JP5443122B2 - Scum remover - Google Patents

Description

  The present invention relates to a scum removing device for removing scum generated in a water treatment facility such as a sedimentation basin or a water basin of a sewage treatment plant, and in particular, a part of a scum intake is submerged in water. The present invention relates to the shape of air ejecting means that, when taking in scum, ejects air along the wall surface that forms the scum inlet and promotes scum taking-in.

  Conventionally, scum generated on the water surface of a settling basin is configured to be removed by a scum removing device provided on the downstream side of the settling basin. As such a scum removing device, for example, as shown in FIG. 4 of Patent Document 1, the axial direction is parallel to the water surface, and an elongated opening is formed along the axial direction (longitudinal direction). And a pipe that can be rotated about its axis, and when the scum is discharged, the pipe is rotated so that a part of the opening is positioned below the surface of the water, and the scum is opened in the opening. A pipe-type scum discharge mechanism is known that takes in and discharges from the pipe into the pipe. Further, as another scum removing device, as shown in FIG. 1 of Patent Document 1 and Patent Document 2, etc., the scum removing device is configured by a trough having an inflow weir that moves up and down. It is also known that the upper end is located below the surface of the water and the scum is taken into the trough via its inflow weir and discharged.

  However, in the conventional scum removing device, the scum near the opening and the inflow weir flows into the pipe and the trough immediately after the opening of the pipe and the inflow weir of the trough are located below the water surface. The scum is slightly accompanied by the water and flows into the pipe or trough, and it takes a long time to remove the entire scum. As a result, a large amount of water is required to remove the scum.

  In other words, the scum generated and floating on the water surface has one large flat plate shape, and the scum has a certain thickness, hardness and adhesion (adhesive force). Before the operation, the one side of the flat scum is attached to the pipe or trough, and the other side is attached to the tank wall. A part of the scum near the fitting pipe and inflow weir (trough) flows into the pipe through the opening and inflow weir, but after that, only water easily flows into the pipe and trough, and the entire scum can be removed in a short time. There was a drawback that it could not be removed. When a large amount of water flows into the pipes and troughs, there is a drawback that the processing load increases in the subsequent scum processing device.

  Furthermore, in the conventional scum removing device, for example, as shown in Patent Document 3 or the like, in accordance with the movement of the opening of the pipe below the surface of the water or the movement of the trough inflow weir below the surface of the water. In order to apply a moving force to the scum in the pipe or trough side direction, pressure water having an inclination angle is sprayed on the upper surface of the scum. However, in the conventional scum discharge method that uses only the flow of water to move the scum, only the water flows into the pipes and troughs, and the inflowed water is returned to the settling basin and the like. Since the water is pumped up again to the water treatment facility, there is a disadvantage that power is wasted and power costs are increased.

  Therefore, the present applicant has previously provided a scum removing device for solving the above-mentioned drawbacks in Patent Document 4 (Japanese Patent No. 3934551). In the scum removing device (hereinafter referred to as “patent device”) according to this patent, the scum in the tank can smoothly flow into the scum inlet, and the scum can be moved smoothly. Is discharged efficiently.

  That is, the above-mentioned patent device generates the scum by moving it to the scum discharge mechanism side on the water flow and immersing a part of the scum inlet of the scum discharge mechanism in the water when discharging the scum. A scum removing device for removing scum, which is provided on a wall surface side of a wall surface forming a scum inlet of the scum discharge mechanism and on which the scum flows, and is made of, for example, compressed air along the wall surface It is characterized by providing ejection means for ejecting fluid (air) upward.

  Furthermore, this patent apparatus also ejects air toward the tank wall side in the vicinity of the tank wall upstream of the position where the scum discharge mechanism is provided, and the air is directed upward along the tank wall. It is characterized by providing the jetting means to be made. In addition, this patent device is installed upstream of the installation position of the scum discharge mechanism, and at the time of scum discharge, water is injected obliquely downward on the scum discharge mechanism side, and the water injection pressure A water injection means for moving the scum to the scum discharge mechanism side is provided.

  In the patent apparatus having the above-described configuration, the scum can smoothly flow into the scum inlet, and the entire scum can be moved smoothly, so that the scum can be discharged quickly. For this reason, this patent apparatus can reduce the outflow amount of water accompanying discharge of scum to 1/20 to 1/30 compared with the conventional scum removing apparatus. As described above, the amount of water accompanying the discharged scum is extremely small as compared with the conventional device, so that the equipment cost of the post-treatment device such as the pressure levitation device can be reduced, and the pump It has the feature that it consumes less power and can contribute to energy saving.

An actual verification test conducted at a certain sewage treatment plant using this patent apparatus will be described. The scum removing device equipped with the pipe-type scum discharge mechanism used in this demonstration test has a pipe opening length of 5 m. Then, when a scum having a thickness of 7 to 10 cm is generated up to 5 m from the pipe upstream from the pipe, the scum is completely discharged when a part of the opening of the pipe is submerged for 5 to 7 minutes. I was able to. Further, in a demonstration test at another sewage treatment plant, it has been confirmed that scum can be completely removed by submerging a part of the opening of the pipe for 5 minutes every 24 hours and 5 minutes every 36 hours. Therefore, since this patent device only needs to submerge a part of the opening of the pipe for about 10 minutes once a week, it is given the nickname of “Weekichi-kun” (Torengoku Trademark). It is also introduced in “Monthly Sewer Special Issue (P.71)” issued on February 28th.

  However, in the above-mentioned patent apparatus, when a large scum lump with a diameter exceeding 10 cm exists on the scum inlet side, the scum is removed by the force of air even if a fluid made of air is ejected upward. There was a risk that the scum could not be smoothly flowed into the pipe and the scum could be discharged.

  Such a large scum lump has a property that it is likely to be generated in heavy rain, particularly in the case of a combined type in which sewage and rainwater are collected in a single pipe and flowed to a sewage treatment plant. In addition, such a large mass of scum has sludge containing oil and fat contained in the sewage adhered to the inner surface of the sewage pipe, where it has grown and formed into oil balls, or the organic matter in the sludge is in an anaerobic state. These are generated by being kept in the water, and these are separated from the inner surface of the sewage pipe by a water flow or water pressure during heavy rain, and become a lump and flow into the sewage treatment plant.

  In the above-mentioned patent apparatus, since there is no large scum lump that has a diameter (thickness) exceeding 10 cm on the scum inlet side during normal times other than during heavy rain, the scum is attached to the edge of the scum inlet only by air force. And the scum can smoothly flow into the pipe. However, after a heavy rain, there is a case where a large scum lump exists as described above, and there is a possibility that the discharge of the scum may be hindered.

  Therefore, in the case of Patent Document 5, even if a large scum lump having a diameter exceeding 10 cm exists on the scum inlet side, the present applicant lifts the large scum lump to the edge of the scum intake and Has proposed a scum removing device that can smoothly flow in. The scum removing device according to this proposal not only lifts the scum to the edge of the scum intake port by the force of the air, but also part of the scum intake port is submerged in the water. From time to time until the scum starts to flow into the scum intake port, the pressure water is jetted upward along the wall surface on the side where the scum flows. Therefore, the scum removing device according to this proposal is arranged along the wall surface on the side where the scum flows from when a part of the scum inlet is submerged in the water until the scum starts to flow into the scum inlet. Since the pressure water can be ejected upward, even if a large scum lump with a diameter exceeding 10 cm exists in the scum, the large scum lump is caused to flow out of the scum inlet by the water flow to be ejected. It can be lifted up to the edge and smoothly flowed into the scum inlet, and the scum can be discharged quickly.

Japanese Patent Laid-Open No. 9-19682 JP 2000-202436 A Japanese Patent Laid-Open No. 9-276860 Japanese Patent No. 3934551 International Publication No. 2009/047864

The scum removing device according to Patent Documents 4 and 5 described above can reduce the amount of water outflow accompanying discharge of scum to 1/20 to 1/30 compared to a conventional scum removing device. The equipment costs of the aftertreatment device can be reduced and the power consumption of the pump is low, which contributes to energy saving. Great care must be taken to prevent clogging of the holes. This is because the compressed air ejecting means of the scum removing device according to Patent Documents 4 and 5 includes a pipe connected to a compressed air supply source along the wall surface forming the scum inlet, This is because a large number of ejection holes having a small diameter of about 2 mm are provided at predetermined intervals along the longitudinal direction, so that the ejection holes are easily clogged by scum or the like.
In the scum removing device according to Patent Documents 4 and 5, the ejection hole is devised so as to open downward and not directly contact the scum. Further, as shown in FIG. 6 of Patent Document 5, a cover is provided above the ejection hole so as not to directly contact the scum. However, since these ejection holes are in sewage where scum is generated, the ejection holes having a small diameter are placed in an environment where clogging is likely to occur. Moreover, it can be said that the time during which air is ejected from the ejection holes is several tens of seconds per week, so that the environment is more easily clogged. When clogging occurs in the ejection hole, air is not ejected from the clogged ejection hole, and spots are generated in the air ejection state. May not be performed smoothly, and scum may not be discharged quickly. Moreover, in order to eliminate the clogging of the ejection holes where such clogging occurred, it was necessary to prepare high-pressure compressed air.
For this reason, it has been desired to reliably prevent clogging of the ejection holes even when the ejection holes are left for a long time without ejecting air.

  The scum removing device according to the present invention is made in order to meet the above-mentioned demand, and its purpose is to ensure that the ejection hole is not clogged even if the ejection hole is left for a long time without ejecting air. It is to provide a scum removing device that can be prevented.

In order to achieve the above object, a scum removing device according to the present invention is provided in a settling basin, and is provided in a scum discharge mechanism provided on the downstream side of the water flow in the settling basin, and in the scum discharge mechanism. A scum intake provided so that a part of the scum is submerged in the water at the time of discharging the scum, and an air ejection means for ejecting air provided on a wall surface on the side from which the scum flows among the wall surfaces forming the scum intake. The air ejecting means includes a pipe member connected to a compressed air supply source, a rod-like body provided with an opening facing downward in the pipe member, the pipe member and the pipe member It is characterized by comprising a hole portion that communicates the inside of the pipe material provided at the joint with the rod-shaped body and the inside of the rod-shaped body.
The scum removing device according to the present invention is characterized in that longitudinal slits of a predetermined length are provided at equal intervals in the circumferential direction on the opening side of the rod-shaped body.
In the scum removing device according to the present invention, a tank wall air jet that blows air upward along the tank wall in the vicinity of the tank wall upstream of the position where the scum discharge mechanism is provided. It is characterized by providing means.
Further, in the scum removing device according to the present invention, the tank wall air ejecting means includes a pipe member connected to a compressed air supply source, a rod-like body provided with an opening downward in the pipe member, and the pipe material to be inside the pipe member provided at the junction between the bowl-like body and wherein the benzalkonium such from which the inside of the bowl-shaped member and the hole communicates.
Further, the scum removing device according to the present invention is characterized in that longitudinal slits of a predetermined length are provided at equal intervals in the circumferential direction on the opening side of the rod-like body of the tank wall air ejection means. Yes.
In the scum removing device according to the present invention, water is jetted obliquely downward above the water surface upstream from the installation position of the scum discharge mechanism at the time of scum discharge, and the scum is moved to the scum discharge mechanism side. It is characterized in that water jetting means is provided.
Furthermore, the scum removing device according to the present invention has a scum discharge mechanism in which the axial direction is parallel to the water surface and has an elongated opening along the axial direction, and rotates around the axial center. A pipe-type scum discharge mechanism that takes a scum into the pipe when the part of the opening of the pipe is located below the water surface, or an inflow weir that moves up and down It is a trough-type scum discharge mechanism that takes scum into the trough from the inflow weir when the upper part is located below the water surface.

A scum removing device according to the present invention includes a pipe member having air blowing means connected to a supply source of compressed air, a rod-like body provided with an opening downward in the pipe member, the pipe member and the rod-like shape. Since it is configured with a hole that communicates the inside of the pipe material provided at the joint with the body and the inside of the rod-shaped body, the hole does not come into contact with sewage when air is not blown out. Clogging can be effectively prevented. Therefore, since the scum removing device according to the present invention is able to eject the air well, the scum can be smoothly flowed into the scum inlet, and the scum can be discharged quickly.
Further, the scum removing device according to the present invention is configured such that when the longitudinal slits having a predetermined length are provided at equal intervals with respect to the circumferential direction on the opening side of the rod-shaped body, the jet of air from the rod-shaped body is opened. Can be released uniformly.
And the scum removing device according to the present invention is a tank wall air jetting means for jetting air upward along the tank wall in the vicinity of the tank wall upstream of the position where the scum discharge mechanism is provided. When the scum is provided, the scum is not attached to the tank wall by air, and the scum can be efficiently moved to the scum discharge mechanism side.
Furthermore, the scum removing device according to the present invention includes a pipe member that connects the tank wall air jetting means to a compressed air supply source, a rod-like body provided with an opening downward in the pipe member, and the pipe member. When the hole is connected to the inside of the pipe member and the inside of the rod-like body provided at the junction between the rod-like body and the inside of the rod-like body, the hole is in contact with sewage in a state where air is not blown out. Without clogging, clogging can be effectively prevented.
In addition, the scum removing device according to the present invention is provided with a longitudinal slit having a predetermined length at equal intervals in the circumferential direction on the opening side of the bowl-like body of the tank wall air jetting means. It is possible to uniformly discharge air from the opening.
Then, the scum removing device according to the present invention is configured to inject water obliquely downward above the water surface upstream from the installation position of the scum discharge mechanism to move the scum to the scum discharge mechanism side. When the jetting means is provided, the movement of the scum can be further promoted by the jetting pressure of the diagonally downward water.
Furthermore, the scum removing device according to the present invention can easily implement the scum discharging mechanism when the scum discharging mechanism is constituted by a pipe-type scum discharging mechanism or a trough-type scum discharging mechanism. The air ejection means can be easily attached to the discharge mechanism.

It is a partial top view of the state which removed the upper cover of the sedimentation basin to which the scum removal apparatus which concerns on one embodiment of this invention was applied. It is the sectional view on the AA line of FIG. It is sectional drawing of a pipe in the state where the opening part of a pipe is located on the water surface. It is sectional drawing of a state pipe in which a part of opening part of a pipe is located under the water surface. (A) is a front view of the air ejection means showing the right half in a state where air is not being ejected, and (b) is an air ejection means showing the right half in a section where air is being ejected. FIG. (A) is the front view of the other air ejection means which showed the right half of the state which is not ejecting air in the cross section, (b) is the other which showed the right half of the state which is ejecting the air in cross section It is a front view of the air ejection means. It is explanatory drawing when a trough scum discharge mechanism is employ | adopted as the scum removal apparatus which concerns on this invention. It is explanatory drawing when employ | adopting the trough scum discharge mechanism of another type in the scum removal apparatus which concerns on this invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a plan view of a part of a sediment 1 in a sewage treatment plant to which a scum removing device according to an embodiment is applied, and FIG. 2 is a cross-sectional view taken along the line AA in FIG. The upper cover 2 is removed. The sedimentation basin 1 may be of any nature as long as it is a water tank in which scum is generated at the initial or final settlement of a sewage treatment plant, or through these water conduits.

  1 and 2, a water conduit (not shown) for inflowing raw water is provided on the left side, and an overflow trough 3 for taking out treated water is provided on the downstream side. Therefore, in the illustrated example, water is configured to flow from the left side toward the right side as indicated by an arrow a. And this sedimentation basin 1 is comprised so that the waterway width | variety of the downstream (right side in the example of illustration) of the flow of water may become narrower than an upstream. Moreover, in FIG.1 and FIG.2, in order to avoid the complexity of drawing, the scum produced | generated on the upper surface of the sedimentation basin 1 is abbreviate | omitted. This scum is indicated by the symbol “S” in FIGS. 3 and 4 described later.

  In the figure, reference numeral 4 denotes a sludge scraping mechanism of the sedimentation basin 1, which is configured by providing scraping plates 6, 6... The sludge scraping mechanism 4 is configured so that sludge (precipitate) accumulated on the bottom of the settling basin 1 can be discharged to a pit (not shown) on the forward side of the chain conveyor 5. The scum is configured to be movable toward the pipe-type scum discharge mechanism described later.

  In the figure, 10 is a pipe-type scum discharge mechanism corresponding to the scum discharge mechanism of the present invention provided on the downstream side of the sedimentation basin 1, 20 is an air ejection means, 30 is a tank wall air ejection means, 40 Is a water jetting means. First, the pipe-type scum discharge mechanism 10, the air jetting means 20, and the tank wall air jetting means 30 will be described with reference to FIGS.

  The pipe-type scum discharge mechanism 10 is configured such that a pipe 11 having a predetermined thickness provided so that its axis substantially coincides with the water surface crosses the sedimentation basin 1. One end side (upper end side in FIG. 1) of the pipe 11 is located in a drainage pit 12 provided on one side wall (upper side wall in FIG. 1) 1a of the sedimentation basin 1, and the other end of the pipe 11 On the other side, the other side wall 1b is provided with a rotation mechanism 13 including a motor or the like that reciprocally rotates the pipe 11 as indicated by an arrow b in FIG. The pipe 11 is provided with an opening 14 corresponding to an elongated scum inlet of the present invention along the axial direction. In the illustrated example, the opening 14 is formed to have the same opening length as the horizontal width of the settling basin 1, and the opening width corresponds to an angle of approximately 90 ° with respect to the center position of the pipe 11. Is formed. In addition, the said side walls 1a and 1b are equivalent to the tank wall of this invention.

  When the pipe 11 does not discharge the scum, the rotating mechanism 13 rotates so that the opening 14 of the pipe 11 is located on the water surface as shown in FIGS. 2 and 3, and at the time of discharging the scum, As shown in FIG. 4 to be described later, it can be rotated by a predetermined angle (a predetermined angle in the counterclockwise direction in the example of FIG. 4) so that a part of the opening 14 of the pipe 11 is located below the water surface. It is configured as follows.

The air ejecting means 20 supports a pipe member 21 made of a pipe made of steel or synthetic resin for ejecting compressed air, a rod-like body 22 provided on the pipe member 21, and the pipe member 21 on the pipe 11. And a support member 23.
The axial direction of the pipe material 21 is parallel to the axial direction of the pipe 11 and is supported by the side wall on the side where the scum S of the pipe 11 flows (in the illustrated example, the left side wall of the pipe 11). It is provided via the member 23 and is provided so as to be positioned at least below the generated scum S. Since the pipe material 21 provided in the pipe 11 moves with the rotation of the pipe 11, a flexible tube (not shown) is connected to the connection portion between the air supply pipe connected to the compressed air supply source and the pipe material 21. Is provided. Here, the pipe material 21 is attached to the pipe 11 via the support member 23. However, both ends of the pipe material 21 are fixed to the tank walls 1a and 1b without being attached to the pipe material 11, respectively. Can also be installed. However, as shown in the figure, the structure is simpler and more easily attached to the pipe 11 as shown in the figure.

  A plurality of the rod-shaped bodies 22 are provided along the axial center direction of the pie material 21 and at predetermined intervals. The mounting interval of the rod-shaped body 22 with respect to the pie material 21 is such that air is ejected from the rod-shaped body 22, as will be described later, and the scum S of the pipe 11 flows through the ejected air. It is determined so that it will be supplied to the side wall of the wall without any spots.

  5 (a) and 5 (b) show one rod-like body 22, and FIG. 5 (a) shows a state when a part of the opening 14 of the pipe 11 is located on the water surface (FIG. 5). FIG. 3B shows a state when a part of the opening 14 of the pipe 11 is located below the water surface (see FIG. 4). The rod-like body 22 has a bowl shape having a large opening, and is fixed to the pie material 21 so that the opening is directed downward.

  That is, the nut portion 25 having the screw portion 24 at the tip is integrally provided on the upper portion (opposite side of the opening portion) of the rod-shaped body 22, and the shaft centers of the screw portion 24 and the nut portion 25 are provided. In the direction, a hole 26 having a small diameter penetrating inside the rod-shaped body 22 is provided. In addition, the screw part 24 and the nut part 25 are corresponded to the junction part of this invention. The screw portion 24 is screwed in an airtight manner to a female screw 21 a provided in the pie material 21. The joining of the pie material 21 and the rod-like body 22 may be performed by other methods such as welding instead of screwing as illustrated. In any case, it is constructed so that water does not enter the pipe material 21 from the joint.

  The shape of the rod-shaped body 22 shown in the figure is a state in which the “wax (rooster)” is faced down, but may be a bell shape or a cylindrical shape with the upper part closed. As shown in FIG. 5A, the rod-like body 22 forms an air pocket so that water does not enter the pipe member 21 from the hole 26 when the supply of air to the pipe member 21 is cut off. Any space that can form a space that can be used can be employed. Therefore, in the present invention, the term “wax-like body” refers to a space in which an air pool can be formed so that water does not enter the pipe member 21 from the hole 26 when the supply of air to the pipe member 21 is cut off. It must be interpreted as having.

  The tank wall air ejection means 30 has air diffusers 31a and 31b attached to both side walls 1a and 1b of the sedimentation tank 1, respectively. These aeration pipes 31a and 31b are provided on the side wall surfaces 1a and 1b via fittings (not shown) in water about 10 cm below the water surface of the settling basin 1, and these aeration pipes 31a and 31b are the same as the pipe material 21. A plurality of small holes are formed at predetermined intervals along the longitudinal direction of a pipe made of steel or synthetic resin. When air is ejected from these air diffusers 31a and 31b, the scum S adhering to the both side walls 1a and 1b of the settling basin 1 is peeled off, and the movement by the water flow is performed smoothly.

  The tank wall air ejection means 30 is configured by opening a plurality of small holes at predetermined intervals along the longitudinal direction of the pipe when air is constantly ejected from the air diffusers 31a and 31b. However, when the air is ejected only when the scum is discharged or only when the scum is discharged from near the time when the scum is discharged, the air diffusers 31a and 31b are also energized in the same manner as the air ejecting means 20 described above. The structure 22 is attached. In this case, the air diffusers 31a and 31b correspond to the pipe material of the present invention. When the supply of air to the diffuser tubes 31a and 31b is cut off, an air pocket can be formed in the rod-shaped body 22 so that water does not enter the diffuser tubes 31a and 31b from the hole portion 26. 26 can be effectively prevented (see FIG. 5A).

  The water injection means 40 is located at a position upstream of the pipe-type scum discharge mechanism 10 by a predetermined distance (in the illustrated example, a position slightly upstream from the portion where the width of the sedimentation basin 1 becomes narrow) and the sedimentation basin 1. The header pipe 41 is provided so as to extend in a direction orthogonal to the water flow. The header pipe 41 is configured by arranging a plurality of nozzles 42, 42,... At predetermined intervals along the longitudinal direction of the header pipe 41. Each of the nozzles 42, 42... Is configured to be able to inject pressure water toward the pipe-type scum discharge mechanism 10 side, that is, toward the lower side in the downstream direction of the settling basin 1.

  Each of the nozzles 42, 42... Is not shown in the figure, and its outer shape is formed to be flat and wide so that film-like pressure water can be ejected from a slit opened at the end face of the wide end. . Therefore, from each of the nozzles 42, 42..., Pressure water can be sprayed over a wide area of the scum, and the scum S can be efficiently moved toward the pipe-type scum discharge mechanism 10 side.

  In FIG. 1, 51a is an air supply pipe provided with an automatic open / close valve (not shown) in the middle for supplying compressed air from a compressed air supply source (not shown) to the pipe material 21 described above, It is an air supply pipe for supplying compressed air from the supply source of compressed air which is not illustrated to diffuser pipes 31a and 31b mentioned above. When air is not always ejected from the air diffusers 31a and 31b, an automatic open / close valve is also provided in the air supply pipe 51b. As a supply source of compressed air, when the sedimentation basin 1 is provided in the sewage treatment plant, a part of the compressed air used in the aeration tank can be used. Of course, a compressor can be installed to obtain compressed air.

The scum discharge operation of the scum removing device having the above configuration will be described.
Now, when the time for discharging the scum S arrives, for example, if one week has passed since the last scum discharge, the pipe 11 is partially submerged in the water by the rotating mechanism 13 as shown in FIG. To rotate for a predetermined time (for example, 10 minutes). Further, the water ejection means 40 is also started to drive at the same time that a part of the opening 14 of the pipe 11 is submerged in the water, and the pressure water is ejected onto the scum S from the nozzles 42, 42. Therefore, the scum S is given a scum moving force by the pressure water in addition to the scum movement by the water flow (see arrow a) of the settling basin 1, and the movement toward the pipe-type scum discharge mechanism 10 side is further promoted.

  Further, a part of the opening 14 of the pipe 11 is submerged in water, and at the same time, the automatic opening / closing valve is opened for a predetermined time (for example, 30 seconds), air is supplied to the pipe material 21, and air is supplied from the opening of the rod-shaped body 22. Is ejected (see FIG. 4 and FIG. 5B). The scum S in the vicinity of the opening 14 of the pipe 11 is lifted by the bubbles by the jetted air, and the lifted scum S is smoothly guided into the pipe 11 beyond the end 14a of the opening 14 (FIG. 4 arrow g). Once the scum S enters the pipe 11 from the opening 14, the entire scum S that follows is smoothly guided into the pipe 11. The introduction of the scum S into the opening 14 by air ejection is sufficient for about 30 seconds, which is an extremely short time, and thereafter, the scum S is guided smoothly and smoothly into the pipe 11 by the flow of the scum S. In this way, since the air ejection is completed in a short time, the scum can be discharged at a lower cost. In addition, it can also be set as the time (for example, 10 minutes) when a part of opening part 14 of the pipe 11 is immersed in water. However, it has been proved that an air jet is sufficient for the initial short time when a part of the opening 14 of the pipe 11 is submerged in water. When the automatic on-off valve is closed and the supply of air to the pipe material 21 is cut off, the inside of the rod-shaped body 22 is placed in a state filled with air (see FIG. 5A). Therefore, the hole 26 does not come into contact with water (sewage), and the clogging of the hole 26 is effectively prevented.

  Moreover, when discharging the scum, the scum S is completely separated from the surfaces of the side walls 1a and 1b by the air bubbles from the air diffusers 31a and 31b, so that the entire scum moves smoothly, and the entire scum Moves quickly from the opening 14 into the pipe 11. For this reason, in this scum removing device, the amount of water taken into the pipe 11 for discharging the entire scum S is 1/20 to 1 of the amount of water when only the water injection means 40 is driven to discharge the entire scum S. It is possible to obtain an extremely excellent effect that it can be reduced to / 30.

  The scum S taken into the pipe 11 is guided to the drain pit 12 and sent from here to a scum processing device (not shown) equipped with a dehydrator and the like for processing. Even in this scum treatment device, since the amount of water contained in the scum S is extremely small, it is possible to have an effect of reducing the treatment cost.

After the scum S is taken into the pipe 11 and removed from the water surface of the settling basin 1, the pipe 11 is in its original position, that is, the opening 14 of the pipe 11 is positioned on the water surface (see FIG. 3). In addition, the rotation mechanism 13 is rotated, and the driving of the water injection means 40 is stopped, and the series of scum discharge operations is completed.
The rod-like body 22 in a state where the automatic opening / closing valve is closed and the supply of air to the pipe material 21 is cut off is such that air is trapped in the rod-like body 22 as shown in FIG. Therefore, the hole 26 does not come into contact with sewage, and clogging is effectively prevented. The air pressure supplied to the pipe material 21 and the air diffusers 31a and 31b is sufficient to eject air from the rod-like body 22 located 20 to 50 cm below the water surface. An effect that does not require a high-pressure compression supply source that can also eliminate clogging can be obtained.

  FIGS. 6A and 6B show another type of rod-shaped body 22a, and FIG. 6A shows a state where a part of the opening 14 of the pipe 11 is located on the water surface. FIG. 3B shows a state when a part of the opening 14 of the pipe 11 is located below the water surface (see FIG. 4). The rod-shaped body 22a is also shaped like a rod-shaped body having a large opening, like the rod-shaped body 22 shown in FIGS. 5 (a) and 5 (b), and the pie material so that the opening is directed downward. It is fixed to 21.

  On the opening side of the rod-shaped body 22a, longitudinal slits 22b having a predetermined length are provided at equal intervals in the circumferential direction. As described above, when the slit 22b is provided around the opening of the rod-shaped body 22a, it is possible to obtain an effect that air blown from the rod-shaped body 22a can be uniformly discharged from the entire opening.

  7 and 8 show a scum discharging mechanism of the scum removing device according to the present invention realized by a trough scum discharging mechanism. 7 includes an inflow weir 61 that moves up and down on the upstream side (left side in FIG. 7) of the trough 60 for taking in the scum. Further, on the upstream side of the inflow weir 61, the ejection means 20 including the pipe material 21, the rod-shaped body 22, and the support member 23 is provided.

  Moreover, FIG. 8 implement | achieves the scum discharge mechanism of the scum removal apparatus which concerns on this invention with the trough scum discharge mechanism of another type. In this trough-type scum discharge mechanism, a side wall upper portion 71 on the upstream side (left side in FIG. 8) of the trough 70 for taking in the scum is rotatably provided via a hinge 72. And when taking in scum, the upper end part of the side wall upper part 71 is rotated so that it may be immersed in water, and it is comprised so that scum can be taken in in the trough 70. FIG. Similarly to the trough 60 described above, the jetting means 20 is provided on the upstream side of the trough 70.

  Although one embodiment of the present invention has been described with reference to the drawings, the specific configuration is not limited to the above-described embodiment, and design changes and the like can be made without departing from the scope of the present invention. Is possible. For example, when a sedimentation basin is installed in a combined sewage treatment plant and a large lump of scum is generated during heavy rain, the side on which the scum flows as shown in Patent Document 5 in addition to the air jetting means You may make it provide the pressure water ejection which spouts a pressure water upward along the wall surface.

  The scum removing device according to the present invention can be applied not only to a sewage treatment plant, but also to a water tank where scum is generated in wastewater treatment facilities such as various factory wastewaters. Furthermore, the present invention can also be applied to separation of valuable materials by floating in food factories or chemical factories. Accordingly, the term “water” in the present invention means not only sewage and wastewater but also various liquids.

DESCRIPTION OF SYMBOLS 1 ... Sedimentation basin, 1a, 1b ... Side wall (tank wall), 2 ... Upper cover, 3 ... Overflow trough, 4 ... Sludge scraping mechanism, 5 ... Chain conveyor, 6 ... Scraping plate 10 ... Pipe type scum discharge mechanism , 13 ... rotating mechanism, 14 ... opening (scum intake), 11 ... pipe, 12 ... drainage pit,
DESCRIPTION OF SYMBOLS 20 ... Air ejection means, 21 ... Pipe material, 22, 22a ... Corrugated body, 22b ... Slit, 23 ... Support member, 24 ... Screw part (joint part), 25 ... Nut part (joint part), 26 ... Hole 30 ... Bath wall air ejection means, 31a, 31b ... Aeration pipe (pipe material)
DESCRIPTION OF SYMBOLS 40 ... Water injection means, 41 ... Header pipe, 42 ... Nozzle 51a, 51b ... Air supply pipe 60 ... Trough, 61 ... Inflow weir 70 ... Trough, 71 ... Upper part of side wall, 72 ... Hinge

Claims (7)

A scum discharge mechanism provided in the settling basin and provided downstream of the water flow in the settling pond;
A scum inlet provided in the scum discharge mechanism and provided so that a part of the scum is submerged in water when discharging the scum;
Of the wall surfaces forming the scum inlet, air ejecting means for ejecting air provided on the wall surface on the side where the scum flows;
A scum removing device comprising:
The air jetting means is provided at a pipe member connected to a compressed air supply source, a rod-like body provided with an opening downward in the pipe member, and a joint portion between the pipe member and the rod-like body. A scum removing device comprising a hole communicating the inside of the pipe material and the inside of the rod-shaped body.   2. The scum removing device according to claim 1, wherein longitudinal slits having a predetermined length are provided at equal intervals in the circumferential direction on the opening side of the rod-shaped body.   The tank wall air jetting means for jetting air upward along the tank wall is provided in the vicinity of the tank wall upstream of the position where the scum discharge mechanism is provided. Item 3. The scum removing device according to Item 1 or 2. The tank wall air ejecting means includes a pipe member connected to a compressed air supply source, a rod-like body provided with an opening downward in the pipe member, and a joint portion between the pipe member and the rod-like body. scum removal apparatus according to claim 3, wherein the benzalkonium such and a hole for communicating the inside of the provided the the pipe material and the inside of the bowl-shaped body.   The scum removing device according to claim 4, wherein longitudinal slits having a predetermined length are provided at equal intervals in the circumferential direction on the opening side of the rod-shaped body.   Water injection means is provided above the water surface on the upstream side of the installation position of the scum discharge mechanism to inject water obliquely downward and move the scum to the scum discharge mechanism side at the time of scum discharge. The scum removing device according to any one of claims 1 to 5.   The scum discharge mechanism has a pipe whose axial direction is parallel to the water surface and has an elongated opening along the axial direction, and which rotates around the axial center. When a part of the opening is located below the surface of the water, a pipe-type scum discharge mechanism that takes scum into the pipe from the opening, or when the upper part of the inflow weir that moves up and down is located below the surface of the water, The scum removing device according to any one of claims 1 to 6, wherein the scum removing device is a trough-type scum discharging mechanism for taking scum into the trough from the inflow weir.

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