Sludge scraper

Abstract

To provide a mud scraping machine which can return a flight movable body to a normal position while preventing deformation of a guide rail even if sloshing causes the flight movable body to get into under the guide rail.SOLUTION: A mud scraping machine includes: a guide wheel 5 disposed in a sedimentation pond 1; a chain 7 wound around the guide wheel 5; a flight movable body 8 which is driven by the chain 7 and scrapes mud in the sedimentation pond 1; and a guide rail 11 which guides traveling of the flight movable body 8. A gap G1 is formed between an end 11a of the guide rail 11 and the guide wheel 5 when viewed from an axial direction of the guide wheel 5, and the gap G1 is larger than a height H1 of a portion, to which the chain 7 is fixed, of the flight movable body 8.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a sludge scraper that is installed in a sedimentation tank to scrape up sludge that has accumulated on the bottom of the sedimentation tank and scrape up scum that floats on the water surface of the sedimentation tank. [Background technology]

[0002] Conventionally, there has been known a sludge scraper in which long flight plates circulate inside a sedimentation tank as a chain travels, scraping up sludge that has accumulated on the bottom of the sedimentation tank as the flight plates travel along the bottom, and scraping up scum floating on the surface of the water as the flight plates travel on the water surface of the sedimentation tank (see, for example, Patent Document 1). In these sludge scrapers, the flight plates travel along guide rails inside the sedimentation tank as a chain stretched around a sprocket wheel travels, scraping up sludge and scum as described above.

[0003] In recent years, earthquakes have occurred all over Japan, causing great damage, and this has also affected the sludge collectors mentioned above in sedimentation tanks, which are the main equipment of sewage treatment plants. Earthquakes cause a phenomenon called sloshing, in which the water in the sedimentation tank swells violently, and it has been reported that the flight plates shake violently while in motion, causing them to fall off the guide rails and the chains to come off the sprocket wheels.

[0004] To prevent the flight plates from falling off due to such earthquakes, a measure has been taken in which guard plates are provided adjacent to the flight plates, as shown in Patent Document 1. These guard plates restrict the vertical and horizontal movement of the flight plates, thereby preventing the flight plates from falling off even in the event of an earthquake, and preventing the chain from falling off the sprocket wheel. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-326483 Summary of the Invention [Problem to be solved by the invention]

[0006] Normally, flight plates circulate within the sedimentation tank while being supported by multiple guide rails arranged along their travel path. However, earthquakes can cause unexpectedly large swells in the sedimentation tank, and the water swaying exerts a large force on the flight plates, causing them to detach from the guide rails. Flight plates are particularly prone to shaking between the surface and submerged guide rails. In actual cases, when a flight plate moves from the surface guide rail to the submerged guide rail, it does not land on the top of the submerged guide rail, but instead sinks below it.

[0007] For example, as shown in Figure 13, flight plate 500 is normally driven by chain 501 to travel above guide rail 505, but due to sloshing, flight plate 500 may fail to land on the upper side of guide rail 505 and travel below guide rail 505, as shown in Figure 14. Guide wheel 507 is located downstream of guide rail 505, and flight plate 500 traveling below guide rail 505 may be pulled up by guide wheel 507, deforming guide rail 505 as shown in Figure 15. Such deformation of guide rail 505 may hinder safe operation of the sludge scraper.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a sludge scraper that can return a movable flight body to its normal position while preventing deformation of the guide rail, even if the movable flight body sinks under the guide rail due to sloshing. [Means for solving the problem]

[0009] In one aspect, a sludge scraper is provided, comprising a guide wheel placed within a sedimentation tank, a chain hung on the guide wheel, a movable flight body driven by the chain to scrape sludge from within the sedimentation tank, and a guide rail to guide the movement of the movable flight body, wherein a gap is formed between the end of the guide rail and the guide wheel when viewed from the axial direction of the guide wheel, and the gap is larger than the height of the part of the movable flight body where the chain is fixed.

[0010] In one embodiment, the gap is 1 to 8 times the height of the portion of the flight movable body where the chain is fixed.

[0011] In one aspect, a sludge collector is provided, comprising a guide wheel arranged in a sedimentation tank, a chain hung on the guide wheel, a movable flight body driven by the chain to scrape sludge from the sedimentation tank, a guide rail to guide the movement of the movable flight body, and a tilting rail connected to an end of the guide rail that can be tilted upward, the tilting rail being located between the end of the guide rail and the guide wheel.

[0012] In one aspect, the tilt rail is connected to the end of the guide rail by a hinge. In one aspect, the hinge does not allow the tilt rail to tilt downward. In one aspect, at least a portion of the tilting rail is flexible. [Effects of the Invention]

[0013] According to the present invention, the flight movable body passes through the gap when transferring from the guide rail to the guide wheel, so no undue force is applied to the guide rail, and therefore the guide rail is not deformed. Furthermore, according to the present invention, the flight movable body tilts the tilting rail upward when transferring from the guide rail to the guide wheel, so no excessive force is applied to the guide rail, and therefore the guide rail is not damaged. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram showing an embodiment of a sludge scraper. [Figure 2] 1A and 1B are diagrams illustrating an embodiment of a flight movable body. [Figure 3] FIG. 10 is a diagram showing a flight movable body on a water surface guide rail. [Figure 4] 1 illustrates one embodiment of an arrangement of underwater guide rails and guide wheels. FIG. [Figure 5] 10A and 10B are diagrams illustrating the state in which the flight movable body has slipped under the underwater guide rail. [Figure 6] 10 is a diagram illustrating how the flight movable body is pulled up by the chain from below the guide wheel through the gap. FIG. [Figure 7] 10A and 10B are diagrams showing another embodiment of a flight movable body. [Figure 8] FIG. 10 is a diagram showing another embodiment of the sludge scraper. [Figure 9] 1 illustrates one embodiment of a hinge and tilt rail. FIG. [Figure 10] 10A and 10B are diagrams illustrating how the tilting rail is tilted upward by the flight movable body. [Figure 11] 10A and 10B show another embodiment of the tilting rail. [Figure 12] 10A and 10B are diagrams illustrating how the tilting rail is tilted upward by the flight movable body. [Figure 13] 10A and 10B are diagrams illustrating how the flight plate travels above the guide rail. [Figure 14] 10 is a diagram illustrating a state in which the flight board fails to land on the upper side of the guide rail and runs on the lower side of the guide rail. FIG. [Figure 15]10 is a diagram illustrating how a flight plate running under the guide rail is pulled up by a guide wheel, deforming the guide rail. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 shows one embodiment of a sludge collector. The sludge collector is installed, for example, in a sedimentation tank of a sewage treatment plant. This sludge collector includes a drive unit 2, a drive wheel 3 installed inside the sedimentation tank 1, guide wheels 4, 5, and 6, a pair of endless chains 7 hung on the wheels 3 to 6, and a plurality of movable flights 8 fixed to the chain 7 at predetermined intervals.

[0016] A pair of chains 7 are arranged in parallel inside the sedimentation tank 1, and these chains 7 are circulated by a drive wheel 3 connected to a drive device 2. As the chains 7 circulate, a flight movable body 8 travels inside the sedimentation tank 1.

[0017] As shown in Figure 1, when the movable flight bodies 8 travel along the bottom side of the sedimentation tank 2, they scrape sludge accumulated at the bottom into the sludge storage section 1a, and when they travel along the water surface, they scrape scum floating on the water surface into the scum skimmer 9. To guide the travel of the movable flight bodies 8, water surface guide rails 10 and underwater guide rails 11 are arranged along the side walls of the sedimentation tank 1. Furthermore, pond bottom guide rails 12 are laid on the bottom of the tank to guide the travel of the movable flight bodies 8. The water surface guide rails 10, underwater guide rails 11, and pond bottom guide rails 12 are made of metal such as stainless steel, or hard resin.

[0018] The drive wheel 3 is a sprocket wheel that transmits its rotation to the chain 7. The drive wheel 3 is connected to a sprocket wheel (not shown) that receives power from the drive unit 2 via the drive chain 2a. The guide wheels 4, 5, and 6 are all driven wheels. The underwater guide wheel 5 is configured to be able to move back and forth horizontally to adjust the tension of the chain 7.

[0019] An overflow weir is attached to the scum skimmer 9 so that it can be opened and closed freely, and the scum floating on the liquid surface of the sedimentation basin 1 is forced to flow into the trough 9a together with the water by the movable flight 8. The scum skimmer 9 may also be a pipe skimmer that rotates a pipe with a notch. The sedimentation basin 1 is provided with an overflow weir 14, and the water level in the sedimentation basin 1 is kept constant by discharging the water in the sedimentation basin 1 over this overflow weir 14.

[0020] 2 is a diagram showing one embodiment of the movable flight body 8. The movable flight body 8 includes a flight plate (scraper plate) 20 that scrapes sludge and scum, first guide shoes 23 attached to the upper part of both sides of the flight plate 20, and second guide shoes 24 attached to the lower part of both sides of the flight plate 20. A chain 7 is fixed to the lower part of the flight plate 20, and the movable flight body 8 is pulled by the chain 7 to travel.

[0021] FIG. 3 is a diagram showing the flight movable body 8 on the water surface guide rail 10. The water surface guide rail 10 is supported by rail brackets 30 fixed to the side wall 1b of the sedimentation basin 1. The rail brackets 30 are arranged at equal intervals along the water surface guide rail 10. A second guide shoe 24 is located above the water surface guide rail 10. Although not shown, the submerged guide rail 11 is also supported by a rail bracket fixed to the side wall 1b of the sedimentation basin 1.

[0022] When the chain 7 is driven by the drive wheel 3 and the flight movable body 8 travels on the water surface, the second guide shoe 24 slides on the water surface guide rail 10 and travels guided by the water surface guide rail 10. When the flight movable body 8 travels on the underwater guide rail 11, the second guide shoe 24 slides on the underwater guide rail 11 and travels guided by the underwater guide rail 11. The first guide shoe 23 is for allowing the flight movable body 8 to travel guided by the pond bottom guide rail 12 when it travels on the pond bottom.

[0023] In this way, the flight movable body 8 has two types of guide shoes 23, 24, one for the pond bottom and one for the water surface and underwater, and the flight movable body 8 runs while sliding on the pond bottom guide rails 12, underwater guide rails 11, and water surface guide rails 10.

[0024] Figure 4 shows one embodiment of the arrangement of the underwater guide rail 11 and the guide wheel 5. The guide wheel 5 is located downstream of the underwater guide rail 11 in the direction of travel of the flight movable body 8. The underwater guide rail 11 is located lower than the top of the guide wheel 5. As shown in Figure 4, a gap G1 is formed between the end 11a of the underwater guide rail 11 and the guide wheel 5 when viewed from the axial direction of the guide wheel 5. More specifically, the gap G1 is the gap between the end 11a of the underwater guide rail 11 and the inner end of the guide wheel 5. This gap G1 is larger than the height H1 of the portion of the flight movable body 8 to which the chain 7 is fixed. In this embodiment, as shown in Figure 2, the chain 7 is fixed to the flight plate 20 of the flight movable body 8, so the gap G1 is larger than the height H1 of the flight plate 20.

[0025] As shown in Figure 1, there is a section C called a catenary between the water surface guide rail 10 and the underwater guide rail 11. In this section C, the flight movable body 8 is not supported by the guide rails 10, 11. For this reason, when sloshing occurs, the flight movable body 8 is likely to swing significantly in section C and may sink below the underwater guide rail 11, as shown in Figure 5. In such a case, the flight movable body 8 slides along the underside of the submersible guide rail 11 and moves toward the guide wheel 5. Then, as shown in Figure 6, the flight movable body 8 is pulled up by the chain 7 from below the submersible guide rail 11 through the gap G1 and moves to the guide wheel 5.

[0026] In this way, the flight movable body 8 passes through the gap G1 when transferring from the underwater guide rail 11 to the guide wheel 5, and does not push up strongly against the underwater guide rail 11. This prevents deformation of the underwater guide rail 11. If the gap G1 is too small, the flight movable body 8 will not be able to pass through the gap G1 and will push up against the underwater guide rail 11, causing it to deform. On the other hand, if the gap G1 is too large, when the flight movable body 8 is reversed to remove any trapped foreign matter, the flight movable body 8 in the gap G1 between the guide wheel 5 and the underwater guide rail 11 will descend under its own weight, and the second guide shoe 24 of the flight movable body 8 may collide with the underwater guide rail 11.

[0027] From this perspective, in one embodiment, the size of the gap G1 is 1 to 8 times, and preferably 1.5 to 5 times, the height H1 of the portion to which the chain 7 of the flight movable body 8 is fixed. For example, if the height H1 of the flight plate to which the chain 7 of the flight movable body 8 is fixed is 200 mm, the size of the gap G1 is 200 mm to 1600 mm, and preferably 300 mm to 1000 mm.

[0028] 7 is a diagram showing another embodiment of the movable flight body 8. The movable flight body 8 of this embodiment has a flight plate (scraper plate) 20 that scrapes sludge and scum, end pieces 21 attached to both ends of the flight plate 20, a first guide shoe 23 fixed to the upper part of each end piece 21, and a second guide shoe 24 fixed to the lower part of each end piece 21. A chain 7 is fixed to the lower part of the end piece 21, and the movable flight body 8 is pulled by the chain 7 to travel.

[0029] In the embodiment shown in Figure 7, the chain 7 is fixed to the end piece 21, so the gap G1 between the end 11a of the underwater guide rail 11 and the guide wheel 5 is larger than the height H1 of the end piece 21. The relationship between the gap G1 and the height H1 of the end piece 21 is the same as in the embodiment described with reference to Figures 4 to 6.

[0030] The embodiments described so far are applicable not only to the gap G1 between the submersible guide rail 11 and the guide wheel 5, but also to the gap between the water surface guide rail 10 and the guide wheel 4. In other words, a gap larger than the height of the part where the chain 7 of the flight movable body 8 is fixed may be provided between the end of the water surface guide rail 10 and the guide wheel 4. This is because the flight movable body 8 running on the water surface guide rail 10 may sink below the water surface guide rail 10 due to sloshing.

[0031] Next, another embodiment of the sludge scraper will be described with reference to Figures 8 to 10. The configuration of this embodiment that is not particularly described is the same as the embodiment described with reference to Figures 1 to 7, so duplicated explanations will be omitted. As shown in Figure 8, the sludge scraper is equipped with a tilting rail 27 that is connected to the end 11a of the submersible guide rail 11 and can tilt upward. The tilting rail 27 is located between the end 11a of the submersible guide rail 11 and the guide wheel 5. The tilting rail 27 is connected to the end 11a of the submersible guide rail 11 by a hinge 28 so as to be able to tilt.

[0032] As shown in Figure 9, the hinge 28 is configured to allow the tilting rail 27 to tilt above the submersible guide rail 11, but not below the submersible guide rail 11. When the flight movable body 8 sinks below the submersible guide rail 11, it slides along the underside of the submersible guide rail 11 and moves toward the guide wheel 5. Then, as shown in Figure 10, the flight movable body 8 is pulled up by the chain 7 from below the submersible guide rail 11 while pushing up the tilting rail 27, and moves toward the guide wheel 5. When the flight movable body 8 separates from the tilting rail 27, the tilting rail 27 returns to its original position by its own weight or by a spring (not shown).

[0033] In this way, the flight movable body 8 tilts the tilting rail 27 upward when transferring from the underwater guide rail 11 to the guide wheel 5, so it does not push up strongly on the underwater guide rail 11. This prevents deformation of the underwater guide rail 11. When the flight movable body 8 is reversed to remove trapped foreign matter, the tilting rail 27 does not tilt downward, so the flight movable body 8 can smoothly transfer from the guide wheel 5 to the underwater guide rail 11 via the tilting rail 27.

[0034] If the tilting rail 27 is too short, the flight movable body 8 cannot pass through the gap between the upwardly inclined tilting rail 27 and the guide wheel 5, causing deformation of the underwater guide rail 11. From this perspective, the length L1 of the tilting rail 27 is greater than the height H1 of the portion of the flight movable body 8 to which the chain 7 is fixed.

[0035] Figure 11 shows another embodiment of the tilting rail 27. The configuration and operation of this embodiment, unless otherwise specified, are the same as those of the embodiment described with reference to Figures 8 to 10, and therefore redundant explanations will be omitted. In the embodiment shown in Figure 11, at least a portion of the tilting rail 27 is flexible. The entire tilting rail 27 may be flexible, or only the upstream portion of the tilting rail 27 connected to the underwater guide rail 11 may be flexible. To provide flexibility to the tilting rail 27, at least a portion of the tilting rail 27 is made of an elastic material such as rubber. The length L1 of the tilting rail 27 is greater than the height H1 of the portion of the flight movable body 8 to which the chain 7 is fixed.

[0036] 12, the flight movable body 8 that has slipped under the underwater guide rail 11 is pulled up by the chain 7 from below the underwater guide rail 11 while pushing up the tilting rail 27, and moves to the guide wheel 5. When the flight movable body 8 leaves the tilting rail 27, the tilting rail 27 returns to its original position due to its own weight and / or its elasticity.

[0037] When the flight movable body 8 transfers from the underwater guide rail 11 to the guide wheel 5, it tilts the tilting rail 27 upward, so it does not push up the underwater guide rail 11 strongly. This prevents deformation of the underwater guide rail 11. When the flight movable body 8 is reversed to remove a trapped foreign object, the tilting rail 27 tilts slightly downward when the flight movable body 8 moves from the guide wheel 5 to the tilting rail 27, but the tilting rail 27 prevents the second guide shoe 24 (see Figures 2 and 7) of the flight movable body 8 from colliding with the underwater guide rail 11. This means that the flight movable body 8 can smoothly transfer from the guide wheel 5 to the underwater guide rail 11 via the tilting rail 27.

[0038] The tilting rail 27 of the embodiment described with reference to Figures 8 to 12 may be provided not only between the underwater guide rail 11 and the guide wheel 5, but also between the water surface guide rail 10 and the guide wheel 4. In other words, the tilting rail 27 may be connected to the end of the water surface guide rail 10.

[0039] The above-described embodiments have been described for the purpose of enabling a person of ordinary skill in the art to practice the present invention. Various modifications of the above-described embodiments would be obvious to a person skilled in the art, and the technical concept of the present invention may be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is to be interpreted in the broadest scope in accordance with the technical concept defined by the claims. [Explanation of symbols]

[0040] 1 Sedimentation tank 1a Sludge storage section 2. Drive unit 2a drive chain 3 drive wheels 4,5,6 Guide wheels 7 Chain 8 Flight Movable Body 9 Scum Skimmer 9a Trough 10 Water surface guide rail 11 Underwater guide rail 12 Pond bottom guide rail 14 Overflow weir 20 Flight board (raking board) 21 End Piece 23 First guide shoe 24 Second guide shoe 27 Tilt rail 28 Hinge 30 Rail bracket G1 Gap

Claims

1. a guide wheel disposed within the settling tank; A chain hung on the guide wheel; a flight movable body driven by the chain to scrape sludge in the settling basin; A guide rail is provided to guide the flight movable body, a gap is formed between the end of the guide rail and the guide wheel when viewed from the axial direction of the guide wheel, The sludge scraper, wherein the gap is larger than the height of a portion of the flight movable body to which the chain is fixed.

2. A guide wheel disposed in the sedimentation tank; A chain hung on the guide wheel; a flight movable body driven by the chain to scrape sludge in the settling basin; A guide rail is provided to guide the flight movable body, a gap is formed between the end of the guide rail and the guide wheel when viewed from the axial direction of the guide wheel, The sludge scraper, wherein the gap is 1 to 8 times the height of the portion of the flight movable body where the chain is fixed.

3. a guide wheel disposed within the settling tank; A chain hung on the guide wheel; a flight movable body driven by the chain to scrape sludge in the settling basin; a guide rail for guiding the travel of the flight movable body; a tilting rail connected to an end of the guide rail and tiltable upward; The tilting rail is located between the end of the guide rail and the guide wheel.

4. 4. The sludge scraper according to claim 3, wherein the tilting rail is connected to the end of the guide rail by a hinge.

5. 5. The sludge collector according to claim 4, wherein the hinge does not allow the tilting rail to tilt downward.

6. The sludge scraper according to claim 3 , wherein at least a portion of the tilting rail is flexible.

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