JP2004105943A - Method and apparatus for raking sludge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for raking sludge whereby an operation loss can be minimized. <P>SOLUTION: In the method, foul water in a state of straightened flow is caused to flow from a position above a sludge pit at one end of the longitudinal direction of a pond into a treatment pond such as a rectangular sedimentation pond; and sludge settled on the bottom of the pond is put into the sludge pit with a raking member. Sludge settled near the sludge pit on the bottom of the pond is raked to the sludge pit side more intensively than other sludge. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
[Industrial applications]
The present invention relates to a method and an apparatus for scraping sludge.
[0002]
[Prior art]
The rectangular sedimentation basin has left and right side walls, and forms a rectangular pond with a direction orthogonal to the opposite direction as a longitudinal direction. A rectifying plate having a rectifying hole is provided on one end face in the longitudinal direction to promote precipitation. A sludge pit is recessed in the bottom of the settling pond at one end, and the sludge accumulated in the bottom of the pond is scraped by a sludge scraper and scraped into the pit.
On the other hand, there are various types of sludge scraping devices. As one of them, a flight system in which flights are arranged in a chain that circulates in a pond and scrapes sludge at the bottom of the pond by these flights in a pit direction has been used as a conventional flight system.
[0003]
[Problems to be solved by the invention]
By the way, as typified by the flight method, the conventional sludge scraping device has been configured to continuously and continuously scrape from the anti-pit side to the pit side along the pond bottom at the pond bottom. . In addition, the scraping device is configured to move upward from the pit side and the flight moves on the water surface, where it scrapes the scum on the water surface, and then circulates back to the bottom of the pond and is returned. It has been. Such a circulating motion requires considerable operating energy and is wasteful.In particular, the range of the bottom of the pond where the sludge settles from the sewage discharged from the rectification hole is limited to the pond bottom inside the pit and near the same pit. On the contrary, the conventional method in which the other bottom of the pond is constantly scraped in the same manner has a large operation loss.
[0004]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to provide a sludge scraping method and an apparatus thereof capable of minimizing an operation loss.
[0005]
[Means for Solving the Problems]
The present invention has been made to solve the above-mentioned problem, and the invention according to claim 1 allows sewage to flow into a treatment pond such as a rectangular sedimentation pond in a state where the sewage is rectified from a position above the sludge pit at one end in the pond longitudinal direction. A sludge scraping method in which sludge settled on the bottom of the pond is dropped into the sludge pit by a scraping member, and the sludge settled near the sludge pit on the bottom of the pond is more important than other sludge. So that it rushes to the sludge pit side.
[0006]
The invention according to claim 2 is provided with a rectification means for rectifying and flowing sewage water at one end in the longitudinal direction with a direction perpendicular to the direction in which the left and right side walls are opposed to each other, and a sludge pit formed at the bottom of the lower pond. Sludge formed in a treatment pond such as a rectangular sedimentation pond, in which the sludge at the bottom of the pond is scraped in the direction of the sludge pit and scraped into the pit by a scraping operation of a scraping member attached to the bottom of the pond. A scraping device, in which the device is divided into a plurality of stages of scraping devices in the longitudinal direction, and the scraping device on the most sludge pit side has a large scraping capacity per time and moves to the opposite pit side. Therefore, it is characterized in that it is driven with a reduced scraping ability per time.
[0007]
The invention according to claim 3 is the device according to claim 2, wherein the apparatus is constituted by a first scraping device on the sludge pit side and a second scraping device on the anti-sludge pit side than the device. These scraping devices are driven by a single drive source in a simultaneous drive relationship.
[0008]
According to a fourth aspect of the present invention, in the second aspect of the present invention, a step is formed at the bottom of the pond in the direction of the sludge pit, and the sludge from the scraping device in the preceding stage flows through the step. They are connected and delivered to the next subsequent stage scraping device.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.
1 and 2 show an embodiment of the present invention. As shown in these figures, a treatment pond is a rectangular sedimentation basin 1, and the sedimentation basin 1 has left and right side walls 2, 2. The sedimentation basin is provided with end walls 3 and 3 opposing in the direction orthogonal to the opposing direction, and is provided with pond bottoms 4 and 5 and has a rectangular sedimentation pond that is long in one direction when viewed from above.
[0010]
A sludge pit 6 is recessed at one end of the sedimentation basin 1, and a rectifying plate 8 having rectifying holes 7 is integrally or separately provided on a surface of the end wall 3 above the sludge pit 6. Have been. As shown in the lower section of FIG. 2, the pond bottom is inclined downward at a small angle θ ° toward the sludge pit 6, and the long second pond bottom 5 on the opposite side of the pit, The first pond 4 is formed lower than the second pond 5, and in between, the first pond 4 is inclined downward toward the pit. A step 9 having an angle of 45 ° or more is formed.
The step 9 is formed by a linear inclined surface, but may be a curved surface having an upwardly convex or concave shape. A combination of an inclined surface and a curved surface may be used. These surfaces may be finished with a resin plate or the like so that the sludge slides down well. These facts can be similarly applied to other embodiments described later.
[0011]
Reference numeral 11 denotes a settling control plate. The control plate 11 is constituted by a plurality of bent plates whose concave side is directed to the upstream side X, which is the direction of the rectifying hole 7, and is fixedly installed so that the upper ends thereof are gradually increased and they are spaced apart in the front-rear direction. ing. This interval is such that the upper portion is slightly narrower and becomes wider as it goes to the lower portion, so that the speed of sewage is reduced and the sedimentation is promoted within this interval. Further, as shown in the figure, the control plate 11 has a structure in which the two sheets on the upstream side X are punched metal structures and the last sheet on the downstream side is a normal flat plate, and the sludge content is reduced through the punched holes as much as possible. It is trapped between 11 and settles easily.
The sedimentation control plate 11 can employ various techniques so far.
[0012]
The sludge scraping device is divided into a first scraping device A on the upstream side X and a second scraping device B on the downstream side, and is configured in a stepwise manner. The first scraping device A has a large scraping ability, and the scraping ability of the second scraping device B is about 1/3 of the first scraping device A in this embodiment. This ratio can be set arbitrarily according to the situation of sludge settling. For example, when the precipitation ratio is more biased toward the upstream side X, such as 1: 1/5 or 1: 1/10.
[0013]
Reference numeral 13 denotes a first sprocket shaft, and two shafts each having a pair of first sprockets 14 are rotatably suspended between the side walls 2 and 2 by brackets 15 at both ends of the shaft. There are two arrangements, one on the sludge pit 6 side and one below the step 9. Reference numeral 16 denotes a second sprocket shaft, which has a pair of second sprockets 17 and is rotatably suspended between the side walls 2 by brackets 18 at both ends of the shaft. There are two arrangements, one on the step 9 and one on the downstream end. The first and second sprockets 14 and 17 have the same diameter and the same.
[0014]
A pair of left and right first chains 20 is provided between the pair of first sprocket shafts 13 via the four first sprockets 13, and four second chains are provided between the pair of second sprocket shafts 16. A pair of left and right second chains 21 is stretched over sprockets 17. Around the chains 20, 21, first and second scraping members (also referred to as flights) 22, 23, which move and circulate along a pond bottom guide rail (not shown) at regular intervals. Are arranged. The scraping members 22, 23... Have the same configuration. For example, a scraping member made of wood or resin and a scraper made of a metal plate (such as SUS) are used. Either may be used. This is the same in other embodiments described below.
[0015]
These drive systems are as follows. Reference numeral 25 denotes a drive source, which is installed on the pond as a single drive source common to both scraping devices A and B. Specifically, the drive source is a combination of a motor and a speed reducer, and further has a drive sprocket 26 on its output shaft. ing. On the other hand, a first driven sprocket 27 and a second driven sprocket 28 are provided on the outer periphery of the same side end of the first sprocket shaft 13 and the second sprocket shaft 16 near the step 9 so as to be rotatable along with the shafts 13 and 16 respectively. A drive chain 29 is wound around the drive sprocket 26 on both sprockets 27 and 28. Reference numeral 30 denotes a weight type tensioner. The gear ratio of the first driven sprocket 27 and the second driven sprocket 28 is set to 1: 3. That is, the first scraping device A is driven to rotate in the same direction at a speed three times (but not limited to) the speed of the second scraping device B. Note that the drive chain 29 may be configured to be able to be linked to the sludge pit 6 side or the opposite pit side as shown by a virtual line in FIG. In this case, the driven sprockets 27 and 28 and the interlocking chain between them are formed.
[0016]
Although the first scraping member 22 and the second scraping member 23 are arranged at the same interval, the interval between the second scraping members 23 may be long. In this case, the gear ratio of the first and second driven sprockets 27 and 28 does not need to be set to 1: 3 as described above.
The scum removal device that swallows and removes scum on the water surface can use the power of the drive source 25. In this case, an intermittent motion mechanism can be adopted.
For example, a single driving source may cope with an adjacent sedimentation basin with a single unit.
Further, the upper circumference of the chains 20, 21 may be guided by a guide rail, or a tensioner may be separately provided.
Further, the first scraping member 22 and the second scraping member 23 are formed by flights in the same mode. For example, the first scraping member 22 is made larger in height, and the second scraping member 22 is made larger. The scraping ability may be selected by making the member 23 lower than that. Therefore, the scraping ability is appropriately determined from factors such as the height dimensions and arrangement intervals of the scraping members 22 and 23 and the gear ratio.
[0017]
Therefore, the sewage flows in as indicated by the arrows in FIGS. 1 and 2, but the settling control plates 11... Concentrate the sludge on the sludge pit 6 and the first pond bottom 4. Here, the sedimentation control plate 11 is not essential, and the concentrated (deflective) sedimentation phenomenon occurs even when the sedimentation control plate 11 is not provided. Then, the continuous driving of the driving source 25 drives the first scraping device A quickly and the second scraping device B slowly by a fraction of a second, whereby a large amount of sludge on the first pond bottom 4 is focused. The small sludge on the second pond bottom 5 is slowly scraped, so that the whole can be operated with less driving energy.
[0018]
The arrangement of the sedimentation control plates 11 is not limited to that shown in the figure, and may be arranged to extend further downstream. Although the scraping members 22 and 23 have a vertical shape, they may be set to be inclined in a scraping direction when they come below. Further, in the above embodiment, the driving source can be set individually for the scraping devices A and B. Further, the sedimentation control plates 11 may be angle-changeable with the upper end (or the lower end or between the upper and lower sides) as a fulcrum. Further, the plates 11 can be of a hanging type so that their intervals and set positions can be changed freely. In this case, the angle may be further changed by the hanging means. In addition, as shown in FIG. 2, a second rectifying plate 70, a third rectifying plate 71, and second to fifth inclined plates 72 to 75 may be provided in addition to the settling control plate 11. In addition, the first to fourth porous filter media 76 may be provided below the overflow weir 77 or the like.
[0019]
FIG. 3 shows another embodiment. In this embodiment, the first pond bottom 4 is formed to be inclined downward in the direction of the sludge pit 6, and by making such an inclination, the scraping resistance can be reduced and the driving energy can be further reduced. It should be noted that the slope may be steeper than shown.
[0019]
FIG. 4 shows another embodiment. In the present embodiment, reference numeral 33 denotes a pond, which is an existing one or a new one, is formed integrally with or separate from the pond 33 and has a stepped portion 36 having a gentle upper surface 34 and a slightly steep step 35. Is provided. As a separate object, it can be formed of metal, resin or other material and can be fixed by fastening. Then, the second scraping member 37 of the second scraping device B is moved along the gradient 34, and the first scraping member 38 of the first scraping device A is brought close to the step 35 to the limit. To exercise. 39 is a tensioner.
[0020]
FIG. 5 shows another embodiment. In this embodiment, the first scraping member 42 of the first scraping device A rotates between the second scraping members 41 of the second scraping device B without interfering with each other so that the first scraping member 42 rotates without interference. The dropped sludge is surely held by the first scraping member 42.
[0021]
6 and 7 show another embodiment. In this embodiment, a sedimentation basin 45 is provided with a side wall 46, an end wall 47, a pond bottom 48, a sludge pit 49 and a straightening plate (not shown). The first and second scraping devices C and D are arranged before and after moving along the guide rail 50 in a straight line. The guide rail 50 may be installed not only at the center of the pond but also at the lower surface of the side wall 46 or at both ends of the pond bottom.
[0022]
In the first and second scraping devices C and D, reference numeral 52 denotes a bogie, which is provided with a scraper shaft 53 rotatable before and after the bogie. A traveling wheel 54 located in the bogie 52 around the scraper shaft 53, and a bogie. 52 and a scraper 55 located outside. Although the scraper shaft 53 and the scraper 55 rotate together, the traveling wheel 54 rotates independently of the scraper shaft 53. A pair of right and left running wheels 54 is provided, and a pair of interlocking levers 56 projecting around the scraper shaft 53 are provided therebetween, and a connecting rod 57 is connected between them.
[0023]
These scraping devices C and D are driven forward and backward by a submersible motor (with a reduction gear) (not shown) or forward and backward from a pond by a wire rope, a link chain, or the like. Then, the scraping device C scrapes between the solid line scraping start state and the virtual line scraping end state. The scraping device D is in a scraped end state from the scraping start state indicated by the solid line to a position closer to the sludge pit 49 than the scraping start state of the scraping device C. Then, the scraping device C reciprocates more times than the scraping device D.
Therefore, the scraping device C has a higher scraping ability than the scraping device D, and ideal scraping can be performed without operating loss according to the sedimentation state of the sludge. In this embodiment, a sedimentation control plate as shown in FIGS. 1 and 2 is also provided.
[0024]
8 (vertical sectional view along VIII-VIII in FIG. 9) and FIG. 9 (plan view in FIG. 8) show the scum S floating over the water surface 81 of the rectangular sedimentation basin 80 on the right in FIGS. An example of a scum scraping device that is raked in a direction and is attracted and removed by a scum removing device 82 installed therein is shown.
[0025]
As shown in these figures, the sedimentation basin 80 includes left and right side walls 83, 83, end walls 84, 84 facing in a direction orthogonal to the facing direction, and a pond bottom 85. It is a rectangular sedimentation basin that is long in one direction.
[0026]
A sludge pit (hopper) 86 is recessed at one end of the pond bottom 85, and a rectifying plate 88 provided with rectifying holes 87 is integrally or separately provided on the surface of the end wall 84 above the sludge pit (hopper). It is provided as. The pond bottom 85 is shown horizontally in FIG. 8, but is actually inclined downward at a small angle toward the sludge pit 86. This is the same in the following embodiments. Hereinafter, the left-right direction in the figure is the pond longitudinal direction, and the direction perpendicular to the pond width direction is the pond width direction. In the settling basin 80, a flight type sludge scraper 90 is provided as an existing one.
[0027]
The scraping device 90 is of a three-axis type including a drive shaft 91 located near the water surface above the pit 86, an underwater idle shaft 92 below the pit 86, and a take-up shaft at a position (not shown) to the right in FIG. As shown in FIG. 9, a pair of drive sprockets 93, idle sprockets 94, and take-up sprockets are provided on the outer periphery of each shaft including the take-up shaft, as shown in FIG. On the sprockets 93 and 94, a chain 95 in the pond is mounted in a pair on the left and right. Flights 96 are arranged at regular intervals on the outer periphery of the chain 95, and sludge settled on the pond bottom 85 is disposed. 8 and is scraped into the pit 86. In this example, a three-shaft system is used. However, a sedimentation basin equipped with a so-called four-shaft scraping device having an intermediate shaft at a position corresponding to between the drive shaft 91 near the water surface and the scum removing device 82 is also used. May be targeted. The same applies to the following embodiments.
[0028]
In order to drive the flight type sludge scraping device 90, a drive source 97 composed of a motor with a speed reducer is installed on the pond, and a first drive sprocket 98 is provided on an output shaft of the drive source 97, and the drive shaft is provided. The drive shaft 91 is driven by the first chain 100 mounted between the driven sprocket 99 and the driven sprocket 99 provided on the outer periphery of the flight 91, and the flight type sludge scraping device 90 is driven to rotate clockwise in FIG. .
[0029]
The scum removing device 82 has a communication trough 102 passed through a side wall 83 and a trough 103 mounted therebetween. A trough 103 is provided at a front side of the trough 103 so as to be vertically movable. Here, the weir 104 is hollow and can return to the surface of the water by buoyancy, but may return with a weight. An arcuate receiving cam 105 is provided on the weir 104 so as to be located in the middle of the pond width direction. When the weir 104 sinks below the water surface, the scum on the water surface is swallowed into the trough 103, and when the seat 104 rises, the swallowing stops, and the swallowing is intermittently repeated to attract and remove the floating scum. . Reference numeral 106 denotes an attraction guide, which guides the scum that has been swept into the effective attraction width of the scum removal device 82, and is provided on the pond side wall 83 side or the weir 104 side.
[0030]
As shown in FIG. 8, the flight type sludge scraping device 90 of the three-axis drive type is configured such that the flight 96 rises and goes down obliquely to the right after passing through a location where the drive sprocket 93 is provided. Since the space between the scum removing device 82 and the flight 96 is long and wide as a region where the flight 96 does not scratch the water surface 81, the scum floating there is difficult to be swallowed by the scum removing device 82 as it is. The same applies to the four-axis type having the intermediate shaft. That is, between the intermediate shaft and the scum removing device, there are quite a few times during which the flight does not rake, and in particular, there are some sedimentation ponds that have a long time between them. set to target.
Therefore, as shown in the following example, the scum scraping device 107 is provided as an efficient and inexpensive device. Hereinafter, the upstream side, on which sewage flows, is X, the downstream side is Y, the scraping direction of the scum (sometimes referred to as front or front) is F, and the returning direction (rear or rear). ) Is described as R.
[0031]
The scum scraping device 107 includes a frame 108. The frame 108 connects a pair of left and right spaced guide rails 109 whose longitudinal direction is oriented in the longitudinal direction of the pond as shown in FIG. And a pair of front and rear support beams 110 whose both ends are supported and fixed on the pond. The support beam 110 may be provided between the middle of the guide rail 109 in the longitudinal direction and the top of the pond as shown by a virtual line in FIG.
[0032]
The two guide rails 109 are disposed so as to face the central line on the pond so as to face the longitudinal direction of the pond, and these guide rails 109 are provided with channel steel so that their grooves face each other. The traveling rollers 111 are provided at four points so as to fit in the grooves and travel forward and backward.
[0033]
From these running rollers 111, a bogie 113 is provided via a suspension stay 112 so as to advance and retreat along the water surface 81 below the guide rail 109. This cart 113 has a shape in which a part of the upper surface (a part of the scraping direction side F) of the four-sided frame-shaped main body portion is covered with an upper cover 114, and the remaining rear portion is left as a square opening 115. A pair of left and right cam rollers 116 is mounted on the front end bottom side of the receiving cam 105, and a pair of left and right receiving cylinders 117 are fixed to the rear part of the carriage 113, via the receiving cylinder 117. A rotating shaft 119 with a scum scraper 118 is rotatably supported. The scum scraper 118 is provided with an end scraper 120 made of rubber at its end, which is slightly shorter than the width of the pond, so as to be in contact with or close to the side wall 83 so that the scum can be thoroughly scraped.
[0034]
At a position located in the opening 115 of the rotating shaft 119, a pair of left and right interlocking cams 121 having an inverted triangular side surface are protruded so as to rotate together with the rotating shaft 119, and are set up as shown in FIG. A state of being rotated and falling into the opening 115 is obtained. Reference numeral 122 denotes a stopper for regulating the scum scraper 118 in a vertical scraping state as shown in FIG. A pair of left and right return projections 123 is fixed to the rear end of the carriage 113 as low projections, while a pair of left and right hinges 124 are provided on the upper surface of the front part of the carriage 113, and through these hinges 124. A pair of left and right scraping protruding pieces 125 are provided so as to extend higher than the return protruding piece 123 and are provided so as to be swingable right and left. As shown in FIG. 12, these scraping protruding pieces 125 are preferably provided with a roller 126 and are mutually pulled by a spring 127 as shown in FIG. 9, and an angle stopper 128 is provided at the lower end of the protruding piece. The angle stopper 128 defines the two scraping protruding pieces 125 in a C-shape so as to leave a certain interval between them. Is displaceable.
[0035]
On the other hand, at the front and rear ends between the guide rails 109, two sprockets, a front sprocket 130 and a rear sprocket 131, are provided rotatably supported by a front shaft 132 and a rear shaft 133, respectively. The rear shaft 133 is a shaft extending to one side wall 83, and a driven sprocket 134 is provided on the shaft, and an interlocking gear mounted between the rear shaft 133 and a second driving sprocket 135 provided on the output shaft is provided. The scum chain 137 hung between the front and rear sprockets 130 and 131 by the chain 136 is continuously rotated clockwise in FIG. The scum chain 137 may be moved intermittently, or the length of the intermittent time may be controlled to be longer or shorter. The scum chain 137 includes a wire rope, a link chain, and the like in addition to a general chain (this applies to other embodiments).
[0036]
The scum chain 137 passes through the center between the two guide rails 109, and at one point is provided with a circulation roller 138 around an axis extending left and right as shown in FIG. The scraping piece 125 is pushed in the scraping direction as shown in FIG. 8, while passing between the opened scraping pieces 125 as shown by the imaginary line in FIG. A mountain-shaped cam plate 139 is fixed between the guide rails 109 so as to open automatically when the scraping piece 125 is moved forward. When the circulating roller 138 is lowered, the rising interlocking cam 121 is tilted into the opening 115 and locked, the scum scraper 118 is lifted, and then the carriage 113 is brought back and interlocked with the return projecting piece 123. Since the return protrusion 123 is low, when the circulation roller 138 comes to the left end in FIG. 8 and rises counterclockwise, the carriage 113 is separated from the return protrusion 123 and stops there.
[0037]
10 to 17 show a series of operations of the scum scraping device 107. FIG. 10 shows a state in which the cam roller 116 further proceeds from the scraping state in FIG. 8 to press the receiving cam 105 and begin to sink the weir 104 below the water surface. The scraping piece 125 is closed in a C-shape as shown by the solid line in FIG. 12, the scraping piece 125 is hooked by the circulation roller 138, and the carriage 113 is driven forward. The scum scraper 118 is in a free and vertical scraping state.
[0038]
FIG. 11 shows a state further advanced from the state shown in FIG. 10, in which the carriage 113 is advanced while being pushed forward by the circulation roller 138 in a U-shape. The piece 125 comes into contact with the cam plate 139 and expands as shown by the imaginary line in FIG. 12, and the lower cam roller 116 presses the receiving cam 105 to press the weir 104 below the water surface to attract the scum.
[0039]
FIG. 13 shows a state in which the scraping protruding piece 125 is opened and the circulation roller 138 passes therebetween and turns around the front sprocket 130. At this time, the weir 104 is pressed down and swallows the scum. The circulation roller 138 comes over the carriage 113 and comes to the base of the scraping piece 125. After the scraping piece 125 passes through, the spring 127 is automatically closed by a spring 127 in a C-shape. Since the width between the base portions of the projecting pieces 125 is wider than the left and right width of the circulation roller 138 as shown in FIG. 12, the passage of the circulation roller 138 that has fallen below is allowed, and the space between the suspension stays 112 is also larger than the width of the circulation roller 138. The circulation roller 138 also passes here because it is wide. The state is shown by an arrow in FIG.
[0040]
As shown in FIG. 15, the circulation roller 138 hits the interlocking cam 121 and falls down to lift the scum scraper 118 horizontally forward. The interlocking cam 121 falls into the opening 115 to be in a locked state, and the circulation roller 138 comes into contact with the return protrusion 123 at the same time, whereby the carriage 113 is lifted while the scum scraper 118 is lifted. Since the scum scraper 118 is lifted up, the carriage 113 is returned without scraping the scum on the water surface 81 because the scum scraper 118 is lifted.
[0041]
As shown in FIG. 16, when the carriage 113 comes to the rear end, the circulation roller 138 turns around the rear sprocket 131 from bottom to top, so that the circulation roller 138 comes off the return projection 123 and the interlock cam The scum scraper 118 is also separated from the scum scraper 118 by the interlocking cam 121 which is stopped and becomes free at the same time.
[0042]
The circulation roller 138 comes upward as shown in FIG. 17, and the scraping piece 125, which has been automatically closed by the spring 127, is hooked and interlocked, so that the carriage 113 scrapes. proceed. The trough 103 may be suspended and supported on the frame 108 side (this applies to other embodiments as well).
[0043]
In another embodiment, as shown in FIG. 18, a guide rail 109 may be arranged on one side of the settling basin 80 to support the scum scraper 118 in a cantilever manner. Also, as shown in FIG. 19, the guide rail 109 may be disposed slightly away from the side wall 83 as compared with FIG.
[0044]
As shown in FIG. 20, the weir 104 may be inclined inward into the trough 103, that is, a so-called inward fall type (in FIG. 8, the outward fall type). In this case, the weir 104 is connected to the weight 142 and the stopper 143. , And the receiving plate 144 is protruded from the weir 104 and the weir 104 is pressed down by the cam roller 116.
[0045]
As shown in FIG. 21, when the scum removing device is constituted by a round pipe-shaped scum skimmer 147 having a swallow port 146 opened at the upper portion, the skimmer 147 is supported by a weight (with a stopper) 148 in the illustrated return state. The skimmer 147 is provided with a receiving plate 149 so that the skimmer 147 can be pressed by the cam roller 116.
[0046]
FIG. 22 shows that, when the scum scraping devices 107 are installed in a plurality of adjacent sedimentation basins 80, one of the common shafts 151 passed through the guide rails 109, 109 of the left and right ponds, and the coaxial 151 A common sprocket 152 is disposed around the both scum scraping devices 107, 107 so that they can be driven simultaneously by a single drive system. In this case, the upper part of the central side wall 83 breaks a part C unnecessary for installation.
[0047]
23 to 26 show another driving method of the scum scraping device. FIG. 23 shows a system in which scum is blown by nozzles 154. Reference numeral 155 denotes a water distribution pipe, which is mounted on the carriage 113 as a long pipe extending over the entire width of the pond, and the nozzles 154 are attached at a plurality of locations. Pond water is sent to the water distribution pipe 155 by a pump 156 mounted on the cart 113. The pump 156 may be of a submersible type. Electric power is supplied to the pump 156 by a telescopic power distribution cord 157. Reference numeral 158 denotes front and rear limit switches. The pump 156 stops when the carriage 113 hits the front switch 158, and the pump 156 operates when hitting the rear switch 158. The nozzle 154 may be variable in height and / or angle.
[0048]
In addition, as shown in FIG. 23, the scraping piece 125 is fixed, a stay 159 erected on the front part of the guide rail 109 is provided with a holding sprocket 160, and the front sprocket 161 is formed of a large diameter. The scum chain 137 at the upper end is guided obliquely upward, whereby the circulation roller 138 also escapes upward, so that the scraping piece 125 comes off at this point and stops. Things. What is said in this paragraph applies to other embodiments as well. In this case, a scraping method may be used instead of the spraying method.
[0049]
In FIG. 24, a bogie 113 is provided with a water distribution pipe 164 with a nozzle 163, and a hose 165 from the side of the pond is guided and connected to the water distribution pipe 164. That is, the pump is installed on the side wall.
Separately shown at the same time separately shows a scraping drive system. This example shows another method in which the circulation roller 138 is separated from the scraping piece 125. The scraping piece 125 can be bent, and the scraping piece 125 is fixed to a stopper 166 fixed to the guide rail 109 side. When the lower part of the roller contacts the upper part, only the upper part is bent forward, whereby the circulating roller 138 passes over the scraping piece 125. A self-standing force is applied between the upper and lower sides of the scraping piece 125 by an elastic member such as a spring. As a result, it is possible to stop the scraping protruding piece 125 just before it hits the support shaft of the front sprocket 130. What is said in this paragraph applies to other embodiments as well. In this case, a scraping method may be used instead of the spraying method.
[0050]
FIGS. 25 and 26 (cross-sectional views taken along the line PP in FIG. 25) show the H-shaped steel as the guide rails 167 with the grooves on both sides facing outward. A carriage 170 is suspended via a stay 169. The guide rail 167 has a support beam 172 provided thereon via a spacer base 171 and both ends thereof are fixed on a pond. The position is not limited to the illustration. Also, a pair of left and right front sprockets 173 and rear sprockets 174 are provided at the front and rear ends of the guide rail 167. The scum chains 175 and 175 respectively hung on the left and right sides have the same circulation rollers 176 as rollers. On the side of the carriage 170, a long scraping piece 177 is provided at the front, and a short returning piece 178 is provided at the rear, so that the circulating roller 176 is alternately provided. ing. A contact piece 179 protrudes from the carriage 170 at a position where the circulation roller 177 passes, so that the scum scraper 180 rotates together.
[0051]
The state in FIGS. 25 and 26 is a scraped state. That is, the circulation roller 176 hooks the left and right scraping protrusions 177 and accompanies, whereby the carriage 170 and the scum scraper 180 advance while scraping. When the circulation roller 176 reaches the front sprocket 173, the circling roller 176 moves downward while pushing the scraping piece 177 forward, and the carriage 170 stops moving forward. When the circulating roller 176 comes down, the scum scraper 180 is lifted by hitting the abutment piece 179 and then hit by the short return projection piece 178 to pull and link the carriage 170. As shown by the virtual line at the left end of FIG. 25, when the carriage 170 comes to the rear, the circulation roller 176 circulates and moves upward to come off the return projection 178, and the carriage 170 stops here, When the circulation roller 176 comes upward and hits the scraping projection 177, the carriage 170 moves forward and starts scraping.
[0052]
25 and 26 are similarly applied to other embodiments. For example, there is an application to a nozzle injection method. Further, in the same drive system, the guide rail 167 is an H-shaped steel, but may be constituted by only one channel steel. This can be applied particularly when the guide rail is arranged near the side wall.
[0053]
FIG. 27 shows an additional proposal example. In this example, a weight for erecting a receiving arm 185 in a sedimentation basin equipped with a four-axis (or three-axis) flight type sludge scraper 182 and a trough 184 equipped with an external weir 183. The weir 183 is pushed down by the interlocking arm 187 with 186, and the eccentric pin plate 188 which is rotationally driven by the driving source is provided for interlocking the receiving arm 185, so that the link 189 can swing back and forth back and forth. The reciprocating rod 191 is moved by the roller 190. The movement of the rod 191 is converted into the fine angular rotation of the ratchet 192, which is the clockwise circulation of the chain 195 hung between the front sprocket 193 and the rear sprocket 194. The receiving arm 185 is moved by the circulation roller 196 of the chain 195. Such a ratchet type may be applied to a type equipped with a trough 199 with a weir 198 of an inverting type shown in FIG. 28, or to a type equipped with a scum skimmer 200 shown in FIG.
[0054]
Although the four-shaft type is provided with an intermediate shaft 203 and an intermediate sprocket 204 as shown in FIG. 28, the intermediate shaft 203 and the intermediate sprocket 204 may be linked to each other by using this as a drive source.
[0055]
As shown in FIG. 30, when the weir 207 is provided in the trough 206 in an inward or outward manner and the weir 207 is returned by the weight 208 (the same applies to the scum skimmer type) as described above. While the circulation roller 210 is moved by the chain 209, the weir 207 is formed by making the response member 212 such as a wire rope or a chain stretched between the fixing pin 211 and the weight 208 correspond to the orbit of the circulation roller 210. You may make it interlock.
[0056]
FIG. 31 and FIG. 32 show a configuration in which an advancing / retracting drive type sludge scraping device is substituted for the flight type sludge scraping device based on the above-mentioned various methods. The settling basin 214 has a pond bottom 216 with a pit 215, side walls 217 and end walls 218. 219 is a pond bottom rail. In these figures, the left direction is the front F in the scraping direction, and the right direction is the rear R in the return direction.
[0057]
In these figures, reference numeral 221 denotes a pair of left and right guide rails, which are fixed to the end wall 218 by the front bracket 222 and the rear bracket 223 so as to be at the center of the pond width and at a height slightly higher than the pond bottom 216. Fixed to. The guide rail 221 has grooves facing each other. A carriage 225 suspended from the guide rail 221 via a traveling roller 224 has a fixed long scraping piece 226 in the front and a fixed short return piece 227 in the back. At the rear, an interlocking cam 230 is provided on a rotating shaft 229 supported by a receiving cylinder 228, and a sludge scraper 231 is provided below the rotating shaft 229 with a stopper 232. Have been.
[0058]
The front sprocket 233 has a larger diameter than the rear sprocket 234, and the sludge chain 235 hung between the front sprocket 233 is held down by a holding sprocket 237 provided on a stay 236 above the guide rail 221. The holding sprocket 237 is rotated and interlocked with the driving sprocket 238 on the pond via the interlocking chain 239, so that the sludge chain 235 is continuously circulated counterclockwise.
[0059]
The state of FIG. 31 and FIG. 32 shows a sludge scraping state. In this state, the sludge chain 235 is driven counterclockwise, and the circulating rollers 240 protruding on both sides of the chain 235 hook the high scraping pieces 226 to move the cart 225 in the direction of the pit. The sludge is scraped by the vertical sludge scraper 231. When the circulation roller 240 further advances and passes over the holding sprocket 237, the sludge is dropped into the pit 215, and at that time, the same roller 240 is lifted up diagonally, so that it comes off the scraping piece 226. Here, while the carriage 225 stops, the circulation roller 240 turns around the front sprocket 233 and moves downward. Under the rotation, the circulation roller 40 catches the interlocking cam 230 and falls down, and at the same time, the sludge scraper 231 lifts. When the circulation roller 240 hits the return projection 227, the carriage 225 returns to the rear R and returns. The imaginary line at the right end in FIG. 31 shows a state in which the carriage 225 returns and the circulation roller 240 moves away from the return protrusion 227. At this point, the carriage 225 stops, and the interlocking cam 230 becomes free to turn the sludge scraper 231. Returns to a vertical raked state under its own weight. At this time, the sludge scraper 231 receives a scraping force by the stopper 232. When the circulating roller 240 that circulates upward and away from the colliding projection piece 226, the carriage 225 is pulled in the opposite scraping direction F.
[0060]
In addition, as shown in FIG. 32, an intermediate beam 241 that supports the middle of the guide rail 221 in the longitudinal direction may be added. Also in this example, similarly, the guide rail 221 may be arranged at the pond end as shown by the imaginary line in FIG. Further, this sludge scraping device may be of the type shown in FIGS. 23, 24, 25 and 26.
Further, as shown in FIG. 31, the scum scraping device 243 may be driven using the same drive source. Since this configuration is substantially the same as described above, the same reference numerals are given.
[0061]
FIGS. 33 and 34 show that the weir 246 is rotatably supported in an inwardly falling manner toward the inside of the trough 245, and is urged by the weight 247 so that the weir 246 is raised. An example is shown in which the weir 246 is brought into a state of being attracted beneath the surface of water by response, and the response is made by the column 249 standing upright from the sludge scraping device that moves up and down the bottom of the pond. That is, a scraper 250 that scrapes scum on the water surface is made to fall and fall on the support 249 by the link 251, and a roller 252 for pushing the response member 248 is protrudingly provided on the front side of the support 249.
[0062]
FIG. 35 (plan view of FIG. 36) and FIG. 36 (longitudinal side view cut along the center of the pond width of FIG. 35) show a pond bottom reciprocating drive type, a long frame type bogie, and four front and rear (limited number). (Not shown) shows an embodiment of a sludge scraping apparatus provided with a scraper.
[0063]
A sludge pit 256 is recessed at a longitudinal end of the pond bottom 255, and a longitudinal end of the settling basin is an end wall 257. Reference numeral 258 denotes a guide rail, and the guide rail 258 is made of H-shaped steel with its groove oriented sideways. Of course, the guide rail 258 may be formed by arranging channel steel on the left and right as in the examples of FIGS. 43 and 44. The guide rail 258 is installed so as to extend over the sludge pit 256 along the center of the pond width of the pond bottom 255, and is fixed by a fastener (not shown) in FIG. ).
[0064]
Reference numeral 260 denotes a bogie, which includes a front bogie 261 and a rear bogie 262 on the left side in the drawing, and is a traveling body capable of rolling on the guide rail 258 with a flat rectangular frame body straddling the front and rear bogies 261 and 262. Rollers 263... At the rear end of the front bogie 261 and at the front end of the rear bogie 262, a rod receiver 264 having a rod through hole is erected, and a connecting pipe 265 made of a round pipe is mounted and fixed therebetween.
[0065]
The connecting rod 265 is provided so that the interlocking rod 266 is driven forward and backward while passing through the pipe and protruding forward and backward. At the front end of the front bogie 261, at the rear end of the rear bogie 262, and at two places before and after the connecting pipe 265, scraper shafts 267 are provided via brackets so as to extend in the pond width direction, and scrapers 268. It is provided to be switchable between vertical and horizontal. The circle on the outer periphery of the scraper shaft 267 rotates together with the scraper 268 on the upper pipe 269.
[0066]
As shown in FIG. 36, the front and rear intervals of the plurality of scrapers 268 are g..., And the advance and retreat stroke is G, which is slightly longer than the interval g. Accordingly, if the second, third, and fourth scrapers 268 from the front advance in the leftward direction F in the scraped state in FIG. 36, they come slightly forward from the positions of the first, second, and third scrapers 268 in FIG. 36, respectively. The sludge is scraped up to that point. For example, the scraped sludge by the fourth scraper 268 is scraped up to the Z position in FIG. Then, the fourth scraper 268 is lifted horizontally there and returns to its original position. Since the third scraper 268 has now returned to the position shown in FIG. 36 behind the Z position, the next time the third scraper 268 advances, it scrapes the sludge one step before. By repeating such an operation, the sludge brought in front of the first scraper 268 is dropped into the sludge pit 256 by the advance of the scraper 268. Therefore, compared to the sludge scraping device using only the front bogie 261, according to the sludge scraping device of the long type, the sludge can be dropped to the pit 256 by the reciprocating movement of the extremely short stroke G.
[0067]
In such movement, in order to switch the scrapers 268... Between the vertical scraping state and the horizontal returning (or returning) state, a pair of left and right first levers 271 is moved from the first upper pipe 269 from the front. Similarly, a pair of left and right second and third levers 272 project from the third upper pipe 269 so as to face diagonally forward when scraped. 36, the front end of the interlocking rod 266 is connected to the first lever 271 via the elongated hole 273, and the second and third levers 272 are connected to the front end of the interlocking rod 266. The protrusions protruding left and right are projected through long holes 274 indicated by thick black lines in FIG. 36, and the protrusions are connected via long holes formed in the second and third levers 272. The fourth lever 275 and the interlocking rod 266 are connected via a direction changing lever 276 so that the fourth scraper 268 operates in the opposite direction to the other scrapers 268. Incidentally, reference numeral 277 denotes an auxiliary cart, which is provided via a stay projecting from the connecting pipe 265, but may not be provided.
[0068]
In order to switch these scrapers 268... And to drive the entire device forward and backward, a chain drive device 280 is configured here. The device 280 has one first frame 281 that is parallel above and separated from the front of the guide rail 258. The frame 281 has a front end fixed to the end wall 257 and is fixedly supported at the center of the pond by two front and rear second frames 282 extending in the pond width direction. 283 is a spacer.
[0069]
Front and rear sprockets 284 are provided in front and rear of the first frame 281 so as to rotate one-to-one in synchronism with the left and right. A chain 285 is wound around the outer periphery of the sprocket 284, and a circulation roller 286 is provided at one position of the chain 285 so as to be a pair of left and right.
[0070]
The first lever 271 is extended slightly longer so that the circulating roller 286 engages downward on the side of the carriage 260 that is the driven side, and is returned from the front carriage 260 so that the circulating roller 286 engages upward. A protruding piece 287 is provided so as to be swingable back and forth longer than the first lever 271. The first lever 271 and the return projection 287 are connected by an interlocking link 288. A stopper 289 defines the scraper 268 vertically, and a stopper for horizontally defining the scraper 268 is also provided.
[0071]
A driven sprocket 290 is provided on the rotation shaft of the front sprocket 284 as shown in FIG. 35, and receives power from the pond to rotate the chain 285 clockwise in FIG. In the embodiment, the first frame 281 is supported by the two second frames 282. However, the number of the second frame 282 may be one, regardless of whether or not the second frame 282 is provided. The first frame 281 may be supported by the hanging member 291 as shown by a diagonal line of the virtual line in FIG. 36, or the first frame 281 may be supported by the vertical frame 292 erected from the guide rail 258. When using the vertical frame 292, a suspension member 293 may be further added.
[0072]
The state shown by the solid line in FIG. 35 and FIG. 36 is the state in which sludge scraping is started. The circulation roller 286 pushes the first lever 271 from the state of the imaginary line to the front oblique state of the solid line around the right end of FIG. 36, and also sets the scraper 268 in a vertical scraping state. Thereby, the other scrapers 268... Are also raked through the interlocking rod 266. When the circulation roller 286 is driven in the F direction, the first lever 271 is pushed by the circulation roller 286, and the carriage 260 moves forward in the F direction. When the circulation roller 286 comes to the position of the virtual line at the left end in FIG. 36, the roller 286 moves upward and gradually comes off the first lever 271. Here, while the carriage 260 stops moving in the scraping posture, the circulation roller 286 rotates the front sprocket 284 in the clockwise direction, and hits a long return projection 287 facing the projection. Will accompany you. As a result, the return protrusion 287 is rotated backward, and the first lever 271 is also rotated in the same direction via the interlocking link 288, thereby lifting the scraper 268 horizontally. The other scrapers 268 are also lifted in conjunction.
[0073]
As a result, the scraper 268 does not reclaim the sludge at the bottom of the pond, and in this state, the carriage 260 starts to retreat for the first time. This state is indicated by a virtual line in FIG. 36, and the circulation roller 286 moves further backward and rotates around the rear sprocket 284, thereby moving downward while discharging the long return projection piece 287 to the outside. Then, the first lever 271 having a short rearward diagonal posture is caused to be brought into a forward diagonal creeping state. At this time, a long return projection 287 is raised from behind the circulation roller 286 and returned obliquely forward. This is done via interlocking link 288.
[0074]
The drive system shown in FIGS. 9, 23 and 24 in which the sprockets are arranged between the frames can be applied to the embodiment shown in FIG. The drive system shown in FIG. 36 may be installed on the rear side of the pond.
[0075]
FIG. 37 shows a case where the driving is performed by the cylinder 295. The cylinder 295 may be hydraulic, but is preferably, for example, a hydraulic type because oil leakage may occur. Alternatively, it may be driven by a liquid that does not cause contamination. The cylinder 295 is provided with a lower parallel auxiliary rod 297 at the tip of a rod 296, and the tip of the rod 297 is connected to the elongated hole 273 of the first lever 271 so as to be responsive. The cylinder 295 is supported and fixed by the support link 298 between the cylinder 295 and the guide rail 258, but may be supported by the method in the embodiment shown in FIG. Further, the cylinder 295 may be arranged behind the pond. When the rod 296 contracts from the scraping state in FIG. 37, the carriage 260 advances in the F direction to perform scraping. When the rod 296 extends in the state of the imaginary line, the first lever 271 is tilted in the R direction, the scraper 268 is lifted, and then the carriage 260 makes a return movement backward. Do this repetitive exercise. Reference numeral 299 denotes a support member for the guide rail 258.
[0076]
FIG. 38 shows an example in which the fixed base 300 is erected on the guide rail 258 and the cylinder 295 is supported by the fixed base 300.
39 and 40 show that the frame of the fixed base 302 embraces and holds the cylinder 303 and extends the frame to guide and hold the roller 305 as the roller guide 304 to stably drive the rod 306 and the auxiliary rod 307. It was done.
[0077]
FIG. 41 is a front view showing a case where a hydraulic rope cylinder 313 provided with a sheave 310 on the front and rear and connected to an internal piston 311 and passed around the sheave 310 is driven forward and backward by an engagement piece 314 protruding from the rope 312. One lever 271 is made to respond.
[0078]
In FIG. 42, a cylinder 317 is installed in a space inside a guide rail 258 composed of a pair of left and right frames, and the rod 318 expands and contracts to allow both the scraper 268 and the carriage 260 to respond. That is, by connecting the rod 318 and the interlocking rod 266 with the interlocking member 319 to expand and contract the rod 318, the first lever 271 is switched between the scraping state and the returning state, and When the interlocking member 319 is provided with the front and rear stoppers 320 and moves by a fixed amount, the truck 260 is alternately brought into contact with one of the front and rear stoppers 320 to drive the carriage 260 forward and backward.
[0079]
In FIG. 42, the state where the scraper 268 is lifted and returned is shown by a solid line. In this state, the rod 318 extends to the full extent, and the rod 318 contracts as much as a, so that the scraper 268 enters a vertical scraping state via the interlocking member 319, the interlocking rod 266 and the first lever 271. At that time, the interlocking member 319 hits the front stopper 320, and moves the carriage 260 forward. When the rod 318 contracts by about b, the scraping ends, and the scraper 268 is lifted by the rod 318 extending by about a, and then the carriage 260 is returned to the original position by further extending by about b. In FIG. 43, the groove of the channel steel is directed outward, but a guide rail may be formed with the groove directed inward as shown in FIG.
[0080]
FIG. 45 shows a rear carriage 324 that can be advanced and retracted by a connecting pipe 323 on a guide rail 322 and a plurality of front and rear levers 325 and a scraper 326 in which a cylinder 327 is installed in the rear part of the guide rail 322. In particular, one end of the rod 328 of the cylinder 327 is caused to respond to one of the levers 325, and after the bogie 324 is moved in the left direction of the arrow, the cylinder 327 is separately vertically operated from the pond, and then the head 329 is moved. The rod 328 can be pulled out and replaced by loosening it.
[0081]
【The invention's effect】
In the method according to the first aspect of the present invention, the sludge which has flowed into a treatment pond such as a rectangular sedimentation pond in a state where it is rectified from a position above the sludge pit at one end in the pond longitudinal direction is used to scrape sludge settled on the bottom of the pond by a scraping member. This is a sludge scraping method configured to be dropped into the sludge pit. Sludge settled near the sludge pit on the bottom of the pond is scraped to the sludge pit side more heavily than other sludges, so operation is started. It is possible to provide a sludge scraping method and a device capable of minimizing loss.
[Brief description of the drawings]
FIG. 1 is an overall plan view of a pond equipped with a scraping device showing an embodiment of the present invention.
FIG. 2 is a vertical side view of the scraping device of FIG. 1;
FIG. 3 is a side sectional view showing another embodiment.
FIG. 4 is a side sectional view showing another embodiment.
FIG. 5 is a side sectional view showing another embodiment.
FIG. 6 is a plan view showing another embodiment.
FIG. 7 is a side sectional view of FIG. 6;
FIG. 8 is a sectional view taken along line VIII-VIII in FIG. 9;
FIG. 9 is a plan view of FIG. 8;
FIG. 10 is an operation explanatory diagram of FIG. 8;
FIG. 11 is an operation explanatory view of FIG. 8;
FIG. 12 is a cross-sectional view showing a relationship between a scraping piece and a circulation roller.
FIG. 13 is an operation explanatory view of FIG. 8;
FIG. 14 is an operation explanatory view of FIG. 8;
FIG. 15 is an operation explanatory view of FIG. 8;
FIG. 16 is an operation explanatory view of FIG. 8;
FIG. 17 is an operation explanatory view of FIG. 8;
FIG. 18 is a longitudinal sectional view showing another embodiment.
FIG. 19 is a longitudinal sectional view showing another embodiment.
FIG. 20 is a side sectional view showing another embodiment.
FIG. 21 is a side sectional view showing another embodiment.
FIG. 22 is a longitudinal sectional view showing another embodiment.
FIG. 23 is a side sectional view showing another embodiment.
FIG. 24 is a side sectional view showing another embodiment.
FIG. 25 is a side sectional view showing another embodiment.
FIG. 26 is a sectional view taken along line PP of FIG. 25;
FIG. 27 is a side sectional view showing another embodiment.
FIG. 28 is a side sectional view showing another embodiment.
FIG. 29 is a side sectional view showing another embodiment.
FIG. 30 is a side sectional view showing another embodiment.
FIG. 31 is a side sectional view showing another embodiment of the sludge scraping device.
FIG. 32 is a transverse sectional view of FIG. 31.
FIG. 33 is a side sectional view showing another embodiment.
FIG. 34 is a plan view of FIG. 33;
FIG. 35 is a plan view of FIG. 36;
FIG. 36 is a side view of the center vertical section in FIG. 35;
FIG. 37 is a longitudinal sectional side view showing another embodiment.
FIG. 38 is a longitudinal sectional side view showing another embodiment.
FIG. 39 is a side view of a main part showing another embodiment.
40 is a view as seen from the direction of arrow Q in FIG. 39.
FIG. 41 is a longitudinal sectional side view showing another embodiment.
FIG. 42 is a longitudinal sectional side view showing another embodiment.
FIG. 43 is a sectional view taken along line MM of FIG. 42;
FIG. 44 is a longitudinal sectional front view showing another embodiment.
FIG. 45 is a longitudinal sectional side view showing another embodiment.
[Explanation of symbols]
A: First scraping device B: Second scraping device 1: Sedimentation basin 6: Sludge pit
7 rectifying holes 22, 23 scraping member 25 driving source.

Claims (4)

Sewage is flowed into a treatment pond such as a rectangular sedimentation pond in a state where it is rectified from the upper position of the sludge pit at one end in the longitudinal direction of the pond, and the sludge settled on the bottom of the pond is dropped into the sludge pit by a scraping member. A method for scraping sludge, wherein sludge settled near a sludge pit on a pond bottom is scraped to a sludge pit side more preferentially than other sludge. A treatment basin such as a rectangular sedimentation basin having a rectification means for rectifying and flowing sewage water at one end in the longitudinal direction with a direction orthogonal to the direction in which the left and right side walls are opposed to each other and a sludge pit formed at the bottom of the lower pond. A sludge scraping device configured to scrape sludge at the bottom of the pond in the direction of the sludge pit and scrape the sludge into the pit by a scraping operation of a scraping member attached to the bottom of the pond. Is divided into a plurality of stages of scraping devices in the longitudinal direction before and after, and the scraping device on the sludge pit side has the largest scraping ability per hour, and the scraping ability per hour becomes larger as it goes to the opposite pit side. A sludge scraping device characterized by being driven small. 3. The apparatus according to claim 2, wherein the apparatus comprises a first scraping device on the sludge pit side and a second scraping device on the anti-sludge pit side with respect to the same device. Sludge scraping device that is driven in a simultaneous drive relationship by a drive source. In the second aspect, at the bottom of the pond, a step which is lowered in the direction of the sludge pit is formed, and the sludge from the pre-stage scraping device flows through the step to flow into the next post-stage. Sludge scraper that is to be delivered to the scraper.

Images