JPH0420554Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> This invention is a sedimentation tank that performs weight separation, which is used to treat wastewater such as sewage, human waste, and industrial wastewater, and to separate reaction products in various chemical industries. The present invention relates to a scum removal device for scraping and removing floating substances (hereinafter referred to as scum) floating on the liquid surface in a condensation tank, flotation separation tank, etc.

<Prior art> As such a scum removal device, the one shown in FIG.
(see publication).

That is, the retention part 1 of the tank is provided with a skimmer arm 2 that rotates around the central axis around the liquid surface WL in the retention part 1.
Scum skimmer 3 that collects the scum that floats to the top
is supported by a pin 4 so as to be freely rotatable in the direction of movement. Below this scum skimmer 3, a scum box 5 for deriving scum is disposed with its upper end 5a protruding from the liquid surface WL, and on the side of this upper end 5a facing the rotating scum skimmer 3, a scum box 5 (not shown) is disposed. A gate 7 connected to the driving device via a rod 6 is rotatably attached by a pin 8. And a rotational position detector (limit switch) attached to the clearance arm 2.
9 detects that the scum skimmer 3 is close to the scum box 5, activates the drive device, sinks the gate 7 below the liquid surface WL, and transfers the surface tank liquid containing scum collected by the scum skimmer 3 from the gate 7 to the scum box 5. I am trying to guide people inward and remove scum.

Further, in order to prevent the upper end 5a of the scum box 5, the rod 6, etc. from interfering with the scum skimmer 3, a guide bar 10 is provided on the liquid surface above the scum box 5, and the guide bar 10 lifts the scum skimmer 3 from the liquid surface WL. I'm trying to evacuate.

<Problems to be solved by the invention> However, in such a conventional scum removal device, the guide bar 10 is not connected to the scum box 5.
Since it is exposed from the liquid surface above, the scum skimmer 3 can be placed at a position away from the scum box 5.
As a result, the scum scraped up by the scum skimmer 3 is dispersed by rain, wind, etc. in the vicinity of the scum box 5, reducing the efficiency of introducing scum into the scum box 5, and reducing the efficiency of scum removal. The problem arises that efficiency is reduced.

The present invention has been made in view of the problems of the conventional technology, and an object of the present invention is to provide a scum removal device that can improve the scum removal efficiency.

<Means for solving the problem> For this reason, in the present invention, the scum rake is attached to a scum rake that moves on the liquid surface in the tank and moves on the liquid surface to scrape up the scum floating on the surface. The scum skimmer and the upper end of the scum inlet side wall are submerged below the liquid surface, and the upper end of the wall facing the scum inlet side wall protrudes above the liquid surface, and the scum scraped up by the scum skimmer is removed from the upper end of the scum inlet side wall. Scumbox guided inside,
a scum discharge pipe that communicates between the inside of the scum box and the outside of the tank; a normally closed automatic on-off valve installed in the scum discharge pipe; a first guide part which is disposed in a recessed state below and guides the scum collected by the scum skimmer to the scum inlet side wall; The lower end of the scum skimmer is immersed under the scum box, the other end is fixed to or close to the upper end of the wall facing the scum inlet side wall of the scum box, and protrudes above the liquid surface, and the lower end of the scum skimmer moves over the upper end opening of the scum box. a second guide portion that slides toward and guides near the upper end of the wall facing the entrance wall;
a third guide portion extending from above the liquid surface in the moving direction of the scum skimmer at the upper end of the wall opposite to the scum inlet side wall of the scum box and immersed below the liquid surface to slide and guide the lower end of the scum skimmer; a moving position detector that is activated by the movement of the scum box, and opening the automatic opening/closing valve when it is detected that the scum skimmer approaches a predetermined distance in front of the scum box based on a signal from the moving position detector. I tried to let them do it.

<Operation> Since the above configuration is adopted, when it is detected that the scum skimmer has approached the scum box by a predetermined distance, the automatic opening/closing valve opens, and the inside of the scum box is communicated with the outside of the tank.

The lower end of the scum skimmer moves on the first guide part while being immersed below the liquid surface, guides the scum toward the upper end opening of the scum box, and forcibly and efficiently scrapes the scum. In this case, the first guide part extends substantially horizontally toward the scum box inlet side and is submerged below the liquid surface, so that the first guide part is placed in a state where the scum skimmer is submerged below the liquid surface on the scum box inlet side. By moving on the guide part, it is possible to prevent the scum from settling from the liquid surface due to the movement of the scum skimmer and passing through the bottom of the scum box, and to ensure that the scum on the liquid surface is collected and introduced into the scum box. I can do it.

Furthermore, the lower end of the scum gap is guided in sliding contact with the second guide section, thereby introducing the scum into the scum box. In this case, the second guide part has one end close to or fixed to the upper end of the inlet side wall of the scum box and immersed below the liquid surface, and the other end fixed to or close to the upper end of the wall facing the inlet side of the scum box. and protrudes above the liquid surface,
The scum skimmer can smoothly move the upper end of the scum box from the wall on the entrance side of the scum box to the opposing wall, thereby preventing the scum skimmer from colliding with the opposing wall or the second guide portion and being damaged, and Since the water surface is not disturbed and the second guide part does not cover the opening, the inflow of scum from the scum box is ensured.

Further, the lower end portion of the scum skimmer is slidably guided by the third guide portion and re-enters below the liquid surface. In this case, the third guide part extends from above the liquid surface at the upper end of the wall facing the inlet side of the scum box in the direction of movement of the scum skimmer and is submerged below the liquid surface, so that the scum skimmer that has passed over the scum box moves to the liquid level. When re-entering below, the scum skimmer quietly enters below the liquid surface, preventing disturbance of the liquid surface and generation of liquid splashes, and thus preventing disturbance of the scum on the liquid surface.

On the other hand, the scum in the scum box is discharged to the outside of the tank via a scum discharge pipe and an automatic on-off valve.

As described above, the actions of the first to third guide parts described above and the actions of the opening/closing operation of the automatic opening/closing valve that operates based on the signal from the movement position detector are skillfully linked to produce a synergistic action. The flow of clear water into the scum box is prevented as much as possible, and floating scum is scraped and removed without flowing back into the settling tank and collected in the scum box, thereby greatly improving scum removal efficiency.

<Example> An example of the present invention will be described below based on FIGS. 1 to 9.

As shown in FIG. 3, the circular sedimentation tank main body 20 as a tank of the present invention has an annular inspection walkway 2 at its upper edge.
1 is formed, and a linear inspection walkway 22 is formed that extends from a part of the inspection walkway 21 toward the center of the circular sedimentation basin body 20, and this inspection walkway 22 includes:
A staircase 23 is attached. Further, an annular clear water passage 31 is formed at the upper edge of the circular sedimentation basin body 20, and an overflow tank 35 formed at the peripheral edge of the circular sedimentation basin body 20 is formed in this clear water passage 31. The clear water flowing out from the clear water passage 31 is discharged. A wear plate 33 is attached to the inner circumferential wall of the clear water passage 31 and is in contact with the retention section 32 . An annular scum butt full plate 3 is arranged at a predetermined distance on the inner circumferential side of the wear plate 33.
4 is installed. This scum baffle plate 34 partitions the clear water passage 31 and the surface of the retention part 32 so that scum floating on the liquid surface in the retention part 32 does not flow into the clear water passage 31.

As shown in FIG. 2, a rotating shaft 26 of a brake 25 rotated at low speed by a motor 24 is installed at the center of the retention section 32. A plurality of sludge scraping blades 27 are attached to the rake 25 at a predetermined angle in the direction of rotation thereof. Further, this rake 25 is supported by a plurality of rods 29 having turnbuckles 28 interposed in the middle portion of the rotating shaft 26. A sludge return pipe 30 for discharging settled sludge to the outside is attached to the bottom of the circular settling tank body 20. The sludge is then transferred from the sludge return pipe 30 into the return sludge tank 42.

A cylindrical well tube 36 surrounds the upper end of the rotating shaft 26, and a turnbuckle 37 is provided in the middle.
The circular sedimentation tank body 2 is
It is supported on the periphery of 0. A sludge inflow pipe 39 for introducing liquid mixed with sludge into the retention section 32 is installed in the well pipe 36 .

A scum rake 40 extending in the radial direction of the retention section 32 is located near the upper end of the rotating shaft 26.
It is fixed so that it rotates with the This scum rake 40 is connected to the liquid surface WL in the sedimentation tank body 20.
above the liquid surface WL,
Along the longitudinal direction, the lower end 41a is the liquid surface.
A scum skimmer 41 that sinks during WL is attached. A clearance rotating part 41b is formed near the outer circumference of the retention part 32 of the scum skimmer 41, in which the upper end of the scum skimmer 41 is rotatably supported by a pin hinge.

Below this scum clearance 41, a scum box 50 for deriving scum is installed from the scum baffle plate 3.
4 is partially divided and arranged to extend toward the center of the retention section 32.

Here, as shown in FIGS. 1 and 4 to 6, the scum box 50 has a box-like shape with an open upper end, and is cantilevered by a flange 50a on the inner wall of the circular sedimentation basin body 20. It is configured as follows. The shape and dimensions of the scum box 50 are set so that the clearance rotating portion 41b can enter between the upper end portion of the center-side side surface 51 of the retention portion 32 and the scum baffle plate 34.

A long hole 50b is formed through the flange portion 50a, and the mounting position of the scum box 50 can be slightly adjusted in the circumferential direction of the circular sedimentation basin body 20 by the long hole 50b. A side surface 51 on the center side of the retention section 32 of the scum box 50 is an inclined surface from its upper end toward the bottom 50c, and an inclined plate 52 is fixed to the inner wall of the retention section 32. In this way, the scum flowing into the scum box 50 flows smoothly toward the bottom 50c. The bottom portion 50c has a tubular portion 50 that opens into the scum box 50.
d is formed, and a strainer 53 made of wire bent into a hemispherical shape is attached to cover the opening. A flange portion 50e is formed on the end surface of the tubular portion 50d, and a scum discharge pipe 54 is connected to this flange portion 50e. As shown in FIG. 8, this scum discharge pipe 54 is equipped with a limit switch 61 as a moving position detector of the present invention, which will be described later.
An air automatic ball valve 55 is interposed as an automatic opening/closing valve of the present invention that opens and closes in response to a detection signal. Note that a tank (not shown) is provided downstream of the automatic air ball valve 55, and the tank is connected to an activated sludge treatment tank via a pump.

Furthermore, as shown in FIG. 1, in the scum box 50, the upper end of the wall 50f on the side facing the rotating scum 41, that is, the inlet side of the scum box 50, is always submerged below the liquid surface WL, and the upper end of the wall 50f on the inlet side
The upper end of the wall 50h facing the wall 50h is arranged so as to protrude from above the liquid surface WL.

At the upper end of the wall 50f on the entrance side of the scum box 50, there is a guide plate 56 as a first guide portion of the present invention, which extends outward in a substantially horizontal direction and is submerged below the liquid surface. Fixedly mounted.

That is, a plurality of holes 50g are formed in the upper end of the wall 50f in the horizontal direction, and nuts 57 are welded to the outer surfaces of the holes 50g. A dam plate 58 in which a plurality of vertically long long holes 58a are formed corresponding to the holes 50g as shown in FIG.
It is attached with a plurality of bolts 64 so that the vertical position can be freely adjusted. In this manner, by adjusting the vertical position of the dam plate 58 relative to the scum box 50, the amount of surface liquid and scum flowing into the scum box 50 is adjusted.

Also, one end is brought close to the upper end of the wall 50f on the inlet side of the scum box 50 and immersed below the liquid surface,
The other end is fixed to the upper end of the wall 50h facing the inlet side wall 50f of the scum box 50 and protrudes above the liquid surface, and the lower end of the scum skimmer 41 is connected to the opposite wall 50f of the scum box 50 from the inlet side wall 50f. A guide strip 59 serving as a second guide portion of the present invention slidingly guides toward the upper end of the wall 50h.
A is provided.

Furthermore, the scum skimmer 41 extends from above the liquid surface at the upper end of the wall 50h of the scum box 50 in the moving direction of the scum skimmer 41 and is immersed below the liquid surface.
A guide strip 59b is provided as a third guide portion of the present invention that slides and guides the lower end of the guide member. In this embodiment, three guide strips 59a and 59b are provided, and the ends of each guide strip 59b are connected to each other by a connecting plate 60. The guide strips 59a, 59b are arranged at the lower end 41 of the scum gap 41 passing near the upper part of the scum box 50.
a is slidably guided to prevent the scum skimmer 41 from colliding with the upper end 50h of the scum box 50 by the guide strip 59a, while preventing the scum skimmer 41 from disturbing the liquid surface and entering the liquid by the guide strip 59b. are doing.

As shown in FIG. 9, at the upper edge of the circular sedimentation basin body 20, a limit switch 61 as a moving position detector of the present invention is mounted by a suspension member 65, and its movable detection portion 61a comes into contact with the upper edge of the scum skimmer 41. suspended in a safe condition. Thereby, the moving position of the scum skimmer 41 is detected, and the automatic air ball valve 55 is opened and closed in response to this detection signal. As for this opening/closing operation method, the automatic air ball valve 55 is opened at the same time that the scum skimmer 41 contacts the movable detection part 61a, a predetermined time is measured by a timer (not shown), and the automatic air ball valve 55 is closed after the predetermined time has elapsed. That's what I do. That is, the automatic air ball valve 55 is opened only when the scum skimmer 41 is near the front side of the scum box 50, thereby suppressing unnecessary outflow of liquid when the scum discharge process is not performed.

Note that any suitable method can be selected as the method for opening and closing the automatic air ball valve 55 as long as it can prevent unnecessary outflow of liquid. for example,
The timer causes the scum skimmer 41 to move to the movable detection unit 6.
It is also possible to measure a predetermined time after contacting 1a, and open the air automatic ball valve 55 after this predetermined time. Furthermore, two limit switches 61 similar to those described above may be installed at different positions on the circumference, and the automatic air ball valve 55 may be opened and closed in response to signals from the respective limit switches 61.

Next, the operation of this embodiment will be explained.

Surface liquid flows into the scum box 50 from its upper end 50f, and most of the scum box 50 is submerged below the surface of the liquid at all times. Here, when the scum skimmer 41 is a considerable distance from the scum box 50, the automatic ball valve 55 is maintained in the closed state, so that no liquid can flow out.

And Scum Skima 41 is Scum Box 5
When the limit switch 61 detects that the automatic air ball valve 5 has approached a predetermined distance before the
A valve opening signal is issued at 5, and the liquid in the scum box 50 starts flowing out. When the scum skimmer 41 slides on the guide plate 56 and the guide strip 59a, the scum that has been scraped up before is pushed to the upper end opening of the scum box 50 and is discharged from the retention section 32 to the outside along with the surface liquid flow. . Then, when the scum skimmer 41 leaves the scum box 50, the air automatic ball valve 55 is closed.

According to this configuration, since the lower end portion 41a of the scum skimmer 41 is slidably guided by the guide plate 56 and the guide strip 59a in a state where it is substantially submerged below the liquid surface WL, it is substantially constantly immersed below the liquid surface WL. The scum can be reliably collected by the scum skimmer 41 and introduced into the scum box 50. That is, scum can be efficiently discharged without being affected by rain, wind, etc.

Since the guide plate 56 is formed into a plate shape, the scum collected by the scum skimmer 41 can be prevented from escaping to the bottom side of the retention section 32, and the scum introduction efficiency can be improved. On the other hand, since the guide strip 59a is arranged without covering the upper end opening, it does not impede the flow of scum into the scum box 50 from the upper end opening, and the scum introduction efficiency can be improved.

In addition, an air automatic ball valve 55 that opens and closes depending on the rotational position of the scum skimmer 41 is installed in the scum discharge pipe 54 communicating with the scum box 50.
Even if a part of the scum box 50 is submerged below the liquid surface, the air automatic ball valve 55 can be opened only when necessary for scum discharge, and unnecessary liquid outflow can be prevented.

In particular, according to this configuration, the guide plate 56 (first
The guide portion 56 extends substantially horizontally on the inlet side of the scum box 50 and is submerged below the liquid surface.
By moving the scum skimmer 41, the scum can be prevented from settling from the liquid surface and passing through the bottom of the scum box 50, and the scum on the liquid surface can be surely collected and introduced into the scum box 50. I can do it.

Further, the guide strip 59a (second guide portion) has one end proximate to or fixed to the upper end of the wall 50f on the inlet side of the scum box 50 and immersed below the liquid surface, and the other end facing the inlet side of the scum box 50. Since the scum skimmer is fixed to or close to the upper end of the wall 50h and protrudes above the liquid surface, the scum skimmer smoothly moves the upper end of the scum box 50 from the wall 50f of the scum box 50 to the wall 50h, and the scum skimmer smoothly moves the upper end of the scum box 50 from the wall 50f of the scum box 50 to the wall 50h. Damage due to collision with the scum box 59a can be prevented, and the flow of scum into the scum box 50 can be ensured without disturbing the water surface.

Further, the guide strip 59b (third guide portion) is connected to a wall 50h opposite to the entrance side of the scum box 50.
Since the scum skimmer 41 extends from above the liquid surface at the upper end in the moving direction and is immersed below the liquid surface, when the scum skimmer 41 that has passed over the scum box 50 re-enters below the liquid surface, the scum skimmer 41 is immersed in the liquid surface.
enters quietly, preventing disturbance of the liquid surface and generation of liquid splashes, and preventing disturbance of scum on the liquid surface.

As mentioned above, the above-mentioned guide plate 56 and guide strip 59
a. Effect of guide strip 59b and limit switch 6
The opening/closing operation of the automatic air ball valve 55 (automatic opening/closing valve), which operates based on the signal from the automatic air ball valve 55 (moving position detector) 1 (moving position detector), is skillfully linked to produce a synergistic effect, and clear water flows into the scum box 50. to prevent as much as possible,
The floating scum is scraped up and removed without flowing back into the sedimentation tank, and is efficiently collected in the scum box 50, so that the scum removal efficiency is greatly improved.

In addition, since only the upper end 50f of the scum box 50 is submerged below the liquid surface WL and the other three upper ends are exposed above the liquid surface, dispersion of scum can be suppressed by each upper end exposed above the liquid surface. , the scum discharge efficiency from inside the scum box 50 can be improved.

Further, in the above embodiment, one end of the guide strip 59a is placed close to the upper end of the wall 50f on the entrance side of the scum box 50, and the other end is fixed to the upper end of the wall 50h facing the entrance side of the scum box 50. However, it can take various forms as shown in FIG.

That is, in the embodiment shown in FIG.
Connect one end of 9a to the wall 5 on the entrance side of the scum box 50.
0f is fixed to the upper end, and the other end is attached to the scum box 50.
It is arranged close to the upper end of the wall 50h facing the entrance side of the wall 50h. Further, in the embodiment shown in FIG. B, both ends of the guide strip 59a are brought close to the upper ends of the walls 50f and 50h of the scum box 50, and the guide strip 59a is provided with a stay 70 protruding from the inner wall of the scum box 50. In the embodiment shown in Figure C, a guide strip 59a similar to that shown in Figure B is supported by a stay 71 projecting from the inner bottom of the scum box 50.
Furthermore, the embodiment shown in FIG.
One end of the wall 50f of the scum box 50 is located slightly lower than the upper end, and the other end is located slightly higher than the upper end of the wall 50h.

Note that the scum guide surface of the guide strip 59a may be curved.

Further, the guide strip 59a may be provided at the side end or outer side of the scum box 50 as long as the lower end of the scum skimmer 41 that moves through the upper opening strip of the scum box 50 is guided in sliding contact with the guide strip 59a. I do not care.

Further, in the above embodiment, the scum removal device of the present invention was applied to a circular sedimentation tank, but it can also be applied to a rectangular sedimentation tank equipped with a scum skimmer 41 that moves in a straight direction on the liquid surface. I can do it.
Furthermore, it can be applied not only to sedimentation tanks but also to flotation separation tanks.

<Effects of the invention> As explained above, according to the invention, the scum box extends outward from the scum inlet side wall in a substantially horizontal direction and is submerged below the liquid surface. a first guide part which is disposed and guides the scum collected by the scum skimmer toward the scum inlet side wall; ,
The other end is fixed to or close to the upper end of the wall facing the inlet side of the scum box and protrudes above the liquid surface, and the lower end of the scum gap is connected from the scum inlet side wall to the upper end of the wall facing the scum inlet side wall. a second guide portion slidingly guided toward the vicinity; a second guide portion extending in the scum skimmer movement direction from above the liquid surface at the upper end portion of the wall facing the inlet side of the scum box and immersed below the liquid surface; A third guide part is installed in the scum discharge pipe when it is detected that the scum skimmer has approached a predetermined distance in front of the scum box based on a signal from a moving position detector that is activated by the movement of the scum skimmer. Since the normally closed automatic on-off valve is opened, it has the following advantages.

The action of the first guide part prevents scum from settling from the liquid surface and passing through the bottom of the scum box due to the movement of the scum skimmer, and ensures that scum on the liquid surface is collected and introduced into the scum box. can.

Due to the action of the second guide section, the scum skimmer smoothly moves the upper end of the scum box from the wall on the entrance side of the scum box to the wall opposite thereto, and is prevented from colliding with the opposite wall or the second guide section of the scum skimmer. Damage can be prevented, the water surface is not disturbed, and since the upper opening of the scum box is not covered by the second guide part, the flow of scum into the scum box is ensured.

Due to the action of the third guide part, when the scum skimmer that has passed over the scum box re-enters below the liquid surface, the scum skimmer quietly enters into the liquid surface,
Disturbance of the liquid surface and generation of liquid splashes are prevented, and disturbance of scum on the liquid surface can be prevented.

The actions of the first to third guide parts mentioned above and the opening/closing operation of the automatic opening/closing valve that operates based on the signal from the moving position detector are skillfully linked to produce a synergistic action, and clear water is supplied to the scum box. The floating scum is prevented from flowing back into the sedimentation tank.
Since it is scraped and removed and collected in the scum box, it is not affected by conditions such as rain and wind.
Scum removal efficiency is greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part of an embodiment of the present invention (the fourth
Figure 2 is a cross-sectional view of a circular settling tank equipped with the scum removal device shown above, Figure 3 is a plan view of the same as above, Figure 4 is a plan view of the scum box shown above, and Figure 5 is a cross-sectional view of the same as above. is a front view of the same as above, and Fig. 6 is the same as No. 4 of the same.
BB sectional view in the figure, Figure 7 is a front view of the dam plate in the above, Figure 8 is a diagram of the connection between the scum box and scum discharge pipe in the same, Figure 9 is a diagram of the installation of the limit switch in the same, FIG. 10 is a sectional view of another embodiment of the present invention, and FIG. 11 is a diagram showing a conventional scum removal device. 20... Circular sedimentation tank body, 32... Retention part, 4
1...Scum Skima, 50...Scum Box,
50f, 50h...wall, 54...scum discharge pipe,
55... Air automatic ball valve, 56... Guide plate, 5
9a, 59b...guide strip, 61...limit switch.

Claims (1)

[Scope of utility model registration request] a scum skimmer attached to a scum rake that moves on the liquid surface in the tank and moves on the liquid surface to scrape up scum floating on the surface; The upper end of the wall opposite to the scum inlet side wall protrudes above the liquid surface, and the scum scraped by the scum skimmer is guided inside from the upper end of the scum inlet side wall, and the inside of the scum box communicates with the outside of the tank. a scum discharge pipe; a normally closed automatic on-off valve disposed in the scum discharge pipe; a normally closed automatic opening/closing valve extending outward from the scum inlet side wall of the scum box in a substantially horizontal direction and submerged below the liquid surface; a first guide part that guides scum collected by the scum skimmer to the scum inlet side wall; one end of the scum box is immersed below the liquid surface, close to or fixed to the upper end of the scum inlet side wall;
The other end is fixed to or close to the upper end of the wall opposite to the scum inlet side wall of the scum box and protrudes above the liquid surface, and the lower end of the scum gap that moves above the upper end opening of the scum box faces the scum inlet wall. a second guide portion slidingly guided toward the vicinity of the upper end of the wall to which the scum is to be removed; and a second guide portion extending in the direction of movement of the scum skimmer from above the liquid surface at the upper end of the wall facing the scum inlet side wall of the scum box and submerged below the liquid surface. and a third guide portion that slides and guides the lower end of the scum skimmer, and a moving position detector that operates according to the movement of the scum skimmer. A scum removing device characterized in that the automatic opening/closing valve is opened when detecting that the scum has come within a predetermined distance.