Wastewater treatment tank and overflow weir

Abstract

To provide a wastewater treatment tank and an overflow weir that avoid retardation of treatment water flow between an aerobic treatment tank, a separation tank, and a discharge pump tank and are capable of properly avoiding inflow of a broken carrier to the discharge pump tank.SOLUTION: An overflow weir 25 has a hollow (cylindrical) body and one end of a separation tank 13 side is fixed with a cap 41 for preventing inflow of treatment water. A peripheral surface 125 of the overflow weir 25 is provided with a plurality of overflow holes 51 of a size not allowing passage of a broken carrier included in treatment water having flowed into the separation tank 13 via a screen 21 on about 60-90% area of the peripheral surface. Also, the screen 21 has an inclined plane 213 inclined to the vertical direction. A plurality of screen holes 215 are provided on approximately at the front face of the inclined plane 213.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a wastewater treatment tank and an overflow weir for treating wastewater such as water for domestic use. [Background technology]

[0002] There is a wastewater treatment tank that treats wastewater such as water for domestic use. FIG. 7 is a diagram for explaining a wastewater treatment tank according to a comparative example. As shown in FIG. 7, in the wastewater treatment tank according to the comparative example, treated water from an aerobic treatment tank 11 passes through a screen 121 and flows into a separation tank 13. 8, the screen 121 has a structure in which a number of striped members 125 are arranged, and the treated water decomposed in the aerobic treatment tank 11 passes between the striped members (wire mesh) 125 and flows into the separation tank 13. Heavy substances in the treated water that flows into the separation tank 13 sink, and light substances rise to the surface. The sinking substances are returned to the aerobic treatment tank 11 by a pump. At this time, the carriers in the treated water do not pass through the screen 121, but damaged carriers pass through the screen 121 and flow into the separation tank 13. Also, the screen 121 may be damaged and flow into the separation tank 13.

[0003] The treated water in the separation tank 13 flows into the discharge pump tank 15 via the buckle 123. The buckle 123 has, for example, the structure shown in FIG. 9 and is structured to remove floating scum from the treated water flowing out from the separation tank 13 to the discharge pump tank 15 and to allow only clear water to overflow. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-203066 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the process of the treated water flowing from the aerobic treatment tank 11 into the separation tank 13, it is possible that the carriers in the treated water or damaged carriers that do not pass through the screen 121 may pass through the screen 121 and flow into the separation tank 13. In addition, there is a problem that the broken carrier may overflow the buckle 125 and flow into the discharge pump tank 15, causing the pump to become clogged. Furthermore, if the spacing between the stripe members 125 of the screen 121 is narrowed, the screen 121 will become clogged, and the flow of treated water from the aerobic treatment tank 11 to the separation tank 13 will become poor.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and its object is to provide a wastewater treatment tank and overflow weir that can properly prevent damaged carriers from flowing into the discharge pump tank without impeding the flow of treated water between the aerobic treatment tank, separation tank, and discharge pump tank. [Means for solving the problem]

[0007] The present invention is a wastewater treatment tank comprising an aerobic treatment tank containing flowing carriers for biologically treating treated wastewater, a separation tank, a screen for removing the flowing carriers contained in the treated water flowing from the aerobic treatment tank into the separation tank and discharging the treated water into the separation tank, a discharge pump tank, and an overflow weir through which the treated water flowing from the separation tank into the discharge pump tank communicates, wherein the overflow weir allows the treated water from the separation tank to flow into the discharge pump tank through a plurality of overflow holes of a size that does not allow broken carriers contained in the treated water to pass through.

[0008] Preferably, the overflow weir has a shape of a horizontally extending cylinder with one end closed, the hollow body having a polygonal cross section.

[0009] Preferably, the overflow weir further includes an aeration unit that diffuses air to remove the carrier blocking the overflow hole.

[0010] Preferably, the screen has an inclined surface inclined with respect to the horizontal direction, and a plurality of screen holes are formed on the inclined surface.

[0011] Preferably, the plurality of overflow holes are substantially circular.

[0012] Preferably, the overflow hole has a diameter of Φ4 to Φ10.

[0013] Preferably, the plurality of overflow holes are rectangular.

[0014] The present invention also relates to an overflow weir for use in a wastewater treatment tank having an aerobic treatment tank containing flowing carriers for biologically treating treated wastewater, a separation tank, a screen for removing the flowing carriers contained in the treated water flowing from the aerobic treatment tank into the separation tank and discharging the treated water into the separation tank, and a discharge pump tank, the overflow weir having a plurality of overflow holes of a size that does not allow damaged carriers contained in the treated water to pass through, and discharging treated water from the separation tank into the discharge pump tank through the plurality of overflow holes. Effect of the Invention

[0015] According to the present invention, a wastewater treatment tank and overflow weir can be provided that does not disrupt the flow of treated water between the aerobic treatment tank, separation tank, and discharge pump tank, and can appropriately prevent damaged carriers from flowing into the discharge pump tank. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a configuration diagram of a wastewater treatment tank 1 according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is an external view of the screen 21 shown in FIG. [Diagram 3] FIG. 3 is a diagram for explaining the appearance of the overflow weir 25 according to the first embodiment shown in FIG. [Figure 4] FIG. 4 is a diagram for explaining the arrangement of the air diffuser 27 that blows air onto the overflow weir 25 shown in FIG. [Diagram 5]FIG. 5 is a diagram for explaining the appearance of an overflow weir 225 according to the second embodiment of the present invention. [Figure 6] FIG. 6 is a diagram for explaining the arrangement of the air diffuser 27 that blows air onto the overflow weir 225 shown in FIG. [Figure 7] FIG. 7 is a configuration diagram of a wastewater treatment tank according to a comparative example. [Figure 8] FIG. 8 is a diagram for explaining the screen shown in FIG. [Figure 9] FIG. 9 is a diagram for explaining the buckle shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Many garbage disposer wastewater treatment tanks have carrier fluidized beds. The carriers wear out and break, passing through the leak prevention screen into the settling tank, and flowing down the overflow weir of the settling tank into the discharge pump. There, the discharge pump gets clogged, causing discharge problems. The treated water in this embodiment is, for example, wastewater from laundry, washrooms, kitchens, toilets, and baths, and has a BOD of approximately 200-250 ppm.

[0018] The role of the overflow weir installed in the settling tank is to prevent floating sludge from flowing out and to allow the separated clean water to overflow smoothly. However, unfortunately, with the current overflow weir, leaking or damaged carriers still pass through the overflow weir.

[0019] Therefore, the inventors have invented an overflow weir that prevents leaking or broken carriers from passing through the overflow passage. The shape of the overflow weir in this embodiment is square or round. The material is not particularly limited and may be metal, PVC, FRP, or the like. The diameter of the hole is, for example, 5φ, but can be selected depending on the carrier, such as 10φ. Neither the damaged nor undamaged carriers pass through the overflow weir, and the overflow weir is not blocked. The overflow weir has many holes with diameters of Φ4 to Φ10. The diameter of the overflow holes is set arbitrarily depending on the material and shape of the carrier. In addition, air is diffused from an air diffuser to prevent the overflow hole from being blocked by foreign objects such as broken carriers.

[0020] In this embodiment, air diffusion is performed to remove foreign matter from clogging the overflow hole of the overflow weir. The air diffusion also has the function of pulverizing and dropping the floating scum.

[0021] First Embodiment FIG. 1 is a configuration diagram of a wastewater treatment tank 1 according to a first embodiment of the present invention. As shown in FIG. 1, in a wastewater treatment tank 1, for example, an aerobic treatment tank 11, a separation tank (sedimentation tank) 13, and a discharge pump tank 15 are arranged in this order along the flow of treated water.

[0022] The aerobic treatment tank 11 performs aerobic treatment on the treatment water that has flowed in from the preceding tank. Aerobic treatment is a wastewater treatment method that utilizes the ability of aerobic microorganisms to use oxygen in the water to break down organic matter into water and carbon dioxide. This aerobic treatment method is used in wastewater treatment and sewage treatment. It is an activated sludge method that can purify wastewater by utilizing aerobic microorganisms.

[0023] A screen 21 is provided between the aerobic treatment tank 11 and the separation tank 13. The screen 21 removes the carriers from the aerobically treated water from the aerobic treatment tank 11, and the treated water from which the carriers have been removed flows into the separation tank 13. That is, in the process of passing through the screen 21 from the aerobic treatment tank 11 toward the separation tank 13, the carriers in the treated water are separated. On the other hand, some of the broken carriers pass through the screen 21 and flow down into the separation tank 13.

[0024] FIG. 2 is an external view of the screen 21 shown in FIG. As shown in FIG. 2, the screen 21 has an inclined surface 213 that is inclined with respect to the vertical direction. A plurality of screen holes 215 are formed on substantially the entire front surface of the inclined surface 213 . The screen holes 215 are larger than the holes of the overflow weir 25. This allows the flow of treated water from the aerobic treatment tank 11 to the separation tank 13 to be smooth. The screen hole 215 is, for example, substantially circular and has a diameter of Φ6 to Φ10. In the screen 21, the surface on which the overflow weir 25 is formed is the inclined surface 213, so that the carrier can be effectively prevented from passing through the screen holes 215 without reducing the inflow amount of treated water.

[0025] An overflow weir 25 is provided between the separation tank 13 and the discharge pump tank 15. The overflow weir 25 will be described in detail below. FIG. 3 is a diagram for explaining the appearance of the overflow weir 25 according to the first embodiment shown in FIG. As shown in FIG. 3, overflow weir 25 is a hollow body (cylindrical), and a cap 41 for preventing the inflow of treated water is fixed to one end on the separation tank 13 side.

[0026] The overflow weir 25 has multiple overflow holes 51 formed on its peripheral surface 125, covering approximately 60 to 90% of the peripheral surface, and each of the overflow holes 51 is sized to prevent the passage of damaged carriers contained in the treated water flowing into the separation tank 13 through the screen 21. The overflow hole 51 is, for example, substantially circular and has a diameter of Φ4 to Φ10. The cross-sectional diameter of the overflow weir 25 is Φ100 to Φ200. The length of the overflow weir 25 in the longitudinal direction is 500 to 2000 mm.

[0027] Overflow weir 25 is provided above separation tank 13 (near the water surface), has a horizontally elongated shape, and has a circumferential surface that extends horizontally.

[0028] In the overflow weir 25, the treated water contained in the separation tank 13 flows into the cylinder of the overflow weir 25 through the overflow hole 51 and flows out from the opening at the other end of the overflow weir 25 into the discharge pump tank 15. At this time, damaged carriers and the like contained in the treated water stored in the separation tank 13 do not pass through the overflow hole 51 and are separated.

[0029] Here, by using overflow holes 51 formed on the outer periphery of a hollow body rather than on a flat plate-like member, the entire inflow amount is not drained at once, and the drainage adjustment function can be achieved. By forming overflow holes 51 on curved peripheral surface 125 as in FIG. 3, overflow holes are less likely to become clogged than when overflow holes are formed on a flat surface. In other words, the overflow holes 51 are arranged on the entire surface of the overflow weir 25, including the bottom, sides, and top, so that overflow does not occur from one direction but from the entire surface, making it less likely to become clogged.

[0030] The air diffuser 27 blows air toward the peripheral surface of the overflow weir 25 to remove fragments of the carrier blocking the overflow hole 51. The air diffuser 27 is disposed, for example, as shown in Fig. 4. This makes it difficult for the overflow hole 51 to become clogged.

[0031] Based on the measurement results of a water level gauge installed in the discharge pump tank 15, the pump 32 sucks up the treated water in the discharge pump tank 15 and discharges it when the water level reaches a predetermined level.

[0032] As described above, according to the wastewater treatment tank 1, by using the overflow weir 25 having the structure shown in Figure 3, it is possible to properly remove damaged carriers from the treated water and discharge them into the discharge pump tank 15 while properly functioning as an overflow weir. Furthermore, in the wastewater treatment tank 1, by using the screen 21 having the structure shown in FIG. 2, it is possible to prevent a sudden leakage of damaged carriers.

[0033] <Second embodiment> The wastewater treatment tank of the second embodiment has an overflow weir different from that of the first embodiment. The overflow weir of the second embodiment will be described below. FIG. 5 is a diagram for explaining the appearance of an overflow weir 225 according to a second embodiment of the present invention. As shown in FIG. 5, the overflow weir 225 is a hollow body (cylindrical), and a cap 41 for preventing the inflow of treated water is fixed to one end on the separation tank 13 side.

[0034] A plurality of rectangular overflow holes 251 are formed on the peripheral surface 325 of the overflow weir 25, the size of which is such that the leaked carrier contained in the treated water that has flowed into the separation tank 13 through the screen 21 does not pass through. The overflow hole 51 has a width of, for example, Φ100 to Φ200 mm and a length of, for example, 500 mm to 2000 mm. The overflow weir 225 is provided above the separation tank 13 (near the water surface), has a horizontally elongated shape, and has a circumferential surface that extends horizontally.

[0035] In the overflow weir 225, the treated water contained in the separation tank 13 flows into the cylinder of the overflow weir 25 through the overflow hole 251, and flows out from the opening at the other end of the overflow weir 25 into the discharge pump tank 15. At this time, damaged carriers and the like contained in the treated water stored in the separation tank 13 do not pass through the overflow hole 251 and are separated.

[0036] In the second embodiment, the overflow hole 251 has a rectangular shape, which allows smoother overflow compared to the overflow hole 51 of the first embodiment. In addition, the effect of preventing overflow with an adjustment function and overflow of a leaking carrier or a damaged carrier can be improved.

[0037] In this embodiment, the air diffuser 27 blows air toward the peripheral surface of the overflow weir 225 to remove fragments of the carrier blocking the overflow hole 251. The air diffuser 27 is disposed, for example, as shown in FIG.

[0038] The present invention is not limited to the above-described embodiments. In other words, those skilled in the art may make various modifications, combinations, sub-combinations, and substitutions of the components of the above-described embodiment within the technical scope of the present invention or an equivalent scope. [Industrial Applicability]

[0039] The present invention is applicable to wastewater treatment tanks. [Explanation of symbols]

[0040] 1...Wastewater treatment tank 11...Aerobic treatment tank 13...Separation tank 15...Discharge pump tank 32…Pump 21,121…screens 25,225...Overflow weir 27…Aeration section 41…Cap 51,251...Overflow hole 125,325…Surrounding surface 213…Slope surface 215…Screen hole

Claims

1. A carrier flow tank, an aerobic treatment tank containing flowing carriers for biologically treating treated wastewater; A separation tank; a screen that removes the carriers contained in the treated water flowing from the aerobic treatment tank into the separation tank and flows the treated water into the separation tank; A discharge pump tank; An overflow weir through which treated water flowing from the separation tank to the discharge pump tank is communicated; having The overflow weir comprises: The treated water from the separation tank is discharged into the discharge pump tank through a plurality of overflow holes having a size that does not allow the damaged carrier contained in the treated water to pass through. Wastewater treatment tank.

2. The shape of the overflow weir is a horizontally extending cylinder with one end closed, a hollow body with a polygonal cross section. The wastewater treatment tank according to claim 1.

3. an aeration section that performs aeration for removing the carrier blocking the overflow hole with respect to the overflow weir; The wastewater treatment tank according to claim 2, further comprising:

4. The screen has an inclined surface inclined with respect to a horizontal direction, and a plurality of screen holes are formed on the inclined surface, The screen holes are larger than the overflow holes. The wastewater treatment tank according to claim 3.

5. The plurality of overflow holes are substantially circular. The wastewater treatment tank according to claim 4.

6. The overflow hole is Φ4 to Φ10. The wastewater treatment tank according to claim 5.

7. The plurality of overflow holes are rectangular. The wastewater treatment tank according to claim 4.

8. an aerobic treatment tank containing flowing carriers for biologically treating treated wastewater; A separation tank; a screen that removes the carriers contained in the treated water flowing from the aerobic treatment tank into the separation tank and flows the treated water into the separation tank; A discharge pump tank; An overflow weir for use in a wastewater treatment tank having A plurality of overflow holes of a size that does not allow the passage of broken support bodies contained in the treated water. having The treated water from the separation tank is discharged into the discharge pump tank through the plurality of overflow holes. Overflow weir.

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