JP2023103340A - Solid-liquid separation system - Google Patents

Abstract

To provide a solid-liquid separation system that can be driven by small power.SOLUTION: A solid-liquid separation system comprises: a sand lifting pump 2 that transfers sand-mixed water having sand mixed therein; an inner container 3 that has an inflow port 341 into which the sand-mixed water transferred by the sand lifting pump 2 flows and an ejection port 331 through which concentrated water is ejected in which concentration of sand is increased after some liquid components are removed from the sand-mixed water; an outer tank 4 that receives the concentrated water; and a carrying-out device 5 that extends obliquely upward from one side toward the other side in a horizontal direction of the outer tank 4, and carries out solid included in the concentrated water received by the outer tank 4 to the outside of the outer tank 4. The outer tank 4 comprises a side wall 41 arranged closer to outside than an outer peripheral side surface 3b of the inner container 3 and extending upward beyond the ejection port 331. In the inner container 3, the ejection port 331 is provided at a position shifted toward the one side with respect to a center in the horizontal direction of the outer tank 4.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a solid-liquid separation system for separating liquid from solid-entrained water.

Sewage treatment plants are provided with settling basins for removing sand from sewage and sedimentation basins for removing sludge from sewage. In the sedimentation basin, the sand contained in the sewage received is collected in the sand collection pit at the bottom of the basin, and then separated into sand and sewage by a solid-liquid separation system. In the solid-liquid separation system installed in the settling basin, the sand collected in the sand collection pit is transferred together with the sewage by a sand lifting pump above the settling basin. In addition, the sedimentation basin collects sludge contained in the sewage it receives in a sludge pit at the bottom of the basin, and then separates it into sand and sludge by a solid-liquid separation system. In the solid-liquid separation system provided in this sedimentation basin, the sludge collected in the sludge pit is transferred together with the wastewater above the sedimentation basin by a sludge pump, and the sewage is separated from the transferred mixed water of sludge and sewage and returned to the sedimentation basin. Furthermore, in places other than sewage treatment facilities, liquids mixed with solids are separated into solids and liquids by solid-liquid separation systems. For example, there are a solid-liquid separation system that separates water from factory waste water and metal powder, etc., and a solid-liquid separation system that separates water from sediments and the like that have flowed into a reservoir such as a dam lake. Hereinafter, sand, sludge, and residue contained in sewage, metal powder contained in industrial wastewater, and earth and sand flowing into a reservoir together with water are sometimes collectively referred to as solids. Liquid mixed with solids is sometimes referred to as solid-mixed water.

As this solid-liquid separation system, there is known one that includes a separation device main body and a separation container arranged above the separation device main body (see, for example, Patent Document 1, etc.). The separation vessel is connected with a sand lifting pump by a sand lifting pipe. The solid-contaminated water transferred from the settling basin by the sand pump flows into the separation container through an inlet formed in the separation container. In the separation vessel, some liquid components are removed from the solid entrained water. The concentrated water, in which the concentration of solids has been increased by removing some of the liquid components, is discharged from the discharge port formed in the separation container to the main body of the separation device. The liquid component removed from the solid entrained water in the separation vessel is pumped through one end of the delivery tube into the delivery tube and returned to the settling basin. A carrying-out device is provided in the separation device main body, and solids contained in the concentrated water are drained by the carrying-out device and carried out to the outside of the separation device main body. A throttle is formed between the inlet and the outlet of the separation vessel. Conventionally, the amount of condensed water discharged from the discharge port is much smaller than the amount of condensed water that flows into the separation vessel by increasing the amount of constriction at the constricted portion, thereby sending out the liquid component of the solid-contaminated water to the delivery pipe. However, if the throttle amount is increased, the pressure loss generated in the separation container increases. In the solid-liquid separation system of Patent Document 1, the other end of the delivery pipe is arranged near the bottom of the settling basin, and the inside of the delivery pipe is filled with sewage, thereby causing the water mixed with solids in the separation container to flow into the settling basin by the siphon principle. By using this action to reduce the pressure loss caused by the constricted portion, the solid-liquid separation system is driven with small power.

JP 2012-21483 A

The solid-liquid separation system disclosed in Patent Document 1 uses a long delivery tube extending to the bottom of the pond and fills the inside of the delivery tube with liquid in order to maintain the action based on the siphon principle. In addition, it is necessary to provide a valve between the separation apparatus main body and the separation container so that the inside of the delivery pipe can be refilled with the liquid after the liquid in the delivery pipe has been once removed. For these reasons, there is a problem that the solid-liquid separation system becomes expensive. In addition, there is a problem that it is necessary to control the opening and closing of the valve each time the liquid in the delivery pipe is drained, which complicates the work. Therefore, another configuration that can be driven with small power has been desired.

SUMMARY OF THE INVENTION An object of the present invention is to provide a solid-liquid separation system that can be driven with a small amount of power.

The solid-liquid separation system of the present invention for solving the above object comprises a pump for transferring solid-contaminated water containing solids,
an inner container having an inlet into which the solid-contaminated water transferred by the pump flows, and an outlet for discharging concentrated water in which a portion of the liquid component is removed from the solid-contaminated water to increase the concentration of solids;
an outer tank for receiving the concentrated water;
a carrying-out device connected to the lower end of the outer tank, extending obliquely upward from one side of the outer tank to the other side in the horizontal direction, and carrying out solids contained in the concentrated water received by the outer tank to the outside of the outer tank;
The outer tank has a side wall arranged outside the outer peripheral side surface of the inner container and extending upward from the discharge port,
The inner container is characterized in that the discharge port is provided at a position shifted to the one side with respect to the center of the outer tank in the horizontal direction.

In this solid-liquid separation system, the inner container may be provided with the discharge port right above the carry-out device.

ADVANTAGE OF THE INVENTION According to this invention, the solid-liquid separation system which can be driven by small power can be provided.

1 is a schematic configuration diagram showing a solid-liquid separation system corresponding to one embodiment of the present invention; FIG. (a) is a plan view of the inner container, and (b) is a cross-sectional view taken along line AA in FIG. (a) is a plan view showing the inner container and the outer tank, (b) is a front view showing the inner container and the outer tank, and (c) is a cross-sectional view taken along line BB in FIG. (a) is a front view similar to FIG. 3(b) showing a modification of the solid-liquid separation system, and (b) is a sectional view taken along the line CC in FIG. 3(a).

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of this embodiment, an example in which the present invention is applied to a solid-liquid separation system that transfers sewage mixed with sand from a settling basin and separates the sewage and sand from the transferred sand and sewage will be used. A settling basin is placed upstream of a sewage treatment facility to remove sand from wastewater such as sewage or rainwater. Wastewater from which sand has been removed in the settling basin is sent to a sedimentation basin or the like located downstream.

FIG. 1 is a schematic configuration diagram showing a solid-liquid separation system corresponding to one embodiment of the present invention. A settling basin is also shown in this figure.

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

The trough 92 is formed at the bottom of the pond upstream of the pump well 91 and at the center in the width direction of the pond. This trough 92 extends along the direction of sewage flow in the settling basin 9 . On both sides of the trough 92 in the pond width direction, pond bottom inclined surfaces 95 that are inclined downward toward the trough 92 are formed. Sand contained in sewage that has flowed into the settling basin 9 settles toward the bottom of the basin, slides down the sloped surface 95 of the basin bottom, or deposits directly in the trough 92 .

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

The solid-liquid separation system 1 includes a sand pump 2 , an inner container 3 , an outer tank 4 , a carry-out device 5 and a delivery pipe 6 . The sand pump 2 is arranged inside the sand collection pit 94 and near the bottom of the sand collection pit 94 . This sand pump 2 corresponds to an example of a pump. A sand lifting pipe 21 is connected to the sand lifting pump 2 . The sand pump 2 sucks sand collected inside the sand collection pit 94 together with sewage, and transfers sand-mixed sewage to the inner container 3 through the sand pump 21 . The ratio of sand and sewage transferred to the inner container 3 by the sand pump 2 varies depending on the amount of sand collected inside the sand collecting pit 94, but is approximately 5% sand and 95% sewage. The sand transported by the sand pump 2 corresponds to an example of solids, and the sewage mixed with the sands corresponds to an example of water mixed with solids. The sewage mixed with sand transferred by the sand pump 2 is hereinafter referred to as sand mixed water.

The inner container 3 , the outer tank 4 and the unloading device 5 are arranged on the ground in the vicinity of the settling basin 9 . The inner container 3, the outer tank 4, and the carry-out device 5 correspond to an example of a solid-liquid separation device. The inner container 3 is arranged in the tank of the outer tank 4 . The inner container 3 removes part of the liquid component from the transported sand-mixed water by sending it to a delivery pipe 6, and discharges to the outer tank 4 condensed water in which the concentration of sand is increased by partly removing the liquid component. Hereinafter, the liquid component obtained by removing the sand from the sand-mixed water is referred to as separated water. Separated water delivered from the inner container 3 is returned to the settling basin 9 through the delivery pipe 6 . The delivery pipe 6 has one end portion 61 (see FIG. 2) inserted into the inner container 3, a horizontal portion extending horizontally above the inner container 3, and a vertical portion bent from the horizontal portion and extending downward. The other end 6a, which is the lower end of the vertical portion, is arranged below the inner container 3 and above the settling basin 9 outside the outer tank 4. As shown in FIG. These inner container 3 and outer tank 4 will be described in detail later.

The unloading device 5 is connected to the lower end of the outer tank 4 and extends obliquely upward. This carry-out device 5 has a screw conveyor 51 and a drop port 52 . The screw conveyor 51 is arranged inside the unloading device 5 . The axial direction of the screw conveyor 51 coincides with the extending direction of the unloading device 5 . The sand contained in the concentrated water discharged into the outer tank 4 settles inside the outer tank 4 and gathers at the lower end of the outer tank 4 . The sand collected at the lower end of the outer tank 4 is conveyed obliquely upward while being drained by the rotation of the screw conveyor 51 . The drop port 52 is arranged near the upper end of the screw conveyor 51 . The sand drained by the screw conveyor 51 is dropped downward from the drop port 52 . That is, the carrying-out device 5 carries out the sand contained in the concentrated water received by the outer tank 4 to the outside of the outer tank 4 . Note that, instead of the screw conveyor 51, another transport mechanism such as a belt conveyor may be used.

FIG. 2(a) is a plan view of the inner container, and FIG. 2(b) is a sectional view taken along line AA in FIG. 2(a). One end portion of the delivery tube is also shown in FIGS. 2(a) and 2(b).

As shown in FIG. 2B, the inner 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. As shown in FIG. The inner container 3 of this embodiment is a so-called hydrocyclone device. The fluid introduction part 31 is provided in the upper part of the inner container 3 . The narrowed portion 32 is connected at its upper end to the lower end of the fluid introducing portion 31 . Also, the upper end of the discharging portion 33 is connected to the lower end of the throttle portion 32 . The inner peripheral surface 3 a of the inner container 3 is composed of the inner peripheral surface 31 a of the fluid introduction portion 31 , the inner peripheral surface 32 a of the throttle portion 32 , and the inner peripheral surface 33 a of the discharge portion 33 . An internal space S<b>1 is defined by the inner peripheral surface 3 a of the inner container 3 . That is, the fluid introduction portion 31, the throttle portion 32, and the discharge portion 33 constitute a hollow tank having an internal space S1.

The fluid introduction portion 31 includes a cylindrical portion 311 having a cylindrical inner peripheral surface 31 a and a lid 312 closing the upper end of the cylindrical portion 311 . The cylindrical portion 311 is formed by processing a steel plate with a thickness of 3.2 mm into a cylindrical shape with an inner diameter of 500 mm. The lid 312 is formed by processing a steel plate having a thickness of 6.0 mm into a ring 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 S1. Further, the cylindrical portion 311 may have a conical shape or a dome shape in which the cross-sectional area of the internal space S1 increases downward. Furthermore, the cylindrical portion 311 may have a conical or dome shape in which the cross-sectional area of the internal space S1 increases as the upper portion formed with an inlet 341 described later goes downward, and the lower portion may have a cylindrical shape. A pair of mounting portions 36 are fixed to the outer peripheral surface of the cylindrical portion 311 . This mounting portion 36 is for fixing the inner container 3 to the outer 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 2 and the fluid inflow pipe 34 shown in FIG. 1 are connected via the sand lifting pipe 21 . The sand lifting pipe 21 and the fluid inflow pipe 34 are detachably connected by fastening flanges provided at connection ends with bolts. The fluid inflow tube 34 is a tube with an inner diameter of 100 mm. As shown in FIG. 2B, an inflow port 341 is formed in the connecting portion between the fluid inflow pipe 34 and the cylindrical portion 311 . As indicated by the straight arrow in FIG. 2(a), the sand-mixed water sucked up by the sand pump 2 is introduced into the internal space S1 from the tangential direction of the inner peripheral surface 31a of the cylindrical portion 311 through the inlet 341. As shown in FIG. In the internal space S<b>1 , sand-mixed water is introduced between the outer peripheral surface of the one end portion 61 of the delivery pipe 6 and the inner peripheral surface 31 a of the cylindrical portion 311 . As a result, a swirling flow of water mixed with sand is formed in the internal space S1.

The throttle portion 32 is arranged between the inflow port 341 and the discharge portion 33 . In this narrowed portion 32 , the cross-sectional area of the internal space S<b>1 decreases toward the discharge portion 33 . In other words, the narrowed portion 32 has an inverted conical inner peripheral surface 32 a that gradually decreases in diameter as it moves away from the cylindrical portion 311 . The narrowed portion 32 is formed by processing a steel plate having a thickness of 3.2 mm into a conical shape, and has an inner diameter of 500 mm at the upper end and an inner diameter of 100 mm at the lower end. The material and thickness of the narrowed portion 32 may be appropriately selected according to the size of the internal space S1, the amount of narrowing, and the like. In this embodiment, the cross-sectional area of the lower end of the constricted portion 32 is the same as the cross-sectional area of the inlet 341, but the cross-sectional area of the lower end of the constricted portion 32 may be equal to or larger than the cross-sectional area of the inlet 341, or may be smaller than the cross-sectional area of the inlet 341. However, if the cross-sectional area of the lower end of the constricted portion 32 is made too small, the pressure loss in the inner container 3 increases. Furthermore, the narrowed portion 32 may be formed so that the cross-sectional area of the internal space S1 decreases stepwise as it separates from the cylindrical portion 311 .

The discharge portion 33 is connected to the side of the throttle portion 32 opposite to the side where the fluid introduction portion 31 is provided. That is, the discharge portion 33 is connected to the lower end of the narrowed portion 32 . The discharge portion 33 has a cylindrical shape with an inner diameter equal to that of the lower end of the constricted portion 32 and a flange formed at the lower end. An opening at the lower end of the discharge portion 33 serves as a discharge port 331 . Note that the discharge section 33 may be omitted. If omitted, the opening at the lower end of the narrowed portion 32 becomes the discharge port.

One end portion 61 of the delivery tube 6 vertically penetrates the lid 312 of the fluid introduction portion 31 . The one end portion 61 extends from below the lower end of the lid 312 to above the upper end of the lid 312 along the radial central axis of the cylindrical portion 311 and is watertightly joined to the lid 312 by welding. Accordingly, the lower portion of the one end portion 61 protrudes into the internal space S1. However, the lower portion of the one end portion 61 may not protrude into the internal space S1, 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. The 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 delivery tube 6 , and the opening of the one end becomes the delivery port 611 . Accordingly, the one end portion 61 and the delivery port 611 are connected to the inner container 3 . Also, the delivery port 611 of this embodiment is arranged in the internal space S1. Separated water, which is a liquid component obtained by removing the sand from the sand-mixed water, is returned to the settling basin 9 through the delivery pipe 6 from the delivery port 611 . The delivery port 611 is arranged below the inflow port 341 . A portion of the delivery tube 6 other than the one end portion 61 and the one end portion 61 are detachably coupled by fastening with bolts. The length of the one end portion 61 in the extending direction is arbitrary, and for example, the lower portion of the one end portion 61 (the portion within the internal space S<b>1 ) may be formed longer than the fluid introducing portion 31 . When formed in this manner, the delivery port 611 is formed in a region defined by the inner peripheral surface 32a of the narrowed portion 32 in the internal space S1. Although the cross-sectional area of the delivery port 611 is the same as the cross-sectional area of the lower end of the narrowed portion 32, the cross-sectional area of the delivery 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 delivery port 611 can be increased, and the pressure loss in the inner container 3 can be reduced.

Next, the action of the inner container 3 will be described mainly with reference to FIG. As described above, by driving the sand pump 2 (see FIG. 1), the sand-mixed water flows into the internal space S1 from the inlet 341, and a swirling flow of the sand-mixed water is formed in the internal space S1. 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 inner container 3 by centrifugal force and gradually drops downward while swirling along the inner peripheral surface 3a. On the other hand, the separated water from which the sand has been removed from the sand-mixed water gathers at the radial center portion of the cylindrical portion 311 . The separated water is delivered from the delivery port 611 . However, since the size of the inlet 341 and the outlet 331 of the inner container 3 of the present embodiment are the same, depending on the amount per unit time of the sand-containing water flowing in from the inlet 341, the outer tank 4, which will be described in detail later, must be provided in order to send the sand-mixed water from the outlet 611. As shown in FIG. 1, the sent separated water is discharged from the other end 6a of the sending pipe 6 toward the settling basin 9 through the sending pipe 6. As shown in FIG. The other end 6a of the delivery pipe 6 is located below the delivery port 611 formed at one end of the delivery pipe 6. Therefore, when the delivery pipe 6 is filled with liquid, the sand-mixed water (separated water) in the internal space S1 is forced to flow out from the delivery port 611 into the settling basin 9 due to the siphon principle. As a result, even if the power of the sand lifting pump 2 is small, the sand-containing water can be transferred to the inner container 3 . The other end 6a side of the delivery pipe 6 may be extended below the water surface WL1 of the settling basin 9 so that the other end 6a is submerged in water. Alternatively, an intermediate tank may be installed between the inner container 3 and the settling basin 9, and the other end 6a of the delivery pipe 6 may be arranged inside 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. Also, even if some sand is delivered from the delivery port 611 together with the separated water, the sand is allowed to settle in the intermediate tank, thereby further suppressing the sand from being returned to the sedimentation basin 9.例文帳に追加

3(a) is a plan view showing the inner container and the outer tank, FIG. 3(b) is a front view showing the inner container and the outer tank, and FIG. 3(c) is a cross-sectional view taken along line BB in FIG. 3(b).

As shown in FIGS. 3( a ) and 3 ( b ), the outer tank 4 has a side wall 41 arranged outside the outer peripheral side surface 3 b of the inner container 3 and extending above the discharge port 331 . As shown in FIG. 3( c ), in this embodiment, the side wall 41 extends above the tube top end 6 c of the delivery tube 6 . The inner container 3 is detachably fixed in the tank of the outer tank 4 by connecting a mounting part 36 with a bolt to a pair of arms 42 extending inward with one end fixed to the inner peripheral surface of the side wall 41. - 特許庁As shown in FIGS. 3(b) and 3(c), the delivery pipe 6 and the sand lifting pipe 21 pass through the side wall 41. As shown in FIG. The penetrating portions of the delivery pipe 6 and the sand lifting pipe 21 are welded to the side wall 41 so that the penetrating portions are watertight.

The outer tank 4 is a substantially square-shaped tank in a plan view having two tank inclined surfaces 41a formed in the lower part thereof. The lower end of the outer tank 4 is cut obliquely upward at the same angle as the carry-out device 5 . The tank inclined surface 41 a is formed at a constant height from the lower end of the outer tank 4 . A lower end of the tank inclined surface 41 a is connected to the unloading device 5 . The sand contained in the concentrated water discharged from the discharge port 331 of the inner container 3 slides down the tank inclined surface 41 a and deposits on the carrying-out device 5 connected to the lower end of the outer tank 4 . As described above, the sand deposited on the carry-out device 5 is discharged outside the solid-liquid separation system 1 by the screw conveyor 51 . As shown in FIG. 3(c), an overflow port 43 is formed above the discharge port 331 and slightly below the upper end of the outer tank 4. As shown in FIG. The overflow port 43 allows the supernatant liquid of the concentrated water to flow out from the outer tank 4 when too much concentrated water is discharged from the discharge port 331 . The supernatant liquid flowing out from the overflow port 43 is returned to the settling basin 9 (see FIG. 1) through the overflow pipe 7 . By providing the overflow port 43 , the concentrated water is prevented from overflowing from the upper end of the side wall 41 of the outer tank 4 .

Next, the action of the outer tub 4 will be described mainly with reference to FIG. When the inner space S1 (see FIG. 2) of the inner container 3 and the inner space S1 of the outer tank 4 are empty, when the sand pump 2 and the carrying-out device 5 shown in FIG. Most of the sand-containing water supplied to the internal space S<b>1 is discharged from the discharge port 331 . As the concentrated water discharged from the discharge port 331 is stored in the tank of the outer tank 4, the tank water surface WL2, which is the water surface formed by the concentrated water stored in the outer tank 4, gradually rises. When the tank water surface WL2 reaches the discharge port 331, the discharge port 331 is blocked with concentrated water, so the amount of concentrated water discharged from the discharge port 331 decreases. That is, the resistance due to the reduction in the cross-sectional area of the internal space S1 in the constricted portion 32 and the water pressure of the concentrated water applied to the discharge port 331 combine to make it difficult for the concentrated water to be discharged from the discharge port 331, and the separated water starts to be discharged from the discharge port 611. As the tank water surface WL2 rises, the water pressure of the concentrated water applied to the discharge port 331 increases. In addition, as described above, when the delivery pipe 6 is filled with liquid, the separated water acts to flow out from the delivery port 611 to the settling basin 9 due to the siphon principle, so the amount of separated water delivered from the delivery port 611 further increases, and the amount of concentrated water discharged from the discharge port 331 further decreases. When the amount of sand-containing water supplied to the internal space S1 is, for example, 1.0 m3/min, when the tank water surface WL2 is slightly below the inlet 341 (see FIG. 2(b)), almost only sand is discharged from the outlet 331, and the tank water surface WL2 does not rise. FIGS. 3(b) and 3(c) show the tank water surface WL2 at this time. The discharged sand accumulates in the lower end portion of the outer tank 4 and is carried out while being drained by the carry-out device 5 (see FIG. 1). In addition, the carry-out device 5 may start to be driven after a certain amount of sand is deposited on the lower end portion of the outer tank 4, or may be intermittently driven. Further, when the amount of sand-containing water supplied to the internal space S1 is set to, for example, 1.5 m3/min, the amount of separated water sent from the outlet 611 also increases, but concentrated water containing a certain proportion of sewage is discharged from the outlet 331, and the tank water surface WL2 rises. After the water surface WL2 of the tank reaches the overflow port 43, the supernatant of the sand-containing water flows out from the overflow port 43 at a rate of about 0.3 m3/min. In addition, before the sand pump 2 is driven, sewage or tap water stored in the sedimentation tank may flow into the outer tank 4 to fill the outer tank 4 with liquid. When the outer tank 4 is filled with the liquid, the inner space S1 is also filled with the liquid to the same height as the outer tank 4 . Therefore, if the liquid is stored so that the tank water surface WL2 is higher than the delivery port 611, the separated water can be delivered from the delivery port 611 almost simultaneously with the drive of the sand pump 2 (see FIG. 1). Therefore, when the sand pump 2 is driven for the second time or later, the separated water can be sent out from the outlet 611 substantially simultaneously with the driving of the sand pump 2 unless the liquid stored in the outer tank 4 is removed.

According to this embodiment, since the outlet 331 is blocked by the liquid stored in the outer tank 4 , the hydraulic pressure of the liquid stored in the outer tank 4 is generated at the outlet 331 . This water pressure makes it difficult for the concentrated water to be discharged from the outlet 331, so that the amount of separated water sent from the outlet 611 can be increased. That is, since the ratio of the separated water delivered from the delivery port 611 to the concentrated water delivered from the delivery port 331 increases, the separation efficiency in the inner container 3 increases. Also, since the amount of concentrated water discharged to the outer tank 4 is small, the outer tank 4 can be made smaller. Furthermore, the amount of concentrated water discharged from the discharge port 331 can be suppressed even if the amount of constriction (decrease in cross-sectional area) in the constriction portion 32 is reduced. Since the pressure loss in the inner container 3 can be reduced by reducing the throttle amount in the throttle portion 32, the power of the sand pump 2 can be reduced. Furthermore, the concentrated liquid discharged from the discharge port 331 does not scatter, and the sand contained in the concentrated liquid easily settles to the bottom of the outer tank 4 in a short period of time. In addition, the separation water is caused to flow out from the delivery port 611 to the settling basin 9 by the siphon principle, so the power of the sand lifting pump 2 can be further reduced. In addition, since the carrying-out device 5 is connected to the outer tank 4 and the outer tank 4 and the inner container 3 are arranged at overlapping positions in the height direction, the height of the solid-liquid separation system 1 as a whole can be reduced. Further, since the inner container 3 can be arranged at a position close to the ground, the pump head required for the sand lifting pump 2 can be lowered, and solid-mixed water can be transferred to the inner container 3 with even smaller power.

In this embodiment, the side wall 41 of the outer tank 4 extends above the upper end of the internal space S1, so that the liquid can be stored in the outer tank 4 up to the upper end of the internal space S1. By storing the liquid up to the upper end of the internal space S1, the water pressure applied to the discharge port 331 increases, and the force of the liquid component in the sand-containing liquid in the internal space S1 to flow out from the discharge port 331 due to gravity can be canceled. As a result, the amount of liquid components discharged from the discharge port 331 is further suppressed, and the concentration of sand in the concentrated water can be further increased. In addition, since the amount of concentrated water discharged from the discharge port 331 to the outer tank 4 is reduced, the size of the outer tank 4 can be reduced. Furthermore, the pressure loss can be further reduced by reducing the reduction amount of the narrowed portion 32 . In addition, since the height of the side wall 41 of the outer tank 4 is set higher than the pipe upper end 6c of the delivery pipe 6, even if the throttle amount of the throttle part 32 is extremely reduced, when the tank water surface WL2 reaches the pipe upper end 6c, the inside of the delivery pipe 6 is filled with separated water, so that the effect of the siphon principle can be obtained.

Next, a modified example of this embodiment will be described. In the following description, the same reference numerals as those used so far may be assigned to the same component names as the component names described so far, and redundant description may be omitted.

FIG. 4(a) is a front view similar to FIG. 3(b), showing a modification of the solid-liquid separation system, and FIG. 4(b) is a sectional view taken along line CC in FIG. 4(a).

As shown in FIG. 4(a), the solid-liquid separation system 1 of this modified example differs from the solid-liquid separation system 1 shown in FIGS. In this modification, nanobubble water generated by a nanobubble water generator (not shown) is supplied to the sand lifting pipe 21 through the fine bubble water supply pipe 8 . However, instead of nanobubble water, microbubble water may be supplied to the sand pumping pipe 21 , or micro-nanobubble water in which nanobubble water and microbubble water are mixed may be supplied to the sand pumping pipe 21 . The microbubble water supply pipe 8 corresponds to an example of microbubble supply means. Nanobubble water means water containing air bubbles with particle sizes on the order of nanometers. Also, microbubble water means water containing micrometer-order air bubbles. As the nanobubble water, water containing nanometer-order oxygen bubbles may be used. Similarly, water containing micrometer-order oxygen bubbles may be used as the microbubble water. Alternatively, the microbubble water supply pipe 8 may be directly connected to the inner container 3 . That is, the microbubble water supply pipe 8 may be connected between the sand pump 2 (see FIG. 1) and the discharge port 331 . Since the nanobubble water and the microbubble water have a cleaning effect, they can be added to the sand-mixed water to clean the sand and liquid components contained in the sand-mixed water. By adding nanobubble water or microbubble water to the sand-containing water between the sand pump 2 (see FIG. 1) and the discharge port 331, the sand-containing water can be washed with a high cleaning effect in the inner space S1 (see FIG. 2) of the inner container 3. That is, the nanobubbles and microbubbles are mixed with the sand-containing water in the internal space S1 by the swirling flow generated in the internal space S1, so that a high cleaning effect can be exhibited.

The side wall 41 of the outer tank 4 extends to a height above the upper end of the inner container 3 and below the upper end 6c of the delivery tube 6 . By raising the side wall 41 of the outer tank 4 as in the previous embodiment, it is also possible to make the tank water surface WL2 of the outer tank 4 higher than the upper end 6c of the delivery pipe 6 . As described above, the water pressure applied to the discharge port 331 increases in accordance with the height of the tank water surface WL2. Therefore, the height of the tank water surface WL2 is preferable in terms of further increasing the concentration of sand in the concentrated water and reducing the pressure loss. However, if the side wall 41 of the outer tank 4 is too high, the height of the solid-liquid separation system 1 as a whole will be high, and the manufacturing cost of the outer tank 4 will also be high. If the side wall 41 extends above the discharge port 331, the discharge port 331 can be blocked by the liquid stored in the tank of the outer tank 4. However, in this modified example, the height of the solid-liquid separation system 1 as a whole and the balance of the water pressure applied to the discharge port 331 are emphasized. The overflow port 43 may be appropriately arranged according to the height of the side wall 41, but in this modified example, it is set at the same height as the inlet 341 (see FIG. 2(b)). Also, only a part of the configurations of the modified examples described above may be applied to the previous embodiment.

The present invention is not limited to the above-described embodiments, and can be modified in various ways within the scope of the claims. For example, in the present embodiment, an example in which the solid-liquid separation system 1 is installed in the settling basin 9 has been described, but the solid-liquid separation system 1 may be installed in a sedimentation basin or a reservoir such as a dam lake. It may also be used as a solid-liquid separation system 1 for separating water, metal powder, and the like from industrial wastewater generated in a factory or the like. In addition, although a so-called fluid cyclone device is used for the inner container 3, it may be a simple container as long as it has a narrowed portion 32 between the outlet port 331 and the inlet port 341 and has a structure capable of delivering the liquid component from the sand-mixed water that has flowed in. Further, the narrowed portion 32 may have a cross-sectional area of the internal space S<b>1 that decreases stepwise toward the discharge port 331 . That is, the narrowed portion 32 may have a smaller cross-sectional area of the internal space S1 on the discharge port 331 side than on the inlet 341 side.

According to the embodiments and modifications described above, it is possible to provide a solid-liquid separation system that can be driven with a small amount of power.

The solid-liquid separation system described above includes a pump for transferring solid-containing water containing solids,
an inner container having an inlet into which the solid-contaminated water transferred by the pump flows, and an outlet for discharging concentrated water in which a portion of the liquid component is removed from the solid-contaminated water to increase the concentration of solids;
an outer tank for receiving the concentrated water;
a delivery tube receiving the liquid component from one end connected to the inner container and discharging the liquid component from the other end located below the one end;
The inner container has a narrowed portion between the inlet and the outlet, in which the cross-sectional area of the internal space defined by the inner peripheral surface of the inner container is smaller on the outlet side than on the inlet side,
The outer tank may be provided with a side wall that is arranged outside the outer peripheral side surface of the inner container and extends upward from the outlet, so that the concentrated water received by the outer tank can be reduced in the amount of the concentrated water that is discharged from the outlet.

Further, a pump for transferring solid-mixed water containing solids,
an inner container having an inlet into which the solid-contaminated water transferred by the pump flows, and an outlet for discharging concentrated water in which a portion of the liquid component is removed from the solid-contaminated water to increase the concentration of solids;
an outer tank for receiving the concentrated water;
The inner container has a narrowed portion between the inlet and the outlet, in which the cross-sectional area of the internal space defined by the inner peripheral surface of the inner container is smaller on the outlet side than on the inlet side,
The solid-liquid separation system may be characterized in that the outer tank is provided with a side wall arranged outside the outer peripheral side surface of the inner container and extending upward from the discharge port.

According to this solid-liquid separation system, since the side wall extends above the discharge port, the discharge port is blocked by the liquid stored in the outer tank, and the hydraulic pressure of the liquid stored in the outer tank is generated at the discharge port. This water pressure and the throttle section make it more difficult for the concentrated water to be discharged from the discharge port, thereby increasing the amount of liquid components removed from the solid-containing water and increasing the concentration of solids in the concentrated water. Moreover, since the water pressure described above is generated, even if the amount of decrease in the cross-sectional area of the narrowed portion is reduced, the amount of the concentrated water discharged from the discharge port can be suppressed. By reducing the amount of reduction in the cross-sectional area of the constricted portion, the pressure loss in the inner container is reduced, so that the solid-liquid separation system can be driven with small power.

Here, the outlet may be blocked with concentrated water. Moreover, the side wall may extend upward from the upper end of the internal space. By doing so, the liquid can be stored in the outer tank up to the upper end of the inner space, and the water pressure applied to the discharge port can be further increased. By increasing the water pressure, the amount of the concentrated water discharged from the outlet can be further suppressed, and the concentration of solids in the concentrated water can be further increased. Furthermore, the pressure loss can be further reduced by reducing the amount of reduction in the cross-sectional area of the constricted portion.

In this solid-liquid separation system, the inner container includes a cylindrical portion having a cylindrical inner peripheral surface,
The inlet is provided in the cylindrical portion and introduces the solid-containing water from the tangential direction of the cylindrical portion,
The narrowed portion may have an inverted conical shape.

By doing so, a swirling flow can be generated in the cylindrical portion. The solids contained in the solid-mixed water move downward while being pressed against the inner peripheral surface by the centrifugal force generated by the swirling flow. On the other hand, the liquid component moves downward while swirling in the cylindrical portion, and most of the liquid component is reversed upward in the conical constricted portion and gathers at the center portion in the radial direction of the inner container. This enhances the solid-liquid separation performance. A delivery port for delivering the liquid component may be arranged at the radial center of the inner container.

Further, in this solid-liquid separation system, the outer tank may be provided with an overflow port above the outlet for discharging the supernatant liquid of the concentrated water discharged from the outlet to the outside of the outer tank.

By doing so, the discharge port can be reliably blocked by the liquid stored in the outer tank, and when more than a predetermined amount of concentrated water is discharged from the discharge port, the supernatant liquid of the concentrated water can be discharged from the overflow port, so that the concentrated water can be prevented from overflowing from the upper end of the side wall.

Here, the overflow port may be formed above the upper end of the internal space. By forming in this way, the liquid can be quickly stored in the outer tank up to a height above the inner space.

Further, in this solid-liquid separation system, a delivery pipe having a delivery port at one end for delivering the liquid component to the outside of the inner container, the one end being connected to the inner container,
The delivery port may have a cross-sectional area equal to or greater than that of the inlet.

By doing so, the pressure loss in the inner container is further reduced, so that the solid-liquid separation system can be driven with even smaller power.

Furthermore, in this solid-liquid separation system, a carry-out device may be provided which is connected to the outer tank and carries out the solids contained in the concentrated water received by the outer tank to the outside of the outer tank.

In the solid-liquid separation system disclosed in Patent Document 1, since the separation device main body having the separation tank and the screw conveyor is provided below the separation container at a distance, the total height of the separation container and the separation device main body is increased. In the aspect of the present invention described above, by connecting the carrying-out device to the outer tank, the outer tank to which the carrying-out device is connected functions as the separation device main body in Patent Document 1. Also, the inner container functions as the separation container in Patent Document 1. Further, since the outer tank and the inner container are arranged at overlapping positions in the height direction, the height of the entire solid-liquid separation system can be reduced. In addition, since the inner container can be arranged at a position close to the ground, the lift necessary for the pump can be lowered, and the solid-containing water can be flowed into the inner container with a small power.

REFERENCE SIGNS LIST 1 solid-liquid separation system 2 sand lifting pump 3 inner container 3a inner peripheral surface 3b outer peripheral side surface 4 outer tank 32 throttle section 41 side wall 331 outlet 341 inlet S1 internal space

Claims (2)

a pump for transferring solid-contaminated water containing solids;
an inner container having an inlet into which the solid-contaminated water transferred by the pump flows, and an outlet for discharging concentrated water in which a portion of the liquid component is removed from the solid-contaminated water and the concentration of solids is increased;
an outer tank for receiving the concentrated water;
a carrying-out device connected to the lower end of the outer tank, extending obliquely upward from one horizontal side of the outer tank toward the other side, and carrying out solids contained in the concentrated water received by the outer tank to the outside of the outer tank;
The outer tank has a side wall arranged outside the outer peripheral side surface of the inner container and extending upward from the outlet,
The solid-liquid separation system, wherein the inner container is provided with the discharge port at a position shifted to the one side with respect to the center of the outer tank in the horizontal direction. 2. The solid-liquid separation system according to claim 1, wherein said inner container is provided with said discharge port right above said carry-out device.

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