Screen residue transport device and screen residue transport method

Abstract

To provide a residue conveying device and a residue conveying method capable of promoting residue conveyance in the mixing section where residue and water are mixed, and also suppressing overflow in the mixing section to improve the residue conveying efficiency.SOLUTION: The residue conveying device includes a mixing part that mixes residue and water, a separation part that separates the mixed water treated in the mixing part into residue and separated water, a circulation channel that circulates the separated water separated in the separation part to the mixing part, and an adjustment part that adjusts the amount of separated water flowing into the mixing part by draining part of the separated water. A residue conveying method using this device is also provided. According to this invention, by using the separated water separated from the mixture of residue and water and by adjusting the inflow amount of the separated water into the mixing part, it is possible to promote residue conveyance in the mixing part, control overflow, and improve the residue conveyance efficiency.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a screen residue transport device and a screen residue transport method. [Background technology]

[0002] In grit basin facilities at sewage treatment plants, pumping stations, and the like, screens in wastewater are collected using bar screens or the like and then scraped up from the grit basin using rakes or the like. The scraped up screens are then dumped into a screens mixing tank via a crusher. Water is then supplied to the screens mixing tank, where the crushed screens and water are mixed. This mixture of crushed screens and water is then transported through piping by the power of a pump to a screens separation tank. This type of screens transport device requires the screens mixing tank to be constantly replenished with a large amount of water, which is not only uneconomical but also unusable when sufficient water cannot be replenished.

[0003] In response to this, for example, Patent Document 1 discloses a method for transporting screen residue by transporting a mixture of screen residue and water to a washing tank and removing and discharging the screen residue from the washing tank, in which the water in the washing tank is returned to the mixed water. Patent Document 1 also describes that this screen residue transport method requires almost no water replenishment, making it possible to transport screen residue even in places where sufficient replenishment water is not available. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-239596 Summary of the Invention [Problem to be solved by the invention]

[0005] In the method of transporting screen residue based on that described in Patent Document 1, when the mixed water of screen residue and water is transported using the power of a pump or the like, the screen residue accumulates at the bottom of the mixing section where the screen residue and water are mixed. Therefore, the inventors discovered that in order to promote the transport of screen residue within the mixing section where the screen residue and water are mixed, the mixed water of screen residue and water processed in the mixing section is separated into screen residue and separated water, and this separated water is circulated in the mixing section, thereby forming a flow of separated water within the mixing section and promoting the transport of the screen residue.

[0006] Furthermore, based on this finding, the inventors conducted further studies and found that when circulating separated water in the mixing section, the amount of separated water flowing into the mixing section increases due to cleaning and other factors during the circulation process, which can cause overflow in the mixing section. If the frequency of overflow in the mixing section increases, the screen residue that should have been transported is discharged outside the system, resulting in a problem of reduced screen residue transport efficiency.

[0007] Therefore, an object of the present invention is to provide a screenage transport device and a screenage transport method that can promote screenage transport in a mixing section where the screenage and water are mixed, and can suppress overflow in the mixing section, thereby improving screenage transport efficiency. [Means for solving the problem]

[0008] As a result of extensive research into the above-mentioned problems, the inventors have discovered that when circulating the separated water separated from the mixture of screen residue and water into the mixing section, by draining a portion of the separated water and adjusting the amount of separated water flowing into the mixing section, it is possible to promote the transport of screen residue within the mixing section due to the flow of separated water, as well as to suppress overflow in the mixing section, thereby improving the efficiency of screen residue transport, and have completed the present invention. That is, the present invention provides the following screen residue transport device and screen residue transport method.

[0009] The screen residue transport device of the present invention, which solves the above problems, is characterized by comprising a mixing section that mixes screen residue and water, a separation section that separates the mixed water treated in the mixing section into screen residue and separated water, a circulation path that circulates the separated water separated in the separation section back to the mixing section, and an adjustment section that adjusts the inflow amount of separated water flowing into the mixing section by draining a portion of the separated water. This screen residue transport device uses separated water separated from the mixture of screen residue and water to transport the screen residue, and by forming a flow of separated water within the mixing section for transporting the screen residue without constantly replenishing large amounts of water, the transport of the screen residue within the mixing section can be promoted. In addition, by adjusting the amount of separated water flowing into the mixing section, it is possible to suppress overflow in the mixing section and improve the efficiency of transporting screen residue.

[0010] In one embodiment of the screen residue transport device of the present invention, the adjustment unit is characterized by including an adjustment tank that adjusts the inflow amount of separated water. According to this feature, by adjusting the inflow rate via the adjustment tank, it is possible to appropriately adjust the inflow rate of separated water supplied to the mixing section, even in the event of a sudden change in the amount of separated water, without having to perform mechanical operations frequently.

[0011] Furthermore, one embodiment of the screen residue transport device of the present invention is characterized in that a weir is provided in the adjustment tank. According to this feature, a constant amount of separated water can be circulated to the mixing section simply and easily by passing it through a weir installed in the preparation tank. In addition, since no mechanical operation is required to adjust the flow rate of the separated water, there is an advantage in that malfunctions are less likely to occur.

[0012] In one embodiment of the screen residue transport device of the present invention, the adjustment unit is characterized by including a pipe branched off from the circulation path and an on-off valve. This feature makes it possible to adjust the separated water circulated in the mixing section using only the space required for installing piping, thereby reducing the costs associated with installation and renewal.

[0013] The screen residue transport method of the present invention for solving the above problems is characterized by comprising a mixing step of mixing screen residue and water, a separation step of separating the mixed water treated in the mixing step into screen residue and separated water, a circulation step of circulating the separated water separated in the separation step back to the mixing step, and an adjustment step of adjusting the inflow amount of separated water flowing into the mixing step by draining a portion of the separated water. According to this screen residue transport method, separated water separated from the mixture of screen residue and water is used to transport the screen residue, and a flow of separated water for transporting the screen residue can be formed without constantly replenishing a large amount of water, thereby facilitating the transport of the screen residue in the mixing step. In addition, by adjusting the amount of separated water flowing into the mixing step, it is possible to suppress overflow during the mixing step and improve the efficiency of transporting the screen residue. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a screenage transport device and a screenage transport method that can promote screenage transport in a mixing section where the screenage and water are mixed, and suppress overflow in the mixing section, thereby improving the screenage transport efficiency. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic explanatory diagram showing the structure of a screen residue transport device according to a first embodiment of the present invention. [Figure 2] FIG. 4 is a schematic explanatory view showing another example of the adjustment unit in the screen residue transport device according to the first embodiment of the present invention. [Figure 3] FIG. 4 is a schematic explanatory diagram showing the structure of a screen residue transport device according to a second embodiment of the present invention. [Figure 4] FIG. 10 is a schematic explanatory diagram showing the structure of a screen residue transport device according to a third embodiment of the present invention. [Figure 5] FIG. 10 is a schematic explanatory diagram showing the structure of a screen residue transport device according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] The screen residue transporting device and screen residue transporting method of the present invention are used to transport screen residue that has been collected in a settling basin facility such as a sewage treatment plant or a pumping station and then raked up from the settling basin by a rake or the like. Furthermore, the screen residue transporting device and screen residue transporting method of the present invention transport the screen residue through piping using a pump, etc. According to the present invention, since the screen residue is transported through piping, it is possible to prevent the scattering of sewage, the leakage of odors, etc.

[0017] Hereinafter, with reference to the drawings, embodiments of the screen residue transporting device and screen residue transporting method according to the present invention will be described in detail. Note that the screen residue transporting method of the present invention will be substituted for the description of the structure and operation of the screen residue transporting device below. Furthermore, the screen residue transporting device described in the embodiments is merely an example for explaining the screen residue transporting device according to the present invention, and is not limited thereto.

[0018] [First embodiment] FIG. 1 is a schematic explanatory diagram showing the structure of a screen residue transport device 1A according to a first embodiment of the present invention. As shown in FIG. 1, the screen residue transport device 1A according to this embodiment includes a mixing section 2A, which receives screen residue and water and mixes them; a crushing section 3A installed inside the mixing section 2A and crushes the screen residue; a separation section 4, which separates the mixed water of crushed screen residue and water (hereinafter simply referred to as "mixed water") into screen residue and separated water; a circulation path L1, which circulates the separated water discharged from the separation section 4 back to the mixing section 2A; and an adjustment section 5A, which adjusts the inflow rate of the separated water into the mixing section 2A by draining a portion of the separated water discharged from the separation section 4. The circulation path L1 in this embodiment is composed of a circulation path L1a, which supplies the separated water from the separation section 4 to the adjustment section 5A, and a circulation path L1b, which introduces the separated water, the inflow rate of which has been adjusted by the adjustment section 5A, into the mixing section 2A. The arrows in FIG. 1 indicate the flow of water.

[0019] The screen residue conveyance by the screen residue conveyance device 1A according to this embodiment will be outlined below. First, screen residue and water are fed into the mixing section 2A, and the screen residue is crushed in the crushing section 3A provided within the mixing section 2A. The mixed water is then discharged from the mixing section 2A from the rear side of the crushing section 3, and this mixed water is separated into screen residue and separated water in the separation section 4. This separated water is then supplied to the adjustment section 5 via the circulation path L1, thereby adjusting the inflow rate of the separated water flowing into the mixing section 2A, and the separated water with the adjusted flow rate is further supplied to the mixing section 2A, so that the separated water circulates within the screen residue transport device 1A. Hereinafter, each component of the screen residue transport device 1A in this embodiment will be described.

[0020] [Mixing section] The mixing section 2A is used to perform a mixing step of mixing the screen residue with water, and may be formed of a channel-type tank in which water is stored up to a predetermined water level. The screened residue scraped up (removed) from the settling basin facility is introduced into the mixing section 2A by a screened residue conveyor, and water for turning the screened residue into a slurry is also introduced. In this embodiment, there are no particular limitations on the means for introducing the screened residue and water into the mixing section 2A and the structure for introducing them. For example, a mixing tank (not shown) for premixing the screened residue and water may be provided upstream of the screened residue transporting device 1A, or a separate point for introducing the screened residue and a separate point for introducing the water into the screened residue transporting device 1A may be provided. Furthermore, the water fed into the mixing section 2A is not particularly limited, and examples thereof include tap water, service water, treated water, etc. Considering the cost of procuring water, it is particularly preferable to utilize treated water discharged from treatment facilities such as sewage treatment plants.

[0021] The screened residue transport device 1A in this embodiment is provided with a separated water inlet 21A at one end of the mixing section 2A, into which screened residue and water are introduced and which introduces separated water that has undergone solid-liquid separation treatment in the separation section 4 and flow rate adjustment in the adjustment section 5, which will be described later, and a mixed water outlet 22 at the other end of the mixing section 2A, which discharges mixed water that has passed through the crushing section 3A. A separated water flow F1 for transporting screened residue is formed inside the mixing section 2A. As shown in Figure 1, the direction of the separated water flow F1 in the screen residue transport device 1A of this embodiment is from the separated water inlet 21A toward the crushing section 3A installed inside the mixing section 2A, and this separated water flow F1 can transport the screen residue accumulated at the bottom of the mixing section 2A to the crushing section 3A. Furthermore, the mixed water that has passed through the crushing section 3A is transported to the mixed water discharge section 22 by the separated water flow F1.

[0022] The means for forming the separated water flow F1 within the mixing section 2A is not particularly limited. For example, as shown in FIG. 1, the bottom of the mixing section 2A may be inclined to create a difference in elevation between the separated water inlet section 21A, where the separated water is introduced, and the mixed water outlet section 22, where the mixed water is discharged, thereby utilizing the potential energy within the mixing section 2A. Other means for forming the separated water flow F1 include using energy such as a pump or gravity to circulate the separated water through the circulation path L1, or providing a device (such as an agitator) within the mixing section 2A that forms a flow using the power of a screw or other device. Alternatively, the separated water flow F1 within the mixing section 2A may be formed by the action of a pump P or the like that transports the mixed water discharged from the mixed water outlet section 22 to the separation section 4, without providing a device (such as an agitator) for forming a flow within the mixing section 2A.

[0023] A plurality of means for forming the separated water flow F1 may be provided. For example, the screen residue conveying device 1A in this embodiment may utilize potential energy generated by tilting the bottom surface of the mixer 2A, or may utilize energy for circulating the separated water in the circulation path L1 to form the separated water flow F1 near the bottom of the mixer 2A. In a specific configuration, the separation section 4 is installed above ground, and this separation section 4 is connected to the mixer 2A installed underground by the circulation path L1 consisting of piping. Then, the separated water can be circulated from the separation section 4 into the circulation path L1 by the potential energy of the mixer 2A. Note that any energy may be used for circulating the separated water in the circulation path L1, and a pump or the like may be used.

[0024] The mixer 2A may be provided with various configurations for smooth transport of the screen residue. For example, a water level meter S may be provided in the mixing section 2A, and measures may be taken according to the observed water level. For example, the inflow rate may be adjusted in the adjusting section 5, which will be described later, according to the measurement results of the water level meter S. Furthermore, if the water level drops below a predetermined value, measures may be taken to increase the amount of water input when continuing to transport the screened residue. This maintains the amount of water necessary to transport the screened residue within the mixing section 2, thereby achieving stable transport of the screened residue. Furthermore, a drain section may be provided in the mixing section 2A, so that residue and mixed water remaining in the mixing section 2A can be discharged to the outside of the system as a drain, if necessary.

[0025] [Crushing section] The crushing unit 3A is used to perform the crushing step of crushing the screen residue. Crushing the screen residue can further facilitate the transport of the screen residue within the mixing unit 2A. Screen residue includes metals and plastics contained in sewage and wastewater, as well as fibers such as underwear, rags, and absorbent cotton. This screen residue can become entangled in downstream equipment such as pumps, dehydrators, and mixers, causing equipment failure. Therefore, crushing the screen residue using the crushing unit 3A can prevent equipment failure. Crushing the screen residue can also improve the efficiency of cleaning the screen residue.

[0026] The installation location of the crushing unit 3A is not particularly limited and it may be installed at any location. For example, as shown in FIG. 1, it may be installed inside the mixing unit 2A, or the crushing unit 3A may be installed at the location where the screen residue is introduced into the mixing unit 2A.

[0027] The crushing section 3A may be a crusher. Any type of crusher may be used, for example, a biaxial crusher with a plurality of crushing blades on a drive shaft. In this embodiment, since the crusher is installed inside the mixing section 2A, a vertical biaxial crusher with a vertical drive shaft is particularly preferred. Furthermore, it is preferable to install the crusher at an angle relative to the water surface in the mixing section 2A. More specifically, it is preferable to install the vertical twin-shaft crusher so that the drive shaft is inclined or perpendicular to the inclined bottom surface of the mixing section 2A. This prevents the residue from accumulating upstream of the crusher, allowing the residue to easily flow into the crusher. As a result, crushing of the residue can be further promoted.

[0028] The mixed water, which is a mixture of water and the crushed residue from the crushing unit 3A, is discharged from the mixed water discharge unit 22. The mixed water discharged from the mixing unit 2A is transported to the separation unit 4 through the mixed water transport path L2 by the pump P. The mixed water transport path L2 also branches into a mixed water return path L3 that returns the mixed water to the mixing unit 2A. The mixed water return path L3 allows the pump P of the mixed water transport path L2 to be kept driven when, for example, the separation unit 4 is temporarily stopped. It also promotes the flow of separated water within the mixing unit 2A.

[0029] The mixed water return line L3 may be connected directly or via a branch to the circulation line L1, whereby the returned mixed water is used to form a flow of separated water, thereby further facilitating the transport of the residue accumulated at the bottom of the mixing section 2A.

[0030] [Separation section] The separation section 4 is for carrying out a separation step of separating the mixed water supplied from the mixer 2A via the mixed water transport path L2 into screen residue and separated water. The separation section 4 may be any device that can perform solid-liquid separation, and examples thereof include a drum-type filtration device and a centrifugal separator. The separated water separated in the separation unit 4 is supplied to the adjustment unit 5A through the circulation path L1 (circulation path L1a). On the other hand, the screen residue separated in the separation unit 4 is treated in a dehydrator, a screen residue washer, or the like.

[0031] Washing water for washing the inside of the apparatus after solid-liquid separation treatment is supplied to the separation section 4. This washing water is supplied to the adjustment section 5A together with the separated water.

[0032] [Adjustment section] The adjusting section 5A is used to perform an adjusting step of adjusting the inflow amount of separated water that flows into the mixing section 2A when the separated water separated in the separating section 4 is circulated to the mixing section 2A. The adjustment section 5A may be any section capable of adjusting the inflow rate of separated water flowing into the mixing section 2A. A specific example is one that is provided on the circulation path L1 connecting the separation section 4 and the mixing section 2A, and adjusts the inflow rate of separated water flowing into the mixing section 2A via the circulation path L1b by draining a portion of the separated water introduced via the circulation path L1a.

[0033] As mentioned above, the separated water from the separation section 4 contains wash water used to wash the separation section 4, resulting in a situation where the amount of water is greater than the mixed water transported from the mixing section 2A. For this reason, if the separated water from the separation section 4 is circulated directly to the mixing section 2A, overflow will occur in the mixing section 2A. If this overflow occurs more frequently, the screen residue introduced into the mixing section 2A by the screen residue transporter will be discharged outside the mixing section 2A before being transported to the crushing section 3A, resulting in a problem of reduced screen residue transport efficiency. The screen residue transport device 1A in this embodiment is provided with an adjusting section 5 that adjusts the amount of separated water flowing into the mixing section 2A, thereby making it possible to suppress overflow in the mixing section 2A.

[0034] In this embodiment, the adjustment section 5A is not particularly limited in its specific structure as long as it can allow a constant amount of separated water to flow into the mixing section 2A even when the amount of separated water changes due to processing or operations in the screen residue conveying device 1A (such as cleaning operations of the separation section 4). As an example of the adjustment section 5A, as shown in FIG. 1, there is one including an adjustment tank 51, a weir 52, an overflow section 53, and a drain pipe .

[0035] The adjustment tank 51 may be any tank having a structure capable of storing separated water, and there are no particular limitations on the size or shape. By providing an adjustment tank 51 to temporarily store the separated water, it is possible to respond to sudden changes in the amount of separated water supplied from the separation section 4. This makes it possible to appropriately adjust the inflow amount of separated water without frequently performing mechanical operations when adjusting the flow rate of the separated water flowing into the mixing section 2A.

[0036] In addition, a weir 52 is provided in the adjustment tank 51, and only the separated water that has passed over the weir 52 is circulated to the mixing section 2A via the circulation path L1b. In this case, by designing the shape of the weir 52 and the height and position of the weir 52 disposed in the adjustment tank 51, it is possible to allow a constant amount (predetermined amount) of separated water to flow into the mixing section 2A, and to properly circulate the separated water as the screen residue transport device 1A. This has the advantage that no mechanical operation is required to adjust the flow rate of the separated water, making it less likely to cause malfunctions. There is no particular limitation on the structure of the weir 52. For example, a structure known as a triangular weir or a square weir can be formed by providing a triangular or square cutout in a plate-like member arranged vertically in the adjusting tank 51.

[0037] There is no particular limitation on the means for causing the separated water that has passed over the weir 52 to flow into the mixing section 2A. For example, similar to the separation section 4, an adjustment tank 51 may be installed above ground, and the bottom of this adjustment tank 51 may be connected to the mixing section 2A installed underground by a circulation path L1b. Then, the separated water can be caused to flow from the adjustment tank 51 by the potential energy of the mixing section 2A. Alternatively, a pump or the like may be provided on the circulation path L1b.

[0038] On the other hand, in addition to the weir 52, an overflow section 53 and a drainage pipe 54 are provided as a structure to drain the separated water from the adjustment tank 51 in order to adjust the inflow rate of the separated water flowing into the mixing section 2A and to respond to the case where the water level in the adjustment tank 51 rises suddenly. The overflow section 53 is provided at the upper end of the regulating tank 51, and is arranged so that the point where the water overflows is higher than the weir 52. The separated water discharged from the overflow section 53 is then discharged outside the system via a pipe 53a. The drain pipe 54 is provided at the bottom of the adjustment tank 51 and serves to appropriately drain the separated water from the adjustment tank 51. The separated water discharged through the drain pipe 54 is either combined with the separated water discharged through the pipe 53a or discharged separately from the system. At this time, the separated water discharged outside the system is treated water after solid-liquid separation treatment by the separation unit 4. Therefore, if no further treatment is required, this separated water may be discharged into a river or the like, or may be returned to a grit chamber facility or the like for retreatment, or may be reused as a water resource in a water treatment facility.

[0039] In this embodiment, the adjustment section 5A is provided on the circulation path L1 connecting the separation section 4 located above ground and the mixing section 2A located underground, and is not limited to providing an adjustment tank 51 on the aboveground side as shown in Figure 1. FIG. 2 is a schematic explanatory diagram showing another example of the adjustment section 5A in the screen residue transport device 1A of this embodiment. As shown in Fig. 2, another aspect of the adjustment section 5A of this embodiment is a structure in which the adjustment tank 51 and the mixing section 2A are provided adjacent to each other in a substantially horizontal direction, and the separated water inlet 21A and the weir 52 are integrated. In this case, of the separated water supplied to the adjustment tank 51, only the separated water that passes through the separated water inlet 21A having the weir 52 structure is supplied to the mixing section 2A. Therefore, in the adjustment section 5A shown in Fig. 2, the adjustment section 5A and the mixing section 2A are directly connected via the separated water inlet 21A, and therefore the circulation path L1b is omitted. In this case, the separated water input section 21A may be a trough-shaped or tubular member having a structure known as a triangular or square weir (a so-called overflow weir), and may be a structure integrated with the weir 52. Alternatively, a certain amount of separated water may be allowed to flow into the mixing section 2A by arranging the trough-shaped or tubular member relative to the adjustment section 5A.

[0040] As described above, the screened residue transport device and screened residue transport method of this embodiment utilizes separated water separated from a mixture of screened residue and water to transport screened residue, and by forming a flow of separated water within the mixing section for transporting the screened residue without constantly replenishing large amounts of water, the transport of screened residue within the mixing section can be promoted. Furthermore, by adjusting the inflow rate of separated water flowing into the mixing section, overflow in the mixing section can be suppressed, and the efficiency of screened residue transport can be improved.

[0041] [Second embodiment] FIG. 3 is a schematic explanatory diagram showing the structure of a screen residue transport device 1B according to a second embodiment of the present invention. As shown in FIG. 3, the screen residue transporting device 1B according to this embodiment includes an adjusting section 5B having a structure different from that of the adjusting section 5A in the screen residue transporting device 1A of the first embodiment. Note that, among the configurations of the screen residue transporting device 1B in this embodiment, the description of the same configurations as those of the screen residue transporting device 1A in the first embodiment will be omitted.

[0042] As shown in Fig. 3, the adjustment unit 5B in this embodiment includes a branch pipe 55 separated from the circulation line L1 and an on-off valve 56. By opening this on-off valve 56, it is possible to drain a portion of the separated water flowing in the circulation line L1 and adjust the amount of separated water flowing into the mixing unit 2A. The separated water discharged through the branch pipe 55 is either discharged outside the system or returned to a settling basin facility or the like for reprocessing or reuse.

[0043] At this time, the opening and closing operation of the on-off valve 56 may be performed by an operator as appropriate, or a control unit may be provided to control the opening and closing operation. Examples of control related to the opening and closing operation of the on-off valve 56 by the control unit include periodically repeating the opening and closing operation at predetermined intervals, and controlling the opening and closing operation based on the measurement results of a water level meter S provided in the mixing section 2A.

[0044] In the screen residue transport device 1B of this embodiment, it is possible to adjust the separated water to be circulated in the mixer section 2A using only the installation space for the branch pipe 55. In addition, it is possible to reduce the costs associated with introducing the adjustment section 5B and updating the screen residue transport device 1B.

[0045] [Third embodiment] FIG. 4 is a schematic explanatory diagram showing the structure of a screen residue transport device 1C according to a third embodiment of the present invention. The screen residue transport device 1C according to this embodiment uses a horizontal biaxial crusher as the crushing section 3B, and the crushing section 3B is installed outside the mixing section 2C. Furthermore, the mixing section 2C of the screen residue transport device 1C according to this embodiment has a structure with a substantially horizontal bottom surface. Note that, among the configurations of the screen residue transporting device 1C in this embodiment, the description of the same configurations as those of the screen residue transporting device 1A in the first embodiment will be omitted.

[0046] In the screen residue transport device 1C of this embodiment, the screen residue is crushed in the crushing section 3B and then fed into the mixing section 2C. This configuration has the effect of preventing the screen residue from accumulating at the bottom of the mixing section 2C because the screen residue is crushed into small pieces.

[0047] In this embodiment, the separated water inlet 21B is configured such that the piping constituting the circulation path L1 extends to near the bottom of the mixing section 2C, and the end of the piping bends toward the mixed water outlet 22 to form a discharge section. Because the separated water inlet 21B injects the separated water toward the mixed water outlet 22, it has the effect of drawing water on the opposite side of the discharge section of the separated water inlet 21B in the direction of the separated water flow. As a result, a separated water flow F2 is also formed on the opposite side (back side) of the discharge section of the separated water inlet 21B. Therefore, although the crushing section 3B is installed on the back side of the discharge section of the separated water inlet 21B, the transport of the screen residue is promoted.

[0048] In this embodiment, the crushing section 3B needs to be washed with washing water after the screen residue is introduced. Therefore, in addition to the introduction of water to turn the screen residue into a slurry, the washing water for the crushing section 3B is supplied to the mixing section 2C, which tends to cause overflow due to an increase in the amount of water in the mixing section 2C. Therefore, in the adjustment section 5A, it is preferable to set the structure and arrangement of the weir 52 taking into consideration the influence of the wash water supplied to the crushing section 3B as well as the influence of the wash water in the separation section 4. This makes it possible to appropriately adjust the inflow (predetermined amount) of separated water flowing into the mixing section 2C and more reliably suppress overflow in the mixing section 2C. 4 shows the adjusting unit according to the adjusting unit 5A shown in FIG. 1 in the first embodiment, but is not limited to this. For example, in addition to the adjusting unit 5A shown in FIG. 2 in the first embodiment, the adjusting unit 5B in the second embodiment may also be used.

[0049] [Fourth embodiment] FIG. 5 is a schematic explanatory diagram showing the structure of a screen residue transport device 1D according to a fourth embodiment of the present invention. As shown in Figure 5, the screen residue transporting device 1D of this embodiment omits the crushing section 3 of the screen residue transporting device 1A of the first embodiment, and the screen residue input position to the mixing section 2D is located in front of the discharge section of the separated water input section 21B. Note that, among the configurations of the screen residue transporting device 1D in this embodiment, the description of the same configurations as those of the screen residue transporting device 1A in the first embodiment will be omitted.

[0050] The screened residue transport device 1D in this embodiment can transport the screened residue without crushing it. Furthermore, with this configuration, the screened residue is introduced into the area where the flow of separated water is strong, which prevents the screened residue from accumulating on the bottom surface of the mixer 2D and further promotes the transport of the screened residue. 5 shows the adjusting unit according to the adjusting unit 5A shown in FIG. 1 in the first embodiment, but is not limited to this. For example, in addition to the adjusting unit 5A shown in FIG. 2 in the first embodiment, the adjusting unit 5B in the second embodiment may also be used.

[0051] The above-described embodiment shows an example of a screened waste transporting device and a screened waste transporting method. The screened waste transporting device and the screened waste transporting method according to the present invention are not limited to the above-described embodiment, and the screened waste transporting device and the screened waste transporting method according to the above-described embodiment may be modified within the scope of the gist of the claims.

[0052] For example, the adjusting section in the screen residue conveying device of this embodiment supplies the separated water in a state in which the inflow amount of the separated water to the mixing section is reduced from the original amount of the separated water. On the other hand, in order to cope with a drop in the water level in the mixing section, a structure for replenishing water to the mixing section may be provided. More specifically, when the water in the mixing section is insufficient or when the water in the mixing section needs to be replaced, a water supply unit equipped with a water supply tank and water supply piping capable of storing water can be provided as a configuration for supplying water to the mixing section. In this case, any water can be stored in the water supply tank of the water supply unit and supplied to the mixing section, and examples of such water include treated water generated from water treatment facilities such as sewage treatment plants, water purification plants, and pumping stations, agricultural water, industrial water, and tap water. In addition, wastewater discharged from the screen residue transport device of the present invention can also be used. This allows for quick water supply by using the water stored in the water supply tank when the water in the mixing section is insufficient. Furthermore, quick start-up is possible when replacing the water in the mixing section, making maintenance work easier.

[0053] In the screen residue conveying device of this embodiment, the mixed water, which is a mixture of the crushed screen residue and water, is discharged from the mixing section through the mixed water discharge section. At this time, if the screen residue content in the mixed water is uneven, it may cause clogging of the mixed water discharge section, so it is desirable to discharge the mixed water uniformly. As a means for homogenizing the mixed water, a means for stirring the mixed water can be provided, which not only homogenizes the mixed water but also promotes the washing of screen residue after crushing. As mentioned above, since screen residue contains fibers, mechanical agitation using an agitator equipped with agitating blades can cause these screen residues to re-gather after crushing or become entangled in the agitating blades, resulting in overloading of the agitator or blockage of the mixed water discharge section. Therefore, it is preferable to provide an agitation means that does not rely on mechanical agitation. For example, clean water can be supplied downstream of the crushing section, and the supplied clean water can generate a swirling flow in the mixing section. This makes it possible to agitate and homogenize the mixed water without relying on mechanical agitation. Furthermore, smooth transport of the mixed water can be more reliably achieved. [Industrial Applicability]

[0054] The screen residue transporting device and screen residue transporting method of the present invention are suitably used for transporting screen residue that has been collected and separated in settling basin facilities in sewage treatment plants, pumping stations, and the like. [Explanation of symbols]

[0055] 1A,1B,1C,1D Sludge conveyor, 2A,2B mixing section, 21A,21B separated water input section, 22 mixed water discharge section, 3A,3B crushing section, 4 separation section, 5A,5B adjustment section, 51 adjustment tank, 52 weir, 53 overflow section, 53a piping, 54 drain pipe, 55 branch piping, 56 On-off valve, L1, L1a, L1b circulation path, L2 mixed water conveyance path, L3 mixed water return path, S water level gauge, P pump, F1, F2 separated water flow

Claims

1. a mixing section for mixing the screen residue and water; A separation section that separates the mixed water treated in the mixing section into screen residue and separated water; a circulation path for circulating the separated water separated in the separation section to the mixing section; and an adjusting unit that adjusts the amount of separated water flowing into the mixing unit by draining a portion of the separated water.

2. The screen residue transport device according to claim 1 , wherein the adjusting unit includes an adjusting tank that adjusts the inflow amount of the separated water.

3. The screen residue transport device according to claim 2, wherein a weir is provided in the adjustment tank.

4. The screen residue transport device according to claim 1 , wherein the adjustment unit includes a pipe branched from the circulation path and an on-off valve.

5. a mixing step of mixing the screen residue with water; A separation step of separating the mixed water treated in the mixing step into screen residue and separated water; a circulating step of circulating the separated water separated in the separating step to the mixing step; and an adjusting step of adjusting the amount of separated water flowing into the mixing step by draining a portion of the separated water.

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