Sludge scraping device

Abstract

To provide a sludge scraping device comprising a guide mechanism which has a high reliability in operation and is less likely to malfunction.SOLUTION: A sludge scraping device comprises: a scraping frame having a plurality of scrapers which guide sludge to a sludge pit; a drive unit which reciprocates the scraping frame in a sedimentation pond; a guide device 40 guides the scraper along a floor surface of the sedimentation pond when the scraping moves forward, and guides the scraper at a higher position than that during forward movement when the scraper moves backward; and a hanging member 30 which so hangs the scraping frame as to be movable with respect to the guide device 40, and travels along the guide device. The hanging member 30 has: a plurality of rollers 31 which move in the guide device 40; a plurality of roller support members 32 which are respectively provided on left and right outsides in a width direction of the guide device 40, and rotatably support the roller 31; and an assembly member 33 which fits the roller support member 32 to the scraping frame.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a sludge scraper for use in a settling basin in water and sewage treatment. [Background technology]

[0002] BACKGROUND ART A sludge scraper has been known as a device for collecting sludge deposited on the floor of a sedimentation basin such as a primary sedimentation basin or a final sedimentation basin into a sludge pit.

[0003] The applicant has proposed a sludge scraper that can scrape sludge with little power while preventing sludge from flying up during sludge scraping (Patent Document 1). The sludge scraper described in Patent Document 1 is installed in a rectangular settling basin with a sludge pit. This sludge scraper comprises a scraper frame equipped with multiple scrapers that guide sludge into the sludge pit, a drive unit that reciprocates the scraper frame, and a guide unit for adjusting the height of the scrapers on the scraper frame. The guide unit has a seesaw-type flap structure that movably hangs the scraper frame, guides the scrapers along the floor of the sludge settling basin when the scraper frame moves forward, and guides the scrapers at a higher height when the scraper frame returns. The sludge scraper also comprises a hanging member equipped with a roller that is guided by the guide unit, and the scraper frame hangs movably from the guide unit via the hanging member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-253468 Summary of the Invention [Problem to be solved by the invention]

[0005] 12 and 14, the sludge collector (10) proposed in Patent Document 1 has a hanging member (40) in which rollers (45) are rotatably attached to both ends of a roller support member (43), and a guide device (50) formed with a pair of seesaw plates (first flap member 59, second flap member 65) and guide rails (50A, 50B) for guiding the two rollers (45). In other words, the roller support member (43) of the hanging member (40) is disposed so as to be sandwiched between the pair of seesaw plates on the guide rails (50A, 50B), and the two rollers (45) attached to the roller support member (43) move on the seesaw plates.

[0006] The two seesaw plates constituting this guide device (50) repeatedly oscillate around a shaft as the rollers (45) move, with one side bouncing up and the other side simultaneously being pushed down. Because the operation of this guide device (50) is directly linked to the reciprocating motion of the scraper frame (20), the guide device (50) is required to be highly reliable. However, the guide device (50) described in Patent Document 1 is configured so that the two seesaw plates each perform an independent oscillating motion. Therefore, if, for example, the two rollers (45) apply uneven loads to each seesaw plate due to the way in which the force required to scrape sludge from the bottom of the sedimentation tank is applied to each seesaw plate, a mismatch in the timing of the two seesaw plates bouncing up and down can occur. Such a mismatch in the timing of the oscillating motion of the two seesaw plates can cause the guide device (50) to malfunction. Furthermore, in Patent Document 1, each guide device (50) is equipped with two seesaw plates, resulting in two operating points per guide device (50). There is room for improvement in terms of improving operational reliability and reducing costs.

[0007] SUMMARY OF THE INVENTION Therefore, a main object of the present invention is to provide a sludge scraper equipped with a guide mechanism that is highly reliable in operation and less prone to breakdowns. [Means for solving the problem]

[0008] The inventor of the present invention has intensively studied means for solving the problems of the above-mentioned conventional inventions, and has found that in a guide mechanism for moving multiple rollers within a guide device, by arranging roller support members for supporting each roller on the left and right outer sides of the guide device in the width direction (Y-axis direction) and sandwiching the guide device between the pair of roller support members, the number of operating points and parts of the guide mechanism can be reduced, and operational reliability and durability can be improved. Based on this finding, the inventor has conceived that the problems of the conventional inventions can be solved and has completed the present invention. Specifically, the present invention has the following configuration.

[0009] The present invention relates to a sludge scraper. The sludge scraper of the present invention is installed in a settling basin having a sludge pit. The sludge scraper comprises a scraper frame, a drive unit, a guide unit, and a hanging member. The scraper frame has multiple scrapers that guide sludge to the sludge pit. The drive unit reciprocates the scraper frame within the settling basin. The guide unit is configured to guide the scrapers along the floor of the settling basin when the scraper frame moves forward and to guide the scrapers at a higher position when the scraper frame returns, and is provided at at least two locations along the length of the scraper frame. The hanging member suspends the scraper frame movably relative to the guide unit and travels along the guide unit. Each hanging member has multiple rollers, multiple roller support members, and an assembly member. Each roller moves within the guide unit. The multiple roller support members are provided on the left and right outer sides of the guide unit in the width direction, and each rotatably supports a roller. In other words, the guide device is sandwiched between two pairs of roller support members from the left and right outside. The assembly members attach the multiple roller support members to the scraper frame. The sludge scraper described in Patent Document 1 has two seesaw plates for the guide device for each of the two rollers of the hanging member. In contrast, the sludge scraper according to the present invention has only one guide device for each of the two rollers of the hanging member. In this way, the present invention reduces the number of operating points and parts in the entire guide mechanism consisting of the hanging member and guide device. Therefore, the present invention can improve the reliability and durability of the guide mechanism.

[0010] In the sludge collector according to the present invention, each of the guide mechanisms preferably includes a roller positioning unit, a floor member, an upper surface member, and a movable guide member. The roller positioning units are provided at both longitudinal ends (X-axis direction) of the guide device and hold the roller at a height at which the scraper moves along the floor surface of the sedimentation basin. The floor member is a linear member connecting the floor surfaces of the two roller positioning units. The upper surface member is a substantially trapezoidal member connecting the upper surfaces of the two roller positioning units. The movable guide member is rotatably supported between the floor member and the upper surface member in an area facing the upper bottom of the upper surface member. In this case, the roller moves on the floor member when the collector frame moves forward, and moves on the movable guide member when the collector frame moves back. This allows the moving height of the scraper to be changed efficiently.

[0011] In the sludge collector according to the present invention, the movable guide member preferably has a shelf portion, a first flap portion, and a second flap portion. The shelf portion is pivotally supported in a region facing the upper bottom of the upper surface member between the floor member and the upper surface member. The first flap portion extends from one end of the shelf portion toward the rear end of the collecting frame and is raised toward the upper surface member to allow the roller to move on the floor member when the collecting frame moves forward. When the collecting frame returns, it is pressed down onto the floor member via the roller to form a roller tread. The second flap portion extends from the other end of the shelf portion toward the front end of the collecting frame. When the collecting frame moves forward, it is raised toward the upper surface member as the roller moves on the floor member and is pressed down onto the floor member after the roller has passed, to form a roller tread when the collecting frame returns. Note that the shelf portion, first flap portion, and second flap portion of the movable guide member are preferably integrated so that they can all swing. By adopting a movable guide member that oscillates like a seesaw in this way, the height of movement of the roller when returning can be mechanically and automatically made higher than the height of movement of the roller when going forward (when scraping).

[0012] In the sludge collector according to the present invention, the guide device preferably includes a tensioning means and an impact absorbing means. The tensioning means pulls the first flap portion of the movable guide member toward the upper surface member and biases it so that it remains in its initial position. The impact absorbing means absorbs the impact applied to the first flap portion when the first flap is pushed down onto the floor member and then pulled up to its initial position by the tensioning means. By providing the tensioning means in this manner, the first flap portion of the movable guide member can be quickly raised, thereby improving the operating speed of the sludge collector. On the other hand, if a tensioning means is used, it is conceivable that a large impact will be applied to the first flap itself and other parts in contact with it when the first flap portion is raised. Therefore, by using the impact absorbing means to absorb the impact applied to the first flap, etc., failure of the entire guide device can be prevented.

[0013] In the sludge scraper according to the present invention, the drive device is preferably a hydraulic or pneumatic cylinder. Because the sludge scraper has a relatively slow operating speed, it can be operated using a hydraulic or pneumatic cylinder with a small amount of compressed air or water. Furthermore, because there is no need for a power supply unit or on-site operation panel for each sludge scraper, the cost of electrical equipment can be kept low.

[0014] In the sludge collector according to the present invention, the drive device preferably includes a piston, a cylinder tube, a valve, and an operating arm. The piston includes a rod connected to the collector frame. The cylinder tube includes a first operating chamber to which a working fluid, such as water or air, is supplied to move the piston forward, and a second operating chamber to which a working fluid is supplied to move the piston back. The valve switches the destination of the working fluid between the first operating chamber and the second operating chamber. The operating arm mechanically links the reciprocating movement of the rod with the valve's operation for switching the supply destination. In this way, by mechanically switching the destination of the working fluid shared by the valve in accordance with the reciprocating movement of the piston's rod, it is possible to automatically switch the reciprocating movement of the piston, and therefore the reciprocating movement of the collector frame. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a sludge scraper equipped with a guide mechanism that is highly reliable in operation and less prone to failure. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a side view showing the overall configuration of the sludge scraper. [Figure 2] FIG. 2 is a side view showing an example of a guide mechanism made up of a guide device and a hanging member. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 5 is a schematic diagram showing the operation of the rollers in the guide device. [Figure 6] FIG. 6 is a schematic diagram showing the configuration of the drive device, and particularly shows the flow of the working fluid when the piston is moved in the forward direction. [Figure 7] FIG. 7 is a schematic diagram showing the configuration of the drive unit, and particularly shows the flow of the working fluid when the piston is moved in the backward direction. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below, and includes appropriate modifications of the embodiments described below within the scope obvious to those skilled in the art. 1 to 4 show an XYZ Cartesian coordinate system. The X-axis direction is the longitudinal direction of the sludge collector, the Y-axis direction is the width direction of the sludge collector, and the Z-axis direction is the height direction of the sludge collector.

[0018] The sludge collector 10 according to this embodiment is installed in a rectangular settling basin having a sludge pit. The sludge collector 10 is configured to guide sludge accumulated on the bottom of the settling basin 1, which is approximately rectangular in plan view, to the sludge pit 2.

[0019] As shown in FIG. 1, the sludge collector 10 mainly comprises a collector frame 20, a hanging member 30, a guide device 40, a suspension support 50, and a drive device 60. The collector frame 20 is arranged along the longitudinal direction of the settling basin 1 and is equipped with multiple scrapers 24, multiple anti-vibration wheels 25, and a scum collector 26. The hanging member 30 is fixed at its lower end to the top of the collector frame 20 and connected at its upper end to the guide device 40. The guide device 40 is fixed by the suspension support 50 between opposing longitudinal walls of the settling basin 1 and is configured to suspend the hanging member 30 via rollers 31 (described below). The drive device 60 is fixed to the wall above the sludge pit 2 of the settling basin 1 and reciprocates the collector frame 20 in the longitudinal direction of the rectangular settling basin 1.

[0020] As shown in FIG. 1 , the scraper frame 20 comprises one upper chord 21 arranged in the longitudinal direction of the sedimentation basin 1, two lower chords 22 arranged parallel to the upper chord 21 in the longitudinal direction of the sedimentation basin 1, and multiple web members 23 connecting the upper chord 21 and the lower chords 22. The upper chord 21, lower chords 22, and web members 23 form a space truss structure. A hanging member 30 is attached to the upper part of the upper chord 21, and multiple scrapers 24 and anti-sway wheels 25 are attached to the lower part of the lower chord 22. The upper chord 21, lower chords 22, and web members 23 may be made of, for example, stainless steel pipes. The tip of the scraper frame 20 in the forward direction (scraping direction) is connected to a piston 64 of a drive unit 60.

[0021] The scrapers 24 have a length approximately equal to the width of the bottom of the sedimentation basin 1 and are attached at approximately equal intervals along the longitudinal direction of the scraper frame 20 in order to guide sludge on the bottom of the sedimentation basin 1 to the sludge pit 2. The scrapers 24 may be made, for example, of L-shaped stainless steel plates or FRP. The scrapers 24 are installed with a gap of approximately 10 to 20 mm between their lower ends and the bottom of the sedimentation basin 1 so that they do not touch the bottom during scraping. The anti-sway wheels 25 are attached to the lower chord 22 of the scraper frame 20 with the wheel contact surface parallel to the bottom. The anti-sway wheels 25 may be installed in appropriate locations on the scraper frame 20. The anti-sway wheels 25 are installed with a gap of about 5 to 10 mm between them and the bottom of the sedimentation basin 1 so that they do not touch the bottom even when at the normal lowest position, in order to protect the scraper 24 in the event of uneven load caused by sludge accumulation or lateral shaking due to an earthquake. In other words, when the scraper frame 20 rotates around an axis in the longitudinal direction of the sedimentation basin 1, the anti-sway wheels 25 touch the bottom of the basin before either end of the scraper 24 touches the bottom.

[0022] The scum scraper 26 guides scum floating on the sedimentation basin 1 to a pipe-type scum skimmer 28. The scum scraper 26 has a length roughly equal to the width of the sedimentation basin 1 and is attached to the top of the scraper frame 20. Like the upper chord 21 and lower chord 22 of the scraper frame 20, the scum scraper 26 is constructed by assembling stainless steel connecting members such as rods or pipes into a frame shape, and its shape can be maintained by bracing or the like. A scum scraper blade 27 is fixed to the top of the scum scraper 26 with a fastener such as a U-bolt. Like the scraper 24, this scum scraper blade 27 may be constructed of an L-shaped stainless steel plate or FRP.

[0023] Furthermore, it is preferable to attach floats 29 to the sluice frame 20. The floats 29 are floating elements that impart buoyancy to the sluice frame 20. The floats 29 are attached to the lower chord 22 (or upper chord 21) of the sluice frame 20 along its entire length or at several discontinuous locations. By providing the floats 29, the sluice frame 20 is pushed up by the buoyancy of the floats 29 when it returns to its original position, thereby reducing the power required by the drive unit 60. The floats 29 are preferably formed by sealing both ends of a pipe made of a synthetic resin such as polyvinyl chloride or a light metal such as aluminum, and filling the pipe with a foam material. While the foam material may be made from any suitable material, resin materials such as polyethylene, polystyrene, polypropylene, and polyurethane can be used. Filling the pipe of the float 29 with a foam material in this way prevents the buoyancy of the float 29 from decreasing even if liquid from the sedimentation basin 1 enters the pipe.

[0024] 2, 3, and 4 are mainly drawn to illustrate the guide mechanism consisting of the hanging member 30 and guide device 40 shown in the outline of FIG. 1. In this embodiment, the guide mechanism combining the hanging member 30 and the guide device 40 is provided at two locations, one on the front side and one on the rear side of the scraping frame 20. Such guide devices 40 must be provided at at least two locations, but may be provided at three or more locations.

[0025] As shown in FIG. 2 , the hanging member 30 is fixed to the upper part of the upper chord member 21 of the gathering frame 20. The hanging member 30 mainly includes a plurality of rollers 31, a plurality of roller support members 32, and an assembly member 33. As can be seen from FIG. 3 , in this embodiment, one hanging member 30 is provided with two pairs of rollers 31, and these pairs of rollers 31 are arranged to face each other in the width direction (Y-axis direction) with a guide device 40 sandwiched therebetween. In other words, the guide device 40 is located between the pair of rollers 31. Similar to the rollers 31, two roller support members 32 are provided in pairs on one hanging member 30, and one roller 31 is rotatably mounted near the upper end of each roller support member 32. In other words, the roller 31 has a rotation shaft 31a pivotally mounted to a bearing 31b, and rotates around this rotation shaft 31a, which is fixed to the upper end of the roller support member 32 by a fastener or the like. Each roller support member 32 extends substantially vertically downward from the fixed portion of the roller 31, and its lower end is fixed to an assembly member 33 by welding or the like. The assembly member 33 is a member for attaching the hanging member 30 to the upper chord member 21 of the gathering frame 20, and the hanging member 30 and the gathering frame 20 are firmly joined to each other by screws or the like.

[0026] As shown in Figures 2 to 4, the guide device 40 has a travel path formed therein for the rollers 31 of the hanging member 30, and the scraper frame 20 is suspended movably via the hanging member 30. First, the guide device 40 has a linear forward path that guides the rollers 31 of the hanging member 30 so that the scraper 24 moves along the bottom of the sedimentation basin 1 when the scraper frame 20 moves forward (during scraping). Second, the guide device 40 has a substantially trapezoidal return path that guides the rollers 31 so that the scraper 24 rises from above the bottom of the sedimentation basin 1 to a position higher than the height at which it was raised and then falls back to the original height when the scraper frame 20 returns to its original position. In this way, the guide device 40 causes the rollers 31 of the hanging member 30 to follow paths at different heights on the way there and back, so that when the scraper frame 20 goes out, the scraper 24 carries the sludge accumulated on the bottom of the pond toward the sludge pit 2, and when the scraper frame 20 returns, the scraper 24 is pulled away from the sludge accumulated on the bottom of the pond, so that the sludge is not stirred up. As shown in Figure 1, the guide device 40 is attached so as to hang down from a suspension support 50 spanning the walls of the sedimentation basin 1, and the position of the guide device 40 within the sedimentation basin 1 does not change even if the rollers 31 move within it.

[0027] More specifically, as shown in Fig. 2, the guide device 40 has a linear floor member 41 disposed substantially parallel to the bottom of the sedimentation basin 1, and wall members 42 provided at both ends of the floor member 41 in the longitudinal direction (X-axis direction). The roller 31 traveling within the guide device 40 comes into contact with the wall member 42 and is temporarily stopped. Thus, at both ends of the longitudinal direction of the floor member 41, at the positions where the floor member 41 and the wall member 42 intersect, roller positioning units 40(A) and 40(B) are formed to hold the roller 31 at a height that allows the scraper 24 to move along the bottom of the sedimentation basin 1. The upper surfaces of these roller positioning units 40(A) and 40(B) are connected by an upper surface member 43 that is substantially trapezoidal in side view. That is, the top surface member 43 has parallel surfaces 43a parallel to the floor member 41 at the top of each of the roller positioning portions 40(A) and 40(B), has inclined surfaces 43b extending diagonally upward from these parallel surfaces 43a toward the longitudinal center of the guide device 40, and has a top surface 43c between the two inclined surfaces 43b that is again parallel to the floor member 41. The space surrounded by the floor member 41, the wall member 42, and the parallel surfaces 43a functions as the roller positioning portions 40(A) and 40(B). The two parallel surfaces 43a, the two inclined surfaces 43b, and the top surface 43c of the top surface member 43 may each be formed by separate plate-like members, or may be formed by bending a single plate-like member.

[0028] The guide device 40 is provided with a movable guide member 44 at an intermediate position between the floor member 41 and the top surface member 43 in the height direction (Z-axis direction), i.e., in the region where the floor member 41 and the top surface member 43 face each other. As shown in FIG. 2, the movable guide member 44 is rotatably supported via a rotation shaft 45 on a partition wall 46 provided at approximately the center of the guide device 40 in the longitudinal direction (X-axis direction). The movable guide member 44 has a shelf portion 44a located directly above the rotation shaft 45, a first flap portion 44b extending from one end of the shelf portion 44a toward the rear end side of the scraper frame 20 (i.e., the roller positioning portion 40(A) side), and a second flap portion 44c extending from the other end side of the shelf portion 44a toward the front end side of the scraper frame 20 (i.e., the roller positioning portion 40(B) side). The shelf portion 44a, first flap portion 44b, and second flap portion 44c of the movable guide member 44 form an integrated seesaw structure, and the entire structure moves in conjunction with each other when rotating around the rotation shaft 45. The shelf portion 44a, first flap portion 44b, and second flap portion 44c each have a tread surface (running surface) that comes into contact with the rollers 31 when they run. When the tread surface of the shelf portion 44a is approximately parallel to the floor member 41, the tread surfaces of the first flap portion 44b and the second flap portion 44c each form a slope that slopes downward from the shelf portion 44a.

[0029] As shown in FIG. 2, a support plate 49 is attached to the first flap portion 44b, and this support plate 49 is connected to a tension spring 47. The tension spring 47 has an upper end fixed to the upper surface of the housing of the guide device 40 and a lower end fixed to the support plate 49 of the first flap portion 44b, thereby pulling the first flap portion 44b upward. Therefore, as shown in FIG. 2, the first flap portion 44b is constantly urged by the tension spring 47 to push up toward the inclined surface 43b of the upper surface member 43, and this state is the initial position of the first flap portion 44b. As a result, when the roller 31 is in the roller positioning portion 40(A) on the rear end side of the scraper frame 20, it can move straight on the floor member 41 toward the roller positioning portion 40(B) on the opposite side without being obstructed by the first flap portion 44b of the movable guide member 44. Meanwhile, as the roller 31 moves straight on the floor member 41 from the roller positioning portion 40(A) on the rear end side toward the roller positioning portion 40(B) on the opposite side, it comes into contact with the underside of the second flap portion 44c of the movable guide member 44. Then, as the roller 31 continues to move straight, the second flap portion 44c is pushed up by the roller 31, while the first flap portion 44b is pushed down by a reaction force with the pivot shaft 45 as a fulcrum. When the first flap portion 44b is pushed down in this way, the tension spring 47 temporarily expands, but then contracts again, acting to pull the first flap portion 44b upward.

[0030] As shown in FIG. 2, a shock absorbing spring 48 is attached to the support plate 49 of the first flap portion 44b. The shock absorbing spring 48 has a spring 48b housed in a cylinder 48a, and the spring 48b is compressed as the piston rod 48c retracts. The cylinder 48a of the shock absorbing spring 48 is fixed to the upper surface of the housing of the guide device 40, and the tip of the piston rod 48c is fixed to the support plate 49 of the first flap portion 44b. As described above, the first flap portion 44b is pushed downward and then bounced upward by the action of the tension spring 47. When the first flap portion 44b rises during this bounce, the piston rod 48c temporarily compresses the spring 48b in the cylinder 48a, and then the spring 48b returns to its original state. In this way, the shock absorbing spring 48 absorbs the shock when the first flap portion 44b bounces up. When the first flap portion 44b is flipped up, there is a possibility that it may come into contact with the inclined surface 43b of the upper surface member 43 of the first flap portion 44b, but the impact at the time of flipping up is absorbed by the shock absorbing spring 48, thereby preventing damage to the first flap portion 44b, the upper surface member 43, etc.

[0031] The second flap portion 44c is constantly pressed downward by the action of the tension spring 47. Therefore, as shown in FIG. 2, the second flap portion 44c is constantly biased downward toward the floor member 41 by the tension spring 47, and this state is the initial position of the second flap portion 44c. As a result, when the roller 31 is in the roller positioning portion 40(B) on the front end side of the scraping frame 20, it can proceed on the tread surface of the movable guide member 44 toward the roller positioning portion 40(A) on the opposite side without being obstructed by the second flap portion 44c of the movable guide member 44. On the other hand, when the roller 31 proceeds on the tread surface of the movable guide member 44 from the roller positioning portion 40(B) on the front end side toward the roller positioning portion 40(A) on the opposite side, it comes into contact with the inclined surface 43b of the upper surface member 43. As the roller 31 continues to move forward, the first flap portion 44b is pushed down as the roller 31 moves forward, while the second flap portion 44c is pushed up by a reaction force with the pivot shaft 45 as a fulcrum. When the second flap portion 44c is pushed up in this way, the tension spring 47 temporarily expands, but then contracts again, acting to push the second flap portion 44c downward.

[0032] As shown in FIG. 2, a partition wall 46 is provided in the center of the guide device 40 in the longitudinal direction (X-axis direction), and a rotation shaft 45 of the movable guide member 44 is fixed to this partition wall 46. As shown in FIG. 3, this partition wall 46 is formed in the center of the guide device 40 in the width direction (Y-axis direction), and divides the tread surface of the floor member 41 of the guide device 40 into left and right halves in the width direction. That is, the floor member 41 of the guide device 40 is divided into a first guide rail 41(A) located on the left side in the width direction across the partition wall 46, and a second guide rail 41(B) located on the right side in the width direction across the partition wall 46. As shown in FIG. 3, the guide device 40 is sandwiched between two pairs of rollers 31, and the roller 31 on the left side in the width direction runs on the first guide rail 41(A), and the roller 31 on the right side in the width direction runs on the second guide rail 41(B). A partition 46 is located between a pair of rollers 31, but the width of the rollers 31 and the width of each guide rail 41(A), 41(B) are adjusted so that each roller 31 does not come into contact with this partition 46 while the floor member 41 is moving.

[0033] 4 mainly shows the movable guide member 44 in a plan view. The movable guide member 44 includes a first seesaw plate 44d on the left side of the partition wall 46 in the width direction and a second seesaw plate 44e on the right side of the partition wall 46 in the width direction, and is configured by connecting the first seesaw plate 44d and the second seesaw plate 44e. That is, each seesaw plate 44d, 44e has a support plate 49 attached to each of the front end side and the rear end side of the partition wall 46. The support plate 49 of the first seesaw plate 44d and the support plate 49 of the second seesaw plate 44e are joined together with fasteners 49a such as bolts and nuts, thereby integrating the two seesaw plates 44d, 44e. Each seesaw plate 44d, 44e has a notch formed near the center in the longitudinal direction to prevent interference with the partition wall 46. In this way, the movable guide member 44 has a structure in which two seesaw plates 44d, 44e, which are divided into left and right halves in the width direction, are joined together, and the two seesaw plates 44d, 44e repeatedly swing in unison. This reduces the number of operating points within the guide device 40. Furthermore, when two pairs of rollers 31 run on the tread surfaces of the movable guide member 44, the roller 31 on the left side in the width direction runs on the first seesaw plate 44d, and the roller 31 on the right side in the width direction runs on the second seesaw plate 44e.

[0034] Figure 5 is a schematic diagram showing the operation of the guide mechanism consisting of the aforementioned hanging member 30 and guide device 40. In particular, Figure 5 shows the operation of roller 31 of hanging member 30 and movable guide member 44 of guide device 40, and the guide mechanism reciprocates scraper frame 20 in settling basin 1 by repeatedly performing the operations in the order of (1) to (6) in Figure 5.

[0035] First, as shown in FIG. 5(1), the roller 31 held by the roller positioning portion 40(A) at the right end of the guide device 40 moves straight on the floor member 41 toward the roller positioning portion 40(B) at the left end of the drawing, as shown in FIGS. 5(2) and 5(3). At this time, the first flap portion 44b is constantly pulled up toward the upper surface member 43b of the upper surface member 43 by the tension spring 47. Because the floor member 41 is a linear, flat surface, the series of movements shown in FIGS. 5(1) to 5(3) causes the scraper frame 20 to move straight along the bottom of the sedimentation basin 1. In this way, the scraper frame 20 moves the lower ends of the multiple scrapers 24 at intervals of approximately 10 to 20 mm from the bottom of the sedimentation basin 1, thereby moving the sludge accumulated on the bottom toward the sludge pit 2.

[0036] Next, as shown in FIG. 5(3), when the roller 31 abuts against the second flap portion 44c blocking its travel path, the second flap portion 44c is pushed up toward the slope 43b of the upper surface member 43 as the roller 31 moves. Before the second flap portion 44c abuts against the roller 31, the second flap portion 44c is constantly pressed down toward the floor member 41 by the tension spring 47, as shown in FIGS. 5(1) and 5(2). Therefore, when the roller 31 moves to the roller positioning portion 40(B) at the left end of the drawing, the second flap portion 44c is again pressed down toward the floor member 41 by the tension action of the tension spring 47. This point marks the end of the distance over which the drive device 60 pulls the scraper frame 20.

[0037] Next, as shown in FIG. 5(4), the roller 31 held by the roller positioning portion 40(B) at the left end of the guide device 40 moves on the tread of the movable guide member 44 toward the roller positioning portion 40(A) at the right end of the drawing, as shown in FIGS. 5(5) and 5(6). At this time, the roller 31 is gradually lifted above the floor member 41 as it moves on the second flap portion 44c. As the roller 31 moves, the scraper frame 20 also moves upward. As a result, the multiple scrapers 24 gradually rise from the pond bottom along the movement trajectory of the scraper frame 20. Therefore, the scrapers 24 are lifted away from the sludge accumulated on the pond bottom, and they are less likely to stir up sludge when they return. Then, when the roller 31 is transferred onto the shelf portion 44a, the roller 31 changes to traveling parallel to the floor member 41 (or the pond bottom) as shown in FIG. 5(5).

[0038] Next, as shown in FIG. 5(6), the roller 31 moves from the shelf portion 44a onto the tread of the first flap portion 44b, pushing down the first flap portion 44b as it moves. Then, as shown in FIG. 5(1), the roller 31 again reaches the roller positioning portion 40(A) at the right end of the drawing. This point marks the end point for the drive unit 60 to push out the scraper frame 20. As shown in FIG. 1, the scum scraper blades 27 of the scum scraper 26 are positioned across the entire width of the sedimentation basin 1, with their upper ends visible above the water surface. Therefore, when the scraper frame 20 returns, the scum scraper 26 guides scum floating near or on the water surface to the pipe-type scum skimmer 28, where it can be removed.

[0039] Thereafter, the process described here is repeated in sequence. By repeating this process, the sludge deposited on the bottom of the settling basin 1 is gradually sent toward the sludge pit 2 by the scraper 24, and is finally sent into the sludge pit 2 by the scraper 24 located at the tip of the scraper frame 20.

[0040] Next, a preferred embodiment of a drive device 60 for causing the scraper frame 20 to perform the above-mentioned reciprocating motion will be described with reference to Figures 6 and 7. As shown in Figures 6 and 7, the drive device 60 in this embodiment mainly includes a supply source 61, an adjustment device 62, a speed control valve 63, a piston 64, a cylinder tube 65, a valve 66, and an operating arm 67.

[0041] The supply source 61 supplies a working fluid for moving the piston 64 back and forth. In this embodiment, water or air is used as the working fluid. The working fluid is ultimately released into the settling basin 1 or into the atmosphere, so it is not preferable to use oil as the working fluid. In the case of a hydraulic system, the supply source 61 is a water pump, and in the case of a pneumatic system, the supply source 61 is an air compressor.

[0042] The adjusting device 62 has a regulator for adjusting the pressure and flow rate of the working fluid supplied from the supply source 61, and optimizes the supply of the working fluid to the speed control valve 63. The adjusting device 62 also preferably has a filter for removing foreign matter and impurities from the working fluid.

[0043] The speed control valve 63 is a component for adjusting the flow rate of the working fluid when it is discharged by adjusting the opening degree. The operating speed of the piston 64 can be controlled by adjusting the opening degree of the speed control valve 63. The speed control valve 63 has two systems: a first system 63a that discharges the working fluid supplied from a first discharge port 66e of the valve 66, and a second system 63b that discharges the working fluid supplied from a second discharge port 66f of the valve 66. A known valve component such as a needle valve or a throttle valve can be used as the speed control valve 63.

[0044] The piston 64 and cylinder tube 65 constitute a hydraulic or pneumatic cylinder. The piston 64 is a movable part housed within the cylinder tube 65, and is driven by the pressure of the working fluid to move back and forth linearly within the cylinder tube 65. The piston 64 includes a disk-shaped head 64a that is in close contact with the inner diameter of the cylinder tube 65 and moves under the pressure of the working fluid, and a rod-shaped rod 64b that extends from the center of the head 64a to the outside of the cylinder tube 65. The movement of the head 64a is transmitted to the outside by the rod 64b. A connecting link 64c is provided at the tip of the rod 64b, and the rod 64b is connected to the scraper frame 20 described above via this connecting link 64c (see Figure 1).

[0045] The cylinder tube 65 is a fixed cylindrical portion that houses the piston 64 (particularly the head 64a and rod 64b) and reciprocates the piston 64 by the pressure of the working fluid. The sealed space inside the cylinder tube 65 is divided into a first working chamber 65a on the rod 64b side and a second working chamber 65b on the opposite side, with the head 64a of the piston 64 as the boundary. The cylinder tube 65 also has a first flow path 65c for supplying and discharging the working fluid to and from the first working chamber 65a, and a second flow path 65d for supplying and discharging the working fluid to and from the second working chamber 65b.

[0046] The valve 66 is a device for switching between a supply path of the working fluid to the cylinder tube 65 and a discharge path of the working fluid from the cylinder tube 65. The valve 66 may be attached, for example, to the top of the cylinder tube 65. The valve 66 has a physical toggle switch-type lever 66a, which can be tilted to the left or right as viewed in FIG. 6. Changing the position of the lever 66a switches between the supply path and the discharge path of the fluid within the valve 66. A rotating disk-shaped spool (not shown) is located inside the valve 66, and the connection relationship between the ports changes depending on the position of the grooves in the spool. The rotation of the spool within the valve 66 is controlled by the lever 66a. In this embodiment, a five-port valve is used as the valve 66. Specifically, the valve 66 has a supply port 66b to which the working fluid is supplied from the supply source 61 via the adjustment device 62, a first working port 66c connected to the first working chamber 65a of the cylinder tube 65, a second working port 66d connected to the second working chamber 65b of the cylinder tube 65, a first exhaust port 66e that discharges the working fluid to the first system 63a of the speed control valve 63, and a second exhaust port 66f that discharges the working fluid to the second system 63b of the speed control valve 63.

[0047] The actuating arm 67 is attached to a portion of the rod 64b of the piston 64 that always protrudes outside the cylinder tube 65, and is a member that moves as the rod 64b moves back and forth. The actuating arm 67 is an L-shaped member when viewed from the side. One end of the actuating arm 67 is fixed near the tip of the rod 64b of the piston 64. The actuating arm 67 has a vertical portion extending upward from that end and a horizontal portion that bends at a right angle from the upper end of the vertical portion and extends toward the valve 66. The horizontal portion of the actuating arm 67 is provided with a first striker 67a and a second striker 67b that come into contact with the lever 66a of the valve 66. When the actuating arm 67 moves as the piston 64 moves back and forth, either the first striker 67a or the second striker 67b comes into contact with the lever 66a of the valve 66, switching the position of the lever 66a. Specifically, the piston 64 moves forward (in the scraping direction) and pulls the scraping frame 20. When the scraping frame 20 reaches the end point closer to the sludge pit 2, the first striker 67a contacts the lever 66a of the valve 66, causing the lever 66a to tilt leftward as shown in FIG. 6. Conversely, the piston 64 moves backward and pushes out the scraping frame 20. When the scraping frame 20 reaches the end point farther from the sludge pit 2, the second striker 67b contacts the lever 66a of the valve 66, causing the lever 66a to tilt rightward as shown in FIG. 7. In this way, as the piston 64 moves forward and backward, the orientation of the lever 66a is physically changed by the two strikers 67a, 67b of the actuating arm 67. This allows the forward and backward movement of the piston 64 to be automatically switched.

[0048] 6 shows the flow of hydraulic fluid when hydraulic fluid is supplied from the valve 66 to the first working chamber 65a of the cylinder tube 65 to move the piston 64 in the forward direction (pushing direction). In this state, hydraulic fluid supplied from the adjustment device 62 to the supply port 66b of the valve 66 is supplied from the first working port 66c to the first flow path 65c of the cylinder tube 65 and flows into the first working chamber 65a. As a result, the piston 64 of the cylinder tube 65 moves in the forward direction (pushing direction), pulling the pusher frame 20 in the same direction. Meanwhile, hydraulic fluid in the second working chamber 65b of the cylinder tube 65 is discharged from the second flow path 65d as the piston 64 moves and flows into the second working port 66d of the valve 66. Thereafter, the working fluid that has flowed into the second operating port 66d of the valve 66 is supplied from the first discharge port 66e to the first system 63a of the speed control valve 63, and is discharged from the first system 63a of the speed control valve 63 to the atmosphere. If the working fluid is a liquid (water), the liquid discharged from the first system 63a of the speed control valve 63 will accumulate in the settling basin 1. This forward movement of the piston 64 continues until the first striker 67a of the operating arm 67 comes into contact with the lever 66a of the valve 66 and changes the direction of the lever 66a.

[0049] FIG. 7 shows the flow of hydraulic fluid when hydraulic fluid is supplied from the valve 66 to the second working chamber 65b of the cylinder tube 65 to retract the piston 64 in the backward direction. Changing the orientation of the lever 66a of the valve 66 switches the state shown in FIG. 6 to the state shown in FIG. 7. In this state, hydraulic fluid supplied from the adjusting device 62 to the supply port 66b of the valve 66 is supplied from the second working port 66d to the second flow path 65d of the cylinder tube 65 and flows into the second working chamber 65b. This causes the piston 64 of the cylinder tube 65 to retract in the backward direction, pushing the scraper frame 20 in the same direction. Meanwhile, hydraulic fluid in the first working chamber 65a of the cylinder tube 65 is discharged from the first flow path 65c as the piston 64 retracts and flows into the first working port 66c of the valve 66. Thereafter, the working fluid that has flowed into the first operating port 66c of the valve 66 is supplied from the second discharge port 66f to the second line 63b of the speed control valve 63, and is discharged into the atmosphere from the second line 63b of the second line of the speed control valve 63. This retraction of the piston 64 in the returning direction continues until the second striker 67b of the operating arm 67 comes into contact with the lever 66a of the valve 66 and changes its direction.

[0050] As described above, the two strikers 67a, 67b of the actuating arm 67 physically change the orientation of the lever 66a in response to the forward and backward movement of the piston 64. Simply continuing to supply hydraulic fluid to the supply port 66b of the valve 66 automatically switches the forward and backward movement of the piston 64. Essentially, the entire sludge collector 10 can be driven by a single supply source 61 (air compressor or water supply pump). Therefore, in a sewage treatment plant, the supply source 61 can be used as a pressure source when there is surplus treated water for efficient use. It can also be used as a pressure source when there is excess compressed air consumed in the water supply and sewage treatment facilities. Therefore, in this embodiment, there is no need to install a power supply unit or on-site control panel for each sludge collector 10, thereby reducing electrical equipment costs. In particular, no electric device such as a motor is required to drive the sludge collector 10.

[0051] In the above description of the present invention, the embodiments of the present invention have been described with reference to the drawings in order to express the contents of the present invention. However, the present invention is not limited to the above embodiments, and includes modifications and improvements that are obvious to those skilled in the art based on the matters described in the present specification. [Explanation of symbols]

[0052] 1... Sedimentation basin 2... Sludge pit 10... Sludge scraper 20... Sludge scraper frame 21...Upper chord 22...Lower chord 23...Belly material 24...Scraper 25... Anti-vibration wheel 26... Scum scraping member 27...Scum scraping blade 28...Pipe-type scum skimmer 29...Float 30...Suspending member 31... Roller 31a... Rotating shaft 31b...bearing 32...roller support member 33...Assembly member 40...Guide device 40(A)...Roller positioning part 40(B)...Roller positioning part 41...Floor member 41(A)...First guide rail 41(B)... Second guide rail 42... Wall member 43...Top surface member 43a...Parallel surface 43b…Slope 43c…Top surface 44... Movable guide member 44a... Shelf portion 44b...First flap portion 44c...Second flap portion 44d...First seesaw board 44e...Second seesaw board 45...rotating shaft 46...partition wall 47...Tension spring 48...Shock absorbing spring 48a...Cylinder 48b...Spring 48c...piston rod 49...support plate 49a... Fastener 50... Suspension support 60...Driver 61...Power source 62...Adjusting device 63...Speed ​​control valve 63a...1st system 63b...2nd system 64...Piston 64a...Head 64b...Rod 64c...Connecting link 65...Cylinder tube 65a...First working chamber 65b... Second working chamber 65c... First flow path 65d... Second flow path 66... ​​Valve 66a... Lever 66b... Supply port 66c...First operating port 66d...Second operating port 66e...First discharge port 66f...Second discharge port 67...operating arm 67a...first striker 67b…Second striker

Claims

1. A sludge scraper installed in a sedimentation basin having a sludge pit, a scraper frame having a plurality of scrapers for guiding sludge to the sludge pit; a drive device that reciprocates the scraper frame within the settling basin; guide devices provided at at least two locations in the longitudinal direction of the scraper frame, which guide the scraper along the floor of the sedimentation basin when the scraper frame moves forward and guide the scraper at a higher position when the scraper frame moves back than when it moved forward; a hanging member that movably hangs the scraping frame relative to the guide device and travels along the guide device; Each of the depending members comprises: A plurality of rollers that move within the guide device; a plurality of roller support members provided on the left and right outer sides of the guide device in the width direction, each of which rotatably supports the roller; An assembly member is provided to attach the roller support member to the scraping frame. Sludge scraper.

2. Each of the guide devices comprises: roller positioning units provided at both longitudinal ends for holding the rollers at a height at which the scraper moves along the floor of the settling basin; a linear floor member connecting the floor surfaces of the roller positioning units; a substantially trapezoidal upper surface member connecting the upper surfaces of the roller positioning portions; a movable guide member rotatably supported in an area facing an upper bottom of the upper surface member between the floor member and the upper surface member, The roller moves on the floor member when the scraping frame moves forward, and moves on the movable guide member when the scraping frame moves back. The sludge scraper according to claim 1.

3. The movable guide member is a shelf portion rotatably supported in an area facing an upper bottom of the upper surface member between the floor member and the upper surface member; a first flap portion extending from one end of the shelf portion toward the rear end of the scraping frame, springing up toward the upper surface member so that the roller can move on the floor member when the scraping frame moves forward, and pressing down onto the floor member via the roller when the scraping frame moves back, thereby forming a tread surface of the roller; a second flap portion extending from the other end of the shelf portion toward the tip end of the scraping frame, which is bounced up onto the floor member as the roller moves when the scraping frame moves forward, and which is pushed down onto the floor member after the roller has passed, thereby forming a tread surface of the roller when the scraping frame returns; The sludge scraper according to claim 2.

4. The guide device further includes: a tensioning means for pulling the first flap portion of the movable guide member toward the upper surface member and biasing the first flap portion so that the first flap portion remains at an initial position; and a shock absorbing means for absorbing a shock applied to the first flap portion when the first flap is pulled up to the initial position by the tensioning means after being pushed down onto the floor member. The sludge scraper according to claim 3.

5. The drive device is a hydraulic cylinder or a pneumatic cylinder. The sludge scraper according to claim 1 or 2.

6. The drive device is a piston having a rod connected to the scraper frame; a cylinder tube having a first working chamber to which a working fluid such as water or air is supplied to move the piston forward, and a second working chamber to which the working fluid is supplied to move the piston backward; a valve that switches the supply destination of the working fluid between the first working chamber and the second working chamber; An operating arm is provided to mechanically link the reciprocating movement of the rod with the switching operation of the supply destination of the valve. The sludge scraper according to claim 5.

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