JP2016007604A - Scum flow control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scum flow control apparatus which improves water quality by suppressing building up of scum beyond the bottom water region of a scum removal device and rejection from an overflow weir.SOLUTION: In a scum flow control apparatus, a scum removal device for swallowing scum floating on the water surface is arranged in the downstream of the current plate in a sedimentation basin which is provided with a side wall, front and back end walls and a pit-provided bottom wall and a current plate allowing sewage to flow in on the side of the front end wall, and on the upstream side with respect to the scum removal device in the sedimentation basin, an air blowout pipe which stops the downstream flow of scum flowing under the water surface in the downstream direction is provided.

Description

  The present invention relates to a scum flow control device.

The sedimentation basin has a rectangular shape with left and right side walls and front and rear end walls, and has a three-dimensional structure with a bottom wall with a pit, and the front end wall corresponding to the upper side of the pit is the upstream side. On the upper side, an inflow trough for introducing sewage introduced from the outside of the settling basin is provided, and sewage is discharged through a rectifying hole in a porous rectifying wall provided transversely at the outlet to the pond of the inflow trough. The flow is slowed while being rectified, and sent to the sedimentation basin as it is slowly flowed to the downstream side as it is, so that sedimentation is facilitated and eliminated on the upstream side as much as possible. On the other hand, since the scum rises separately from the settling on the upstream side, the scum is automatically removed by a scum removing device provided near the water surface in the downstream direction.
One example of such a scum removing device is disclosed in Patent Document 1.

  JP2006-21181

The scum removing device disclosed in Patent Document 1 is mainly composed of a trough shaped trough mounted between the left and right side walls and a weir that is on the front side that is upstream of the trough and that can float and sink with the water surface as a boundary. The scum removing device is arranged in front of an end wall (intermediate walkway) that is integrally installed on the downstream side.
FIG. 7 shows another example equipped with such a scum removing device. In the figure, 1 is a settling pond, the left is the upstream side and the right is the downstream side, 2 is one of the left and right side walls forming the settling pond 1, and 3 is a walkway that is integrally stretched between the front and rear end walls. There is a case where the walkway is not provided, and 4 is a water surface in the sedimentation basin 1 and 5 is a scum removing device. The scum removing device 5 includes a trough 7, front and rear weirs 8 and 8, and a water level adjusting gate 10 with a float 9. The weir 8 is poured as indicated by an arrow, and the weirs 8 and 8 are alternately or synchronously depending on the weight. The water tank 11 that is moved up and down is arranged in the front and rear, and a regular weir motion is performed so that scum from the water surface is swallowed and removed through the trough.
In such a sedimentation basin, the scum that floats on the water surface 4 can be swallowed and removed by the scum removing device 5, but the scum that flows without floating on the water surface 4 rather than the slightly lower surface is shown by the arrow X in the figure. In this way, a phenomenon has been observed in which the scum is removed from the lower part of the scum removing device 5 and then scum S as it passes over the lower side of the corridor 3 and gradually accumulates in the area.
When the scum S accumulates in this manner, it is sucked into the overflow weir (with V notch) 13 on the downstream side as indicated by the arrow Y and is removed together with water, and as a result, the resulting discharge There was a problem that water was mixed with scum S and the purpose of water purification was not achieved.

  The present invention is intended to solve the above-described problem, and provides a scum flow control device which improves water quality so that scum accumulates beyond the bottom water area of the scum removal device and is not excluded by an overflow weir. For the purpose.

  In order to achieve the above object, the invention described in claim 1 comprises a side wall, front and rear end walls, and a bottom wall with a pit, and a rectifying plate that allows sewage to flow into the front end wall. A scum removing device for swallowing scum floating on the water surface downstream of the rectifying plate in the settling basin is installed on the upstream side of the scum removing device in the settling pond. The air jet pipe which prevents the flow of the scum flowing in the direction in the downstream direction is provided.

  As described above, the invention described in claim 1 is characterized in that the rectification in the sedimentation basin is provided with a rectifying plate that includes side walls, front and rear end walls, and a bottom wall with pits, and that allows sewage to flow into the front end wall side. The scum removing device for swallowing the scum floating on the water surface downstream of the plate is installed on the upstream side of the scum removing device in the sedimentation basin. Since it is equipped with an air jet pipe that prevents the flow in the downstream direction, the scum penetrates the bottom water area of the scum removing device and accumulates on the water surface at the back of the device so that it is not excluded by the overflow weir. Thus, it is possible to provide a scum flow control device that improves the water quality as a whole.

  The cross-sectional view corresponding to the II line of FIG. 2 which shows one Embodiment of this invention.   II-II sectional view taken on the line of FIG.   The cross-sectional view corresponding to the III-III line of FIG. 4 which shows other embodiment.   IV-IV sectional view taken on the line of FIG.   The VV line cross-sectional view of FIG. 6 which shows other embodiment.   VI-VI sectional view taken on the line of FIG.   The longitudinal side view which shows an example of a prior art.

An embodiment of the present invention will be described below with reference to FIGS.
In these figures, 20 is a sedimentation basin, the left of the figure is the upstream side and the right is the downstream side, 21 is the left and right side walls forming the sedimentation basin 20, 22 is the upstream end wall of the front and rear end walls, Reference numeral 23 denotes an inflow trough, reference numeral 25 denotes a current plate, and reference numeral 26 denotes a walkway integrally formed between the front and rear end walls. The walkway is integrally formed on the upstream side of the overflow weir 27. The walkway 26 is not provided. There may be no.

  Reference numeral 28 denotes a water surface in the sedimentation basin 20, and reference numeral 30 denotes a scum removing device. The scum removing device 30 includes a trough 31, front and rear weirs 32, 32, and a water level adjusting gate 34 with a float 33. The weir 32 is poured as indicated by an arrow, and the weirs 32, 32 are pushed down or drained by its weight. The scum from the water surface is swallowed and removed through the trough 31 by arranging a water supply / drainage type water tank 35 that is returned to the water surface by the front and rear and performing a regular up and down motion.

  On the other hand, on the bottom wall 37 side in the sedimentation basin 20, a sludge scraping device 40 which is an advancing / retracting drive type with a lifting scraper is provided. The sludge scraping device 40 is fixedly laid on the bottom wall 37 so as to pass through the center in the width direction, and is supported by the front and rear brackets 42 so that the tip portion extends on the pit 41. 43, a traveling carriage 46 provided on the left and right frame portions of the rail 43 via a traveling wheel 45 capable of moving forward and backward, and a pair of front and rear sludge scrapers 48 capable of moving up and down via a hinge 47, Is provided.

  The front and rear of the sludge scraper 48 can be linked simultaneously by the link 50, and the traveling carriage 45 is provided with the same front and rear two units connected via a pipe-like interlocking member 51. By inserting a rod that moves forward and backward, the sludge scraper 48 of the front and rear shown in the figure moves in conjunction with each other.

  53 is a transmission member which is an endless annular material such as a wire rope or a link chain, and is driven coaxially with the drive wheel 55 via wheels 54 provided at a plurality of points such as the front, rear and other driving on the pond shown in the figure. The traveling carriage 46 can be driven forward and backward by the power source, so that the traveling carriage 46 advances to the left side in FIGS. 1 and 2 and moves backward to the right side.

  Then, as shown by the broken line in FIG. 2, the traveling carriage 46 moves forward with the sludge scraper 48 in a vertical scraping state and approaches the pit 41, so that the transmission member 53 is pushed to the right, whereby the sludge scraper 48. Is switched to the ascending posture without scraping, and then it is swung back in the backward direction in the ascending posture. The sludge scraped off into the pit 41 is sucked into the next treatment tank (concentration tank or aeration tank) after being sucked by the sludge extraction pipe 57 whose lower end opens into the bottom of the pit 41 and acts on suction. It is supposed to be carried as.

In such a sedimentation basin, a horizontal lateral air jet pipe 60 serving as a scum flow blocking means is provided at a position about 3 m from the water surface 28 on the upstream side of the upstream end of the trough 31 of the scum removing device 30 and about 3 m. Thus, the compressed air from the aeration tank or the like can be ejected from the lower two rows of ejection ports. This blown air climbs vertically as an underwater air curtain 61 and becomes a slightly upwardly rising flow as shown in FIG. 2 due to a slow flow in the downstream direction of the sewage, and further toward the scum removing device 30 on the water surface 28. It is designed to be a flowing air current.
Therefore, as shown in FIG. 2, even if the scum is about to flow from the upstream side toward the bottom flow area of the scum removing device 30 as shown in FIG. As a result, it reaches the front area of the overflow weir 27 and is not excluded together with the clear water by the weir 27.

As shown in the upper right column of FIG. 2, a swash plate 62 that receives the air curtain 61 and guides it obliquely and guides it in the direction of the scum removing device 30 is provided above the air jet pipe 60 in water. The scum that is provided and floats may be guided in the direction of the scum removing device 30.
Further, as shown in FIG. 2, a scum flow may be prevented by hanging a shielding plate 63 that extends over the entire pond width on the bottom surface of the trough 31. This shielding plate 63 is a plate material that hangs down from the front end of the trough 31 so that no scum accumulates in the front area thereof, or as shown in the upper right column of FIG. By configuring as above, it is possible to prevent scum from accumulating in the front area of the shielding plate 63. The shield plate 63 may be a perforated plate, a net-like material, or an interdigital plate other than a planar plate such as metal or resin, and only the scum is captured and water can be passed therethrough.

As shown in FIG. 2, a floating layered region 64 is often formed in a region several meters above the bottom wall 37 in the sedimentation basin 20 as a result of the specific gravity being smaller than that of the sediment. In view of this, the air jet pipe 65 is formed in a straight tube shape, and a plurality of front and rear or single pipes are fixedly arranged to promote the rise of the scum. On the other hand, the air jet pipe 65 flows from the current plate 25 and flows further downstream. It is also possible to increase the amount of sedimentation on the upstream side by preventing sludges that can settle and prevent sedimentation downward. As a result, sedimentation and levitation are effectively promoted at an earlier stage closer to the upstream. As a result, the separation promotion effect is improved and the water quality can be improved.
In addition, as shown in FIG. 1, you may make the air ejection pipe 66 into a donut shape, and you may install it so that it may become the downward height of the floating layered area | region 64, or the height in an area | region. An elliptical or oval air ejection pipe 66 ′ as shown in the lower column of FIG. 1 may be used.

3 and 4 show another embodiment. In this embodiment, the air jet pipe 68 is curved and fixedly installed at a height position of 1.5 to 2 m, which substantially corresponds to the upper position just behind the pit 41. In the lower part of the floating layered area 64, the floating thing is made to act on either floating or sinking so as to correspond to the inner area so that the separation promoting effect can be obtained.
In addition, as shown by the phantom line in FIG. 3, the air ejection pipe 68 may be arranged such that another curved pipe 68 that is similarly curved is symmetric in the front-rear direction to further promote the sedimentation.

  5 and 6 show another embodiment. The same embodiment can also be provided so as to move forward and backward with the air ejection pipe 70 on the sludge scraping device 40 whose stroke St advances and retreats as shown in FIG. As an example, the pipe 70 can be installed on the link 50 or the carriage 46 so that air is guided from above by a flexible tube. Since the air from the pipe 70 acts while moving forward and backward under the floating layered region 64, the separation effect can be effectively obtained. The pipe 70 may be provided with another air ejection pipe 70 at a downstream side position in addition to the illustrated position so that air acts on a wider area of the floating layer region 64.

  DESCRIPTION OF SYMBOLS 20 ... Sedimentation basin 21 ... Side wall 22 ... End wall 23 ... Inflow trough 25 ... Rectification plate 27 ... Overflow weir 30 ... Scum removal device 31 ... Trough 40 ... Sludge scraping device 60, 65, 66, 66 ', 68, 70 … Air jet pipe.

Claims (1)

  In order to swallow scum floating on the water surface downstream of the rectifying plate in the settling basin provided with side walls, front and rear end walls and a bottom wall with pits, and provided with a rectifying plate that allows sewage to flow into the front end wall side. The scum removing device is provided with an air jet pipe for blocking the downstream flow of the scum that flows downstream under the water surface downstream of the scum removing device in the settling basin. A scum flow control device.

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