JP3968990B2 - Scum remover - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a scum removing device that removes scum floating on a water surface, and more particularly, to a scum removing device provided in a sludge scraper used for processing sewage, industrial waste water, or the like.
[0002]
[Prior art]
Conventionally, sewage treatment facilities for treating various types of wastewater such as public sewers, hot spring effluents, factory effluents (hereinafter simply referred to as “sewage”) have a sedimentation tank for separating sewage into supernatant water and sludge. . This separation process is performed by allowing the sewage to flow into the settling tank and causing the sludge to settle to the bottom, so that the sewage on the water surface side becomes the supernatant water. However, scum sometimes floats on the surface of the supernatant water, and this scum becomes an obstacle to the treatment of the supernatant water. Therefore, a scum removing device for removing the scum from the supernatant water is provided in the sedimentation tank.
[0003]
The scum removing device includes a scum clearance arm that moves on the water surface while scraping off the scum, and a scum box that collects and discharges the scum to the outside. One conventional scum removing device is one that keeps the tip of the scum box higher than the surface of the water to prevent the inflow of supernatant water and flows the scum when the scum gap crosses the scum box. As another scum removing device, there is a scum box provided near the water surface in water and a manual opening / closing valve provided in the 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 that has flowed into the scum box to the outside, and when the flow is finished, the scum can be removed by closing the flow path again.
[0004]
[Problems to be solved by the invention]
However, the conventional scum removing device has the following problems.
In the scum removing device that holds 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 does not have much fluidity, the scum remains in the scum box and clogs the discharge path, which may hinder the scum removal operation. In addition, when the scum box is held on the water surface, the scum separated by the scum gap is separated from the water when it flows into the scum box. For this reason, there has been a problem that when the scum clearance is deteriorated, the performance of removing the scum is greatly reduced.
[0005]
The scum removing device provided with an open / close valve while holding the scum box in water requires a worker to open and close the manual valve every time the scum removal work is performed, and the work load is large. Moreover, since there are individual differences in the timing of opening and closing the valve and the opening time, the supernatant water more than necessary for scum removal is discharged. Since the supernatant water has a high quality from which sludge has been removed, it has been desired to remove the scum while minimizing the amount of the supernatant water to be discharged.
[0006]
In any scum removing device, since the effect of removing scum is affected by fluctuations in the water level, a scum removing device that can stably remove scum irrespective of fluctuations in the water level has been desired. .
[0007]
An object of the present invention is to provide a scum removing device that can prevent the supernatant water from being discharged more than necessary and can reliably discharge the scum.
Another object of the present invention is to provide a scum removing device that can stably remove scum regardless of fluctuations in water level.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the scum removing device according to the present invention has a scum scraping portion that moves along the water surface, and an scum receiving portion that has an opening and an external discharge path and is formed in a bowl shape. The scum receiving portion formed in a bowl shape is formed by submerging at least a part of the side wall on the upstream side in the movement direction of the scum scraping portion, and the scum scraping portion is close to the scum receiving portion by a certain distance. A first detecting means for detecting; and a second detecting means for detecting that the scum scraping portion has passed through the scum receiving portion, and is provided in an external scum discharge path connected to the scum receiving portion. and the solenoid valve, said by the detection signal from the first detecting means and the second detecting means and the opening and closing controllable, is projected on the water the flexible member is provided on the upstream side of the scum receiving portion, the scum take- That the movement path of the submitted portions was crossable has a structure characterized by.
[0009]
Since it comprised as mentioned above, a scum scraping part moves, scraping the scum which floated on the water surface. When the first detection means detects that the scum scraping portion has approached the scum receiving portion by a certain distance, a detection signal is oscillated to open the electromagnetic valve provided in the scum discharge path. As a result, the scum discharge path is opened to the outside, and the scum that has flowed into the scum receiving portion is discharged to the outside. While the scum scraping part moves while flowing the scum into the scum receiving part, the open state of the scum discharge path is maintained and the scum discharge operation is continued. When the second proximity switch detects that the scum scraping part has passed the scum receiving part, the detection signal is oscillated to close the electromagnetic valve provided in the scum discharge path. Thereby, after the scum scraping portion passes, the water flowing into the scum receiving portion is held without being discharged to the outside. Since it did in this way, the water more than needed for scum removal is not discharged | emitted outside to a scum receiving part. 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 prior art is unnecessary, and the work load can be reduced. Further, even when the water level fluctuates, it is possible to prevent water from flowing into the scum receiving portion, so that the scum removing operation can be performed stably regardless of the fluctuation of the water level. The box-shaped scum receiving part is preferably a box body, but is not limited to this, and a tubular one may be used. In the above configuration, if the downstream side of the scum receiving part is formed higher than the water surface, the scum scraped by the scum receiving part is blocked by the downstream side of the scum receiving part and does not flow downstream from the scum receiving part. For this reason, the scum scraped by the scum scraping part can surely flow into the scum receiving part and be discharged to the outside, and maximum scum removal can be performed by one scum removing operation. .
[0010]
In the present invention, in addition to the above-described configuration, a flexible member is provided on the upstream side of the scum receiving portion and protrudes from the water surface so that the movement path of the scum scraping portion can be traversed . As the flexible member, a plate-shaped member or a box-shaped member can be preferably used. If comprised as mentioned above, water will not flow in into a scum receiving part from the upstream of a scum receiving part by a flexible member. Further, as described above, the downstream side of the scum receiving portion is formed higher than the water surface. For this reason, water does not flow into the scum receiving portion except during the scum inflow operation by the scum scraping portion, and the amount of water necessary for scum removal can be further reduced.
[0011]
In the above configuration, a float may be provided on the bottom surface of the flexible member. If comprised as mentioned above, even if it is a case where a water level fluctuates, since a flexible member protrudes on the water surface by the buoyancy of a float, the water stop of a scum receiving part can be hold | maintained.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
A scum removing device according to an embodiment of the present invention will be described in detail with reference to the drawings. In this embodiment, a case where the scum removing device is attached to a sludge scraper will be described. The scum removal device is preferably installed because sludge removal and scum removal can be performed simultaneously. However, the scum removal device is not limited to this, and the scum removal device itself is independent of the sludge scraper. May be provided.
[0014]
FIG. 1 is a cross-sectional view of a sludge scraper 2 provided in the settling tank 1. A feed well 3 through which sewage flows is provided above the center of the sedimentation 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 into the feed well 3 from the sewage supply pipe 4. Sewage flows into the feed well 3 and is separated into supernatant water and sludge by sedimentation. That is, sludge accumulates at the bottom of the sedimentation tank 1, and the sewage surface side becomes supernatant water. Sludge accumulated on the bottom of the sedimentation tank 1 is scraped off by a rake 7 attached to the rake arm 6. The base end portion of the rake arm 6 is connected to the bottom side of the main shaft 5 provided so as to extend vertically in the center of the sedimentation tank 1. The main shaft 5 is directly connected to a drive motor (not shown) and rotates at a constant rotational speed. As a result, the rake arm 6 rotates to scrape off sludge by the rake 7 and drop it into the mud collecting pit 8 at the bottom of the settling tank 1. It is. In addition, an overflow trough 9 is provided at the upper part of the wall of the sedimentation tank 1, and the supernatant water is caused to flow into the outside from the overflow trough 9.
[0015]
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 in the present embodiment.
[0016]
The scum scraping portion that scrapes the scum 21 floating on the surface of the supernatant water includes 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, and swivels above the supernatant water surface as the main shaft 5 rotates. A rubber scum skimmer 24 is attached to the lower surface of the scum skimmer arm 22 and swivels together with the scum skimmer arm 22 to scrape the scum 21.
[0017]
On the other hand, a scum box 28 as a scum receiving portion is provided on the supernatant water surface side facing the scum skimmer arm 22. The scum box 28 is provided between the feed well 3 and the settling tank 1 wall surface, and is formed in a substantially triangular shape with a deep wall surface side of the settling tank 1. A scum discharge pipe 30 connected to the outside is connected to the bottom surface on the settling tank 1 side so that 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 by a control signal.
[0018]
The electromagnetic valve 32 is electrically connected to the first proximity switch 34a as the first detection means and the second proximity switch 34b as the second detection means via the control means 36. As shown in FIGS. 1 and 2, the first proximity switch 34 a and the second proximity switch 34 b are provided on the upper side of the overflow weir 9 at the same height as the tip surface of the scum skimmer arm 22. When the pivoting scum skimmer arm 22 reaches a position facing the first proximity switch 34a and the second proximity switch 34b, the first proximity switch 34a and the second proximity switch 34b oscillate detection signals and transmit them to the control means 36, respectively. To do. In response to the detection signal, the control means 36 opens the electromagnetic valve 32 in the case of the detection signal from the first proximity switch 34a, and closes the electromagnetic valve 32 in the case of the detection signal from the second proximity switch 34b. The control signal is oscillated.
[0019]
A scum inflow start position and a scum inflow end position in the present embodiment will be described. As shown in FIG. 3A, the upstream side 28a of the scum box 28 in the moving direction of the scum skimmer arm (hereinafter referred to as “scum box upstream side 28a”) is formed lower than the supernatant water surface and guides the scum skimmer arm 24. It is tapered so that it can be made. On the other hand, the downstream side 28b of the scum box 28 in the moving direction of the scum skimmer arm (hereinafter referred to as "scum box downstream side 28b") is formed so as to protrude from the supernatant water surface to prevent the inflow of the supernatant water. The first proximity switch 34a is provided at the same position as the tip of the scum box upstream side 28a in a top view. The second proximity switch 34b is provided at the same position as the tip of the scum box downstream side 28b in a top view. In the present embodiment, the first proximity switch 34a detects that the scum skimmer arm 22 has approached the scum box 28 by a certain distance, and the second proximity switch 34b detects that the scum skimmer arm 22 has passed the scum box 28. To make it happen. The arrangement positions of the first proximity switch 34a and the second proximity switch 34b can be changed as necessary.
[0020]
The operation of the scum removing device configured as described above will be described. 3 and 4 are explanatory views of the operation of the scum removing device 20, respectively.
As shown in FIG. 3A, the scum skimmer 24 attached to the scum skimmer arm 22 swirls the scum 21 and turns on the supernatant water surface to approach the scum box 40. At this time, the solenoid valve 32 of the scum discharge pipe 30 is closed, and the supernatant water in the scum box 28 does not flow out to the outside.
[0021]
As shown in FIG. 3B, it is detected that the scum skimmer arm 22 has reached the position facing the first proximity switch 34a, and the detection signal A is oscillated. Upon receiving the detection signal A, the control means 36 oscillates the control signal A ′ to the electromagnetic valve 32 and opens the electromagnetic valve 32. Thereby, the flow path of the scum discharge pipe 30 is opened, and the removal operation of the scum 21 is started.
[0022]
As shown in FIG. 4A, the scum clearance 24 crosses the upper surface of the scum box 28 while allowing the scum 21 to flow into the scum box 28. During this time, the flow path of the scum discharge pipe 30 remains open, and the scum 21 can be removed continuously. As described above, the scum box downstream side 28b is formed higher than the supernatant water surface. For this reason, the scum 21 scraped by the scum skimmer 24 is blocked by the scum box downstream side 28b and does not flow downstream from the scum box downstream side 28b. Therefore, the scum 21 scraped by the scum skimmer 24 can surely flow into the scum box 28 and be discharged to the outside, and maximum scum removal can be performed by one scum removal operation.
[0023]
As shown in FIG. 4B, when the inflow of the scum 21 into the scum box 28 is finished and the tip surface of the scum skimmer arm 22 reaches a position facing the second proximity switch 34b, the second proximity switch 34b is A control signal B is sent to the control means 36. The control means 36 receives the detection signal B, oscillates the control signal B ′ to the electromagnetic valve 32 and closes the electromagnetic valve 32. The scum removal operation can be performed by repeating these series of steps.
[0024]
As described above, in the present embodiment, after the scum inflow into the scum box 28 is finished, the supernatant water is not discharged from the scum box 28 to the outside. Removal work can be performed. Moreover, a series of scum removal work can be continuously performed by the turning movement of the scum scraping portion, and the work load can be reduced. In the embodiment, the case in which the scum scraping part moves while turning has been described. However, the form in which the scum scraping part moves is not limited to this, and can be applied to, for example, a straight movement. Further, by making at least the region of the scum removing device 20 held in water plastic, corrosion due to rust of the scum removing device 20 can be prevented, and the scum removing device 20 itself can be reduced in weight.
[0025]
A scum removing device 60 in the second embodiment of the present invention will be described. FIG. 5 is a cross-sectional view of a main part of the scum removing device 60 in the present embodiment. In addition, the same code | symbol is attached | subjected to the member similar to 1st embodiment, and the description is abbreviate | omitted. Further, other constituent members whose descriptions are omitted are the same as those in the above embodiment.
[0026]
The scum box 28 in this embodiment is provided with a flexible plate 62 that is a flexible member on the scum box upstream side 28a. The flexible plate 62 has a tip protruding on the supernatant water surface and is provided so as to cross the moving path of the scum skimmer 24. The scum box downstream side 28b is formed higher than the supernatant water surface. Thus, the supernatant water does not flow into the scum box 28 except when crossing the scum skimmer 22 and the supernatant water can be stopped more reliably. A float 64 is provided at the tip of the back surface of the flexible plate 62, and the tip of the flexible plate 62 is held on the supernatant water surface by the buoyancy of the float 64. Therefore, even if the water level of the supernatant water slightly varies, the inflow of the supernatant water into the scum box 28 is more reliably prevented, and the amount of the discharged supernatant water can be further reduced.
In the embodiment, the pair of the first proximity switch 34a and the second proximity switch 34b are used as the first detection means and the second detection means, but the present invention is not limited to this as long as the position of the scum scraping means can be detected. Absent. In the embodiment, the scum box 28 is used as the scum receiving body. However, the scum box 28 is not limited to the box shape and may be a tubular one. Further, in the embodiment, the control means 36 connected to the proximity switch 34 is provided and the electromagnetic valve 32 is opened and closed by the control signal. Opening and closing may be performed.
[0027]
【The invention's effect】
As described above, in the present invention, water more than necessary for scum removal does not flow into the scum receiving portion. In addition, since a series of scum removal operations can be performed automatically by the movement of the scum scraping portion, unnecessary processing such as opening and closing of a manual valve as in the prior art is unnecessary, and the work load can be reduced. . Even when the water level fluctuates, the inflow of water into the scum receiving portion is prevented by opening and closing the solenoid valve, so that the scum removing operation can be performed stably regardless of the fluctuation of the water level. In addition, the effect that water does not flow into the scum receiving portion from the upstream side of the scum receiving portion can be exhibited by the flexible member.
[Brief description of the drawings]
FIG. 1 is a cross-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 showing an operation of the scum removing device of the first embodiment.
FIG. 4 is a diagram showing an operation of the scum removing device of the first embodiment.
FIG. 5 is a cross-sectional view showing a scum removing device of a second embodiment.
[Explanation of symbols]
1 ......... Settling tank, 2 ......... Sludge scraper, 3 ......... Feedwell,
4 ......... Sewage supply pipe, 5 ...... Spindle, 6 ...... Rake arm,
7 ……… Rake, 8 ……… Mudging pit, 9 ……… Overflow trough,
20 ......... Scum removal device, 21 ......... Scum,
22 ......... Scum clearance arm, 24 ......... Scum clearance,
28 ......... Scum box, 30 ......... Scum discharge pipe, 32 ......... Solenoid valve,
34a ......... first proximity switch, 34b ......... second proximity switch,
36... Control means 60... Scum removing device 62 62 Flexible plate
64 ... Float

Claims (2)

A scum raking part that moves along the water surface,
A scum receiving part having an opening and an external discharge path, formed in a bowl shape,
The scum receiving part formed in the bowl 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 part,
First detecting means for detecting that the scum scraping portion is close to the scum receiving portion by a certain distance;
A second detection means for detecting that the scum scraping portion has passed through the scum receiving portion;
The electromagnetic valve provided in the external scum discharge path connected to the scum receiving portion can be controlled to open and close by a detection signal from the first detection means and the second detection means,
A scum removing device characterized in that a flexible member is provided on the upstream side of the scum receiving part and protrudes from the water surface so that the movement path of the scum scraping part can be traversed . The scum removing device according to claim 1 , wherein a float is provided on a bottom surface of the flexible member.

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