JP2013154348A - Scum skimmer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scum skimmer which can lift a large scum mass to an edge of a scum intake and can make the mass smoothly flow into a pipe.SOLUTION: A controlling section 71 carries out driving controlling of a scum discharge mechanism 10 according to a set operational mode and further drives an automatic opening/closing valve Vat the same time when a part of an opening 14 of a pipe 11 sinks in water so that compressed air is ejected for a predetermined time from an air ejecting pipe 21 along a wall surface on a side where the scum flows. Afterward, an automatic opening/closing valve Vis driven so that compressed water is ejected upward from a compressed water ejecting pipe 22 till the scum begins to flow in the opening 14. Thereby, even massive scum with thickness (diameter) of >10 cm can be smoothly guided into the pipe 11, and water discharge amount accompanying scum discharge can be decreased to 1/20 to 1/30.

Description

  The present invention relates to a scum removing device for removing scum generated in a water treatment facility such as a sedimentation basin of a sewage treatment plant, and in particular, to improve the mobility of the scum so that the scum can be discharged efficiently. It relates to what was made.

  Conventionally, scum generated on the water surface of a settling basin is configured to be removed by a scum removing device provided on the downstream side of the settling basin. As such a scum removing device, for example, as shown in FIG. 4 of JP-A-9-19682, the axial direction is parallel to the water surface and along the axial direction (longitudinal direction). It has a long and narrow opening and is configured to be a pipe that can rotate around its axis, and when the scum is discharged, the pipe is rotated so that a part of the opening is positioned below the water surface. A pipe-type scum discharge mechanism is known that takes in and discharges the liquid from the opening into the pipe. The scum removing device is composed of a trough having an inflow weir that moves up and down as shown in FIG. 1 of the above-mentioned JP-A-9-19682, JP-A-2000-202436, etc. It is also known that sometimes the upper end of the inflow weir of the trough is positioned below the water surface, and the scum is taken into the trough through the inflow weir and discharged.

  However, in the conventional scum removing device, the scum near the opening and the inflow weir flows into the pipe and the trough immediately after the opening of the pipe and the inflow weir of the trough are located below the water surface. The scum is slightly accompanied by the water and flows into the pipe or trough, and it takes a long time to remove the entire scum. As a result, a large amount of water is required to remove the scum.

  In other words, the scum generated and floating on the water surface has one large flat plate shape, and the scum has a certain thickness, hardness and adhesion (adhesive force). Before the operation, the one side of the flat scum is attached to the pipe or trough, and the other side is attached to the tank wall. At the same time, a part of the scum near the pipe and the inflow weir (trough) flows into the pipe through the opening and the inflow weir. After that, only water easily flows into the pipe and the trough. There was a disadvantage that it could not be removed. When a large amount of water flows into the pipes and troughs, there is a drawback that the processing load increases in the subsequent scum processing device.

  Further, in the conventional scum removing device, for example, as disclosed in Japanese Patent Application Laid-Open No. 9-276860, etc., the pipe opening is moved below the surface of the water or the trough inflow weir is moved below the surface of the water. In accordance with the movement, in order to apply a moving force to the scum in the pipe or trough side direction, pressure water having an inclination angle is sprayed on the upper surface of the scum. However, in the conventional scum discharge method that uses only the flow of water to move the scum, only the water flows into the pipes and troughs, and the inflowed water is returned to the settling basin and the like. Since the water is pumped up again to the water treatment facility, there is a disadvantage that power is wasted and power costs are increased.

  Therefore, the present applicant has previously provided a scum removing device for solving the above-mentioned drawbacks in Japanese Patent No. 3934551. In the scum removing device (hereinafter referred to as “patent device”) according to this patent, the scum in the tank can smoothly flow into the scum inlet, and the scum can be moved smoothly. Can be discharged efficiently.

  That is, the above-mentioned patent device generates the scum by moving it to the scum discharge mechanism side on the water flow and immersing a part of the scum inlet of the scum discharge mechanism in the water when discharging the scum. A scum removing device for removing scum, which is provided on a wall surface side of a wall surface forming a scum inlet of the scum discharge mechanism and on which the scum flows, and is made of, for example, compressed air along the wall surface It is characterized by providing ejection means for ejecting fluid (air) upward.

  Furthermore, this patent apparatus also ejects air toward the tank wall side in the vicinity of the tank wall upstream of the position where the scum discharge mechanism is provided, and the air is directed upward along the tank wall. It is characterized by providing the jetting means to be made. In addition, this patent device is installed upstream of the installation position of the scum discharge mechanism, and at the time of scum discharge, water is injected obliquely downward on the scum discharge mechanism side, and the water injection pressure A water injection means for moving the scum to the scum discharge mechanism side is provided.

  In the patent apparatus having the above-described configuration, the scum can smoothly flow into the scum inlet, and the entire scum can be moved smoothly, so that the scum can be discharged quickly. For this reason, this patent apparatus can reduce the outflow amount of water accompanying discharge of scum to 1/20 to 1/30 compared with the conventional scum removing apparatus. As described above, the amount of water accompanying the discharged scum is extremely small as compared with the conventional device, so that the equipment cost of the post-treatment device such as the pressure levitation device can be reduced, and the pump It has the feature that it consumes less power and can contribute to energy saving.

  An actual verification test conducted at a certain sewage treatment plant using this patent apparatus will be described. The scum removing device equipped with the pipe-type scum discharge mechanism used in this demonstration test has a pipe opening length of 5 m. Then, when a scum having a thickness of 7 to 10 cm is generated up to 5 m from the pipe upstream from the pipe, the scum is completely discharged when a part of the opening of the pipe is submerged for 5 to 7 minutes. I was able to. Further, in a demonstration test at another sewage treatment plant, it has been confirmed that scum can be completely removed by submerging a part of the opening of the pipe for 5 minutes every 24 hours and 5 minutes every 36 hours. Therefore, since this patent device only needs to submerge a part of the opening of the pipe for about 10 minutes once a week, it is given the nickname “Weekly-kun” and issued on February 28, 2006. "Monthly sewer extra issue" (P.71) etc.

  However, in the above-mentioned patent device, when there is a large scum lump whose diameter exceeds 10 cm on the scum inlet side, the scum is scummed by the force of air even if a fluid made of air is ejected upward. There was a risk that the scum could not be smoothly flowed into the pipe, and the scum discharge could be hindered.

  Such a large scum lump has a property that it is likely to be generated in heavy rain, particularly in the case of a combined type in which sewage and rainwater are collected in a single pipe and flowed to a sewage treatment plant. In addition, such a large mass of scum has sludge containing oil and fat contained in the sewage adhered to the inner surface of the sewage pipe, where it has grown and formed into oil balls, or the organic matter in the sludge is in an anaerobic state. These are generated by being kept in the water, and these are separated from the inner surface of the sewage pipe by a water flow or water pressure during heavy rain, and become a lump and flow into the sewage treatment plant.

  In the above-mentioned patent apparatus, since there is no large scum lump that has a diameter (thickness) exceeding 10 cm on the scum inlet side during normal times other than during heavy rain, the scum is attached to the edge of the scum inlet only by air force. And the scum can smoothly flow into the pipe. However, after the heavy rain, as described above, there is a case where a large scum lump is present, and there is a possibility that the discharge of the scum may be hindered.

  Further, in the conventional scum removing device including the above-mentioned patent device, a part of the scum passes under the pipe, that is, a part of the scum goes around under the scum discharge mechanism and enters the treated water, There was a possibility of deteriorating the quality of treated water.

  Therefore, the present invention has been made to solve the above-described drawbacks, and the purpose of the present invention is, for example, when there is a large scum lump whose diameter exceeds 10 cm on the scum inlet side, for example, during heavy rain Another object of the present invention is to provide a scum removing device that allows a large scum lump to be lifted up to the edge of the scum intake port to smoothly flow into the pipe in accordance with an operation mode such as normal time other than during heavy rain.

  In order to achieve the above object, the scum removing device according to the present invention moves the generated scum to the scum discharge mechanism side in a water flow, and at the time of discharging the scum, part of the scum inlet of the scum discharge mechanism is submerged. In the scum removing device for removing the generated scum, the ejection means provided on the wall surface side on which the scum flows out of the wall surfaces forming the scum inlet of the scum discharge mechanism, and the scum removal Means for setting the operation mode of the apparatus, and a control unit for driving and controlling the scum discharge mechanism and the ejection means according to the operation mode, the control unit from when a part of the scum intake is submerged in water Until the scum starts to flow into the scum intake, pressure water or air is jetted upward along the wall surface on the side where the scum flows. It is characterized by driving the serial ejection means.

  In addition, the present invention moves the generated scum to the scum discharge mechanism side in a water flow, and at the time of discharging the scum, immerses a part of the scum inlet of the scum discharge mechanism in water, In the scum removing device to be removed, the pressure water ejecting means provided on the wall surface side through which the scum flows out of the wall surfaces forming the scum inlet of the scum discharging mechanism, and the pressure water ejecting means are disposed side by side. A compressed air jetting means; a means for setting an operation mode of the scum removing device; and a controller for driving and controlling the scum discharge mechanism, the pressure water jetting means, and the compressed air jetting means according to the operation mode, The controller controls the pressure so that compressed air is ejected for a predetermined time along the wall surface on the side where the scum flows while a part of the scum intake is submerged in water. After driving the air injection means, scum is characterized in that until the start flowing into the inlet thereof scum, pressure water upward to drive the pressure water jetting unit as ejected.

  The present invention further includes air blowing means for blowing air upward in the water near the tank wall upstream of the position where the scum discharge mechanism is provided and along the tank wall. It is characterized by that.

  Furthermore, the present invention is characterized in that the air ejection of the air ejection means is always performed.

  Further, the present invention is installed upstream of the installation position of the scum discharge mechanism, and at the time of scum discharge, water is injected obliquely downward on the scum discharge mechanism side, and the scum is injected by the injection pressure of the water. It is characterized in that water injection means for moving to the scum discharge mechanism side is provided.

  The present invention is characterized in that the scum discharge mechanism is a pipe-type scum discharge mechanism or a trough-type scum discharge mechanism.

  Furthermore, the present invention is characterized in that the compressed air is ejected from the compressed air ejecting means through small holes provided at predetermined intervals along the longitudinal direction of the lower portion of the air supply pipe.

  Further, according to the present invention, the compressed air is ejected from the compressed air ejecting means by providing a small hole at a predetermined interval along the longitudinal direction of the upper portion of the air supply pipe, and a predetermined interval above the small hole. It is characterized by the fact that a cover is provided while maintaining.

  The present invention is characterized in that the ejection of water from the water ejecting means is performed by pumping up the middle layer of water in the tank and is formed from a flat and wide nozzle.

  According to the present invention, jetting means is provided on a wall surface side through which scum flows out of the wall surfaces forming the scum inlet of the scum discharge mechanism, and the jetting means is driven in accordance with a preset operation mode of the scum removing device. From the time when a part of the scum intake is submerged in the water until the scum starts to flow into the scum intake, the pressure water or air is directed upward along the wall surface on which the scum flows. Even if a large scum lump with a diameter exceeding 10 cm exists in the scum, the large scum lump is lifted up to the edge of the scum inlet by the water flow or air flow to be ejected. It is possible to smoothly flow into the scum inlet, and the scum can be discharged quickly.

  Further, the present invention provides a pressure water ejecting means on the wall surface side through which the scum flows out of the wall surfaces forming the scum intake port of the scum discharge mechanism, and the compressed air ejecting means is provided adjacent to the pressure water ejecting means. The scum discharge mechanism is driven and controlled in accordance with a preset operation mode, and at the same time a part of the scum inlet is submerged in water, and at the same time, compressed air is ejected along the wall surface on which the scum flows. After the compressed air ejecting means is driven, the pressure water ejecting means is driven so that the pressure water is ejected upward until the scum starts to flow into the scum intake port. The scum is peeled off from the wall surface, and the peeled scum is smoothly introduced by the pressure water ejected to the scum inlet.

  And this invention provides the air ejection means which injects air toward the upper direction along the tank wall in the water near the tank wall upstream from the position where the scum discharge mechanism is provided. Therefore, the scum is not attached to the tank wall by the air, and the scum can be efficiently moved to the scum discharge mechanism side.

  Further, in the present invention, since the air is always ejected by the air ejecting means, the scum is not attached to the tank wall by the air, and the scum can be moved more efficiently and quickly to the scum discharge mechanism side. .

  Further, the present invention is installed upstream of the installation position of the scum discharge mechanism, and at the time of scum discharge, water is injected obliquely downward on the scum discharge mechanism side, and the scum is injected by the injection pressure of the water. Since the water injection means for moving to the scum discharge mechanism side is provided, the movement of the scum can be further promoted.

  In the present invention, since the scum discharge mechanism is a pipe-type scum discharge mechanism or a trough-type scum discharge mechanism, the scum discharge mechanism can be easily implemented and can be easily applied to an existing scum discharge mechanism. Can be attached.

  Further, according to the present invention, since the ejection of the air from the ejection means is performed from the small holes provided at predetermined intervals along the longitudinal direction of the lower portion of the air supply pipe, the clogging of the small holes is effectively prevented. Can be prevented.

According to the present invention, a small hole is provided at a predetermined interval along the longitudinal direction of the upper portion of the air supply pipe, and a small hole is provided above the small hole to cover the discharge of air from the discharge means. Therefore, clogging of the small holes can be effectively prevented.

  Further, according to the present invention, the water jetting of the water jetting means is performed by pumping up the middle layer of water in the tank, and is made from a flat and wide nozzle, so that water can be jetted out easily. In addition, the pressure water can be sprayed over a wide area of the scum, and the scum can be moved efficiently.

It is a partial top view of the state which removed the upper cover of the sedimentation basin to which the scum removal apparatus which concerns on one embodiment of this invention was applied. It is the sectional view on the AA line of FIG. It is sectional drawing of a pipe in the state where a part of opening part of a pipe is located on the water surface. FIG. 4 is a top view of the pipe shown in FIG. 3. It is line sectional drawing of the ejection means when a small hole is provided maintaining the predetermined space | interval along the longitudinal direction of the lower part of an air supply pipe | tube. It is line sectional drawing when a small hole is provided at predetermined intervals along the longitudinal direction of the upper part of an air supply pipe. It is a perspective view of the nozzle which injects pressure water. It is a block diagram of the controller of the scum removal apparatus which concerns on one embodiment of this invention. It is sectional drawing of a pipe when the part of opening part of a pipe is located in the lower surface of a water, and when the big scum lump whose diameter exceeds 10 cm does not exist in a scum. It is sectional drawing of a pipe when the big scum lump whose diameter exceeds 10 cm exists in the state in which a part of opening part of the pipe is located below the water surface. It is a time chart which shows the control operation | movement of the scum discharge in the scum removal apparatus which concerns on one embodiment of this invention. It is explanatory drawing when a trough scum discharge mechanism is employ | adopted as the scum removal apparatus which concerns on one embodiment of this invention. It is explanatory drawing when employ | adopting the trough scum discharge mechanism of another type in the scum removal apparatus which concerns on one embodiment of this invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a plan view of a part of a settling basin 1 of a sewage treatment plant to which a scum removing device according to an embodiment is applied, and FIG. 2 is a cross-sectional view taken along the line AA in FIG. 2 from the top cover 2 is shown. The sedimentation basin 1 may be of any nature as long as it is a water tank in which scum is generated at the initial or final settlement of a sewage treatment plant, or through these water conduits.

  1 and 2, a water conduit (not shown) for inflowing raw water is provided on the right side, and an overflow trough 3 for taking out treated water is provided on the downstream side thereof. Therefore, in the illustrated example, water is configured to flow from the left side toward the right side as indicated by an arrow a. And this sedimentation basin 1 is comprised so that the waterway width | variety of the downstream (right side in the example of illustration) of the flow of water may become narrower than an upstream. Moreover, in FIG.1 and FIG.2, in order to avoid the complexity of drawing, the scum produced | generated on the upper surface of the sedimentation basin 1 is abbreviate | omitted. In addition, this scum is shown by the code | symbol of "S, S '" in FIG.9 and FIG.10 mentioned later.

  In the figure, 10 is a pipe-type scum discharge mechanism provided on the downstream side of the sedimentation basin 1, and 20 is an ejection means according to the present invention, 30 is an air ejection means according to the present invention, and 40 is according to the present invention. This is a water jetting means. First, the pipe-type scum discharge mechanism 10, the jetting means 20, and the air jetting means 30 will be described with reference to FIGS.

  The pipe-type scum discharge mechanism 10 is provided so that a pipe 11 having a predetermined thickness provided so that its axis substantially coincides with the water surface crosses the sedimentation basin 1. One end side (upper end side in FIG. 1) of the pipe 11 is located in a drainage pit 12 provided on one side wall (upper side wall in FIG. 1) 1a of the sedimentation basin 1, and the other end of the pipe 11 On the side, there is provided a rotation mechanism 13 including a motor or the like that reciprocally rotates the pipe 11 as indicated by an arrow b in FIG. The pipe 11 is provided with an opening 14 corresponding to an elongated scum inlet of the present invention along the axial direction. In the illustrated example, the opening 14 is formed to have the same opening length as the horizontal width of the settling basin 1, and the opening width corresponds to an angle of approximately 90 ° with respect to the center position of the pipe 11. Is formed.

  When the pipe 11 does not discharge the scum, the rotating mechanism 13 rotates so that the opening 14 of the pipe 11 is located on the water surface as shown in FIGS. 2 and 3, and at the time of discharging the scum, As shown in FIGS. 9 and 10 described later, a predetermined angle (in the example of FIGS. 9 and 10, a predetermined amount in the counterclockwise direction is set so that a part of the opening 14 of the pipe 11 is located below the water surface. Angle), and can be rotated.

  In FIG. 3, reference numeral 15 denotes a blocking plate, which is provided at the lower part of the pipe 11. The blocking plate 15 extends along the axial direction of the pipe 11 and extends downward from the lower portion of the pipe 11 by a predetermined length, for example, about 30 cm. Thus, when the blocking plate 15 is provided in the pipe 11, it is possible to effectively prevent the scum from flowing around the pipe 11 and flowing downstream, and to prevent the scum from being mixed into the treated water. . This blocking plate 15 can increase the effect of preventing scum from being mixed into the treated water as the downward extension becomes longer, but if it is too long, it will adversely affect the sedimentation effect of the settling basin. preferable.

  The jetting means 20 has an air jet pipe 21 made of a pipe made of synthetic resin or the like for jetting compressed air, and a pressure water jet pipe 22 made of a pipe made of synthetic resin or the like for jetting pressure water. Yes. The axial center direction of these pipes 21 and 22 is parallel to the axial center direction of the pipe 11 and is supported by the side wall (the left side wall of the pipe 11 in the illustrated example) where the scum of the pipe 11 flows. The pipes 21 and 22 are provided via the member 23 so as to be positioned at least below the generated scum. Of these pipes 21 and 22, the air ejection pipe 21 is provided closer to the pipe 11 than the pressure water ejection pipe 22.

  The pressure water jet pipe 22 can be provided closer to the pipe 11 than the air jet pipe 21. Furthermore, although these pipes 21 and 22 are attached to the pipe 11, the pipes 21 and 22 are attached to the tank walls 1 a and 1 b without fixing them to the pipe 11. You can also. However, as shown in the figure, the mechanism attached to the pipe 11 has a simpler mechanism and easier installation.

  As shown in an enlarged view in FIG. 5, the air ejection pipe 21 has a plurality of small holes 24, 24... At a predetermined interval along the longitudinal direction at the lower part of the air ejection pipe 21. Are configured so that compressed air is ejected downward from the small holes 24, 24... And then directed upward by buoyancy (see arrow c in FIG. 5). Further, as shown in an enlarged view in FIG. 5, the pressure water ejection pipe 22 has a plurality of small holes 25 at a predetermined interval along the longitudinal direction of the pressure water ejection pipe 22. .. Are opened so that the pressure water can be sent upward from these small holes 25 (see arrow d in FIG. 5).

  FIG. 6 shows another example of the air jet pipe 21. The small holes 24, 24... Provided in the air jet pipe 21 are the upper part of the air jet pipe 21 and in the longitudinal direction thereof. Along the small holes 24, 24,..., Covers 26, 26,... Are provided above the small holes 24, 24,. Therefore, the air rises around the cover 26 as indicated by an arrow e in FIG. Thus, when the covers 26, 26,... Are provided above the small holes 24, 24..., Even if the small holes 24, 24. , The small holes 24, 24... Can be effectively prevented from being blocked by the scum in the same manner as the small holes 24, 24. 6, the pressure water jet pipe 22 is configured in the same manner as in FIG. 5, so that the pressure water can be jetted upward from the small holes 25, 25. Arrow f).

  The air ejection means 30 has air diffusers 31a and 31b attached to both side walls 1a and 1b of the sedimentation tank 1, respectively. The air diffusers 31a and 31b are respectively provided on the side wall surfaces 1a and 1b via attachment fittings (not shown) in water about 10 cm below the surface of the sedimentation basin 1, and the air diffusers 31a and 31b are connected to the air jet pipe 21 and the air jet pipe 21, respectively. Similarly, a plurality of small holes are formed at predetermined intervals along the longitudinal direction of a pipe made of synthetic resin or the like.

In Figure 1, 51a is an air supply pipe provided with an automatic on-off valve V ₁ on the way to supply compressed air from a source of compressed air (not shown) to the air ejection pipe 21 described above, 51b was described above It is an air supply pipe for supplying compressed air from the supply source of compressed air which is not illustrated to diffuser pipes 31a and 31b. As a supply source of compressed air, when the sedimentation basin 1 is provided in the sewage treatment plant, a part of the compressed air used in the aeration tank can be used. Of course, a compressor can be installed to obtain compressed air. In the illustrated example, since the air ejection pipe 21 provided in the pipe 11 moves as the pipe 11 rotates, a flexible portion (not illustrated) is provided at a connection portion between the air supply pipe 51 a and the air ejection pipe 21. A sex tube is provided.

  The water injection means 40 is located at a position upstream of the pipe-type scum discharge mechanism 10 by a predetermined distance (in the illustrated example, a position slightly upstream from the portion where the width of the sedimentation basin 1 becomes narrow) and the sedimentation basin 1. The header pipe 41 is provided so as to extend in a direction perpendicular to the water flow. A plurality of nozzles 42, 42... Are arranged on the header pipe 41 at a predetermined interval along the longitudinal direction of the header pipe 41. Each of the nozzles 42, 42... Is configured to be able to inject pressure water toward the pipe-type scum discharge mechanism 10 side, that is, toward the lower side in the downstream direction of the settling basin 1.

  As shown in FIG. 7, each of the nozzles 42, 42,... Has an outer shape that is flat and widened, and is formed into a film from slits 42a, 42a,. It is comprised so that each pressure water can be injected. Therefore, from each of the nozzles 42, 42..., Pressure water can be sprayed over a wide area of the scum, and the scum can be efficiently moved toward the pipe-type scum discharge mechanism 10 side.

In FIG. 1, reference numeral 52 a denotes an automatic open / close valve for supplying pressure water pumped up by the pump P from the middle layer downstream from the installation position of the pipe-type scum discharge mechanism 10 to the pressure water jet pipe 22 described above. A pressure water supply pipe provided with V _2, and 52 _b is a pressure water supply pipe for supplying pressure water pumped up by the pump P to the header pipe 41 described above.

  2, 60 is a sludge scraping mechanism of the sedimentation basin 1, and is configured by providing scraping plates 62, 62... At predetermined intervals on an endless chain conveyor 61. The sludge scraping mechanism 60 is configured such that sludge (precipitate) accumulated on the bottom of the settling basin 1 can be discharged to a pit (not shown) on the forward side of the chain conveyor 61, and on the backward side of the chain conveyor 61. The scum can be moved to the pipe-type scum discharge mechanism 10 side.

FIG. 8 is a block diagram of a controller 70 composed of a program controller that controls the drive control of the scum removing device. The controller 70 has a control unit 71 configured mainly with a CPU. The control unit 71 sets the rotation time of the pipe 11 and the opening / closing times of the automatic opening / closing valves V ₁ and V ₂ , and sets the scum removing device in a normal mode other than during heavy rain or during heavy rain ( A setter 72 that selects and sets the heavy rain mode and other various modes, and a pipe rotation driver 73 that drives and controls the motor of the rotation mechanism 13 to drive the rotation of the pipe 11. A pump driver 74 that drives and controls the pump P and a valve driver 75 that drives and controls the automatic open / close valves V ₁ and V ₂ are connected.

  The scum discharging operation of the scum removing device having the above configuration will be described with reference to the explanatory diagrams of FIGS. 9 and 10 and the time charts of FIGS. 11 (a), 11 (b), and 11 (c). 9 and 10, when the scum is discharged, the pipe 11 rotates counterclockwise by a predetermined angle from the position shown in FIG. 3, and ends (edges) on the upstream side (left side in the illustrated example) of the opening 14. ) 14a shows a state where it is located below the water surface by a predetermined depth. FIG. 9 shows a normal state other than during heavy rain when the generated scum S has a thickness of 10 cm or less. FIG. 10 shows a state during heavy rain in which the generated scum S includes a large lump scum S ′ having a thickness (diameter) exceeding 10 cm. Further, FIG. 11A shows a time chart in a normal mode that is not during heavy rain, and FIGS. 11B and 11C show time charts in a heavy rain mode.

  Now, let's assume that there is no heavy rain. In this case, the scum removing device is set to the normal mode via the setting device 72. In this case, until the time for discharging the scum S arrives, the pipe 11 of the pipe-type scum discharge mechanism 10 is positioned on the water surface as shown in FIG. Therefore, since the scum S is not discharged from the pipe 11, it is gradually accumulated in a plate shape on the upstream side of the pipe 11. Further, compressed air is always supplied from the air diffusers 31a and 31b, and bubbles are ejected along the both side walls 1a and 1b of the settling tank 1 of the pipe 11, so that the scum S is located on both side walls. It is kept in a state where it is not attached (adhered) to 1a, 1b, that is, a plate-like scum S lump is completely floated on the water surface.

  Next, when the time for discharging the scum S arrives, for example, when one week has passed since the previous scum discharge, the pipe 11 is part of the opening 14 by the rotating mechanism 13 as shown in FIG. Is rotated for a predetermined time (for example, 10 minutes) so as to be immersed in water (see FIG. 9). Further, the water ejection means 40 is also driven at the same time that a part of the opening 14 of the pipe 11 is submerged in water, and pressure water is ejected from the nozzles 42, 42. Therefore, the scum S is given a scum moving force by the pressure water in addition to the scum movement by the water flow (see arrow a) of the settling basin 1, and the movement toward the pipe-type scum discharge mechanism 10 side is further promoted.

Furthermore, at the same time that a part of the opening 14 of the pipe 11 is submerged in water, the automatic opening / closing valve V ₁ is opened for a predetermined time (for example, 30 seconds), and air is ejected from the air ejection pipe 21. The scum S in the vicinity of the opening 14 of the pipe 11 is lifted by the bubbles by the jetted air, and the lifted scum S is smoothly guided into the pipe 11 beyond the end 14a of the opening 14 (see FIG. 9 arrow g). Once the scum S enters the pipe 11 from the opening 14, the entire scum S that follows is smoothly guided into the pipe 11. The introduction of the scum S into the opening 14 by air ejection is sufficient for about 30 seconds, which is an extremely short time, and thereafter, the scum S is guided smoothly and smoothly into the pipe 11 by the flow of the scum S. In this way, since the air ejection is completed in a short time, the scum can be discharged at a lower cost.

  Moreover, when discharging the scum, the scum S is completely separated from the surfaces of the side walls 1a and 1b by the air bubbles from the air diffusers 31a and 31b, so that the entire scum moves smoothly, and the entire scum Moves quickly from the opening 14 into the pipe 11. For this reason, in this scum removing device, the amount of water taken into the pipe 11 for discharging the entire scum S is 1/20 to 1 of the amount of water when only the water injection means 40 is driven to discharge the entire scum S. It is possible to obtain an extremely excellent effect that it can be reduced to / 30.

  The scum S taken into the pipe 11 is guided to the drain pit 12 and sent from here to a scum processing device (not shown) equipped with a dehydrator and the like for processing. Even in this scum treatment device, since the amount of water contained in the scum S is extremely small, it is possible to have an effect of reducing the treatment cost.

  After the scum S is taken into the pipe 11 and removed from the water surface of the settling basin 1, the pipe 11 is in its original position, that is, the opening 14 of the pipe 11 is positioned on the water surface (see FIG. 3). In addition, the rotation mechanism 13 is rotated, and the driving of the water injection means 40 is stopped, and the series of scum discharge operations is completed.

  Next, the case of heavy rain will be described. In this case, the scum removing device is set to the heavy rain mode via the setting device 72. In this case, until the time for discharging the scum S has arrived, the opening 14 of the pipe 11 is positioned on the water surface, and the scum S is not discharged from the pipe 11, so that it gradually forms a plate shape upstream of the pipe 11. Accumulated. The scum S includes a large lump scum S ′ having a diameter exceeding 10 cm, which is peeled off from the inner surface of the sewer pipe due to water flow or water pressure during heavy rain. In this case as well, compressed air is always supplied from the air diffusers 31a and 31b, and bubbles are jetted along the side walls 1a and 1b of the settling tank 1 of the pipe 11, and therefore, The state where the scum S is not attached (adhered) to the both side walls 1a and 1b, that is, the lump of the plate-like scum S is kept completely floating on the water surface.

  When the time for discharging the scum S arrives, as shown in FIG. 11B, the pipe 11 is rotated by the rotating mechanism 13 so that a part of the opening 14 is submerged in water (see FIG. 10). For example 10 minutes). Further, the water ejection means 40 is also driven at the same time that a part of the opening 14 of the pipe 11 is submerged in water, and pressure water is ejected from the nozzles 42, 42. Therefore, the scum S is given a scum movement force by the pressure water in addition to the scum movement by the water flow (see arrow a) of the settling basin 1 so that the scum S and S ′ move toward the pipe-type scum discharge mechanism 10 side. More promoted.

Furthermore, at the same time that part of the opening 14 of the pipe 11 is submerged in water, the automatic opening / closing valve V ₂ is opened for a predetermined time (for example, 30 seconds), and pressure water is ejected from the pressure water ejection pipe 22. The scum S ′ in the vicinity of the opening 14 of the pipe 11 is lifted by the jetted water due to the jetted pressure water, and the scum S ′ is smoothly guided into the pipe 11 beyond the end 14 a of the opening 14 ( (See arrow h in FIG. 10). Once the scum S ′ enters the pipe 11 from the opening 14, the entire scum S, S ′ that follows is smoothly guided into the pipe 11. The introduction of the scum S into the opening 14 by the pressure water ejection is sufficient for about 30 seconds, which is an extremely short time, and thereafter, the scum S is guided smoothly and smoothly into the pipe 11 by the flow of the scum S. Thus, since the pressure water ejection is completed in a short time, the scum can be discharged at a low cost.

  In addition, when discharging the scum, the scum S and S ′ are completely separated from the surfaces of the side walls 1a and 1b by the air bubbles from the air diffusers 31a and 31b, so that the entire scum moves smoothly. The entire scum moves quickly from the opening 14 into the pipe 11.

In the scum discharge operation of the time chart shown in FIG. 11C, an operation of releasing air from the air ejection pipe 21 is added to the scum discharge operation shown in FIG. That is, in this air discharge operation, a part of the opening 14 of the pipe 11 is submerged in water, and at the same time, the automatic opening / closing valve V ₁ is opened for a predetermined time (for example, 10 seconds), and air is ejected from the air ejection pipe 21. . The scum S and S ′ adhering to the pipe 11 is effectively peeled off from the pipe 11 by the jetted air, and then the automatic opening / closing valve V ₂ is opened for a predetermined time (for example, 30 seconds), and the pressure water jet pipe Pressure water is ejected from 22. The scum S and S ′ in the vicinity of the opening 14 of the pipe 11 is lifted by the jetted water due to the jetted pressure water, and the scum S and S ′ passes over the end 14 a of the opening 14 and smoothly enters the pipe 11. Led to.

  As described above, even when the scum S generated in the sedimentation basin 1 includes a large lump scum S ′ having a thickness (diameter) exceeding 10 cm, the water flow ejected from the pressure water ejection pipe 22 Since the water can be smoothly guided into the pipe 11, the amount of water discharged due to the discharge of the scum can be reduced to 1/20/1 / compared with the conventional scum removing device that discharges the scum by driving only the conventional water injection means. An extremely excellent effect of being able to reduce to 30 can be obtained.

  12 and 13 show the scum discharging mechanism of the scum removing device according to the present invention realized by a trough scum discharging mechanism. 12 includes an inflow weir 81 that moves up and down on the upstream side (left side in FIG. 12) of the trough 80 for taking in the scum. An ejection means 20 including an air ejection pipe 21 and a pressure water ejection pipe 22 is provided on the upstream side of the inflow weir 81 via a support member 23. In addition, a blocking plate 15 similar to that provided in the pipe 11 described above is provided below the trough 80.

  Moreover, FIG. 13 implement | achieves the scum discharge mechanism of the scum removal apparatus which concerns on this invention with the trough scum discharge mechanism of another type. In this trough-type scum discharge mechanism, a side wall upper portion 91 on the upstream side (left side in FIG. 13) of the trough 90 for taking in the scum is rotatably provided via a hinge 92. And when taking in scum, the upper end part of the side wall upper part 91 is rotated so that it may be immersed in water, and it is comprised so that scum can be taken in into the trough 90. FIG. As with the trough 80 described above, the ejection means 20 is provided on the upstream side of the trough 90, and a blocking plate 15 similar to that of the trough 80 is also provided below the trough 90.

  When the scum discharge mechanism is a trough scum discharge mechanism as described above, the pipe rotation driver 73 of the controller 70 is a driver that moves the inflow weir 81 up and down or a driver that rotates the side wall upper portion 91.

[Experimental example]
A scum discharge experiment was conducted in a settling pond at an actual sewage treatment plant during heavy rain. In the sedimentation basin of this experiment, a pipe-type scum discharge mechanism provided with the ejection means 20 shown in FIG. During heavy rain, a large lump scum having a thickness (diameter) exceeding 10 cm was present in the scum on the upstream side of the pipe of this pipe-type scum discharge mechanism. When pressure water was ejected from the pressure water ejection pipe of the ejection means for 30 seconds when scum discharge arrived, a large lump of scum can be easily lifted to the position of the end of the opening of the pipe, and subsequent scum discharge is smooth Could be done. On the other hand, when only air was ejected from the ejection means, a large lump-like scum could not be lifted up to the position of the end of the opening of the pipe, which hindered subsequent scum discharge.

  The scum removing device according to the present invention can be applied not only to a sewage treatment plant, but also to a water tank where scum is generated in wastewater treatment facilities such as various factory wastewaters. Furthermore, the present invention can also be applied to separation of valuable materials by floating in food factories or chemical factories. Accordingly, the term “water” in the present invention means not only sewage and wastewater but also various liquids.

Claims (9)

In the scum removing device that removes the generated scum by moving the generated scum to the scum discharging mechanism side on the water flow and immersing a part of the scum inlet of the scum discharging mechanism in the water when discharging the scum. ,
Jetting means provided on a wall surface side through which the scum flows out of the wall surfaces forming the scum intake port of the scum discharge mechanism;
Means for setting an operation mode of the scum removing device;
A control unit that drives and controls the scum discharge mechanism and the ejection unit according to the operation mode,
The control unit is configured to pressurize the pressure water upward along a wall surface on a side where the scum flows from when a part of the scum intake is submerged in the water until the scum starts to flow into the scum intake. Alternatively, the scum removing device is characterized in that the ejection means is driven so that air is ejected. In the scum removing device that removes the generated scum by moving the generated scum to the scum discharging mechanism side on the water flow and immersing a part of the scum inlet of the scum discharging mechanism in the water when discharging the scum. ,
Pressure water jetting means provided on the wall surface through which the scum flows out of the wall surfaces forming the scum intake port of the scum discharge mechanism;
Compressed air jetting means disposed alongside the pressure water jetting means;
Means for setting an operation mode of the scum removing device;
A control unit that drives and controls the scum discharge mechanism, the pressure water ejection unit, and the compressed air ejection unit according to the operation mode;
The control unit drives the compressed air ejecting means so that compressed air is ejected for a predetermined time along a wall surface on the side where the scum flows while a part of the scum intake is submerged in water, and then the scum Until the pressure starts to flow into the scum inlet, the pressure water ejecting means is driven so that the pressure water is ejected upward.   The apparatus further comprises air jetting means for jetting air upward in the water near the tank wall upstream of the position where the scum discharge mechanism is provided, and along the tank wall. The scum removing device according to claim 1 or 2.   The scum removing device according to claim 3, wherein the control unit drives the air ejection unit so that the upward air ejection is always performed.   Upstream of the scum discharge mechanism installation position, when scum is discharged, water is injected obliquely downward on the scum discharge mechanism side, and the scum is moved to the scum discharge mechanism side by the water injection pressure. The scum removing device according to any one of claims 1 to 4, further comprising water jetting means for moving.   The scum discharge mechanism includes a pipe whose axial direction is parallel to the water surface, has an elongated opening along the axial direction, and rotates around the axial center when driven by the control unit. A pipe-type scum discharge mechanism that takes in scum into the pipe from the opening when the part of the opening of the pipe is located below the water surface, or an inflow that moves up and down by driving by the control unit 6. The scum removal according to claim 1, wherein the scum removal mechanism is a trough scum discharge mechanism that takes in scum from the inflow weir into the trough when the upper portion of the weir is located below the water surface. apparatus.   The jet of compressed air from the compressed air jetting means is performed from a small hole provided at a predetermined interval along the longitudinal direction of the lower part of the air supply pipe. The scum removing device according to claim 1.   The compressed air is ejected from the compressed air ejecting means by providing a small hole at a predetermined interval along the longitudinal direction of the upper portion of the air supply pipe, and a cover is provided above the small hole at a predetermined interval. The scum removing device according to any one of claims 2 to 6, wherein the scum removing device is provided.   The jet of water from the water jetting means is performed from a flat and wide nozzle that pumps up the middle layer of water in the tank. The scum removing device according to item.

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