JP2011240271A - Scum removal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scum removal device capable of preventing decomposition of a pipe skimmer caused by stay of scum around the skimmer.SOLUTION: In the scum removal device, when an opening 5 provided on the pipe skimmer (a) is positioned on a water surface, the base of a guide plate 6 is positioned below the opening 5. The tip part of the guide plate keeps the depth positioning below the scum S generated on the water surface, and the plate extends to a prescribed length at the upstream side of a water current. Besides, a cover piece 6a is provided between the tip position of the guide plate 6 and the lower part of the pipe skimmer (a).

Description

  The present invention relates to a scum removing device having a pipe skimmer, and in particular, it is possible to suppress the occurrence of scum that tends to stay around the pipe skimmer and to quickly discharge the staying scum. It is about.

  Conventionally, in a scum removing device provided with this type of pipe skimmer, the pipe skimmer is installed in such a manner that a part of the pipe skimmer is submerged in the water surface on the downstream side of the water tank where the scum is generated. For example, if the tank is a sedimentation basin of a sewage treatment facility such as sewage, the pipe skimmer is partially submerged in front of the supernatant water extraction side that is provided on the side opposite to the raw water inflow side of the sedimentation basin. is set up.

  This conventional pipe clearance is made of a pipe material having a length equal to the water channel width in a direction orthogonal to the water flow direction of the settling basin, and the pipe material is provided with an opening (notch) opened in the axial direction. ing. The pipe skimmer is provided with a rotation mechanism that rotates about the longitudinal axis, and is rotated so that a part of the opening is submerged in water when the scum is removed. It is comprised so that it may flow in into a pipe clearance from a part.

  In a scum removing device provided with a pipe skimmer, the removal of scum is performed in association with a water flow. That is, at the time of scum removal, a part of the opening of the pipe skimmer is located in the water, so that water starts to flow into the pipe skimmer through the opening. The scum that has floated on the surface of the water as a result of this flow of water also flows into the pipe skimmer, thereby removing the scum.

  By the way, normally, the flow of water in the water tank in which scum is generated is not fast. For example, when the water tank is a sedimentation basin of a sewage treatment facility, the flow rate is about 3 to 5 cm / sec. If the scum is removed only by the flow of the scum, there is a problem that the discharge time of the scum becomes long. Moreover, in the case of a scum that is inferior in fluidity, there is a problem that the discharge time becomes longer.

  The longer scum discharge time means that the amount of water discharged increases with scum discharge. Since the discharged water is separated from the scum and then returned to the raw water side, there is a problem that the load on the sewage treatment facility is increased.

  In the case where scum is discharged only by the flow of water, there are problems as described above, and various proposals have been made to solve this problem. For example, Patent Document 1 discloses a nozzle tube provided in the water upstream of the position of the opening when the scum is removed so that a part of the opening of the pipe skimmer is submerged in the water. It is disclosed that air is blown out toward the opening to enhance the movement of the scum. Patent Document 2 discloses that a spray nozzle is provided at an upper position of the scum, and pressure water is ejected obliquely downward from the spray nozzle to impart a moving force to the scum.

However, when the generated scum floating on the water surface is in a thin film shape, for example, in the case of a thin film scum generated in the final sedimentation basin of a sewage treatment facility, as shown in Patent Document 1 or Patent Document 2 above The scum moving means cannot be used at all.
For example, it is difficult to increase the movement of the scum by ejecting air from a nozzle pipe provided in the upstream water in the opening of the pipe skimmer of Patent Document 1. This is because the thin film scum floating on the surface of the water floats with a very delicate force relationship, so when air is ejected from the bottom of the scum, turbulence occurs in the water flow, and the scum flocks. This is because the scum mixed in the water rises again at the position moved below the pipe clearance and is discharged and contained in the supernatant water, resulting in a decrease in the quality of the discharged water. Similarly, even if the pressure water for transfer is ejected on the upper surface of the scum shown in Patent Document 2, it is difficult to adopt because the scum is flocked by generating a turbulent flow in the water flow.

Therefore, the present applicant has proposed a scum removing device shown in Patent Document 3 in order to solve the above-mentioned drawbacks. This scum removing device has a depth which is located below the scum generated on the water surface when the opening is located on the water surface at the lower side forming the opening provided in the pipe skimmer. When a guide plate extending a predetermined length is provided on the upstream side of the water flow while maintaining the thickness, and when a part of the opening is located in the water at a predetermined position on the upstream side of the water flow from the position of the tip of the guide plate In addition, water is ejected from the ejection nozzle toward the opening.
According to the scum removing device according to this proposal, a water flow having a higher flow velocity can be generated on the upper surface side of the guide plate compared to the periphery facing the opening, and the scum is flocked with the fast water flow. And can be reliably moved to the opening in a short time. For this reason, while being able to prevent the quality of the treated water discharged | emitted from being deteriorated, the amount of water accompanying scum discharge can be reduced and energy saving can be achieved. That is, the scum removing device according to this proposal has a property that can greatly contribute to so-called ecological measures.

Japanese Utility Model Publication No. 53-88071 Japanese Patent Laid-Open No. 9-276860 JP 2010-046622 A

However, the conventional scum removing device provided with the pipe clearance has a drawback that the scum tends to stay around the pipe clearance. In particular, the scum removing device provided with a guide plate on the lower side of the opening of the pipe skimmer according to the above proposal and provided with a jet nozzle for jetting water toward the opening has an opening on the upper surface side of the guide plate. It is possible to generate a water stream with a high flow velocity compared to the surrounding area, and it can be moved to the opening in a short time and without causing the scum to flock along with the fast water stream. Although the effect can be obtained, a portion where the water flow stagnates is formed in the lower surface portion of the joint portion between the guide plate and the pipe skimmer, and the scum is liable to stay in the portion where the water flow stagnate, and the staying scum is rotted. There was a problem.
Further, in the scum removing device provided with the conventional pipe skimmer, the scum tends to stay on the side opposite to the direction opposite to the water flow direction around the pipe skimmer. In other words, the part of the pipe skimmer around the opposite side of the direction opposite to the direction of the water flow acts so that the pipe skim itself blocks the water flow. There was a tendency for scum to stay.

  Therefore, the present invention has been made to solve the above-described drawbacks, and the object of the present invention is to make it difficult for scum to stay around the pipe skimmer and to quickly remove the scum staying around the pipe skimmer. Another object of the present invention is to provide a scum removing device that can be removed.

In order to achieve the above object, the scum removing device according to the present invention is characterized in that, when the opening provided in the pipe skimmer is located on the water surface, the base is the opening. A scum removing device having a guide plate that is located on the lower side of the section and that has a guide plate extending a predetermined length upstream of the water flow while maintaining a depth at which a tip portion is positioned below the scum generated on the water surface. A cover piece is provided between the tip position and the lower part of the pipe skimmer.
The scum removing device according to claim 2 of the present invention is characterized in that the pipe clearance, the guide plate, and the cover piece are integrally formed.
In order to achieve the above object, the scum removing device according to the present invention is characterized in that the opening of the pipe skimmer is located on the water surface and is located on the water surface. A scum removing device having a rotation drive mechanism for rotating the pipe skimmer so that the opening is positioned below the water surface, wherein the rotation drive mechanism flows the water flow through the opening provided in the pipe skimmer. It is characterized not only by being directed toward the incoming direction but also being directed toward the direction in which the water flows.
In the scum removing device according to claim 4 of the present invention, the opening provided on the pipe skimmer is provided at the lower side of the opening when the opening is directed to the direction in which the water flow flows. Is located on the water surface, the base portion is located on the lower side of the opening, and the tip portion extends a predetermined length upstream of the water flow while maintaining a depth located below the scum generated on the water surface. It is characterized by having a guide plate.

In the scum removing device according to claim 1 of the present invention, since the cover piece is provided between the position of the front end portion of the guide plate and the lower portion of the pipe skimmer, the scum is not flocked in a short time, and Not only can the excellent effect of being surely guided into the pipe clearance be obtained, but also the water flow will not stagnate on the lower surface side of the guide plate, and therefore scum will not stay on the lower surface side of the guide plate. The problem that the scum that stays rots can be solved.
The scum removing device according to claim 2 of the present invention can be easily manufactured when the pipe clearance, the guide plate, and the cover piece are integrally formed.
In the scum removing device according to claim 3 of the present invention, the rotation drive mechanism not only directs the opening provided in the pipe skimmer with respect to the direction in which the water flow flows, but also in the direction in which the water flow flows. Since it is configured so as to face the scum, the scum staying on the side opposite to the direction opposite to the water flow direction in the periphery of the pipe skimmer can be quickly discharged into the pipe skimmer.
Since the scum removing device according to claim 4 of the present invention has the guide plate on the lower side of the opening, the scum can be surely guided into the pipe skimmer in a short time without flocking. it can.

It is a top view of a sedimentation basin provided with the scum removal apparatus concerning one embodiment of the present invention. (A) is an enlarged sectional view taken along line X ₁ -X _{1 in} FIG. 1 when the opening of the pipe skimmer is located on the water surface, and (b) is a part of the opening of the pipe skimmer being underwater. is an enlarged sectional view of the X ₁ -X ₁ line in Figure 1 when located. Opening of the pipe gap is a cross-sectional view of the X ₂ -X ₂ line 1 when positioned on the water surface. Part of the opening of the pipe gap is a cross-sectional view of the X ₂ -X ₂ line in FIG. 1 when positioned in the water. It is explanatory drawing when a part of opening part of a pipe clearance is located in water and a rotation angle differs.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a final sedimentation basin (hereinafter referred to as “sedimentation basin”) of a sewage treatment facility equipped with a scum removal device according to an embodiment of the present invention.

  In the sedimentation basin 1, water is configured to flow from the left side to the right side. The sedimentation basin 1 is provided with a sludge scraping mechanism for discharging the settled sludge, as in the known sedimentation basin 1, but it is not related to the description of the present invention, so that detailed description thereof is omitted. In an actual sewage treatment facility, a plurality of sedimentation basins are provided, but only one sedimentation basin is shown here to simplify the drawing.

  In the figure, a is a pipe clearance, and the water flow in the sedimentation basin 1 is such that a part of the sedimentation tank 1 is submerged in the front side of the supernatant water extraction part 2, that is, a predetermined distance upstream from the supernatant water extraction part 2. It is provided over the entire width of the water channel in the direction orthogonal to the direction.

  One end portion (upper end portion in FIG. 1) of the pipe skimmer a is located in a scum pit 3 that passes through one tank wall of the settling basin 1 and is provided outside the tank wall, and is opened. The water including the scum can be discharged into the scum pit 3 from the one end portion.

And the other end part formed in the closed shape of the pipe skimmer a is pivotally supported by the other tank wall of the sedimentation basin 1, and the pivot is centered on the axis of the pipe skimmer a. A rotation drive mechanism 4 is provided for rotation.
This rotational drive mechanism 4 has a flow of water flowing through the opening from a position (see FIGS. 2B and 4) where a later-described opening of the pipe skimmer a is submerged in the water surface in the direction in which the water flows. It is comprised so that it can rotate to the position (refer FIG. 5) where one part is submerged in the water surface of a going direction.
In addition, the part which penetrates the tank wall of the one end part side of the pipe skimmer a, and the support shaft part which penetrates the tank wall of the other end part are each configured to be able to rotate with the tank wall as a bearing, and the bearings thereof. These mechanisms are each configured to be watertight, and are devised so that water in the sedimentation basin 1 does not leak.

  The pipe clearance a is composed of a pipe material P having a length slightly longer than the water channel width in the direction orthogonal to the water flow direction of the settling basin 1 and a circular cross-sectional shape. An opening (notch) 5 is provided in the opening. The inner diameter of the pipe material P is determined so that water including scum taken in from the opening 5 can be quickly discharged into the scum pit 3.

  In the figure, 6 is a guide plate having a rectangular planar shape made of steel or synthetic resin, and a predetermined distance (from the position of the lower side forming the opening 5 of the pipe material P toward the upstream side) In FIG. 1, they are provided so as to extend toward the left side (distance corresponding to the short side length of the rectangle). That is, the guide plate 6 has one end side (the right side in FIG. 1) corresponding to the base portion of the guide plate 6 joined to the lower side forming the opening 5.

  The other end side (the front end portion of the guide plate 6) side is located in the water near the water surface regardless of the rotational position of the pipe skimmer a, and is always located below the scum S generated on the water surface. (See FIGS. 2A and 2B to FIG. 5). Further, the joint portion between the lower side of the opening 5 and the guide plate 6 and the upper side of the opening 5 are formed in a curved shape, so-called “R”.

  A cover piece 6a is provided between the front end of the guide plate 6 and the lower part of the pipe clearance a (the lower part of the pipe material P). In the illustrated example, the guide plate 6 is formed by folding back the lower side forming the opening 5 of the pipe material P, and the cover piece 6a is formed integrally by folding the leading end of the guide plate 6. Of course, the guide plate 6 and the cover piece 6 a may be configured separately from the pipe material P, or the cover piece 6 a may be configured separately from the guide plate 6.

  As described above, when the cover piece 6a is provided between the front end portion of the guide plate 6 and the lower portion of the pipe skimmer a, there is no stagnation of the flow of water on the lower surface side of the guide plate 6, and the guide plate 6 It is possible to suppress scum retention on the lower surface of the sheet.

  In the figure, 7 is a pressure water supply pipe provided near the water surface, provided at a predetermined distance upstream from the position of the tip of the guide plate 6 and in a direction orthogonal to the water flow direction of the settling basin 1. It has been. The pressure water supply pipe 7 is provided with ejection nozzles 8, 8, and the like that hang down into the water via the connection pipe 9 at a predetermined interval.

  The jet direction of the pressure water of these jet nozzles 8, 8... Is determined so as to face the upper surface side of the plate-like guide plate 6 and the lower side of the opening 5 of the pipe skimmer a. The pressure of the pressure water ejected from the ejection nozzles 8, 8... And the amount of the water are determined to be sufficient to promote the flow of water toward the opening 5 on the upper surface side of the guide plate 6.

  Next, the scum removing operation in the scum removing device of the present embodiment having the above-described configuration will be described. Now, when the sedimentation basin 1 is performing a sedimentation process and the pipe skimmer a is positioned on the water surface as shown in FIGS. 2 (a) and 3, the upstream side of the pipe skimmer a. A thin scum S is generated on the water surface.

  When the generation of the scum S shows a certain area, the pipe skimmer a is rotated via the rotation drive mechanism 4 so that a part of the opening 5 is located in the water (so as to be immersed in the water). Then, the pressure water is supplied to the pressure water supply pipe 7 through a pump (not shown) (see FIGS. 2B and 4).

  Therefore, pressure water is ejected from the ejection nozzles 8, 8 toward the opening 5, thereby promoting the flow of water toward the opening 5 on the upper surface side of the guide plate 6. Then, the scum S is moved into the pipe skimmer a along with the accelerated flow of the water while maintaining a thin film shape without being flocked, and is sucked into the opening 5.

  The timing for rotating a part of the opening 5 to be located in the water via the rotation drive mechanism 4 and the time for the part to be located in the water are the experiments because the scum S generated by the water quality flowing into the sedimentation basin 1 is not uniform. It is desirable to be determined by That is, it is desirable to manually determine the scum S discharge state once a day for the first several days of operation of the apparatus and determine the discharge state of the scum S. Thereafter, automatic operation is performed based on the observation result.

  However, the start control of the automatic operation is not limited to the above example. A scum detection sensor is arranged on a predetermined surface of the settling basin 1 to detect that the scum is filled up to the scum detection sensor arrangement position. Alternatively, scum removal may be performed automatically by arranging a plurality of various detection sensors.

  The timing of supplying pressure water to the pressure water supply pipe 7 and injecting the pressure water from the ejection nozzles 8, 8... Toward the opening 5 is controlled so as to be synchronized with the timing of positioning a part of the opening 5 in the water. Is done. In addition, the timing which positions a part of opening part 5 in water, and the timing which injects pressure water toward the opening part 5 from the ejection nozzles 8,8 ... are not limited at the time of an automatic operation, but always carry out manually. It may be.

  The scum S flowing into the pipe skimmer a passes through the pipe skimmer a and is discharged to the scum pit 3, and the scum S in the scum pit 3 is processed by a processing means such as a sludge processing machine (not shown). Moreover, the supernatant water (processed water) discharged | emitted by the supernatant water extraction part 2 is discharged to water systems, such as a river.

When the supply of the pressure water from the pressure water supply pipe 7 to the ejection nozzles 8, 8... Is stopped, the pipe skimmer a is rotated and the opening 5 is formed on the water surface as shown in FIGS. Located in. Then, the rotation is further continued, and as shown in FIG. 5, the opening 5 is rotated so that a part of the opening 5 is located in the water (submerged in water) on the water surface in the direction in which the water flows. . Thereby, the scum S ′ floating on the water surface in the direction in which the water flow of the pipe skimmer a flows is promptly introduced into the pipe skimmer a.
After the scum S ′ is guided into the pipe clearance a, the pipe clearance a is rotated until the opening 5 is positioned on the water surface as shown in FIGS.
Like the scum S described above, the scum S ′ flowing into the pipe skimmer a passes through the pipe skimmer a and is discharged to the scum pit 3, and the scum S ′ in the scum pit 3 is a sludge treatment machine (not shown) or the like. It is processed by the processing means.

Since the scum removing device having the above-described configuration can be moved to the opening 5 in a short time without causing the scum S to be flocked and accompanied by a fast water flow, the quality of the discharged treated water is prevented from deteriorating. In addition, the amount of water accompanying the discharge of the scum S can be reduced, and an excellent effect that energy saving can be achieved can be obtained. That is, the scum removing device having the above-described configuration has a property that can greatly contribute to so-called ecological measures.
Moreover, since the scum removing device having the above-described configuration is provided with the cover piece 6a between the front end portion of the guide plate 6 and the lower portion of the pipe skimmer a, the stagnation of the flow of water flow is present on the lower surface of the guide plate 6. As a result, the scum stays on the lower surface of the guide plate 6 and the scum S can be prevented from decaying.
Further, the scum removing device having the above-described configuration is rotated so that a part of the opening 5 is positioned underwater on the water surface in the direction in which the pipe skimmer a flows, so that the water flow of the pipe skimmer a flows. The scum S ′ floating on the water surface in the direction can be guided into the pipe clearance a and quickly removed.

The jet nozzle according to the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the above-described embodiment, and design changes and the like can be made without departing from the gist of the present invention. Is possible.
For example, in the above-described example, the cross-sectional shape of the pipe material P is circular, but this can also be rectangular.
In the above example, the ejection nozzles 8, 8... Are applied to the final sedimentation basin of the sewage treatment facility, but the sedimentation basin may be the initial sedimentation basin or another sedimentation basin for factory wastewater. Furthermore, the present invention may be applied to an inflow trough (a water trough). Furthermore, the present invention can also be applied to a recovery tank that floats and collects valuable materials. In the case of this recovery tank, the fluid may not be water, but the “water” of the present invention includes such a fluid.

1 ... Sedimentation basin (final sedimentation basin)
2 …… Supernatant water extraction part 3 …… Scum pit 4 …… Rotation drive mechanism 5 …… Opening part 6 …… Guide plate 6a …… Cover piece 7 …… Pressure water supply pipe 8 …… Blowout nozzle 9 …… Connecting pipe a …… Pipe clearance P …… Pipe material S, S ′ …… Scum

Claims (4)

When the opening provided in the pipe skimmer is located on the water surface, the base is located at the lower side of the opening and the tip is kept at a depth located below the scum generated on the water surface. A scum removing device having a guide plate extending a predetermined length on the upstream side of the water flow,
A scum removing device, wherein a cover piece is provided between a position of a front end portion of the guide plate and a lower portion of the pipe skimmer.   The scum removing device according to claim 1, wherein the pipe clearance, the guide plate, and the cover piece are integrally formed. A scum removing device having a rotational drive mechanism for rotating the pipe skimmer so that the opening provided in the pipe skimmer is positioned above the water surface and the opening located above the water surface is positioned below the water surface Because
The rotation drive mechanism is configured not only to direct the opening provided in the pipe skimmer to the direction in which the water flow flows, but also to the direction in which the water flow flows. A scum removing device characterized by the above.   4. The scum removing device according to claim 3, wherein the opening is provided on the lower side of the opening when the opening provided in the pipe skimmer is directed to the direction in which the water flow flows. A guide plate that extends to the upstream side of the water flow while maintaining a depth where the base is located at the lower side of the opening and the tip is located below the scum generated on the water surface when positioned above A scum removing device comprising:

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