JP2002166272A - Scum removing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scum removing equipment capable of preventing supernatant water from being discharged more than required and steadily discharging the scum. SOLUTION: This equipment has scum raking sections 22, 24 which rake the scum afloat on a water surface and a scum box 28 which allows the scum raked by the raking sections 22, 24 to inflow into the box 28 and outflow it outside the equipment. A side of the box 28 which faces the sections 22, 24 is formed below a water level and an opposite side of the box 28 is formed above the water level. The equipment also has a float 34 elevatably communicated with the sections 22, 24 of the box 28 to prevent an inflow of the water into the box 28 and elevating means 36, 40 which depress the float 34 below the water level when the sections 22, 24 cross the box 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scum removing device for removing scum floating on a water surface, and more particularly to a scum removing device provided in a sludge scraper used for treating sewage and industrial wastewater.

[0002]

2. Description of the Related Art Conventionally, in a sewage treatment facility for treating various kinds of wastewater (hereinafter simply referred to as "sewage") such as public sewerage, hot spring wastewater, and industrial wastewater, sedimentation for separating wastewater into supernatant water and sludge. It has a tank. This separation process is performed by flowing sewage into a sedimentation tank to settle sludge to the bottom side, and the sewage on the water surface side becomes supernatant water. However, scum may float on the surface of the supernatant water, and this scum may hinder the treatment of the supernatant water. Therefore, a scum removal device for removing scum from the supernatant water is provided in the sedimentation tank.

[0003] The scum removing device is provided with a scum skimmer arm that moves on the water surface while scraping the scum, and a scum box that collects and discharges the scum to the outside. As one of the conventional general scum removing apparatuses, there is an apparatus which keeps the front end of the scum box higher than the water surface to prevent the supernatant water from flowing constantly, and allows the scum to flow when the scum skimmer crosses the scum box. As another scum removing device, there is one in which a scum box is provided near the surface of water in water and a manual opening / closing valve is provided in a discharge path to the outside. When the scum gap passes through the scum box, the operator operates the opening / closing valve to flow the scum flowing into the scum box to the outside, and when the flow is completed, closes the flow path again to remove the scum.

[0004]

However, the conventional scum removing device has the following problems. In the scum removing device holding the scum box on the water surface, when the scum flows into the scum box, the supernatant water is separated from the scum. Since the scum itself has little fluidity, the scum remains in the scum box and clogs the discharge path, which may hinder the scum removal operation.

The scum removing device provided with an opening / closing valve while holding the scum box in the water requires an operator to open and close the manual valve every time the scum is removed, and the work load is large. Further, since there are individual differences in the timing of opening and closing and the opening time of the valve, supernatant water that is more than necessary for scum removal is discharged. Since the supernatant water is of high quality from which sludge has been removed, it has been desired to remove scum by minimizing the amount of supernatant water discharged.

Further, in any of the scum removing apparatuses, the effect of removing the scum is affected by the fluctuation of the water level. Therefore, a scum removing apparatus capable of obtaining a stable scum removing effect regardless of the fluctuation of the water level is desired. Was.

An object of the present invention is to provide a scum removing device capable of preventing unnecessarily discharged supernatant water and reliably discharging scum. It is another object of the present invention to provide a scum removing device capable of removing scum stably irrespective of fluctuations in water level.

[0008]

In order to achieve the above object, a scum removing device according to the present invention has a scum scraping portion moving along a water surface and a scum receiving portion formed in a gutter shape. The scum receiving portion formed in a gutter shape is formed by submerging at least a part of the side wall on the upstream side in the moving direction of the scum scraping portion, and connecting the float to the upstream side wall so as to be able to move up and down. The float is provided with a protruding portion that traverses the movement path of the scum raking portion, so that the float can move up and down integrally with the float when the scum raking portion contacts and passes the protruding portion. ,
The protruding portion is formed at a height at which the float can be moved below the water surface at least at the lowermost limit when passing through the scum scraping portion. With the above configuration, the scum scraping unit moves while scraping the scum floating on the water surface. On the other hand, in the scum receiving section, the inflow of water is prevented by the float located on the water surface. When the scum scraping section crosses the scum receiving section and causes the scum to flow into the scum receiving section, the float is lowered by the projecting section, and water flows into the scum receiving section.
This allows a necessary amount of water to flow in at the same time as the scum flows into the scum receiving section, so that the scum can be stably removed without the scum clogging the discharge path. When the scum scraping portion passes through the scum receiving portion, the float moves to prevent water from flowing into the scum receiving portion. With this configuration, no more water than necessary for scum removal flows into the scum receiving portion. In addition, since a series of operations for removing scum can be automatically performed by moving the scum scraping portion, unnecessary processing such as opening and closing of a manual valve as in the related art is unnecessary, and the work load can be reduced. The scum receiving portion is preferably a box-shaped one, but is not limited to this and may be a tubular one. In addition, even when the water level fluctuates, the float moves up and down while maintaining the connection with the scum receiving section to prevent water from flowing into the scum receiving section. It can be performed.

The scum removing device according to the present invention has a scum scraping portion moving along the water surface, and a scum receiving portion formed in a gutter shape and having both side walls higher than the water surface. Is connected to the upstream side wall of the scum receiving portion, and a latch for locking the basin body on the upstream side and holding the basin body underwater is rotatably provided, The latch protrudes the upper part so as to cross the movement path of the scum scraping part, and is rotated when passing through the scum scraping part to release the locking of the basin body and return the latch to the locking position. The striker is provided on the downstream side of the basin body, and the striker traverses the moving path of the scum scraping portion at the upper part and at least the lower limit of the striker when passing through the scum scraping portion. The basin member was formed on a movable height to the locking position Te, and the structure, characterized in that. With the above configuration, when the scum scraping unit pushes down the latch, the locked state with the basin is released, and the basin rises. The scum scraping part moves on the upper surface of the basin body,
Pour scum into the scum receiving section. When the latch is separated from the scum scraping portion, it returns to the locked position again by elastic force. When the scum scraping unit lowers the striker, the basin body is submerged again in the water to keep the latched state with the latch.

In the above configuration, a plurality of the latches and the strikers may be provided. With this configuration, the raising and lowering operation of the basin body can be performed more reliably. In addition, when the scum scraping unit turns, the rotational torque of the scum scraping unit can be reduced.

In the above structure, at least a region held in water may be formed of plastic. In this way, corrosion of the scum removing device due to rust can be prevented, and the weight of the scum removing device itself can be reduced. In the above configuration, a detecting unit for detecting that the scum scraping unit has reached the inflow start position and the inflow end position of the scum to the scum receiving unit, and a scum discharging path to the outside connected to the scum receiving unit is provided. And a solenoid valve that opens and closes the scum discharge path in response to a control signal from the detection means. With the above configuration, even when an unexpected situation such as a sudden rise in the water level or a break in the float occurs, it can be controlled by the solenoid valve. It can be performed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A scum removing apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings. In the present embodiment, a case will be described in which the scum removing device is attached to a sludge scraper. The scum removing device is preferably installed because sludge removal and scum removal can be performed simultaneously.However, the scum removing device is not limited to this.The scum removing device itself is independent of the sludge scraper. May be provided.

FIG. 8 is a sectional view of the sludge scraper 2 provided in the settling tank 1. A feed well 3 into which sewage flows is provided above a central portion of the settling tank 1 formed in a substantially cylindrical shape. A sewage supply pipe 4 connected to the outside is inserted into the bottom surface of the feed well 3, and sewage is supplied from the sewage supply pipe 4 into the feed well 3. Sewage flows into the feed well 3 and is separated into supernatant water and sludge by sedimentation. That is, sludge is deposited on the bottom of the settling tank 1 and the surface of the sewage becomes supernatant water. Sludge deposited at the bottom of the settling tank 1 is supplied to a rake 7 attached to a rake arm 6.
Is scraped off. The base end of the rake arm 6 is connected to the bottom side of the main shaft 5 provided to extend vertically in the center of the settling tank 1. The spindle 5 is a drive motor (not shown)
And the rake arm 6 turns to scrape off the sludge by the rake 7,
It is dropped into the sedimentation pit 8 at the bottom of the settling tank 1.

The scum removing device 20 of this embodiment is provided integrally with the sludge scraper 1 in order to remove the scum 21 floating on the supernatant water surface. FIG. 1 is an explanatory diagram of a scum removing device 20 in the present embodiment. FIG. 2 is a plan view of the scum removing device 20 according to the present embodiment.

The scum scraping section for scraping the scum 21 floating on the surface of the supernatant water has a scum skimmer arm 22. The scum skimmer arm 22 has a base end attached to the main shaft 5 on the upper side of the feed well 3. The scum skimmer arm 22 pivots above the supernatant water surface according to the rotation of the main shaft 5. A rubber scum gap 24 is provided on the lower surface of the scum gap arm 22.
Are attached, and swivel together with the scum skimmer arm 22 to scrape the scum 21.

On the scum gap arm 22, guides 26 (26a, 26b) are formed on both sides of the scum gap 24. In the present embodiment, a pair of guides 26 are provided on the inner peripheral side and the outer peripheral side. The guide 26 is formed in the shape of an inverted octagon with inclined surfaces 27a and 27b provided on both sides of the lower half, and contacts a guide roller 48 attached to the upper portion of the float 34 described later to push down the float 34. Like that.

On the other hand, a scum box 2 serving as a scum receiving portion is provided on the surface of the supernatant water facing the scum skimmer arm 22.
8 are provided. The scum box 28 is provided between the feed well 3 and the sedimentation tank 1, and has a substantially triangular cross section in which the wall surface side of the sedimentation tank 1 is deepened. A scum discharge pipe 30 connected to the outside is connected to the bottom surface on the settling tank 1 side, and the scum 21 flowing into the scum box 28 is discharged from the discharge pipe 30 to the outside. The scum discharge pipe 30 has an electromagnetic valve 32 that opens and closes according to a control signal.
have. The electromagnetic valve 32 is connected to a proximity switch which is a detection unit (not shown), and the proximity switch detects the position of the scum gap arm 22 and controls the opening and closing of the electromagnetic valve 32 by a control signal generated.

In the scum box 28, the side on which the scum skimmer arm 22 pivots is formed lower than the supernatant water level, and the opposite side is formed higher than the supernatant water level. Also,
A float 34, which is an elevating body constituting inflow control means, is connected to the side of the scum box 28 formed lower than the supernatant water level shown in FIG. Float 34
Is normally held so as to float on the supernatant water surface. As described above, since one side of the scum box 28 is formed higher than the supernatant water surface and the other side is stopped by the float 34, the supernatant water does not normally flow into the scum box 28. Therefore, it is possible to prevent the supernatant water from being wastefully discharged except when removing the scum.

The connection mechanism between the float 34 and the scum box 28 will be described. On a bottom surface of the float 34, a connecting rod 36 serving as a lifting / lowering control means of the float 34 is provided so as to extend downward. Meanwhile, scum box 2
A hollow box 38 is provided from the eight sides and penetrated by the connecting rod 36. Stoppers 42 and 44 are provided in the connecting rod 36 and the box 38, respectively, to prevent the connecting rod 36 from falling out of the box 38. In the hollow box 38,
An auxiliary roller 40 is provided so as to be in contact with the connecting rod 36 so that the connecting rod 36 can be moved up and down smoothly.

The scum gap 24 on the upper surface of the float 34
The side has a tapered shape so that the scum 21 raked by the scum gap 24 can be guided to the upper surface of the float. The scum box 28 on the upper surface of the float 34 is provided so that the projecting rod 46 crosses the moving path of the guide 26. A guide roller 48 is provided at the tip of the protruding rod 46. Because of this, the guide roller 48 comes into contact with the inclined surface 27a of the guide 26, and the float 34 is smoothly pushed down by the rolling contact as the guide 26 moves. In this embodiment, when the guide roller 48 of the protruding rod 46 contacts the lower surface of the guide 26, the height position of the protruding rod 46 is adjusted so that the float 34 is positioned below the supernatant water level.

The operation of the scum removing device configured as described above will be described. 3, 4, and 5 are explanatory views of the operation of the scum removing device. As shown in FIG. 3A, the scum skimmer 24 attached to the scum skimmer arm 22 swivels on the supernatant water surface while scraping the scum 21, and comes into contact with the tip surface of the float 30. At this time, the upper part of the float 34 floats on the supernatant water surface, and the inflow of the supernatant water into the scum box 28 is prevented. Also, at this time, the electromagnetic valve 32 of the scum discharge pipe 30 is also closed, and even if the supernatant water flows into the scum box 28 due to a sudden change in the water level, it is not discharged to the outside.

As shown in FIG. 3B, the projecting rod 4
The sixth guide roller 48 comes into contact with the inclined surface 27a of the guide 26, and as the guide 26 moves, the guide roller 48 rolls downward while contacting the inclined surface 27a. As a result, the float 34 is lowered by receiving a force from the projecting rod 46 that holds the guide roller 48. In the present embodiment, the contact of the guide roller 48 with the inclined surface 27a of the guide 26 is detected by a proximity switch (not shown), and a control signal is generated. Thereby, the electromagnetic valve 32 electrically connected to the proximity switch is opened, and the flow path between the scum box 28 and the outside is opened,
The scum 21 can be discharged outside.

As shown in FIG. 4A, the scum 21 raked by the scum gap 24 starts to flow into the scum box 28. At this time, the guide roller 48 is in contact with the bottom surface of the guide 26 due to the movement of the guide 26, whereby the float 34 is pushed down below the water surface. Therefore, the water stoppage state into the scum box 28 is released, and the supernatant water flows in with the scum 21. The scum 21 that has flowed into the scum box 28 is discharged to the outside through the scum discharge pipe 30 together with the supernatant water. Thus, the scum 21 together with the required amount of supernatant water is transferred to the scum box 28.
The scum can be reliably discharged to the outside without the scum clogging the discharge pipe 30.

As shown in FIG. 4B, while the guide roller 48 is in contact with the bottom surface of the guide 26, the float 34 is pushed down below the surface of the water and the scum 2 together with the supernatant water.
1 flows into the scum box 28.

As shown in FIG. 5A, when the scum 21 has completely flowed into the scum box 28, the tip of the scum gap 24 is moved from the float 34 toward the scum box 24. At this time, the contact surface of the guide roller 48 has moved from the bottom surface of the guide 26 to the inclined surface 27b, and as the height of the inclined surface 27b in contact with the guide roller 48 increases, the float 34 floats by its own buoyancy.

As shown in FIG. 5B, when the guide 26 moves out of contact with the guide roller 48, the float 34 floats again on the surface of the supernatant water and the scum box 2
8 is stopped. For this reason, there is no possibility that the supernatant water is discharged more than necessary. In this embodiment, the proximity switch detects that the inclined surface 27b has separated from the guide roller 48, and outputs a control signal. As a result, the electromagnetic valve 32 operates to close the flow path to the outside again. Therefore, even when the supernatant water flows into the scum box 28, there is no possibility that the supernatant water is wastefully discharged to the outside. The scum removal operation can be performed by repeating these series of steps.

As described above, in the present embodiment, the scum box 28 is stopped using the float 34, so that the float 34 floats on the water surface by its own buoyancy even if the level of the supernatant water fluctuates. Because it can hold water,
The scum removal operation can be performed irrespective of water level fluctuation. In addition, a series of scum removal operations can be continuously performed by moving the scum scraping unit, and the work load can be reduced. In the present embodiment, the float 34 and the scum box 28 are connected by the connecting rod 36 and the box 38.
Is not limited to this as long as it is configured to be connected to the scum box 28 so as to be able to move up and down. Further, in the present embodiment, since the guides 26 are provided on the outer peripheral side and the inner peripheral side, it is possible to reduce the load due to the rotational torque during the scum removing operation. Further, in the present embodiment, the case where the scum scraping portion turns is described. However, the moving mode is not limited to this, and can be applied to, for example, a case where the scum scraping portion moves straight. Further, by making at least a region of the scum removing device 20 held in water made of plastic, corrosion of the scum removing device 20 due to rust can be prevented, and the weight of the scum removing device 20 itself can be reduced.

Next, a second embodiment of the present invention will be described.
FIG. 6 is a plan view of the scum removing device 60 in the present embodiment. FIG. 7 shows a scum removing device 6 according to the present embodiment.
FIG. 2 is a cross-sectional view of FIG. The same members as those in the previous embodiment are denoted by the same reference numerals, and description thereof will be omitted. Further, members whose description is omitted are formed in the same manner as in the previous embodiment.

The scum box 28 is formed in a half egg shape in cross section, so that the scum 21 flowing into the scum box 28 is easily collected at the bottom. The upper surface of the scum box 28 is formed slightly higher than the supernatant water so that the supernatant water does not flow into the scum box 28. On the scum scraping portion side of the scum box 28, a basin body 6 which is an elevating body having a float 30 on the lower surface is provided.
2 is provided. The scum box 28 of the basin 62
On the side, a striker 64 which is an arc-shaped elevating control member protruding above the supernatant water surface is provided. The striker 64
As shown in FIG. 6, the scum skimmer arm 22 is provided in such a manner as to open in an inverted figure-eight shape so as to cross the movement path on both ends of the scum skimmer arm 22, and the striker 64 contacts the scum skimmer arm 22 and pushes down. As a result, the basin 62 can be lowered.

On the scum scraping portion side of the basin body 62, a latch 68 as an elevating control member is provided. On the other hand, a stopper 66 is provided at the bottom of the basin 62,
The basin body 62 is held in the supernatant water by the stopper 66 being locked by the latch 68. The latch 68
Has an inverted cross section as shown in FIG.
It is rotatably supported by a support shaft 70 having a spring mechanism as an elastic mechanism at a bending portion. Thus, the locked state with the stopper 66 can be released by rotating about the support shaft 70, and the elastic mechanism can be returned to the locked position. Also,
The latch 68 has an upper portion protruding from the supernatant water surface.
(2) It crosses the turning path at both ends. Thus, when the scum skimmer arm 22 is turned, the latch 6
8 to rotate the latch 68 so that the latch 68
And the stopper 66 can be released from the locked state.

The scum removing device 60 constructed as described above
Works as follows. As shown in FIG. 7A, the basin body 62 for discharging the scum 21 is held in the supernatant water with the stopper 66 locked by the latch 68. The scum skimmer arm 22 moves toward the scum box 28 while the scum 21 is being scraped by the scum skimmer 24. Then, the scum skimmer arm 2 that turns and moves
When the latch 2 comes in contact with the latch 68 and pushes down the latch 68, the locked state between the latch 68 and the stopper 66 is released.

Then, as shown in FIG. 7B, the basin body 62 from which the stopper 66 is disengaged from the latch 68 floats on the supernatant water surface by the buoyancy of the float 34. At this time, the scum 21 raked by the scum skimmer arm 24 and the supernatant water are held on the upper surface of the basin body 62. Therefore, the scum skimmer arm 24 is guided by the raised basin body 62, and the scum 21 and the required amount of clear water flow into the scum box 28.

Thereafter, as shown in FIG. 7C, the scum skimmer arm 22 comes into contact with the striker 64 connected to the basin body 62 and pushes down the striker 64 so that the basin body 62 that has floated is re-purified in the supernatant water. Push back. At this time, the latch 68 has returned to the locked position by the above-described elastic mechanism. When the basin 62 descends, the stopper 66 is moved to the locking position of the latch 68 and is locked again, and the basin 62 is held in the water. Therefore, even when the scum skimmer arm 22 is separated from the striker 64, the basin body 62 is held in the water without floating. By repeating these series of operations, the scum removing operation can be performed continuously.

As described above, in the present embodiment, the scum 21 is moved by the basin body 62 to the scum box 2.
Since the scum 21 flows into the scum 21, even if the scum gap 24 is deteriorated, it does not affect the collection performance of the scum 21. Further, since the scum box 28 contains not only the scum 21 but also the supernatant water, the scum 21 does not remain in the scum box 28. Further, since only the scum 21 and the supernatant water on the basin 62 are discharged, unnecessary supernatant water is not discharged more than necessary. In addition, the concentration of the discharged scum does not decrease. Furthermore, in the present embodiment, since a rotating scum box does not require a necessary bearing or the like, it can be manufactured at lower cost.

The latch 68 is preferably installed so that the fulcrum 70 is located above the water surface in order to prevent the fulcrum 70 from being fixed by solids such as sludge in the supernatant water. Further, in order to reduce the rotational torque of the scum skimmer arm 22, it is desirable that a plurality of latches 68 and strikers 64 be provided instead of one. Also,
It is preferable that the scum skimmer 24 in contact with the basin body 62 be made of a material having a low elasticity so as not to prevent the basin body 22 from rising.

[0036]

As described above, in the present invention, water does not flow into the scum receiving portion more than necessary for removing scum, so that water can be effectively used.
In addition, since a series of operations for removing scum can be automatically performed by moving the scum scraping portion, unnecessary processing such as opening and closing of a manual valve as in the related art is unnecessary, and the work load can be reduced. . Further, even when the water level fluctuates, the float moves up and down while being connected to the scum receiving section to prevent the water from flowing into the scum receiving section, so that the scum removing operation can be stably performed regardless of the fluctuation of the water level. .

[Brief description of the drawings]

FIG. 1 is a sectional view of a scum removing device according to a first embodiment.

FIG. 2 is a plan view of the scum removing device of the first embodiment.

FIG. 3 is a diagram illustrating an operation of the scum removing device according to the first embodiment.

FIG. 4 is a view showing the operation of the scum removing device of the first embodiment.

FIG. 5 is a view showing the operation of the scum removing device of the first embodiment.

FIG. 6 is a plan view of a scum removing device according to a second embodiment.

FIG. 7 is a view showing the operation of the scum removing device according to the second embodiment.

FIG. 8 is a sectional view showing a sludge scraper.

[Explanation of symbols]

1 ... sedimentation tank, 2 ... sludge scraper, 3 ... feed well, 4 ... sewage supply pipe, 5 ... spindle, 6 ...
Rake arm, 7 rake, 8 mud collecting pit, 20 scum removal device, 21 scum, 2
2 ... Scum gap arm, 24 ... Scum gap, 26 ... Guide, 27 ... Slope, 28 ...
Scum box, 30 ... Scum discharge pipe, 32 ...
Solenoid valve, 34 Float, 36 Connecting rod, 38
..., Box, 40, auxiliary roller, 42, stopper, 44, stopper, 46, projecting rod,
48 guide roller, 60 scum removal device,
62 ...... basin body, 64 ...... striker, 66 ......
Stopper, 68 Latch, 70 Support shaft

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shinji Aso 1-1-1 Uchikanda, Chiyoda-ku, Tokyo F-term in Hitachi Plant Construction Co., Ltd. 4D051 AA04 AB03 CA05 CA10 DC02 DC11 DC20 DD23 DD25

Claims (4)

[Claims] 1. A scum scraping portion moving along a water surface and a gutter-shaped scum receiving portion, wherein the gutter-shaped scum receiving portion is located on the upstream side in the moving direction of the scum scraping portion. At least partly submerged, and a float is connected to the upstream side wall so as to be able to move up and down so as to stop water at the scum receiving portion. The float is a projecting portion that traverses the movement path of the scum scraping portion. When the scum scraping portion comes into contact with the projecting portion and passes therethrough, the float can be moved up and down integrally with the float, and the projecting portion moves the float at least at the descent limit when passing through the scum scraping portion. A scum removing device formed at a height that can be moved downward. 2. A scum receiving portion having a scum scraping portion moving along a water surface, a scum receiving portion formed in a gutter shape and having both side walls arranged higher than the water surface, and a vertically movable basin body having a float on a lower surface. Is connected to the upstream side wall of the scum receiving portion, and a latch that locks the basin body at the upstream side and holds the basin body underwater is rotatably provided, and the upper portion of the latch moves the scum scraping portion. An elastic mechanism for projecting so as to cross the path and rotating when the scum scraping portion passes to release the locking of the basin body and returning the latch to the locking position; A striker is provided on the side, and the striker traverses the movement path of the scum scraping unit at the upper part, and the striker can move the basin body to the locking position at least at the lowermost limit when passing through the scum scraping unit. Formed on And, scum removing apparatus, characterized in that. 3. The scum removing device according to claim 2, wherein a plurality of said latches and said strikers are provided at both ends of a scum scraping portion. 4. The scum removing device according to claim 1, wherein at least a region of the scum removing device held in water is formed of plastic.