JP2020062612A - Upflow inclined plate sedimentary sand tank - Google Patents

Abstract

To provide a sedimentary sand tank which can be provided at low cost, which solves a problem in an upflow inclined plate sedimentary sand tank of a prior art, of which a device body is down-sized while maintaining particle removal capacity, of which an installation space is reduced, and of which a weight is saved, thereby enabling easy transportation installation thereof.SOLUTION: An upflow inclined plate sedimentary sand tank in which an inclined plate sedimentation device 1, in which plural inclined plates 2, which are inclined with respect to a horizontal plane, are arranged at constant intervals, is assembled between an inflow side partition wall 3 and an outflow side overflow wall 4. In the tank, the inflow side partition wall 3 and the outflow side overflow wall 4 are installed at an angle same as that of the inclined plate 2, and the inclined plates 2 are so arranged that a plane connecting lower ends 7 thereof are so arranged as to be inclined from the inflow side toward the outflow side below the horizontal plane.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a device for removing particles such as sand mixed in raw water taken from a river or an irrigation canal in a water supply facility or a hydroelectric power generation facility that requires water.

  As a means for removing sand particles mixed in raw water such as river water and agricultural water, it is widely practiced to install a sand basin after water intake. The sand basin functions to separate the sand particles from the raw water by allowing the raw water that has been taken in to stay in a slow horizontal flow for a certain period of time and allowing the particles having a larger specific gravity than the water to settle. However, in order to stably separate the sand particles, it is necessary to give a sufficient allowance to the residence time, and the structure must be large. Therefore, it has the disadvantages that it requires a large installation area, that it requires a construction period because it is built from reinforced concrete, and that construction costs and land acquisition costs are high.

  On the other hand, there is a device called a sand separator as a means for removing sand particles mixed in raw water pumped up from a well or the like using a pump. The sand separator rotates the pumped water in a cylindrical container and performs a centrifugal separation function to separate the water particles from the sand particles (see Patent Document 1). However, in order to stably separate the sand particles, it is necessary to apply pressure to rotate the water, and loss resistance occurs.Therefore, apply pressure using a pump or use it only in a place where there is pressure using the head. Cannot be used. Therefore, there are disadvantages such as the presence or absence of electric power in the place where it can be used and the restriction of the drop, and the size of the sand particles that can be separated is limited.

  Against this background, sedimentation equipment that removes particles such as sand does not spread in small-scale water facilities in the mountains, and it is an urgent issue to secure stable water quality and reduce the maintenance burden of water purification equipment. However, the aging of people involved in management is also compromising the existence of water supply facilities. In addition, it is also a factor of population outflow, which is accelerating the progress of marginal settlements.

  For this reason, a particle sedimentation method has been proposed in order to reduce the size of the apparatus body and save the installation space while maintaining the ability to remove particles such as sand. As the particle settling method, there are an upflow method (FIG. 6) and a crossflow method (FIG. 7). As shown in FIG. 6, the upflow method flows into the inflow tank 35 of the upflow method sand settling tank 30. The incoming inflow A flows as a water flow C below the inflow side partition wall 33, flows upward in the settling tank 31 as a water flow D at an upward flow velocity Vup, and as a water flow E overflows the outflow side overflow wall 34. And flows into the outflow tank 36, and then outflows as an outflow water stream B. In this method, the particles can be separated and settled by setting the upward flow velocity Vup to be smaller than the settling velocity Vs of the particles. In order to reduce the upward flow velocity Vup, the width and length of the sedimentation tank 31 may be increased to increase the flow passage area of the sedimentation tank.

  In the cross-flow method shown in FIG. 7, the inflow water flow A flowing into the inflow tank 45 of the cross-flow sand settling tank 40 penetrates the inflow-side straightening wall 43 and flows into the settling tank 41, and settles as a water flow C at a lateral flow velocity Vh. It flows laterally in the tank 41, penetrates the outflow side flow regulating wall 44, flows into the outflow tank 46, and then flows out as an outflow water flow B. In this method, the depth H of the sedimentation tank 41, the length L of the sedimentation tank 41, the lateral flow velocity Vh in the sedimentation tank 41, and the sedimentation velocity Vs of the particles are H <L (Vs / Vh). This allows the particles to be separated. In this case, it is necessary to widen the width of the settling tank 41 in order to reduce Vh, and it is effective to adopt the above-mentioned upflow method to reduce the installation area.

  In the upflow method, in order to increase the sedimentation efficiency of particles, an inclined plate sedimentation device is incorporated in the sedimentation layer to reduce the size of the sand basin (for example, Patent Document 2). In the upward flow inclined plate sand settling tank 50 shown in FIG. 8, the inclined plate settling device 51 is incorporated between the inflow side partition wall 53 and the outflow side overflow wall 54. The inclined plate settling device 51 is composed of a plurality of inclined plates 52 that are inclined with respect to the horizontal plane, and allows the upward flow of water D to pass between these inclined plates to enhance the sedimentation efficiency of particles. However, in the upward flow inclined plate settling device 50, the inclined plate settling device 51 is incorporated between the inflow side partition wall 53 and the outflow side overflow wall 54 which are vertically installed, and thus the inclined plate is set. Among 52, those close to these walls have a length as short as 1L to 1S. In such a portion where the length of the inclined plate is short, a sufficient sedimentation effect cannot be obtained, and the particle removal rate decreases.

  On the other hand, as in the inclined plate settling device 61 shown in FIG. 9, the attachment angle θs of the inflow side partition wall 63 and the attachment angle θe of the outflow side overflow wall 64 in the tank are the same as the inclination angle θk of the inclined plate 62. It has been proposed to do so (see paragraph 0011 of Cited Document 3, FIG. 2). With such a structure, the length of each inclined plate can be made uniform, the sedimentation effect of all inclined plates can be leveled, and the removal rate of particles can be expected to be increased. However, in the structure shown in FIG. 9, the water flow C flowing under the inclined plate settling device 61 and flowing upward between the inclined plates 62 is different from the flow velocity Vn of the water flow D1 near the inflow tank 65. The flow velocity Vf of the water flow D2 separated from the inflow tank 65 is increased, and in the inclined plate sedimentation device 61, the sedimentation effect varies depending on the position, and the overall particle removal rate is reduced. This is because the water flow C flowing under the inclined plate settling device 61 flows in the horizontal direction, hits the lower part of the outflow side overflow wall 64, and suddenly changes to an upward flow, so that the amount of water flow D2 separated from the inflow tank 65. This is because the flow velocity Vf becomes faster than Vn.

JP, 2017-70890, A JP 63-119811 A JP-A-5-200205

  An object of the present invention is to solve the problems in the above-described conventional upward flow inclined plate sand settling tank, reduce the size of the apparatus main body while maintaining the particle removal capacity, reduce the installation space, reduce the weight, and easily transport. The purpose of the present invention is to provide a sand settling tank that can be installed and can be provided at a low cost, so that it can be promoted to a small water supply facility in the mountain area and the water supply facility can be continued.

  The upflow inclined plate sand settling tank of the present invention includes an inclined plate settling device in which a plurality of inclined plates inclined with respect to a horizontal plane are arranged at regular intervals, between the inflow side partition wall and the outflow side overflow wall. In the installed upflow inclined plate sand settling tank, the inflow side partition wall and the outflow side overflow wall are installed at the same inclination angle as the inclined plate, and the inclined plate has a plane connecting the lower ends from the inflow side. It is characterized in that it is arranged so as to be inclined downward from the horizontal plane toward the outflow side. Further, it is preferable that the inclined plates have the same length.

  The upward flow inclined plate sand settling tank is provided with an inflow flow rate adjusting valve in an inflow path to the inflow tank, and a cutout portion is provided at a center of an upper edge portion of the outflow side overflow wall to measure an outflow flow rate weir. It is preferable that the inflow rate can be adjusted according to the outflow rate measured by the weir. Further, the outflow rate measuring weir is preferably a triangular weir.

  Further, it is preferable that an overflow device is provided in the inflow tank, and a sludge discharge pipe for discharging accumulated sediment is provided in the lower part of the inflow tank, and the lower part of the outflow side overflow wall is not the bottom of the sand settling tank body but the outflow side. It is preferable that the space is fixed on the side surface and the sedimentation space of the sediment is expanded.

  Further, it is preferable that the inclined plate settling device is formed by integrating a plurality of inclined plates into a unit, and is attachable to and detachable from the upward flow inclined plate sand settling tank main body. Further, it is preferable that the constituent materials of the inclined plate settling device and the upward flow inclined plate sand basin body are synthetic resins from the viewpoint of weight reduction.

  In the present invention, particles and earth and sand mean all particles mixed / suspended in water, and include particles such as agglomerates and flocs in addition to earth and sand. All particles that settle.

  In the present invention, the inclined plates arranged at regular intervals in the inclined plate settling device are arranged such that the plane connecting the lower ends thereof is inclined downward from the horizontal plane from the inflow side to the outflow side. Has a structure in which it is gradually lowered as it approaches the outflow side overflow wall from the inflow side partition wall, so the flow velocity of the water flow flowing between the inclined plates is made uniform between the inflow side partition wall and the outflow side overflow wall. As a result, the sedimentation effect of the inclined plate can be leveled, and particles can be efficiently separated and removed even in a downsized sand bath.

  Therefore, it becomes possible to commercialize by factory production as a small sand basin with the function of the sand basin miniaturized, and it can also be installed in the water source of the mountainous area where it is difficult to carry by vehicles or construction requiring heavy machinery. Also, by providing an inexpensive sand basin, greatly reducing installation costs, and shortening the construction period, it will be possible to introduce and disseminate to small-scale water facilities in mountain areas that could not be installed in the past. .

  In addition, the stable separation and removal of particles can be maintained by adjusting the inflow rate based on the measurement of the outflow rate and the overflow device. And because the sediment discharge tank, the expansion of the sedimentation space and the unitization of the inclined plate settling device, the maintenance of the sand basin is lighter than the conventional cleaning work of the sand basin. It will be a sand basin that contributes to reducing the burden on elderly people involved. Furthermore, since the particles of soil and sand can be efficiently separated and removed, the burden on the filtration device at the subsequent stage in the water purification treatment can be reduced, and maintenance and management costs such as cleaning and inspection of the filtration device can be expected to be reduced.

  Furthermore, if it is used as a sand basin of a small hydroelectric power generation facility, in addition to the above-mentioned invention effect, it can be expected to have an effect of suppressing wear of the water turbine, which contributes to reduction of maintenance costs associated with extension of product life of the water turbine. Profitability improvement can be expected in combination with the improvement of operating rate.

Sectional explanatory drawing of the upward flow inclination plate sand settling tank of this invention which incorporated the inclination plate sedimentation apparatus. Sectional explanatory drawing of the upflow inclined plate sand settling tank in which the inflow flow rate control valve, the outflow rate measurement weir, the overflow device, and the discharge pipe of the sediment sediment were provided in the lower part of the tank main body in the said sand settling tank. Explanatory drawing of the main body of a sand basin and the detachable inclined plate unit unitized to the said main body. The top view and cross-sectional side view of a prototype embodiment of the upward-flow inclined plate sand basin of the present invention. Explanatory drawing of the Example which installed the upflow type sand settling tank of this invention in the water weir. Sectional explanatory drawing of the upflow type settling tank of a prior art. Sectional explanatory drawing of the lateral flow type sand settling tank of a prior art. Sectional explanatory drawing of the upward flow inclined plate sand settling tank by the inclined plate sedimentation apparatus of a prior art. Sectional explanatory drawing of the upward-flow inclined plate sand settling tank of another form of FIG.

  Embodiments of the present invention will be described below with reference to FIGS.

  FIG. 1 is a cross-sectional explanatory view for explaining the concept of the upward flow inclined plate sand settling tank of the present invention in which the inclined plate sedimentation device 1 is incorporated. In this upward-flow inclined plate sand settling tank, the inflowing water flow A flows into the inflow tank 5, flows as a water flow C below the inclined plate settling device 1 in which a plurality of inclined plates 2 are arranged at regular intervals, and between the inclined plates. Is flown upward as water streams D1, D2, etc., flows into the outflow tank 6 as a water stream E from which particles have been removed, and flows out of the sand settling tank as an outflow water stream B.

  The inclined plate settling device 1 is incorporated between the inflow side partition wall 3 and the outflow side overflow wall 4, and each inclined plate 2 is arranged to incline toward the inflow side with respect to the horizontal plane. . The inflow side partition wall 3 and the outflow side overflow wall 4 incorporating the inclined plate settling device 1 are similarly inclined, and all the inclined plates 2 are effectively used. The inflow tank 5 formed by the side wall of the settling tank main body and the inflow side partition wall has a structure that expands downward, and the flow of water flowing into the inflow tank 5 becomes gentle and the bottom of the tank The effect of preventing the particles of the accumulated sediment 100 from being rolled up can be obtained.

  Furthermore, in the inclined plate settling device 1, each of the arranged inclined plates 2 is arranged such that the plane connecting the lower ends 7 thereof is inclined downward at an angle θi with respect to the horizontal plane, and The structure is such that it is gradually lowered and arranged as it approaches the outflow side overflow wall 4. With this structure, the water flow C passing below the inclined plate settling device 1 is suppressed by the action of the lower end portion 7 that is sequentially lowered, and the horizontal flow is the lower part of the outflow side overflow wall 4. The situation that suddenly changes to an upward flow at the end of the time is relieved. Therefore, the difference between the respective flow velocities Vn and Vf of the water streams D1 and D2 branched from the water stream C is reduced, and the sedimentation effect of each inclined plate 2 in the inclined plate sedimentation device 1 is leveled and the particle removal efficiency is improved. You can

  Further, as shown in FIG. 1, by making the lengths of the inclined plates 2 all the same, the angle θO at which the plane connecting the upper ends of the inclined plates 2 inclines downward with respect to the horizontal plane becomes equal to the angle θi, and the overflow wall 4 The flow velocity of the water flow E flowing toward is also uniformized, and the effect of suppressing the re-floating of the particles deposited on the inclined plate is obtained. The inclination angle formed between each inclined plate 2 and the horizontal plane is not particularly limited, but is arranged at about 50 to 70 °.

  FIG. 2 is an explanatory diagram of an upward flow inclined plate sand settling tank in which an inflow flow rate adjusting valve 9, an outflow flow rate measuring weir 8, an overflow device 10, and a mud pipe 11 for discharging sediment from the bottom of the tank body are provided. Is. A notch is provided at the center of the upper edge of the outflow side overflow wall 4 in which the water flow D, in which particles have been separated and removed by the upward flow of the water flow D in the inclined plate settling device 1, overflows into the outflow tank 6. The weir 8 is used as an outflow amount measurement weir, and the flow rate of overflow can be measured. Although it is preferable that the notch portion is an inverted triangle and a triangular weir having a scale on it is used, a square weir or a full width weir may be used instead of the triangular weir.

  The upper part of the outflow side overflow wall 4 is used as an outflow amount measurement weir 8 to easily measure the outflow amount, so that the inflow amount of water can be increased with respect to the processing capacity at which the performance of the upward flow inclined plate sand basin can be properly exhibited. Since it is possible to judge at a glance whether or not is appropriate, the flow rate of the water flow A can be adjusted by the inflow flow rate adjusting valve 9 so that the processing capacity can be sufficiently exhibited.

  Further, the overflow device 10 installed in the inflow tank 5 has a function of protecting against an excessive inflow flow rate significantly exceeding the capacity of the device, and an excess inflow water exceeding the upper limit water level HWL in the sand settling tank is provided in the inflow tank. The overflow device 10 discharges the water flow F out of the device. By discharging this excess inflow water, it is possible to suppress re-floating of the particles of the deposited earth and sand 100 accumulated on the bottom part, and also to discharge floating particles and dust having a low density.

  Further, a mud discharge pipe 11 for discharging the sediment 100 to the outside of the tank is provided in the lower part of the settling tank main body, and the sediment 100 can be discharged as a sludge flow G. A discharge valve is provided in this sludge discharge pipe, and the accumulated sediment 100 can be discharged appropriately.

  3 and 4 show an embodiment of an upward-flow inclined plate sand settling tank according to the present invention, in which the sand-setting tank body is a small upward-flow inclined plate sand settling tank having an internal volume of about 500 mm3. In this embodiment, a plurality of slant plates 2 are integrated and integrated as a slant plate unit 12, which is attachable to and detachable from the sand basin body. 3A shows the sand settling body, and FIG. 3B shows the inclined plate unit. The inclined plate unit 12 shown in (b) is configured by attaching a plurality of inclined plates 2 to the inclined plate unit side surface plate 13. In this embodiment, it is attached at an inclination angle of 65 ° with respect to the horizontal plane. Then, these inclined plates 2 are arranged so as to be sequentially pulled down toward the outflow direction, and the lower end 7 of the inclined plate has a structure that is lowered stepwise in the outflow direction. It is possible to suppress the flow of the water flow C flowing into the lower part of the inclined plate unit as the inclined plate settling device, level the water flow flowing between the inclined plates, and improve the particle removal efficiency. The sloping plate unit 12 is inserted into the inserting portion 14 of the sand sunk body shown in (a) and is mounted between the inflow side partition wall 3 and the outflow side overflow wall 4 to be used as a sloping plate settling device. By removing, cleaning work can be facilitated.

  FIG. 4 shows an upward flow inclined plate sand settling tank equipped with an inclined plate unit. The upper diagram is a plan view and the lower diagram is a sectional side view. The inclined plate unit 12 is a inclined plate settling device in which the side plate 13 is brought into close contact with the side surface of the sand basin body and is mounted between the inflow side partition wall 3 and the outflow side overflow wall 4. The inflow water flow A flowing into the inflow tank 5 flows from the inflow pipe 17 that is branched left and right in the inflow tank, then flows into the lower part of the inclined plate unit 12, and flows upward between the inclined plates 2 as a water flow D. Thus, the particles are separated and removed, and then, the water from which the particles have been separated and removed flows over the outflow side overflow wall 4 which is a triangular weir with an inverted triangular cut portion provided in the center of the upper edge, and the water from which the particles are separated and removed is discharged into the outflow tank 6 And flows out as an outflow water flow B from the outflow pipe 18.

  In this sand settling tank, the upper part of the outflow side overflow wall 4 is a triangular weir, and the water level in the tank is kept between the water level HWL and LWL corresponding to the upper end of the wall and the lower vertex of the inverted triangle. To be done. An overflow weir 15 and a discharge pipe 16 are provided in the inflow tank 5 as overflow devices, the upper end of the overflow weir 15 and the water level HWL are set to the same height, and the flow rate of the inflow water A is excessive. When the upper limit water level HWL is exceeded, the excess inflow water overflows the overflow weir 15 and is discharged as a water flow F from the discharge pipe 16 to the outside of the apparatus to maintain stable separation and removal of particles.

  In the small upward-flow inclined plate sand settling tanks shown in FIGS. 3 and 4, from the viewpoint of weight reduction, polycarbonate, which is a synthetic resin, is used as the constituent material of the inclined plate unit that serves as the inclined plate settling device and the sand settling tank body. .

  As the constituent material, not only polycarbonate but also various synthetic resins can be used. For example, polyvinyl chloride, polypropylene, polymethylmethacrylate, polystyrene, polystyrene-based copolymers such as ABS, AS, AAS. , AES, nylon, polyethylene terephthalate, polybutylene terephthalate, and other thermoplastic resins, fiber reinforced thermoplastic resins reinforced with glass fibers and carbon fibers, and polyester resin, epoxy resin and other fiber reinforced thermosetting resins (FRP) And the like.

  FIG. 5 shows an embodiment in which the small upward flow inclined plate sand settling tank 20 of the present invention is used by taking water from a water weir 21. In this embodiment, the water flow introduced from the water intake device 22 installed in the intake weir 21 is taken in by the inflow pipe 17, particles such as sand mixed in by the inclined plate unit 12 are separated and removed, and the particles are taken out by the outflow pipe 18. Has separated and removed water. The water intake device 22 attaches a wedge wire screen, etc. to the upper opening of the device main body when taking in surface water from a river, and removes floating substances such as fallen leaves contained in the surface water. It was installed prior to the processing at 20.

  The runoff water obtained in the above-mentioned examples had the suspended solids and particles separated and removed, and became water that can be preferably used in water supply facilities, hydroelectric power generation facilities, and the like.

1: Inclined plate settling device 2: Inclined plate 3: Inflow side partition wall 4: Outflow side overflow wall 5: Inflow tank 6: Outflow tank 7: Lower end (inclined plate) 8: Outflow rate measurement weir 9: Inflow rate adjustment Valve 10: Overflow device 11: Mud pipe 12: Inclined plate unit 13: Inclined plate unit side plate 14: Inclined plate unit insertion part 15: Overflow weir 16: Discharge pipe 17: Inflow pipe 18: Outflow pipe 19: Sludge Pipe 20: Small up-flow inclined plate sand settler 21: Intake weir 22: Intake device 100: Sediment sediment A: Inflow water flow B: Outflow water flow C, D, E: In-tank water flow F: Overflow drainage flow G: Sludge flow
Vn, Vf: Velocity between inclined plates θi, θo: Angle between lower end line or upper end line of inclined plate set and horizontal line WL: Water level HWL: Upper limit water level LWL: Lower limit water level .
30: Upflow type sand settler 40: Crossflow type sand settler 31, 41: Settling tank 50, 60: Upflow slant plate settler 51, 61: Inclined plate settling device 52, 62: Inclined plate 33, 53, 63 : Inflow side partition wall 34, 54, 64: Outflow side overflow wall 43: Inflow side straightening wall 44: Outflow side straightening wall 35, 45, 55, 65: Inflow tank 36, 46, 56, 66: Outflow tank Vs: Settling velocity of particles Vup: Upward flow velocity Vh; Lateral flow velocity

Claims (9)

  An upward flow inclined plate sand basin in which an inclined plate settling device in which a plurality of inclined plates inclined with respect to the horizontal plane are arranged at regular intervals is installed between the inflow side partition wall and the outflow side overflow wall. The side partition wall and the outflow side overflow wall are installed at the same inclination angle as the inclined plate, and the inclined plate has a plane connecting the lower ends inclined downward from the horizontal plane from the inflow side to the outflow side. Upflow inclined plate sand settling tank characterized by being arranged.   The upflow sloping plate settling tank according to claim 1, wherein the sloping plates have the same length.   An inflow flow rate adjustment valve is provided in the inflow path to the inflow tank, and a notch is provided in the center of the upper edge of the outflow side overflow wall to form an outflow flow rate measurement weir, and depending on the outflow rate measured by the weir. The upward flow inclined plate sand settling tank according to claim 1 or 2, wherein the inflow flow rate is adjustable.   The upward flow inclined plate sand settling tank according to claim 3, wherein the outflow rate measurement weir is a triangular weir.   The upward flow inclined plate sand settling tank according to any one of claims 1 to 4, wherein the inflow tank is provided with an overflow device.   An upward flow inclined plate sand settling tank according to any one of claims 1 to 5, wherein a sludge discharge pipe for discharging the accumulated sediment is provided at the lower part of the inflow tank.   The lower part of the outflow side overflow wall is fixed to the outflow side surface instead of the bottom surface of the upward flow inclined plate sand settling tank main body, and the sedimentation sediment sediment space is expanded. Upflow type sedimentation tank described in paragraph.   The inclined plate settling device is formed by integrating a plurality of inclined plates into a unit, and is attachable to and detachable from an upward flow inclined plate sand settling tank main body. Upflow inclined plate sand settling tank described in.   The upflow type sand basin according to any one of claims 1 to 8, wherein a constituent material of the sloping plate settling device and the upward flow sloping plate sand basin body is a synthetic resin.

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