Solid-liquid separation system

Abstract

To provide a solid-liquid separation system with improved impact resistance and reduced breakage risk.SOLUTION: A solid-liquid separation system 100 includes a settling pond P and an inclined tube settler 10. The inclined tube settler 10 is installed in the settling pond P and includes a plurality of inclined tubes 20. At least one of corners 25-28 on an inner peripheral surface 20a of the inclined tube 20 has an R-shape.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a solid-liquid separation system. Background Art

[0002] A sloped tube sedimentation device provided with a plurality of sloped tubes to increase the sedimentation area has been conventionally used in sedimentation tanks of water purification and sewage treatment plants (see, for example, Patent Document 1). A system for purifying water by promoting the sedimentation of flocs (aggregates formed by aggregating fine particles into large aggregates via a flocculant) using said sloped tube sedimentation device has been developed.

[0003] The sloped tube sedimentation device is manufactured using rigid polyvinyl chloride, which has the property of not floating when installed in water. In addition, the device is designed to be thin-walled and lightweight to prevent flocs in suspension water that could not be treated when passing through the sloped tube sedimentation device during operation from depositing on the device, and also to allow movement by workers during construction. Prior Art Documents Patent Documents

[0004] Patent Document 1 Japanese Patent No. 7045608 Specification Summary of the Invention Problems to be Solved by the Invention

[0005] However, as a harmful effect of thinning and weight reduction, the device has sometimes been damaged by the pressure of high-pressure washing water used when performing cleaning for maintenance. In addition, during construction, in order for workers to work on the sloped tube sedimentation device, a plywood panel or the like is sometimes placed on the device, and at this time, damage may occur, for example, when the corner of the panel touches the sloped tubes.

[0006] An object of the present invention is to provide a solid-liquid separation system capable of improving impact resistance and reducing damage. Means for Solving the Problems

[0007] To achieve the above objective, the solid-liquid separation system according to the first invention comprises a sedimentation tank and an inclined tube sedimentation device. The inclined tube sedimentation device is installed in the sedimentation tank and has a plurality of inclined tubes. At least one corner of the inner surface of the inclined tube has an R shape.

[0008] Having at least one of the inner surfaces have an R-shape improves impact resistance, thereby enhancing resistance to high-pressure cleaning water during washing and impacts when laying the plywood during construction.

[0009] The solid-liquid separation system according to the second invention is the solid-liquid separation system according to the first invention, wherein the inclined tube is rectangular in shape. All corners of the inner surface have a rounded shape.

[0010] This allows for a further improvement in the strength of the inclined pipe, thereby enhancing the overall strength of the inclined pipe sinking device.

[0011] The solid-liquid separation system according to the third invention is a first or second solid-liquid separation system in which the R shape of the inner circumferential surface is formed to be 1R or more and 3R or less.

[0012] When the radius (R) is less than 1R, the improvement in strength is small. Furthermore, when the radius is greater than 3R, the weight increases, and the larger surface area makes it easier for floc to accumulate at the top. Therefore, by setting the radius to between 1R and 3R, it is possible to ensure strength while keeping the weight increase to a minimum.

[0013] The solid-liquid separation system according to the fourth invention is a solid-liquid separation system according to the first or second invention, further comprising an inlet and an outlet. The inlet is into which the water to be treated flows into the sedimentation tank. The outlet is into which the treated water flows out of the sedimentation tank. The inclined pipe sedimentation device further comprises a plurality of plate-shaped support members. The plurality of plate-shaped support members are arranged parallel to a first direction from the inlet to the outlet and to the vertical direction. The inclined pipe has a pair of inclined sides and a pair of vertical sides. The pair of inclined sides are parallel to each other and are arranged opposite each other in the first direction. The pair of vertical sides are arranged opposite each other in a second direction that is perpendicular and horizontal to the first direction, and each is arranged along the vertical direction. The inclined pipe is arranged between the support members, and each of the pair of vertical sides is bonded to a support member arranged outward in the second direction.

[0014] This improves impact resistance even when an impact is applied to the inclined portion of the inclined pipe.

[0015] The solid-liquid separation system according to the fifth invention is the solid-liquid separation system according to the fourth invention, wherein the length of the inclined portion in the second direction is longer than the length of the vertical portion in the first direction.

[0016] By forming a rounded (R) shape at the corners, impact resistance can be improved. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a solid-liquid separation system that can improve impact resistance and reduce damage. [Brief explanation of the drawing]

[0018] [Figure 1] This is a side view showing a solid-liquid separation system according to an embodiment of the present invention. [Figure 2] This is a perspective view showing an inclined tube sedimentation device according to an embodiment of the present invention. [Figure 3] This is an exploded view of an inclined tube sedimentation device according to an embodiment of the present invention. [Figure 4] It is a plan view of an inclined tube sedimentation device according to an embodiment of the present invention. [Figure 5] (a) is a plan view of an inclined tube according to an embodiment of the present invention, (b) is a side view of the inclined tube according to an embodiment of the present invention, (c) is a front view of the inclined tube according to an embodiment of the present invention, and (d) is an enlarged view of part T in FIG. 5(a). [Figure 6] It is a plan view for explaining when an impact is applied to an inclined tube. [Figure 7] It is a diagram for explaining a method for verifying cracking of an inclined tube. [Figure 8] It is a perspective view showing an inclined tube sedimentation device of an example. DESCRIPTION OF EMBODIMENTS

[0019] Hereinafter, a solid-liquid separation system according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0020] <Configuration> (Solid-liquid separation system 100) FIG. 1 is a diagram showing a solid-liquid separation system 100 according to the present embodiment. The solid-liquid separation system 100 according to the present embodiment is applied to solid-liquid separation of water to be treated W in a sedimentation basin P of a water purification plant.

[0021] As shown in FIG. 1, the solid-liquid separation system 100 includes a sedimentation basin P (an example of a sedimentation basin), an inclined tube sedimentation device 10, a baffle plate 11, an overflow weir 12, a water channel (water collection trough) 13, an inflow section 14, an outflow section 15, a sludge scraper 16, and a sludge hopper 17.

[0022] Raw water (water to be treated W) flows into the sedimentation basin P through the inflow section 14. The outflow section 15 is provided on the opposite side of the inflow section 14 in the sedimentation basin P, and the purified water to be treated W flows out from the sedimentation basin P through the outflow section 15.

[0023] The inclined pipe sedimentation device 10 is located in the downstream portion (outlet side 15 side) of the sedimentation tank P, approximately in the center. The inclined pipe sedimentation device 10 has multiple inclined pipes 20.

[0024] The inclined pipe sedimentation device 10 is supported such that it sinks to a predetermined depth from the surface of the water to be treated W and a predetermined space is secured between it and the bottom surface of the sedimentation tank P. This support may be suspended by a suspension member 42 supported by a girder member 41, or it may be placed on a support structure (not shown), for example. Details of the inclined pipe sedimentation device 10 will be described in detail later.

[0025] The flow-blocking plate 11 is located upstream of the inclined pipe sedimentation device 10 (inlet side 14 side) and approximately in the center of the sedimentation tank P. The flow-blocking plate 11 obstructs the flow of treated water W from the water surface to a predetermined depth toward the downstream side (outlet side 15 side). The flow-blocking plate 11 is positioned so that its main surface is perpendicular to the direction of water flow entering from the inlet 14.

[0026] The overflow weir 12 is positioned near the water surface of the treated water W downstream of the flow-blocking plate 11 (towards the outflow section 15). The overflow weir 12 is formed along the direction from upstream to downstream.

[0027] The waterway (collection trough) 13 is formed surrounded by the overflow weir 12 and is connected to the outflow section 15. Note that the configuration is not limited to the overflow weir 12; a pipe with holes may also be used.

[0028] The treated water W that flows into the sedimentation tank P from the inlet 14 is blocked in the direction of water flow (arrow D direction) by the flow-blocking plate 11 and descends towards the area between the lower end of the flow-blocking plate 11 and the bottom of the sedimentation tank P. The treated water W that passes through the area between the bottom of the sedimentation tank P and the lower end of the flow-blocking plate 11 becomes an upward flow J towards the waterway (collection trough) 13 and flows into the area between the inclined pipes 20 from the lower part of the inclined pipe sedimentation device 10 and rises.

[0029] Then, as the sludge of the water to be treated W passes through the inclined pipe settling device 10, it settles and settles on the inner or outer surface of the inclined pipe 20, thereby purifying the water to be treated W. The sludge that has settled on the inner or outer surface of the inclined pipe 20 falls down the slope due to its own weight.

[0030] The sludge scraper 16 is positioned near the bottom of the sedimentation tank P. Settlemented sludge M accumulates near the bottom of the sedimentation tank P. The accumulated sludge M is collected in the sludge hopper 17 by the sludge scraper 16 rotating clockwise in Figure 1, and then discharged. Upstream of the flow barrier plate 11, the sludge scraper 16 passes near the water surface and scrapes up suspended matter as well.

[0031] The sludge hopper 17 is formed on the bottom surface near the inlet 14 of the sedimentation tank P.

[0032] (Inclined tube sedimentation device 10) Figure 2 is a schematic perspective view showing a part of the configuration of the inclined tube sedimentation device 10. Figure 3 is an exploded perspective view of the inclined tube sedimentation device 10 shown in Figure 2. The inclined tube sedimentation device 10 has a plurality of inclined tubes 20 and a plurality of sheet members 30 (an example of support members). The material of the inclined tubes 20 and sheet members 30 can be polyvinyl chloride, and rigid polyvinyl chloride is particularly preferred, but is not limited to this. The material of the inclined tubes 20 and sheet members 30 may be, for example, thermoplastic resins, such as vinyl resins such as polyvinyl chloride, carbonate resins such as polycarbonate, ester resins such as polyethylene terephthalate, olefin resins such as polypropylene and polyethylene, styrene resins such as ABS, or copolymers or mixed resins thereof.

[0033] The sheet member 30 is supported by suspension members 42 and the like, which extend downward from girder members 1 that are fixed across both sides of the sedimentation tank.

[0034] Figure 4 is a partial plan view of the inclined tube sinking device 10. In Figure 4, the inclined tube 20 and the sheet member 30 are hatched for clarity. Note that the hatched areas are solid.

[0035] The direction perpendicular and horizontal to the direction of arrow D (an example of the first direction) described above is defined as the width direction E (an example of the second direction). The right side of the width direction E facing the direction of arrow D is defined as the right direction E1, and the left side of the width direction E facing the direction of arrow D is defined as the left direction E2.

[0036] As shown in Figures 2 and 3, multiple inclined pipes 20 are arranged in a row at predetermined intervals along the direction of arrow D, and multiple rows of these inclined pipes 20 are arranged along the width direction E. Sheet members 30 are also arranged on both sides of the row of inclined pipes 20 in the width direction E. For example, in Figure 2, four rows of inclined pipes 20 are arranged, and they are labeled L1 to L4 sequentially from the end on the right side E1.

[0037] As shown in Figure 2, the inclined pipes 20 in the two central rows L2 and L3 in the width direction E are inclined such that their upper end 20c is located closer to the inlet 14 than their lower end 20d, as shown in Figure 3. Similarly, the inclined pipes in row L1 at the right end E1 and row L4 at the left end E2 are inclined such that their upper end 20c is located closer to the outlet 15 than their lower end 20d, as shown in Figure 3. Note that the inclined pipes 20 in rows L2 and L3 and those in rows L1 and L4 are arranged symmetrically, with opposite inclination directions.

[0038] The figure only shows a configuration in which multiple inclined pipes 20 are arranged in four rows, but there may be more than four rows. For example, an additional row may be provided to the right of row L1 in the E1 direction, and the inclined pipes 20 in that row may be inclined so that the upper end 20c is located closer to the inlet 14 than the lower end 20d. For example, an additional row may be provided to the left of row L4 in the E2 direction, and the inclined pipes 20 in that row may be inclined so that the upper end 20c is located closer to the inlet 14 than the lower end 20d. In this way, multiple rows of inclined pipes 20 may be arranged so that the inclination direction alternates toward the outside of the width direction E (to the right in the E1 direction or to the left in the E2 direction).

[0039] Furthermore, in the configuration shown in Figure 2, the two central rows L2 and L3 inclined pipes 20 are inclined in the same direction, but they may be inclined in opposite directions.

[0040] As shown in Figure 4, in the direction of arrow D, the inclined pipes 20 are not arranged continuously, and a predetermined space S is provided between adjacent inclined pipes 20. Also, in the width direction E, a predetermined space S is provided between adjacent inclined pipes 20. Multiple inclined pipes 20 are arranged in a staggered pattern. For example, to the left of an inclined pipe 20 in row L2 in the width direction E, space S is located in row L3, and to the right of an inclined pipe 20 in row L2 in the width direction E, space S is located in row L1. Also, to the left of space S in row L2 in the width direction E, an inclined pipe 20 is located in row L3, and to the right of space S in row L2 in the width direction E, an inclined pipe 20 is located in row L1.

[0041] The inclined pipes 20 located in rows L2 and L3 and the inclined pipes 20 located in rows L1 and L4 are configured symmetrically, differing only in their inclination direction. Therefore, we will use the inclined pipes 20 located in rows L2 and L3 as an example for explanation.

[0042] Figure 5(a) is a plan view of the inclined pipe 20, Figure 5(b) is a side view of the inclined pipe 20, and Figure 5(c) is a front view of the inclined pipe 20. Figure 5(d) is an enlarged view of section T in Figure 5(a). Note that in Figures 2 to 4 and Figures 6 and 7 described later, the thickness of the inclined pipe 20 and the sheet member 30 are exaggerated for clarity.

[0043] As shown in Figure 5(a), the inclined pipe 20 is rectangular in shape. The inclined pipe 20 includes a first side portion 21 (an example of an inclined side portion), a second side portion 22 (an example of an inclined side portion), a third side portion 23 (an example of a vertical side portion), and a fourth side portion 24 (an example of a vertical side portion). The first side portion 21 is a plate-shaped portion on the inlet portion 14 side of the inclined pipe 20. The second side portion 22 is a plate-shaped portion on the outlet portion 15 side of the inclined pipe 20. The first side portion 21 and the second side portion 22 are arranged opposite each other in the direction of arrow D (an example of a first direction). The first side portion 21 and the second side portion 22 are arranged parallel to each other. The first side portion 21 and the second side portion 22 are arranged parallel to the width direction E. As shown in Figure 5(b), if α is the acute angle between the first side portion 21 and the second side portion 22 and the horizontal direction, then, for example, angle α is generally set to 60°, but the angle may be changed by about ±10° depending on the application.

[0044] The third side portion 23 is a plate-like portion on the rightward E1 side of the inclined pipe 20. The third side portion 23 is positioned to connect the rightward E1 end of the first side portion 21 and the rightward E1 end of the second side portion 22. The third side portion 23 is positioned perpendicular to the width direction E.

[0045] The fourth side portion 24 is a plate-like portion on the left E2 side of the inclined pipe 20. The fourth side portion 24 is positioned to connect the left E2 end of the first side portion 21 and the left E2 end of the second side portion 22. The fourth side portion 24 is positioned perpendicular to the width direction E.

[0046] As shown in Figure 5(a), the lengths of the first side portion 21 and the second side portion 22 in the width direction E are set to be longer than the lengths of the third side portion 23 and the fourth side portion 24 in the direction of arrow D.

[0047] The inclined pipe 20 has a corner 25 formed by the rightward E1 end of the first side portion 21 and the inlet 14 end of the third side portion 23, a corner 26 formed by the leftward E2 end of the first side portion 21 and the inlet 14 end of the fourth side portion 24, a corner 27 formed by the rightward E1 end of the second side portion 22 and the outlet 15 end of the third side portion 23, and a corner 28 formed by the rightward E1 end of the second side portion 22 and the outlet 15 end of the fourth side portion 24.

[0048] Each of the corners 25 to 28 of the inclined pipe 20 has an R shape on its inner circumferential surface 20a. Corners 25 to 28 have similar R shapes. Figure 5(d) shows the R shape of corner 26. It is preferable to set the R shape of corners 25 to 28 to 1R or more and 3R or less. 1R means that it is formed in a circular shape with a radius of 1 mm, and 3R means that it is formed in a circular shape with a radius of 3 mm. In Figure 5(d), the state of 0R is shown by dotted lines N1 and N2. Dotted line N1 is the extension of the portion of the first side surface 21 on the inner circumferential surface 20a. Dotted line N2 is the extension of the portion of the fourth side surface 24 on the inner circumferential surface 20a.

[0049] If the radius (R) of corners 25-28 is less than 1R, the improvement in strength will be small. If the radius is greater than 3R, the weight will increase, and the larger cross-sectional area will make it easier for floc to accumulate at the top. Therefore, by setting the radius to be between 1R and 3R, a balance can be maintained between the increase in weight and the improvement in strength.

[0050] As shown in Figure 5(d), each of the corners 25 to 28 also has an R-shape on the outer surface 20b of the inclined pipe 20. However, if the R is made too small during molding, handling will deteriorate due to the generation of burrs, and if it is too large, flocs may get stuck in the gaps. Therefore, the R is set to be between 0.5 and 1.

[0051] As shown in Figures 2 and 3, the sheet member 30 is a plate-shaped member. The sheet member 30 is arranged parallel to the vertical direction and the direction of arrow D. The sheet member 30 is located on the right side E1 of row L1, between row L1 and row L2, between row L2 and row L3, between row L3 and row L4, and on the left side E2 of row L4. The sheet member 30 has a first main surface 31 on the right side E1 and a second main surface 32 on the left side.

[0052] A pair of first and second side portions 21 and 22 on the widthwise E side of each inclined pipe 20 are bonded to a sheet member 30 located on the outside of each. As shown in Figure 4, the first side portion 21 is bonded to the second main surface 32 of the sheet member 30, and the second side portion 22 is bonded to the first main surface 31 of the sheet member 30. The third side portion 23 and the fourth side portion 24 face the space S.

[0053] Figure 6 is a plan view illustrating what happens when an impact is applied to the inclined pipe 20. For example, as shown by arrow F, when an impact is applied to the first side portion 21 of the inclined pipe 20, the first side portion 21 moves inward. At this time, since the third side portion 23 and the fourth side portion 24 are bonded to the sheet member 30, cracks are likely to occur starting from the bonded portions of the corners 25, 25 (see rounded portions G and H). However, in this embodiment, the corners 25 and 26 have an R shape, which ensures strength and reduces the occurrence of cracks.

[0054] As described above, by having the corners 25-28 of the inner circumferential surface 20a of the inclined pipe 20 have an R shape, the impact strength can be improved, and the strength against high-pressure cleaning water during cleaning and the impact when laying plywood during construction can be improved.

[0055] Furthermore, by setting the radius (R) of the corners 25-28 of the inner circumferential surface 20a to be between 1R and 3R, it is possible to reduce the occurrence of cracks while keeping the increase in weight to a minimum.

[0056] <Other Embodiments> Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above and can be modified as appropriate without departing from the spirit of the invention.

[0057] (A) The number of rows in the inclined tube sedimentation device 10 and the number of inclined tubes 20 in each row are not limited to the configuration of the above embodiment and may be changed.

[0058] (B) In the above embodiment, all corners 25 to 28 have an R shape. From the viewpoint of impact resistance, it is preferable that all corners 25 to 28 have an R shape, but even if at least one corner has an R shape, impact resistance can be improved compared to conventional inclined pipes.

[0059] (C) In the above embodiment, a space S is provided between the inclined pipes 20 in the direction of arrow D, but this is not required. Also, in the width direction E, a space S is provided next to the inclined pipe 20, but an inclined pipe 20 may be placed there as well.

[0060] (D) In the above embodiment, the inclined pipe 20 has a rectangular cross-section perpendicular to the direction in which the pipe extends, but it is not limited to a rectangular shape and may have a polygonal shape with five or more sides.

[0061] (Examples) (Verification of cracks) We investigated the occurrence of cracks in the inclined pipe 20 and confirmed its impact strength.

[0062] The test was conducted as follows: • For the test, an inclined pipe 20 was used, in which corners 25-28 had an R-shape of approximately 1.5R. As shown in Figure 7, the inclined pipe 20 was positioned so that the third side portion 23 and the fourth side portion 24 were vertical, and the guide pipe 51 was placed at the upper end 20c. A pear-shaped weight 52 was dropped through the guide pipe 51 to confirm the height at which the inclined pipe 20 would crack. A conventional inclined pipe with a radius of 0R, in which no radius (R) is formed at all corners 25-28 of the inclined pipe 20, was used as a comparative example. In the comparative example, the corners in which no radius (R) is formed are those formed by extension lines N1 and N2 in Figure 5.

[0063] As a result, the height at which the conventional inclined pipe could not break was 900 mm, while the inclined pipe of this embodiment could not break was 1300 mm. Thus, it can be seen that the inclined pipe 20 of this embodiment has approximately 1.45 times higher impact strength than the conventional inclined pipe.

[0064] (Weight verification) We confirmed the difference in weight due to the addition of a rounded corner shape. The cross-sectional area of ​​the inclined pipe 20 was determined by subtracting the inner circumferential area from the outer circumferential area. The weight of one inclined tube 20 (g / tube) was calculated from the product of the volume of the inclined tube 20 and its specific gravity of 1.4. Since 107 inclined tubes 20 are used, the total weight of all inclined tubes 20 (kg / tube) was calculated by multiplying the weight of one inclined tube 20 (g / tube) by 107.

[0065] Compared to the inclined tube sinking device described above, inclined tube sinking device 10 of this embodiment, which does not have an R-shape formed at the corners, the increase in weight due to forming an R-shape at the corners is only a slight increase of about 1%, or 0.31 kg per unit (W372 mm × L3000 mm × H530 mm), as shown in (Table 1) below. As shown in Figure 8, the length of the width direction E of the inclined tube sinking device 10 is W, the height is H, and the length along the direction of arrow D is L. In (Table 1) below, "length" is the length along the inclination of the inclined tube 20, and is shown as M in Figure 8. In (Table 1) below, "specific gravity" is the specific gravity of the material of the inclined tube 20. In (Table 1) below, "outer circumference area (cm 2 )", "Inner circumferential area (cm 2 )”, “Cross-sectional area (cm 2 )", "Volume (cm 3"Weight (g / tube)" and "Weight (g / tube)" are shown for one inclined tube. "Number of tubes (tubes / unit)" indicates the number of inclined tubes 20 used in one inclined tube sinking device. "Weight (kg / unit)" indicates the weight of one inclined tube sinking device and is the product of "Weight (g / tube)" and "Number of tubes (tubes / unit)".

[0066] [Table 1] This indicates that there are no problems with transporting the inclined pipes during construction. [Industrial applicability]

[0067] The solid-liquid separation system of the present invention exhibits the effect of improving impact resistance and reducing damage, making it useful as a final sedimentation tank in sewage treatment facilities, etc. [Explanation of Symbols]

[0068] 10: Inclined tube sedimentation device 20: Inclined pipe 20a: Inner surface 25-28: Corner 100: Solid-liquid separation system P: Sedimentation pond

Claims

1. Sedimentation tank and, An inclined tube sedimentation device having multiple inclined tubes is installed in the sedimentation tank, The sedimentation tank has an inlet into which the water to be treated flows, The system includes an outlet from which treated water flows out of the sedimentation tank, At least one of the corners of the inner surface of the inclined pipe has an R shape, The inclined pipe sinking device, The system further comprises a plurality of plate-shaped support members arranged parallel to a first direction toward the outflow section and to the vertical direction, The aforementioned inclined pipe is A pair of inclined sides that are parallel to each other and arranged opposite each other in the first direction, It has a pair of vertical sides that face each other in a second direction perpendicular and horizontal to the first direction, and each is arranged along the vertical direction, The inclined pipe is positioned between the support members, and each of the pair of vertical sides is bonded to the support member positioned outward in the second direction. Solid-liquid separation system.

2. The aforementioned inclined tube is rectangular in shape, All corners of the inner surface have an R shape. The solid-liquid separation system according to claim 1.

3. The R-shape of the inner circumferential surface is formed to be 1R or more and 3R or less. The solid-liquid separation system according to claim 1 or 2.

4. The length of the inclined side in the second direction is longer than the length of the vertical side in the first direction. The solid-liquid separation system according to claim 1.

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