liquid separation device, in the filling step, the mixed liquid is received in the cylindrical portion of the concentrating container having a cylindrical portion having a cylindrical inner peripheral surface from the tangential direction of the inner peripheral surface. It may be a step of discharging the concentrated liquid from the discharge port.

By doing so, a swirling flow can be generated in the cylindrical portion. The solid contained in the mixed liquid moves downward while being pressed against the inner peripheral surface by the centrifugal force generated by the swirling flow. On the other hand, since the liquid in the mixed liquid collects in the radial center portion of the cylindrical portion, the separation performance between the solid and the liquid is improved. Here, the filling step may include a delivery step of delivering the liquid in the mixed liquid from the inflow port arranged at the center of the cylindrical portion in the radial direction.

Further, in the driving method of this solid-liquid separation device, in the filling step, the cross-sectional area of the internal space of the concentrating container is larger than that of the cylindrical portion side between the cylindrical portion and the discharge port as the concentrating container. The step may be a step of using one having a reduced squeezing portion on the discharge port side.

By using the one having the throttle portion, the amount of the concentrated liquid discharged from the discharge port can be reduced, and the amount of the liquid sent out from the inflow port can be increased. Here, the filling step may include a delivery step of sending out the liquid in the mixed liquid from the inflow port arranged at the center in the radial direction of the throttle portion.

Further, in the driving method of the solid-liquid separation device of the present invention that solves the above object, a storage tank for storing a mixed liquid in which a solid is mixed in a liquid, an inflow port is arranged in the storage tank, and an outflow port is the storage. The liquid feed pipe located outside the tank and below the inflow port and the lower end of the transport path extending diagonally upward are connected to the bottom of the storage tank, and the upper end of the transport path is connected. A transport device arranged above the inflow port is provided, and the solid in the mixed liquid is collected at the lower end portion, and the transport device is driven at a predetermined drive speed to move the solid along the transport path. It is a driving method of a solid-liquid separation device that transports the liquid in the mixed liquid stored in the storage tank diagonally upward and sends the liquid in the mixed liquid to the outside of the storage tank through the liquid feed pipe.
With the transport device stopped or driven at a drive speed slower than the predetermined drive speed, the mixed liquid is received in the storage tank and the liquid level of the storage tank rises above the uppermost end of the liquid supply pipe. Acceptance process and
The liquid in the mixed liquid stored in the storage tank is sent to the outside of the storage tank through the liquid feed pipe by utilizing the potential energy of the liquid in the mixed liquid, and the liquid level of the storage tank is lowered. The liquid feeding process and
It is characterized by having a transporting step of lowering the liquid level of the storage tank by the liquid feeding step, driving the transporting device at the predetermined driving speed, and transporting the solid collected at the lower end portion.

The method of driving the solid-liquid separation device also drives the transport device after lowering the liquid level in the concentrated liquid tank, so that the transport path in the transport device can be shortened. As a result, the solid-liquid separation device can be miniaturized. Further, in the liquid feeding step, the liquid is fed by utilizing the potential energy of the liquid in the concentrated liquid, so that the liquid in the concentrated liquid tank does not need to be provided with a device such as a pump in the solid-liquid separation device. The surface can be lowered.

Further, in the driving method of the solid-liquid separation device, in the receiving step, the solid is settled from above the covering member by a covering member provided above the inflow port or around the inflow port. It may be a step performed in a state where the inflow is suppressed from entering the inflow port.

Since it is possible to prevent the solid from entering through the inflow port, the solid-liquid separation performance can be improved.

According to the present invention, it is possible to provide a method for driving a solid-liquid separation device that can realize miniaturization of the solid-liquid separation device.

It is a schematic block diagram which shows the solid-liquid separation apparatus corresponding to one Embodiment of this invention. (A) is a plan view of a concentrating container, and (b) is a cross-sectional view taken along the line AA in FIG. (A) is a plan view showing a concentrating container and a concentrating liquid tank, (b) is a front view showing a concentrating container and a concentrating liquid tank, and (c) is a front view showing BB in the figure (b). It is a sectional view. It is a flowchart which shows the operation of the solid-liquid separation apparatus shown in FIG. (A) is a front view similar to FIG. 3 (b) showing a modified example of the solid-liquid separator shown in FIG. 1, and (b) is a sectional view taken along line CC in FIG. 1 (a). is there. (A) is a front view similar to FIG. 3 (b) in a solid-liquid separator of a modified example different from the modified example shown in FIG. 5, and FIG. 5 (b) is a DD in the same figure (a). It is a sectional view. It is the same front view as FIG. 3 (b) in the solid-liquid separation apparatus of 2nd Embodiment. It is a flowchart which shows the operation of the solid-liquid separation apparatus shown in FIG. It is the same front view as FIG. 7 which shows the modification of the solid-liquid separation apparatus shown in FIG. 7.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the present embodiment, an example in which the driving method of the present invention is applied to a solid-liquid separation device in which sewage mixed with sand is transferred from a sand basin is used. The sand basin is located on the upstream side of the sewage treatment facility and is for removing sand from sewage such as sewage or rainwater. The sewage from which the sand has been removed in the sand basin is sent to a sedimentation basin located downstream.

FIG. 1 is a schematic configuration diagram showing a solid-liquid separation device corresponding to an embodiment of the present invention. A sand basin is also shown in FIG.

As shown in FIG. 1, the sand basin 9 of the present embodiment is a pond including a pump well 91, a trough 92, a sand collecting nozzle 93, and a sand collecting pit 94. Sewage flows into the sand basin 9 from the right side of the figure. The sewage that has flowed in slowly flows toward the left side of the figure. In the sand basin 9, while the sewage flows, the sand contained in the sewage sinks toward the bottom of the pond. The pump well 91 is arranged on the most downstream side of the sand basin 9. The pump well 91 stores sewage from which sand has been removed. A pumping pump 911 is provided inside the pump well 91. The pumping pump 911 discharges the sewage stored in the pump well 91 to the outside of the sand basin 9. A pumping pipe 912 is connected to the pumping pump 911. The sewage sucked by the pump 911 is sent to a settling basin (not shown) through the pump pipe 912. Note that FIG. 1 also shows the sewage pond water surface WL1. The position of the pond water surface WL1 changes depending on the amount of sewage flowing into the sand basin 9 in a range where the height from the bottom of the trough 92 is, for example, 1 m or more and 5 m or less.

The trough 92 is a pond bottom upstream of the pump well 91 and is formed in the center in the pond width direction. The trough 92 extends along the flow direction of the sewage in the sand basin 9. On both sides of the trough 92 in the pond width direction, a pond bottom inclined surface 95 is formed so as to be located downward toward the trough 92. The sand contained in the sewage that has flowed into the sand basin 9 settles toward the bottom of the pond, slides down the inclined surface 95 of the bottom of the pond, or deposits directly in the trough 92.

The sand collecting nozzle 93 is arranged at the upstream end of the trough 92. Sewage pumped from the sedimentation basin is supplied to the sand collecting nozzle 93. The sewage supplied to the sand collecting nozzle 93 is discharged from the tip of the sand collecting nozzle 93 toward the downstream side of the sand basin 9. The downstream end of the trough 92 is connected to the sand collection pit 94. The sand deposited in the trough 92 is collected in the sand collection pit 94 by the flow of water discharged from the sand collection nozzle 93. The sand collecting pit 94 is formed between the pump well 91 and the trough 92. The sand collected in the sand collection pit 94 is transferred to the solid-liquid separator 1 together with the sewage and separated into a solid (sand) and a liquid (sewage).

A sand lifting pump 941 is arranged inside the sand collecting pit 94 and near the bottom of the sand collecting pit 94. This sand lifting pump 941 corresponds to an example of a pump. A sand lifting pipe 942 is connected to the sand pump 941. The sand lifting pump 941 sucks the sand collected inside the sand collecting pit 94 together with the sewage, and transfers the sewage mixed with the sand to the solid-liquid separation device 1 through the sand lifting pipe 942. The ratio of sand and sewage transferred to the solid-liquid separator 1 by the sand pump 941 varies depending on the amount of sand collected inside the sand collection pit 94, etc., but 95% of the sewage is 95% of the sand of about 5%. Degree. The sand-mixed water in which sand is mixed with the sewage transferred by the sand-lifting pump 941 corresponds to an example of the mixed liquid. Further, the sand in the sand-mixed water corresponds to an example of a solid, and the sewage contained in the sand-mixed water corresponds to an example of a liquid.

The solid-liquid separation device 1 includes a concentrating container 3, a concentrating liquid tank 4, a transport device 5, and a liquid feeding pipe 6. The concentrating container 3, the concentrating liquid tank 4, and the transport device 5 are arranged on the ground in the vicinity of the sand basin 9. The concentrating container 3 is arranged in the concentrating liquid tank 4. The concentrating container 3 separates a part of the transferred sewage in the sand-mixed water from the sand and sends it out to the liquid feed pipe 6. Hereinafter, the sewage separated from the sand-mixed water will be referred to as separated water. Further, the concentrating container 3 discharges the concentrated liquid in which the concentration of sand with respect to the sewage is increased by removing a part of the sewage to the concentrating liquid tank 4. The sewage contained in this concentrated liquid also corresponds to an example of a liquid. The separated water sent out from the concentrating container 3 is returned to the sand basin 9 through the liquid feeding pipe 6. The liquid supply pipe 6 has one end portion 61 (see FIG. 2) inserted into the concentrating container 3, a horizontal portion extending horizontally above the concentrating container 3, and a vertical portion bent downward from the horizontal portion. Has a part. The outlet 62 formed at the lower end of the vertical portion is arranged above the sand basin 9 below the concentrating container 3 and outside the concentrating liquid tank 4. These concentrating containers 3 and concentrating liquid tanks 4 will be described in detail later.

The transport device 5 extends obliquely upward from the lower end of the concentrating liquid tank 4. The conveyor 5 has a screw conveyor 51, a drop portion 52, and a tubular portion 53 that covers the outside of the screw conveyor 51. The screw conveyor 51 is arranged in the tubular portion 53. The axial direction of the screw conveyor 51 coincides with the extending direction of the transport device 5. The screw conveyor 51 forms a transport path extending diagonally upward. The lower end portion of this transport path is connected to the bottom portion of the concentrating liquid tank 4. Further, the upper end portion of the transport path is arranged above the discharge port 331 (see FIG. 2B) of the concentration container 3. The sand contained in the concentrated liquid discharged into the concentrated liquid tank 4 settles in the concentrated liquid tank 4 and collects at the lower end of the concentrated liquid tank 4. The sand collected at the lower end of the concentrating liquid tank 4 is conveyed diagonally upward by the rotation of the screw conveyor 51, and is conveyed while being drained at the upper end portion of the transfer path of the transfer device 5. The drop portion 52 is a tubular one extending downward from the vicinity of the upper end of the screw conveyor 51, and a drop port 52a is formed at the lower end portion. The upper end of the drop portion 52 is connected to an opening formed in the lower portion near the upper end of the tubular portion 53. The sand drained by the transfer by the screw conveyor 51 is dropped downward from the drop port 52a through the drop portion 52. That is, the transport device 5 transports the sand contained in the concentrated liquid received by the concentrated liquid tank 4 to the outside of the concentrated liquid tank 4. Instead of the screw conveyor 51, another conveyor such as a belt conveyor or a flight conveyor may be used. The dropper 52 may be closed and an opening / closing lid that can be opened and closed may be provided on the dropper 52, and the dropper 52 may be closed when the transport device 5 is not driven. The closing lid is preferably formed at the upper end of the drop portion 52, that is, between the drop portion 52 and the tubular portion 53, but may be provided in the vicinity of the drop port 52a. By providing the opening / closing lid, it is possible to prevent the concentrated liquid from leaking from the drop portion 52 even if the tank water surface WL2 rises above the upper end of the drop portion 52.

FIG. 2A is a plan view of the concentrating container, and FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2A. 2 (a) and 2 (b) also show one end of the liquid feed pipe.

As shown in FIG. 2B, the concentrating container 3 includes a fluid introduction portion 31, a throttle portion 32, a discharge portion 33, a fluid inflow pipe 34, and a pair of attachment portions 36. The concentrating container 3 of this embodiment is a so-called fluid cyclone device. The fluid introduction section 31 is provided on the upper portion of the concentration container 3. The upper end of the throttle portion 32 is connected to the lower end of the fluid introduction portion 31. Further, the upper end of the discharge portion 33 is connected to the lower end of the throttle portion 32. The inner peripheral surface 3a of the concentrating container 3 is composed of an inner peripheral surface 31a of the fluid introduction portion 31, an inner peripheral surface 32a of the drawing portion 32, and an inner peripheral surface 33a of the discharge portion 33. The internal space X1 is defined by the inner peripheral surface 3a of the concentrating container 3. That is, the fluid introduction section 31, the throttle section 32, and the discharge section 33 form a hollow tank having an internal space X1.

The fluid introduction portion 31 includes a cylindrical portion 311 having a cylindrical inner peripheral surface 31a and a lid 312 that closes the upper end of the cylindrical portion 311. The cylindrical portion 311 is made by processing a steel plate having a thickness of 3.2 mm into a cylindrical shape having an inner diameter of 500 mm. The lid 312 is made by processing a steel plate having a thickness of 6.0 mm into an annular shape having an outer diameter of 586 mm and an inner diameter of 114 mm. The shape, material, and thickness of the cylindrical portion 311 and the lid 312 may be appropriately selected according to the size of the internal space X1 and the like. Further, the cylindrical portion 311 may have a conical shape or a dome shape in which the cross-sectional area of the internal space X1 increases toward the bottom. Further, the cylindrical portion 311 has a conical or dome shape in which the cross-sectional area of the internal space X1 increases as the upper portion on which the receiving port 341 is formed, which will be described later, goes downward, and the lower portion is cylindrical. It may be the one that has been used. A pair of mounting portions 36 are fixed to the outer peripheral surface of the cylindrical portion 311. The mounting portion 36 is for fixing the concentrating container 3 to the concentrating liquid tank 4 shown in FIG.

A fluid inflow pipe 34 is connected to the upper portion of the cylindrical portion 311. The sand lifting pump 941 and the fluid inflow pipe 34 shown in FIG. 1 are connected via a sand lifting pipe 942. The sand lifting pipe 942 and the fluid inflow pipe 34 are detachably connected by fastening the flanges provided at the connecting ends with bolts. The fluid inflow pipe 34 is a pipe having an inner diameter of 100 mm. As shown in FIG. 2B, a receiving port 341 is formed at the connecting portion between the fluid inflow pipe 34 and the cylindrical portion 311. As shown by a straight arrow in FIG. 2A, the sand-mixed water sucked up by the sand lifting pump 941 is introduced into the internal space X1 from the tangential direction of the inner peripheral surface 31a of the cylindrical portion 311 through the receiving port 341. To. Therefore, the sand-mixed water received by the concentrating container 3 is introduced between the outer peripheral surface of one end portion 61 of the liquid feeding pipe 6 and the inner peripheral surface 31a of the cylindrical portion 311. As a result, a swirling flow of sand-mixed water is formed in the internal space X1.

The throttle portion 32 is arranged between the receiving port 341 and the discharging portion 33. In the throttle portion 32, the cross-sectional area of the internal space X1 decreases toward the discharge portion 33. In other words, the throttle portion 32 has an inverted conical inner peripheral surface 32a whose diameter gradually decreases as the distance from the cylindrical portion 311 increases. The throttle portion 32 may have the cross-sectional area of the internal space X1 gradually decreasing toward the discharge port 331. That is, the throttle portion 32 is formed so that the cross-sectional area of the internal space X1 is smaller on the discharge port 331 side than on the reception port 341 side. The throttle portion 32 is made by processing a steel plate having a plate thickness of 3.2 mm into a conical shape, and has an upper end having an inner diameter of 500 mm and a lower end having an inner diameter of 100 mm. The material and thickness of the drawing portion 32 may be appropriately selected according to the size of the internal space X1, the drawing amount, and the like. Further, in this embodiment, the cross-sectional area of the lower end of the drawing portion 32 matches the cross-sectional area of the receiving port 341, but the cross-sectional area of the lower end of the drawing portion 32 may be larger than the cross-sectional area of the receiving port 341. , It may be smaller than the cross-sectional area of the receiving port 341. However, if the cross-sectional area of the lower end of the drawing portion 32 is made too small, the pressure loss in the concentrating container 3 increases. Therefore, the cross-sectional area of the lower end of the drawing portion 32 is preferably equal to or larger than the cross-sectional area of the receiving port 341.

The discharge unit 33 is connected to the side of the throttle unit 32 opposite to the side where the fluid introduction unit 31 is provided. That is, the discharge unit 33 is connected to the lower end of the throttle unit 32. The discharge portion 33 has a cylindrical shape having a flange formed at the lower end and having an inner diameter of the same diameter as the lower end of the throttle portion 32. The opening at the lower end of the discharge portion 33 becomes the discharge port 331. The discharge unit 33 may be omitted. If omitted, the opening at the lower end of the throttle portion 32 becomes the discharge port.

One end portion 61 of the liquid feeding pipe 6 penetrates the lid 312 of the fluid introduction portion 31 in the vertical direction. The one end portion 61 extends along the radial central axis of the cylindrical portion 311 from below the lower end of the lid 312 to above the upper end of the lid 312, and is welded to the lid 312 in a watertight state. There is. Therefore, the lower portion of the one end portion 61 projects into the internal space X1. However, the lower portion of the one end portion 61 does not have to protrude into the internal space X1, and for example, the lower surface of the lid 312 and the lower end of the one end portion 61 may be on the same plane. One end portion 61 has a tubular shape with an inner diameter of 100 mm. The lower end of the one end portion 61 becomes one end of the liquid feeding pipe 6, and the opening at one end thereof becomes the inflow port 611. Therefore, the one end portion 61 and the inflow port 611 (one end of the liquid feeding pipe 6) are connected to the concentrating container 3. Further, the inflow port 611 of this embodiment is arranged in the internal space X1. The separated water separated from the sand-mixed water is returned to the sand basin 9 from the inflow port 611 through the liquid feed pipe 6. The inflow port 611 is arranged below the receiving port 341. The portion of the liquid feeding pipe 6 other than the one end portion 61 and the one end portion 61 are detachably connected by being fastened with bolts. The length of the one end portion 61 in the extending direction is arbitrary. For example, the lower portion (the portion in the internal space X1) of the one end portion 61 may be formed longer than the fluid introduction portion 31. When formed in this way, the inflow port 611 is formed in a region of the internal space X1 defined by the inner peripheral surface 32a of the throttle portion 32. Further, although the cross-sectional area of the inflow port 611 matches the cross-sectional area of the lower end of the throttle portion 32, the cross-sectional area of the inflow port 611 is preferably equal to or larger than the cross-sectional area of the discharge port 331. By doing so, the amount of separated water discharged from the inflow port 611 can be increased, and the pressure loss in the concentrating container 3 can be further reduced.

Next, the operation of the concentrating container 3 will be mainly described with reference to FIG. As described above, by driving the sand pump 941 (see FIG. 1), the sand-mixed water flows into the internal space X1 from the receiving port 341, and a swirling flow of the sand-mixed water is formed in the internal space X1. Since the sand contained in the sand-mixed water has a higher specific gravity than the sewage, it is pressed against the inner peripheral surface 3a of the concentrating container 3 by centrifugal force, and gradually falls downward while swirling along the inner peripheral surface 3a. I will do it. On the other hand, separated water from which sand has been removed from the sand-mixed water collects in the radial center portion of the cylindrical portion 311. The separated water is sent out from the inflow port 611. However, in the concentrating container 3 of the present embodiment, since the size of the inlet 341 and the outlet 331 are the same, the amount of sand mixed water received from the inlet 341 per unit time depends on the amount, but from the inlet 611. In order to send out the separated water, it is necessary to provide a concentrating liquid tank 4 which will be described in detail later. As shown in FIG. 1, the separated water that has been sent out is discharged from the outlet 62 formed at the other end of the liquid feeding pipe 6 toward the sand basin 9 through the liquid feeding pipe 6. Since the outlet 62 formed at the other end of the liquid feed pipe 6 is arranged below the inflow port 611 formed at one end of the liquid feed pipe 6, the inside of the liquid feed pipe 6 is filled with the liquid. According to the siphon principle, a force that tends to flow out from the inflow port 611 to the sand sink 9 is generated in the sand mixed water (separated water) in the internal space X1. As a result, even if the power of the sand lifting pump 941 is small, the sand-mixed water can be transferred to the concentrating container 3. The other end of the liquid feed pipe 6 may extend below the water surface WL1 of the sand basin 9 so that the outlet 62 is submerged in water. Further, an intermediate tank may be installed between the concentrating container 3 and the sand basin 9, and the separated water flowing out from the outlet 62 may be stored in the intermediate tank. By providing the intermediate tank, the state of the separated water can be confirmed by the separated water accumulated in the intermediate tank. Further, even if some sand is sent out from the inflow port 611 together with the separated water, the sand is settled in the intermediate tank and the supernatant liquid of the intermediate tank is returned to the sand basin 9, so that the sand becomes the sand basin 9. It is possible to further suppress the return.

FIG. 3A is a plan view showing a concentrating container and a concentrating liquid tank, FIG. 3B is a front view showing a concentrating container and a concentrating liquid tank, and FIG. 3C is the same figure (? It is a cross-sectional view of BB in b).

As shown in FIGS. 3A and 3B, the concentrating liquid tank 4 includes a side wall 41 arranged outside the outer peripheral side surface 3b of the concentrating container 3 and extending above the discharge port 331. ing. As shown in FIG. 3C, in this embodiment, the side wall 41 extends above the upper end 6c of the liquid feed pipe 6. The concentrating container 3 is detachably inside the concentrating liquid tank 4 by connecting the mounting portion 36 with a bolt to a pair of arms 42 having one end fixed to the inner peripheral surface of the side wall 41 and extending inward. It is fixed to. As shown in FIGS. 3 (b) and 3 (c), the liquid feeding pipe 6 and the sand lifting pipe 942 penetrate the side wall 41 of the concentrating liquid tank 4. The penetrating portion of the liquid feeding pipe 6 and the sand lifting pipe 942 is welded to the side wall 41, and the penetrating portion is in a watertight state.

The concentrating liquid tank 4 is a tank having a substantially square tube in a plan view in which two tank inclined surfaces 41a are formed on the lower portion. The lower end of the concentrating liquid tank 4 is cut out obliquely upward at the same angle as the inclination angle of the transport device 5. The tank inclined surface 41a is formed at a constant height from the lower end of the concentrating liquid tank 4. The lower end of the tank inclined surface 41a is connected to the transport device 5. The sand contained in the concentrated liquid discharged from the discharge port 331 of the concentrating container 3 slides down the inclined surface 41a of the tank and is deposited on the transport device 5 connected to the lower end of the concentrated liquid tank 4. As described above, the sand deposited on the transfer device 5 is conveyed diagonally upward by the screw conveyor 51, and is dropped from the drop portion 52 (see FIG. 1) at the upper end portion. As shown in FIG. 3C, an overflow port 43 is formed in a portion above the discharge port 331 and slightly below the upper end of the concentrating liquid tank 4. The overflow port 43 causes the supernatant liquid of the concentrated liquid to flow out from the concentrated liquid tank 4 when too much concentrated liquid is discharged from the discharge port 331. The supernatant liquid flowing out from the overflow port 43 is returned to the sand basin 9 (see FIG. 1) through the overflow pipe 7. By providing the overflow port 43, it is possible to prevent the concentrated liquid from overflowing from the upper end of the side wall 41 of the concentrated liquid tank 4.

FIG. 4 is a flowchart showing the operation of the solid-liquid separation device shown in FIG.

The operations of the sand basin 9 and the solid-liquid separation device 1 are centrally controlled by a control device (not shown). A control device may be provided in each of the sand basin 9 and the solid-liquid separation device 1, so that information or commands can be transmitted and received to each other. At a predetermined time when the amount of sand accumulated on the bottom surface of the sand basin 9 shown in FIG. 1 reaches a certain level, the sand basin 9 discharges sewage from the sand collecting nozzle 93 and collects the sand in the sand collecting pit 94. Perform sand operation. After the sand collecting operation, the solid-liquid separation device 1 starts the solid-liquid separation operation. Here, the predetermined time may be regular, for example, once a month, or may be when the total flow rate of sewage flowing into the sand basin 9 or the total flow rate of sewage discharged from the sand basin 9 reaches a certain amount. The solid-liquid separation operation may be started while sand is being collected in the sand collection pit 94.

In the solid-liquid separation operation, the sand lifting pump 941 is started to be driven with the transport device 5 stopped. By starting this drive, the acceptance of the sand-mixed water in the concentrating container 3 shown in FIG. 3 is started (step S1). The transfer device 5 does not have to be completely stopped. For example, the transfer device 5 may be driven at a very low speed so that the liquid component contained in the concentrated liquid does not reach the drop portion 52 by the drive of the transfer device 5. Absent. That is, the transport device 5 may be driven at a drive speed slower than a predetermined drive speed described later. If the internal space X1 of the concentrating container 3 (see FIG. 2B) and the inside of the concentrating liquid tank 4 are empty before the start of driving the sand lifting pump 941, the sand mixed in the internal space X1 is mixed. Most of the water is discharged from the discharge port 331. As the concentrated liquid discharged from the discharge port 331 is stored in the tank of the concentrated liquid tank 4, the tank water surface WL2, which is the water surface formed by the concentrated liquid stored in the concentrated liquid tank 4, gradually rises. I will do it. This tank water surface WL2 corresponds to an example of the liquid level. Further, the sand contained in the concentrated liquid stored in the concentrated liquid tank 4 settles toward the bottom of the concentrated liquid tank 4 due to its own weight, and collects at the lower end portion in the transport path of the transport device 5. When the tank water surface WL2 reaches the discharge port 331, the discharge port 331 is blocked with the concentrated liquid, so that the amount of the concentrated liquid discharged from the discharge port 331 decreases. That is, the resistance due to the decrease in the cross-sectional area of the internal space X1 in the throttle portion 32 and the water pressure of the concentrated liquid applied to the discharge port 331 make it difficult for the concentrated liquid to be discharged from the discharge port 331, and the inflow port 611 (FIG. 2B). See), the separated water begins to be pumped out. As the tank water level WL2 rises, the water pressure of the concentrated liquid applied to the discharge port 331 increases, so that the amount of the concentrated liquid discharged from the discharge port 331 decreases and the amount of separated water sent out from the inflow port 611 increases. The inside of the liquid feed pipe 6 is filled with separated water (liquid). As described above, when the inside of the liquid feeding pipe 6 is filled with the separated water, the separated water has an action of flowing out to the sand basin 9 according to the siphon principle. That is, the potential energy of the liquid in the sand-mixed water and the liquid in the concentrated liquid starts to send the separated water to the outside of the concentrated liquid tank 4 through the liquid feeding pipe 6. Therefore, the amount of separated water sent out from the inflow port 611 is further increased, and the amount of the concentrated liquid discharged from the discharge port 331 is further reduced. When the amount of sand-mixed water supplied to the internal space X1 is, for example, 1.0 m ³ / min, when the tank water surface WL2 is slightly below the receiving port 341 (see FIG. 2B). At this point, only sand is discharged from the discharge port 331, and the tank water surface WL2 does not rise. FIG. 3 (b) and FIG. 3 (c) show the tank water surface WL2 at this time. Further, when the amount of sand-mixed water supplied to the internal space X1 is set to, for example, 1.5 m ³ / min, the amount of separated water sent out from the inflow port 611 also increases, but contains a certain proportion of sewage. The concentrated liquid is discharged from the discharge port 331, and the tank water surface WL2 continues to rise. After the tank water surface WL2 reaches the overflow port 43, the supernatant liquid of the sand-mixed water ^{flows out from the overflow port 43 by about 0.3 m 3} / min. Further, before the sand lifting pump 941 is driven, the sewage or tap water stored in the settling basin may be allowed to flow into the concentrating liquid tank 4 to fill the concentrating liquid tank 4 with a liquid. When the concentrating liquid tank 4 is filled with a liquid, the internal space X1 is also filled with a liquid having the same height as the concentrating liquid tank 4. Therefore, if the liquid is stored so that the tank water surface WL2 is equal to or higher than the height of the inflow port 611, the separated water can be sent from the inflow port 611 almost at the same time as the drive of the sand lifting pump 941. When the sand pump 941 is driven for the second time or later, the separated water can be sent from the inflow port 611 almost at the same time as the sand pump 941 is driven, unless the liquid stored in the concentrating liquid tank 4 is extracted.

The drive of the sand lifting pump 941 is continued from the start of the drive to the first predetermined time (step S2). Steps S1 and S2 described above correspond to an example of the filling process. This first predetermined time is a sufficient time that the tank water surface WL2 can be raised above the discharge port 331 and the inside of the liquid feeding pipe 6 can be filled with the separated water. A water level sensor for detecting that the tank water surface WL2 has risen above the discharge port 331 may be provided in the concentrated liquid tank 4, and a water detection sensor for detecting that the inside of the liquid feeding pipe 6 is filled with separated water may be provided. It may be provided in the liquid feeding pipe 6. Then, instead of determining whether or not the first predetermined time has passed, it may be determined whether or not the detection by those sensors has occurred.

After the first predetermined time has elapsed, the drive of the sand lifting pump 941 is stopped (step S3). Even after the drive of the sand lifting pump 941 is stopped, due to the effect of the siphon principle described above, the concentrated liquid and the sand-mixed water have an action of flowing out to the sand basin 9 through the liquid feeding pipe 6. .. As a result, the concentrated liquid and the supernatant liquid of the sand-mixed water flow out to the sand basin 9 through the liquid feed pipe 6, and the tank water surface WL2 is lowered. That is, the sewage in the concentrated liquid stored in the concentrated liquid tank 4 is sent to the outside of the concentrated liquid tank 4 through the liquid feeding pipe 6 by utilizing the potential energy of the sewage, thereby lowering the tank water surface WL2. There is. On the other hand, even while the tank water surface WL2 is lowered, the sand contained in the concentrated liquid and the sand-mixed water gradually settles due to its own weight and collects at the lower end portion in the transport path of the transport device 5. When the tank water surface WL2 drops to the discharge port 331, air enters the liquid feeding pipe 6 from the discharge port 331 through the concentrating container 3, and the effect based on the siphon principle ends. The state immediately after the sand lifting pump 941 is stopped is maintained until the second predetermined time elapses after the driving of the sand pump 941 is stopped (step S4). Steps S3 and S4 described above correspond to an example of the liquid feeding process. This second predetermined time is the time during which the tank water surface WL2 drops to the vicinity of the discharge port 331. The second predetermined time is longer than the time when the tank water surface WL2 drops to the vicinity of the discharge port 331 if the tank water surface WL2 drops to a position lower than the height of the upper end portion of the transport path of the transport device 5. It may be a short time. Further, instead of determining whether or not the second predetermined time has elapsed, the water level sensor that detects that the tank water surface WL2 has dropped to a position lower than the height of the upper end portion of the transport path of the transport device 5 is concentrated. It may be provided in the tank 4 and it may be determined whether or not the detection has occurred. Further, in steps S3 and S4, a small amount of sand-mixed water may be supplied to the concentrating container 3 as long as the drive of the sand lifting pump 941 is not completely stopped and the tank water surface WL2 is lowered.

After the second predetermined time has elapsed, the driving of the transport device 5 is started (step S5). When the transport device 5 is driven at a predetermined drive speed, the sand collected at the lower end portion of the transport path is transported to the upper end side of the transport path. At the start of this drive, the tank water surface WL2 is lowered to a position lower than the upper end portion of the transport path, so that the sand transported by the screw conveyor 51 is transported while being drained at the upper end portion of the transport path. .. Then, the sand that has reached the upper end of the drop portion 52 is dropped downward from the drop port 52a. The drive of the transfer device 5 is continued from the start of the drive to the third predetermined time (step S6). Steps S5 and S6 described above correspond to an example of the transfer process. This third predetermined time is a time during which most of the sand collected at the lower end of the transport path can be transported and dropped from the drop portion 52. Instead of determining whether or not the third predetermined time has elapsed, a sand presence / absence sensor for detecting the presence / absence of sand at the lower end of the transport path is provided at the bottom of the concentrating liquid tank 4, and whether the detection has occurred. You may decide whether or not. After the lapse of the third predetermined time, the driving of the transport device 5 is stopped (step S7), and the solid-liquid separation operation is completed.

According to the driving method of this solid-liquid separation device, the transport device 5 is driven after the tank water surface WL2 of the concentrated liquid tank 4 is lowered, so that the sand can be transported while draining even if the transport path is short. it can. That is, the height of the transport path can be made lower than usual by the amount that the tank water surface WL2 is lowered at least in steps S3 and S4 described above. Since the transport path extends diagonally upward, the width of the transport device 5 is shortened by lowering the height of the transport device 5. As a result, the solid-liquid separation device 1 can be miniaturized. Further, in steps S3 and S4 described above, since the potential energy of the sewage in the concentrated liquid is used to send it to the outside of the concentrated liquid tank 4, it is not necessary to provide a device such as a pump in the solid-liquid separating device 1. The liquid level of the concentrating liquid tank 4 can be lowered.

Further, in step S2 described above, since the discharge port 331 is blocked by the liquid stored in the concentrated liquid tank 4, the water pressure of the liquid stored in the tank of the concentrated liquid tank 4 is generated in the discharge port 331. This water pressure makes it difficult for the concentrated liquid to be discharged from the discharge port 331, so that the amount of separated water sent out through the liquid feeding pipe 6 can be increased. That is, since the ratio of the separated water sent out from the inflow port 611 to the concentrated liquid discharged from the discharge port 331 increases, the separation efficiency in the concentration container 3 increases. Further, since the amount of the concentrated liquid discharged to the concentrated liquid tank 4 is small, the concentrated liquid tank 4 can be miniaturized. Further, even if the amount of drawing (decrease in cross-sectional area) in the drawing section 32 is reduced, the amount of concentrated liquid discharged from the discharge port 331 can be suppressed. By reducing the amount of drawing in the drawing section 32, the pressure loss in the concentrating container 3 can be reduced, so that the power of the sand lifting pump 941 can be reduced. Further, the concentrated liquid discharged from the discharge port 331 does not scatter, and the sand contained in the concentrated liquid tends to settle to the bottom of the concentrated liquid tank 4 in a short time. In addition, due to the siphon principle, the separated water has an action of flowing out from the inflow port 611 to the sand basin 9, so that the power of the sand lifting pump 941 can be further reduced. Further, since the transport device 5 is connected to the concentrating liquid tank 4 and the concentrating liquid tank 4 and the concentrating container 3 are arranged at overlapping positions in the height direction, the height of the solid-liquid separating device 1 as a whole can be lowered. .. Since the concentration container 3 can be arranged at a position close to the ground, the lift required for the sand lifting pump 941 is lowered, and the mixed water can be transferred to the concentration container 3 with even smaller power.

Further, in this embodiment, since the side wall 41 of the concentrating liquid tank 4 extends above the upper end of the internal space X1, the liquid is stored in the tank of the concentrating liquid tank 4 up to above the upper end of the internal space X1. can do. By storing the liquid up to the upper end of the internal space X1, the water pressure applied to the discharge port 331 increases, and the force of the sewage in the sand-mixed water in the internal space X1 to flow out from the discharge port 331 due to gravity can be canceled. .. As a result, the amount of sewage discharged from the discharge port 331 can be further suppressed, and the concentration of sand in the concentrate can be further increased. Further, since the amount of the concentrated liquid discharged from the discharge port 331 to the concentrated liquid tank 4 is reduced, the size of the concentrated liquid tank 4 can be reduced. Further, the pressure loss can be further reduced by reducing the amount of reduction of the throttle portion 32. Further, since the height of the side wall 41 of the concentrating liquid tank 4 is set above the upper end 6c of the liquid feeding pipe 6, even if the amount of drawing of the drawing portion 32 is extremely reduced, the water surface WL2 of the tank is 6c at the upper end of the pipe. When it reaches, the inside of the liquid feeding pipe 6 is filled with the separated water, so that the effect of the siphon principle can be obtained.

Subsequently, a modified example of the solid-liquid separation device of the present embodiment will be described. In the following description, the names of the components that are the same as the names of the components described so far may be given the same reference numerals as those used so far, and duplicate description may be omitted.

5 (a) is a front view similar to FIG. 3 (b) showing a modified example of the solid-liquid separator shown in FIG. 1, and FIG. 5 (b) is C- in FIG. 1 (a). It is a C sectional view.

As shown in FIG. 5A, the solid-liquid separation device 1 of this modified example has a point that the fine bubble water supply pipe 8 is connected to the sand lifting pipe 942 and a point that the height of the concentrating liquid tank 4 is low. , Different from the solid-liquid separation device 1 shown in FIGS. 1 to 4. In this modification, the nanobubble water generated by the nanobubble water generator (not shown) is supplied to the sand lifting pipe 942 through the fine bubble water supply pipe 8. However, instead of the nano bubble water, the micro bubble water may be supplied to the sand lifting pipe 942, or the micro nano bubble water in which the nano bubble water and the micro bubble water are mixed may be supplied to the sand lifting pipe 942. The fine bubble water supply pipe 8 corresponds to an example of the fine bubble supply means. Nanobubble water means water containing air bubbles having a particle size on the order of nanometers. In addition, microbubble water means water containing air bubbles on the order of micrometers. As the nanobubble water, water containing nanometer-order oxygen bubbles may be used. Similarly, as the microbubble water, water containing oxygen bubbles on the order of micrometers may be used. Further, the fine bubble water supply pipe 8 may be directly connected to the concentrating container 3. That is, the fine bubble water supply pipe 8 may be connected between the sand lifting pump 941 (see FIG. 1) and the discharge port 331. Since the nano bubble water and the micro bubble water have a cleaning effect, the sand and sewage contained in the sand mixed water can be washed by adding the nano bubble water and the micro bubble water to the sand mixed water. By adding nano-bubble water or micro-bubble water to the sand-mixed water between the sand-lifting pump 941 (see FIG. 1) and the discharge port 331, the sand-mixed water is raised in the internal space X1 (see FIG. 2) of the concentrating container 3. It can be washed with the cleaning effect. That is, since the nanobubbles and microbubbles are mixed with the sand-mixed water in the internal space X1 due to the swirling flow generated in the internal space X1, a high cleaning effect can be exhibited.

The side wall 41 of the concentrating liquid tank 4 extends to a height above the upper end of the concentrating container 3 and below the upper end 6c of the liquid feeding pipe 6. If the side wall 41 of the concentrating liquid tank 4 is raised as in the previous embodiment, the water surface WL2 of the concentrating liquid tank 4 can be made higher than the upper end 6c of the liquid feeding pipe 6. As described above, the water pressure applied to the discharge port 331 increases according to the height of the tank water surface WL2, so that the increase in the tank water surface WL2 means that the concentration of sand in the concentrate is further increased and the pressure loss is reduced. Is preferable. However, if the side wall 41 of the concentrating liquid tank 4 is made too high, the height of the solid-liquid separating device 1 as a whole becomes high, and the manufacturing cost of the concentrating liquid tank 4 becomes expensive. The height of the side wall 41 is preferably low. If the side wall 41 extends above the discharge port 331, the discharge port 331 can be closed by the liquid stored in the concentrating liquid tank 4, but in this modified example, the height of the entire solid-liquid separation device 1 is high. The height is set with an emphasis on the balance between the water pressure applied to the outlet 331 and the outlet 331. The position of the overflow port 43 may be appropriately set according to the height of the side wall 41, but in this modified example, the height is the same as that of the receiving port 341 (see FIG. 2B).

Next, a modified example of the solid-liquid separator shown in FIG. 1 different from the modified example shown in FIG. 5 will be described.

FIG. 6 (a) is a front view similar to FIG. 3 (b) in a solid-liquid separator of a modified example different from the modified example shown in FIG. 5, and FIG. 6 (b) is the same as FIG. 6 (a). It is a DD cross-sectional view in.

In the solid-liquid separation device 1 shown in FIGS. 6 (a) and 6 (b), the concentrating container 3 is not provided with the squeezing portion 32 and the discharging portion 33, the height of the concentrating liquid tank 4 is low, and The position of the overflow port 43 is different from that of the solid-liquid separation device 1 shown in FIGS. 1 to 4. The concentrating container 3 is composed of a fluid introduction unit 31. Therefore, the internal space X1 is defined only by the inner peripheral surface 31a of the fluid introduction portion 31. The lower end of the concentrating container 3 is the lower end of the cylindrical portion 311 and the opening at the lower end serves as the discharge port 331. The discharge port 331 is an opening having a diameter of 500 mm, which is considerably larger than the reception port 341 (see FIG. 2B). Therefore, in this modified example, almost no pressure loss occurs in the concentrating container 3. The concentrated liquid tank 4 is formed lower than the concentrated liquid tank 4 shown in FIG. 3 by the total height of the squeezing portion 32 and the discharging portion 33. Further, the receiving port 341 formed in the concentrating container 3 is arranged at a position close to the lower end of the concentrating liquid tank 4 by the total height thereof. As the height of the concentrating liquid tank 4 is lowered, the length (height) of the transport device 5 can also be lowered. That is, by lowering the height of the concentrating container 3, the height of the entire solid-liquid separation device 1 can be lowered, and the solid-liquid separation device 1 can be miniaturized. Further, since the receiving port 341 is arranged at a position close to the ground, the lift required for the sand lifting pump 941 is lowered, and the mixed water can be transferred to the concentrating container 3 with even smaller power. The overflow port 43 is arranged at the same height as the receiving port 341. However, the overflow port 43 may be arranged at a position higher than the receiving port 341, or may be arranged at a position higher than the upper end 6c of the liquid feeding pipe 6. By arranging it at a high position, the liquid can be quickly stored in the concentrating liquid tank 4 to a position higher than the upper end 6c of the liquid feeding pipe 6, and the principle of siphon after the sand-mixed water starts to be supplied to the internal space X1. It is possible to shorten the time until the effect is produced.

The operation of the solid-liquid separation device 1 of this modified example is the same as that of the solid-liquid separation device 1 shown in FIGS. 1 to 4, but the behavior of the sand-mixed water and the concentrated liquid in steps S1 and S2 shown in FIG. Are slightly different, so these behaviors will be mainly described. When the sand lifting pump 941 shown in FIG. 1 is driven while the internal space X1 of the concentrating container 3 and the inside of the concentrating liquid tank 4 are empty, sand-mixed water starts to be supplied to the internal space X1. In this modification, 2.0 m ³ / min of sand-mixed water is supplied to the internal space X1. Since the sand-mixed water is introduced into the internal space X1 from the tangential direction of the inner peripheral surface 31a of the cylindrical portion 311 through the receiving port 341 (see FIG. 2B), the swirling flow of the sand-mixed water is introduced into the internal space X1. Is formed. Since the sand contained in the sand-mixed water has a higher specific gravity than the sewage, it is pressed against the inner peripheral surface 31a of the cylindrical portion 311 by centrifugal force, and gradually falls downward while swirling along the inner peripheral surface 31a. I will do it. On the other hand, in the vicinity of the radial center of the cylindrical portion 311, separated water from which sand has been removed from the sand-mixed water remains. While the amount of liquid stored in the concentrating liquid tank 4 is small, all of the sand-mixed water supplied to the internal space X1 is discharged as a concentrating liquid from the discharge port 331. The concentrated liquid discharged from the discharge port 331 is stored in the tank of the concentrated liquid tank 4, so that the water surface WL2 in the tank gradually rises. When the tank water surface WL2 reaches the discharge port 331, the discharge port 331 is blocked with the concentrated liquid, and as the tank water surface WL2 rises, the water pressure of the concentrated liquid applied to the discharge port 331 increases. In this modified example, since the throttle portion 32 shown in FIG. 2B is not provided and the discharge port 331 is sufficiently large with respect to the reception port 341, the tank water surface WL2 is predetermined even after the discharge port 331 is closed with the concentrated liquid. All of the sand-mixed water supplied to the internal space X1 is discharged from the discharge port 331 until the height reaches the height of. After that, when the tank water surface WL2 reaches the overflow port 43, the supernatant liquid of the concentrated liquid flows out from the overflow port 43, but sand contamination supplied by the sand pump 941 rather than the supernatant liquid flowing out from the overflow port 43 due to natural flow. Since there is more water, the tank water level WL2 continues to rise. When the tank water surface WL2 reaches the lower end 6d of the liquid feeding pipe 6, the separated water starts to be sent out through the liquid feeding pipe 6. When the tank water surface WL2 reaches the upper end 6c of the pipe, the inside of the liquid feed pipe 6 is filled with liquid, and the action of flowing out from the inflow port 611 to the sand basin 9 occurs in the sand-mixed water according to the siphon principle. The amount of separated water sent out from the tank further increases, the rise of the tank water surface WL2 stops, and then it falls and stabilizes at a fixed position. 6 (a) and 6 (b) show the tank water surface WL2 at this time. When the tank water surface WL2 is stable, the supernatant liquid of about ^{1.2 m 3 / min flows out from the overflow port 43.}

The solid-liquid separation device 1 of this modified example also has the same effect as the solid-liquid separation device 1 shown in FIG. Further, due to the water pressure of the discharge port 331 generated by the liquid stored in the concentrate tank 4, the amount of the concentrate discharged from the discharge port 331 can be suppressed even without the squeezing portion 32. Since there is no drawing portion 32, the pressure loss in the concentrating container 3 becomes almost zero, and the power of the sand lifting pump 941 can be further reduced. Further, even when there is no liquid in the liquid feeding pipe 6, the tank water surface WL2 reaches the height of the upper end 6c of the pipe and the inside of the liquid feeding pipe 6 can be filled with the liquid only by driving the sand pump 941. The action of the siphon principle can be easily produced.

From the above-described embodiments and modifications, a concentrating container that accepts a mixed liquid in which a solid is mixed in a liquid and discharges a concentrated liquid having an increased concentration of the solid with respect to the liquid from a discharge port, and the discharge port inside the tank. The concentrating liquid tank arranged in the concentrating container and storing the concentrated liquid obtained in the concentrating container, and the lower end portion of the transport path extending diagonally upward are connected to the bottom of the concentrating liquid tank, and the upper end portion of the transport path is connected. A transport device arranged above the discharge port, and a liquid supply pipe having an inflow port connected to the concentrating container and an outflow port outside the concentrating liquid tank and arranged below the inflow port. The solid in the concentrated liquid is collected at the lower end portion, and the solid is transported diagonally upward along the transport path by driving the transport device, and the solid in the mixed liquid received by the concentrate container. A solid-liquid separator that sends a liquid to the outside of the concentrating liquid tank through the liquid feeding pipe.
When the concentrating container receives the mixed liquid with the transport device stopped, the liquid level of the concentrating liquid tank rises above the discharge port, and the inside of the liquid feeding pipe is in the mixed liquid. It accepts the mixture until it is filled with the liquid.
The liquid feeding pipe sends the liquid in the concentrated liquid stored in the concentrated liquid tank to the outside of the concentrated liquid tank by utilizing the potential energy of the liquid in the concentrated liquid.
The transfer device starts driving after the liquid level of the concentrated liquid tank is lowered by sending the liquid in the mixed liquid to the outside of the concentrated liquid tank by the liquid feeding pipe, and the solid collected at the lower end portion. It is possible to derive an invention idea such as a solid-liquid separation device characterized by transporting a liquid.

Next, the solid-liquid separation device of the second embodiment will be described.

FIG. 7 is a front view similar to FIG. 3 (b) in the solid-liquid separation device of the second embodiment.

The solid-liquid separation device 1 shown in FIG. 7 is different from the solid-liquid separation device 1 shown in the previous embodiment in that the concentration container 3 is not mainly provided. The solid-liquid separation device 1 includes a storage tank 40, a transfer device 5, and a liquid supply pipe 6. The storage tank 40 has the same configuration as the concentrated liquid tank 4 in the previous embodiment. However, this storage tank 40 receives and stores sand-mixed water without going through the concentration container 3 shown in the previous embodiment, and the supernatant liquid from the inflow port 611 without going through the concentration container 3 (previous implementation). It differs from the concentrated liquid tank 4 in the previous embodiment in that it sends (corresponding to the separated water in the embodiment). A sand lifting pump 941 is connected to one end of the sand lifting pipe 942, and a supply port 9421 is formed at the other end of the sand lifting pipe 942. The sand-mixed water sucked by the sand-lifting pump 941 is directly poured into the tank of the storage tank 40 from the supply port 9421. The sand lifting pipe 942 of the second embodiment is inserted into the tank of the storage tank 40 through the opening at the upper end of the storage tank 40. However, the sand pipe 942 may be inserted into the tank of the storage tank 40 through the side wall 401 of the storage tank 40. The sand pump 941 is actually arranged in the sand collecting pit 94 shown in FIG. 1, but is shown on the side of the solid-liquid separation device 1 in FIG. 7 for simplification of the drawing. ..

The liquid feeding pipe 6 has one end portion 61 arranged in the tank of the storage tank 40, a horizontally extending portion extending horizontally, and a vertical portion bent downward from the horizontal portion. An inflow port 611 is formed at one end of the liquid feeding pipe 6 (the tip of the one end portion 61). The inflow port 611 is arranged in a lower portion in the storage tank 40. A cap-shaped covering member 612 that extends around the inflow port 611 in a plan view is attached to one end portion 61 slightly above the inflow port 611. The covering member 612 is sucked into the inflow port 611 while the sand contained in the sand-mixed water poured into the tank of the storage tank 40 settles in the sand-mixed water stored in the tank of the storage tank 40. It is to prevent it from being lost. The peripheral portion of the covering member 612 may be arranged below the inflow port 611. Further, the covering member 612 may have a disk shape. When a disk-shaped member is used, the covering member 612 may be located at the same height as the inflow port 611. That is, the covering member 612 may be provided above the inflow port 611 or around the inflow port 611. In other words, the covering member 612 may be arranged between the supply port 9421 and the inflow port 611. If a disk-shaped covering member 612 is used, sand will be deposited on the covering member 612, so it is preferable to use a cap-shaped covering member 612. An outlet 62 is formed at the lower end of the vertical portion of the liquid feed pipe 6. The outflow port 62 is arranged below the inflow port 611 and above the sand basin 9 (see FIG. 1) which is outside the storage tank 40.

The operation of the solid-liquid separation device 1 of the second embodiment is similar to the operation of the solid-liquid separation device 1 of the previous embodiment, but the behavior of sand-mixed water and the like are different. Hereinafter, points different from the previous embodiments will be mainly described with reference to FIGS. 7 and 8.

FIG. 8 is a flowchart showing the operation of the solid-liquid separation device shown in FIG. 7.

In the solid-liquid separation operation, the sand-lifting pump 941 is started to be driven with the transport device 5 stopped, so that the storage tank 40 starts receiving the sand-mixed water (step S11). The transport device 5 does not have to be completely stopped. For example, the transport device 5 may be driven at a very low speed so that the liquid component contained in the sand-mixed water does not reach the drop portion 52 by the drive of the transport device 5. I do not care. That is, the transport device 5 may be driven at a drive speed slower than a predetermined drive speed. After that, the water surface WL3 formed by the sand-mixed water stored in the storage tank 40 gradually rises. This water surface WL3 corresponds to an example of the liquid surface. The sand contained in the sand-mixed water stored in the storage tank 40 settles toward the bottom of the storage tank 40 due to its own weight, and collects at the lower end portion of the transport path of the transport device 5. When the water surface WL3 rises above the lower end of the horizontal portion of the liquid feed pipe 6, the supernatant liquid (sewage) of the sand-mixed water begins to flow out from the outflow port 62 through the liquid feed pipe 6. This supernatant liquid also corresponds to an example of a liquid. Further, when the water surface WL3 rises and the water surface WL3 reaches the height of the upper end 6c of the pipe which is the uppermost end of the liquid feed pipe 6, the inside of the liquid feed pipe 6 is filled with the supernatant liquid of the sand-mixed water according to the siphon principle. The effect is produced and the outflow of the supernatant is increased. That is, the potential energy of the liquid in the sand-mixed water causes the supernatant liquid of the sand-mixed water to be sent out of the storage tank 40 through the liquid feeding pipe 6. Due to this effect, a force for sucking sand-mixed water is generated in the vicinity of the inflow port 611, but the sand that has settled in the vicinity of the inflow port 611 slides down on the covering member 612 and falls from the edge of the covering member 612. As it goes, it is kept away from the inflow port 611. As a result, the sand that has settled in the vicinity of the inflow port 611 is suppressed from entering the inflow port 611. When the water surface WL3 further rises and reaches the overflow port 43, the supernatant liquid of the sand-mixed water flows out from the overflow port 43 together with the liquid feed pipe 6 to prevent the water surface WL3 from rising further. The drive of the sand lifting pump 941 is continued from the start of the drive to the fourth predetermined time (step S12). Steps S11 and S12 described above correspond to an example of the receiving process. This fourth predetermined time is a sufficient time for the water surface WL3 to be raised above the uppermost end of the liquid feeding pipe 6. A water level sensor for detecting that the water surface WL3 has risen above the uppermost end of the liquid feed pipe 6 may be provided in the storage tank 40, and water detection for detecting that the inside of the liquid feed pipe 6 is filled with the supernatant liquid. The sensor may be provided in the liquid feed pipe. Then, instead of determining whether or not the fourth predetermined time has passed, it may be determined whether or not the detection by those sensors has occurred.

After the lapse of the fourth predetermined time, the drive of the sand lifting pump 941 is stopped (step S13). Even after the drive of the sand lifting pump 941 is stopped, due to the effect of the siphon principle described above, the sand-mixed water has an action of flowing out to the sand basin 9 through the liquid feeding pipe 6. As a result, the supernatant liquid of the sand-mixed water flows out to the sand basin 9 through the liquid feed pipe 6, and the water surface WL3 is lowered. That is, the water surface WL3 is lowered by sending the supernatant liquid of the sand-mixed water stored in the storage tank 40 to the outside of the storage tank 40 through the liquid feed pipe 6 by utilizing the potential energy of the supernatant liquid. .. When the water surface WL3 drops to the inflow port 611, air enters the liquid supply pipe 6 from the inflow port 611, and the effect of the siphon principle ends. The state immediately after the sand lifting pump 941 is stopped is maintained until the fifth predetermined time elapses after the driving of the sand pump 941 is stopped (step S14). Steps S13 and S14 described above correspond to an example of the liquid feeding process. This fifth predetermined time is the time when the water surface WL3 drops to the vicinity of the inflow port 611. The fifth predetermined time is shorter than the time when the water surface WL3 drops to the vicinity of the inflow port 611 if the time is such that the water surface WL3 drops to a position lower than the height of the upper end portion of the transport path of the transport device 5. It may be. Further, instead of determining whether or not the fifth predetermined time has elapsed, the water level sensor for detecting that the water surface WL3 has dropped to a position lower than the height of the upper end portion of the transport path of the transport device 5 is provided in the storage tank 40. It may be provided in the above and it may be determined whether or not the detection has occurred. Further, in steps S13 and S14, a small amount of sand-mixed water may be supplied to the storage tank 40 as long as the water surface WL3 is lowered without completely stopping the drive of the sand lifting pump 941. Hereinafter, steps S15 to S17 are the same as steps S5 to S7 of the previous embodiment, and thus the description thereof will be omitted.

Also by the driving method of this solid-liquid separation device, the transfer device 5 is driven after the water surface WL3 of the storage tank 40 is lowered by the siphon principle, so that the height of the transfer path is lowered to lower the solid-liquid separation device 1. Can be miniaturized.

FIG. 9 is a front view similar to FIG. 7, showing a modified example of the solid-liquid separation device shown in FIG. 7.

As shown in FIG. 9, the solid-liquid separating device 1 of this modified example has a different configuration of the liquid feeding pipe 6 and the covering member 612 from the solid-liquid separating device 1 shown in FIG. The liquid feed pipe 6 is composed of a horizontally extending portion and a vertical portion that is bent from the horizontal portion and extends downward. In this modification, the opening at the end of the horizontal portion of the liquid feed pipe 6 on the side opposite to the side connected to the vertical portion becomes the inflow port 611. The covering member 612 is attached to the inner side surface of the side wall 401 of the storage tank 40, and projects toward the inside of the storage tank 40 in parallel with the liquid feeding pipe 6. As shown in the arrow E view of FIG. 9, the covering member 612 is made of a plate material having a V-shaped cross section that covers the upper part of the inflow port 611. The covering member 612 prevents sand that has settled in the vicinity of the inflow port 611 from entering the inflow port 611. Also in this modification, the supernatant liquid of the sand-mixed water is sent by the potential energy (own weight) of the liquid in the sand-mixed water while the water surface WL3 drops to the inflow port 611 from the middle of the above-mentioned step S12 to the step S14 or later. It is sent out of the storage tank 40 through the liquid pipe 6.

From the second embodiment described above and the modified example thereof, a storage tank for storing a mixed liquid in which a solid is mixed in a liquid and an inflow port are arranged in the storage tank, and an outflow port is outside the storage tank. The liquid feed pipe arranged below the inflow port and the lower end portion of the transport path extending diagonally upward are connected to the bottom of the storage tank, and the upper end portion of the transport path is closer to the inflow port. The storage tank is provided with a transport device arranged above, collects the solid in the mixed liquid at the lower end portion, and drives the transport device to transport the solid diagonally upward along the transport path. A solid-liquid separation device that sends the liquid in the mixed liquid stored in the liquid to the outside of the storage tank through the liquid supply pipe.
By receiving the mixed liquid in a state where the transport device is substantially stopped, the storage tank receives the mixed liquid above the uppermost end of the liquid feeding pipe.
The liquid feeding pipe receives the mixed liquid into the storage tank above the uppermost end of the liquid feeding pipe, and sends the mixed liquid to the outside of the storage tank by utilizing the potential energy of the liquid in the mixed liquid. And
The transport device starts driving after the liquid level of the storage tank is lowered by sending the liquid in the mixed liquid to the outside of the storage tank by the liquid feed pipe, and transports the solid collected at the lower end portion. It is possible to derive an invention idea such as a solid-liquid separator characterized by being a solid-liquid separator.

In this solid-liquid separation device, a supply port for supplying the mixed liquid to the storage tank is provided above the inflow port.
The storage tank may have a covering member arranged between the supply port and the inflow port.

The covering member is provided above the inflow port or around the inflow port, and the solid in the mixed liquid supplied from the supply port enters the inflow port while the solid is settling. It may be something that suppresses this.

The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of claims. For example, in the present embodiment, the solid-liquid separation device 1 is installed in the sand basin 9, but the solid-liquid separation device 1 may be provided in the sedimentation basin or in a reservoir such as a dam lake. .. Further, it may be used as a solid-liquid separation device 1 for separating water and metal powder or the like from factory wastewater generated in a factory or the like.

According to the embodiments and modifications described above, it is possible to provide a method for driving the solid-liquid separation device, which can realize miniaturization of the solid-liquid separation device.

It should be noted that even if the constituent requirements are included only in the description of each of the above-described embodiments and modifications, the constituent requirements may be applied to other embodiments and modifications.

1 Solid-liquid separation device 2 Sand pump 3 Concentration container 4 Concentrate tank 5 Conveyor device 6 Liquid supply pipe 40 Storage tank 62 Outlet 331 Outlet 611 Inflow port

Claims (5)

A concentrating container that accepts a mixed liquid in which a solid is mixed in a liquid and discharges a concentrated liquid having an increased concentration of the solid with respect to the liquid from a discharge port, and a concentrating container in which the discharge port is arranged in a tank and obtained in the concentrating container. The concentrating liquid tank for storing the liquid and the lower end portion of the transport path extending diagonally upward are connected to the bottom of the concentrating liquid tank, and the upper end portion of the transport path is arranged above the discharge port. The apparatus is provided with a liquid feed pipe having an inflow port connected to the concentrating container and an outflow port outside the concentrating liquid tank and arranged below the inflow port, and the solid in the concentrated liquid is subjected to the above. By collecting at the lower end and driving the transfer device at a predetermined drive speed, the solid is conveyed diagonally upward along the transfer path, and the liquid in the mixed liquid received by the concentration container is transferred to the liquid transfer tube. It is a method of driving a solid-liquid separator that sends the liquid to the outside of the concentrated liquid tank through the liquid.
In a state where the transfer device is driven or stopped at a driving speed slower than the predetermined driving speed, the liquid level of the concentrating liquid tank is raised above the discharge port, and the inside of the liquid feeding pipe is filled with the concentrating container. And the filling process of filling with the liquid in the mixed liquid received by
The liquid in the concentrated liquid stored in the concentrated liquid tank is sent to the outside of the concentrated liquid tank through the liquid feeding pipe by utilizing the position energy of the liquid in the concentrated liquid, and the liquid in the concentrated liquid tank is sent. The liquid feeding process that lowers the surface and
It is characterized by having a transporting step of lowering the liquid level of the concentrated liquid tank by the liquid feeding step, driving the transporting device at the predetermined driving speed, and transporting the solid collected at the lower end portion. How to drive the solid-liquid separator. In the filling step, the mixed liquid is received from the tangential direction of the inner peripheral surface into the cylindrical portion of the concentrating container having a cylindrical portion having a cylindrical inner peripheral surface, and the concentrated liquid is discharged from the discharge port. The method for driving a solid-liquid separation device according to claim 1, wherein the process is a step. The filling step has, as the concentrating container, a squeezed portion between the cylindrical portion and the discharge port, in which the cross-sectional area of the internal space of the concentrating container is reduced on the discharge port side as compared with the cylindrical portion side. The method for driving a solid-liquid separator according to claim 2, wherein the process is a process of using an object. A storage tank for storing a mixed liquid in which a solid is mixed in a liquid, and a liquid feed pipe in which an inflow port is arranged in the storage tank and an outflow port is located outside the storage tank and below the inflow port. The mixed liquid is provided with a transport device in which the lower end portion of the transport path extending diagonally upward is connected to the bottom portion of the storage tank and the upper end portion of the transport path is arranged above the inflow port. The solid inside is collected at the lower end portion, and the transport device is driven at a predetermined driving speed to transport the solid diagonally upward along the transport path, and the mixed liquid stored in the storage tank is charged. A method of driving a solid-liquid separator that sends a liquid to the outside of the storage tank through the liquid feed pipe.
With the transport device stopped or driven at a drive speed slower than the predetermined drive speed, the mixed liquid is received in the storage tank and the liquid level of the storage tank rises above the uppermost end of the liquid supply pipe. Acceptance process and
The liquid in the mixed liquid stored in the storage tank is sent to the outside of the storage tank through the liquid feed pipe by utilizing the potential energy of the liquid in the mixed liquid, and the liquid level of the storage tank is lowered. The liquid feeding process and
It is characterized by having a solid transporting step of lowering the liquid level of the storage tank by the liquid feeding step, driving the transporting device at the predetermined driving speed, and transporting the solid collected at the lower end portion. How to drive the liquid separator. In the receiving step, the covering member provided above or around the inflow port prevents the solid that has settled from above the covering member from entering the inflow port. The method for driving a solid-liquid separator according to claim 4, wherein the process is performed in a state.

Images