JP7048655B2 - Sludge scraper - Google Patents

Description

The present invention relates to a sludge scraper installed in a settling basin.

As the sludge scraper, there is a sludge scraper conventionally described in Patent Document 1 below. The prior art is configured as follows.

Patent Document 1 describes a 4-axis type sludge scraper configured to continuously scrape sludge deposited on the bottom of a sedimentation basin with a plurality of flight members. This sludge scraper prevents the flight member traveling on the guide rail from moving toward the left and right side walls between the drive support shaft and the idler support shaft, and the flight member from floating. It is equipped with a vertical presser member. Further, when the allowable sliding width of the guide shoe attached to the flight member is L and the sliding rail width of the guide rail is r, the distance d between the side surface of the flight member and the lateral pressing member is set to (L-). It is set in the range of r) / 2 <d <(L + r) / 2.

With the above configuration, it is possible to enhance the effect of suppressing the shaking of the flight member due to sloshing. Sloshing is a phenomenon in which the water in the settling pond is greatly shaken vertically and horizontally due to long-period vibration caused by an earthquake.

Japanese Unexamined Patent Publication No. 2019-130482

The above-mentioned prior art has the following problems. The tension of the endless chain becomes the smallest when the sprocket attached to the drive support shaft is exited. In addition, the range of engagement between the sprocket attached to the idler support shaft and the endless chain is relatively small. Therefore, even if the horizontal presser member and the vertical presser member are arranged and the distance between the side surface of the flight member and the lateral presser member is numerically regulated to suppress the shaking of the flight member, sloshing occurs to support the idler. There is still concern that the endless chain will fall off the sprocket attached to the shaft.

An object of the present invention is to provide a sludge scraper having a configuration capable of suppressing the endless chain from falling off from a sprocket, particularly a driven sprocket of an intermediate shaft, due to sloshing. ..

In order to achieve the above object, the sludge scraper of the present invention is configured as follows.

The sludge scraper of the present invention is a pair of left and right endless chains to which a plurality of flights for scraping sludge accumulated at the bottom of a settling basin and the plurality of flights are attached, and a plurality of chain links are connected. A drive shaft having an endless chain and a pair of left and right drive sprockets on which the endless chain is hung, and a drive shaft arranged in the upper part of the sedimentation basin and a pair of left and right drives on which the endless chain is hung. An intermediate shaft having a driven sprocket, which is downstream from the drive shaft and is located in the upper part of the settling basin, and the flight traveling between the drive sprocket and the driven sprocket from below. A pair of left and right guide rails to be supported, including a guide rail arranged in the upper part of the settling basin. The driven sprocket has a driven sprocket main body and a plurality of driven sprocket teeth protruding radially outward from the driven sprocket main body, and has a driven sprocket tooth portion that meshes with the chain link. When the rotating driven sprocket tooth is located at the highest position, the radial tooth tip of the driven sprocket tooth is above the top surface of the guide rail so that the traveling flight is lifted by the driven sprocket. It is said to be in a high position.

According to this configuration, the hooking range between the driven sprocket and the endless chain of the intermediate shaft is wider than before. As a result, it is possible to prevent the endless chain from falling off from the driven sprocket due to the occurrence of sloshing, as compared with the conventional case.

In the present invention, the drive sprocket has a drive sprocket main body, a plurality of drive sprocket teeth protruding radially outward from the drive sprocket main body, and a drive sprocket tooth portion that meshes with the chain link. Then, when the rotating drive sprocket tooth portion is located at the highest position, the radial tooth tip of the drive sprocket tooth portion is such that the raised flight falls on the guide rail at the drive sprocket portion. The position may be higher than the upper surface of the guide rail.

According to this configuration, the hooking range between the drive sprocket and the endless chain is wider than before even in the drive shaft, and as a result, it is possible to prevent the endless chain from falling off from the drive sprocket due to sloshing. can.

Further, in the present invention, a pair of left and right upper derailment prevention rails arranged above the flight traveling between the drive sprocket and the driven sprocket are further provided, and the upper derailment prevention rail is of the intermediate shaft. It is extended to the downstream side of the axis, and the surface facing the flight in the extended downstream part is higher than the surface facing the flight in the middle part of the upper derailment prevention rail. By setting the position, it may be prevented that the distance between the flight and the upper derailment prevention rail is narrowed in the driven sprocket portion.

According to this configuration, it is possible to prevent the endless chain from falling off from the driven sprocket, and it is possible to prevent the flight from being caught between the driven sprocket and the upper wheel derailment prevention rail.

Further, in the present invention, the upper derailment prevention rail is extended to the upstream side of the axis of the drive shaft, and the surface of the extended upstream side portion facing the flight is in the middle. By setting the position higher than the surface of the portion facing the flight, it may be possible to prevent the distance between the flight and the upper derailment prevention rail from being narrowed in the drive sprocket portion.

According to this configuration, it is possible to prevent the endless chain from falling off from the drive sprocket, and it is possible to prevent the flight from being caught between the drive sprocket and the upper wheel derailment prevention rail.

Further, in the present invention, the wide surface of the upper derailment prevention rail facing the flight and the surface of the flight facing the upper derailment prevention rail may be parallel to each other.

According to this configuration, damage to the flight when the flight collides with the upper derailment prevention rail can be suppressed.

Further, in the present invention, a pair of left and right side derailment prevention rails arranged on the settling basin wall side of the flight traveling between the drive sprocket and the driven sprocket are further provided to prevent the side derailment. The wide surface of the rail facing the flight may be parallel to the surface of the flight facing the lateral derailment prevention rail.

According to this configuration, damage to the flight when the flight collides with the lateral derailment prevention rail can be suppressed.

Further, in the present invention, the distance between the wide surface of the upper derailment prevention rail facing the flight and the surface of the flight facing the upper derailment prevention rail, and the flight of the side derailment prevention rail. The distance between the wide surface facing the rail and the surface facing the lateral derailment prevention rail of the flight may be the same.

According to the sludge scraper of the present invention, it is possible to prevent the endless chain from falling off from the sprocket, particularly the driven sprocket of the intermediate shaft, due to the occurrence of sloshing.

It is a side sectional view of the sludge scraper installed in the settling basin. It is an enlarged view of the part A of FIG. It is the B part enlarged view of FIG. It is a CC arrow view of FIG.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The sludge scraper of the present invention is a machine installed in a settling basin such as a sewage treatment plant. 1 to 4 show a 4-axis type sludge scraper 100 according to an embodiment of the present invention.

The sludge scraper 100 includes four shafts, a drive shaft 2, an intermediate shaft 3, a tail shaft 4, and a driven shaft 5. The drive shaft 2, the intermediate shaft 3, the tail shaft 4, and the driven shaft 5 are respectively bridged between one side wall 1a (FIG. 1) and the other side wall 1b (FIG. 4) in the width direction of the settling basin 1. Is done. As shown in FIG. 1, the drive shaft 2 is arranged in the upper part on the upstream side in the settling basin 1, and the driven shaft 5 is arranged below the drive shaft 2. The intermediate shaft 3 is arranged on the downstream side of the drive shaft 2 and at the upper part in the settling basin 1. The tail shaft 4 is arranged on the downstream side of the intermediate shaft 3 and at the bottom of the settling basin 1. Note that FIG. 4 shows a portion on the side wall 1b on the left side when the inside of the sedimentation basin 1 is viewed from the downstream side (tail shaft 4 side) to the upstream side.

The drive shaft 2, the intermediate shaft 3, the tail shaft 4, and the driven shaft 5 each have a pair of left and right drive sprockets 6, a pair of left and right driven sprockets 7, a pair of left and right driven sprockets 8, and a pair of left and right driven sprockets 9. Have. The pair of sprockets 6 to 9 are arranged at positions close to the side walls 1a and 1b of the settling basin 1 at intervals in the width direction of the settling basin 1. An endless chain 10 is hung on each of these pairs of sprockets 6-9. Therefore, there are two endless chains 10 per sludge scraper 100 (a pair of left and right endless chains 10).

The endless chain 10 is formed by connecting a plurality of chain links 11 with an attachment 11a for attaching a flight 12 and a plurality of chain links (not shown) having no attachment 11a. The chain link 11 with the attachment 11a is provided at each pitch (= for example, 3 m) in which the flight 12 is attached, and the chain links 11 are connected to each other by a plurality of chain links having no attachment 11a. The endless chain 10 (chain link) may be made of resin or metal such as stainless steel or carbon steel. Further, the flight 12 for scraping sludge attached to the endless chain 10 may be made of resin or may be made of wood.

The drive shaft 2 is rotationally driven by the drive device 18 via the drive chain 17. The drive device 18 is, for example, an electric motor with a cyclo speed reducer. Since the drive shaft 2 and the drive sprocket 6 are fixed by a key (not shown), the drive sprocket 6 is rotated by the rotation of the drive shaft 2, and the endless chain 10 to which a plurality of flights 12 are attached is the sprocket 6 to 9. Moves endlessly in the settling basin 1. The driven sprockets 7 to 9 are rotatably attached to each of the shafts 3 to 5, and the sprocket itself is not driven from the outside like the drive sprocket 6.

The flight 12 of the present embodiment includes a flight body 13 having a U-shaped cross section, a pair of left and right first guide shoes 14 attached to the flight body 13, and a pair of left and right second guide shoes 15. As shown in FIG. 4, the first guide shoe 14 is attached to the longitudinal end of the flight body 13, and the second guide shoe 15 is attached to the inside of the first guide shoe 14. The chain link 11 is fixed to the flight body 13 at the portion between the first guide shoe 14 and the second guide shoe 15.

As shown in FIG. 1, a pair of left and right pond bottom rails 16 are laid on the bottom of the settling basin 1 along the longitudinal direction of the settling basin 1. While the second guide shoe 15 slides on the pond bottom rail 16, the flight 12 travels toward the sludge pit 1c while attracting the sludge accumulated on the bottom of the settling basin 1.

A pair of left and right guide rails 19 that support the flight 12 traveling between the drive sprocket 6 and the driven sprocket 7 of the intermediate shaft 3 from below are arranged at the upper part in the settling basin 1. As shown in FIG. 4 and the like, the guide rail 19 of the present embodiment is a rail made of a guide rail main body 20 made of angle steel (equal angle steel) and a flat bar (flat steel) welded and fixed to the guide rail main body 20. It is composed of the plate 21. The bracket 23 is fixed to the side wall 1b (1a) of the settling basin 1 with anchor bolts 22, and the guide rail main body 20 is fixed to the upper surface of the bracket 23 via the support member 24. While the first guide shoe 14 slides on the rail contact plate 21 (guide rail 19), the flight 12 travels between the drive sprocket 6 and the driven sprocket 7 toward the downstream side of the settling basin 1.

Further, on the downstream side of the guide rail 19 and the bottom side in the settling basin 1, a pair of left and right tail side guide rails 35 for supporting the flight 12 leaving the driven sprocket 7 from below are arranged.

As shown in FIG. 2, the driven sprocket 7 is composed of a driven sprocket main body 25 and a plurality of driven sprocket teeth 26 protruding radially outward from the driven sprocket main body 25, and the driven sprocket tooth portion 26 is formed. And the chain link 11 constituting the endless chain 10 mesh with each other. More specifically, the side surface of the driven sprocket tooth portion 26 in the rotational direction and the outer peripheral surface of the tubular portion 11b provided between the barrel portions of the chain link 11 come into contact with each other to engage with each other.

Here, as shown by the two-dot chain line in FIG. 2, the traveling track R at the upper end of the flight 12 is provided with the driven sprocket 7 and the guide rail 19 so that the traveling flight 12 is once lifted by the driven sprocket 7. The relative position in the vertical direction has been adjusted. Specifically, when the rotating driven sprocket tooth portion 26 is located at the highest position, the radial tooth tip T1 of the driven sprocket tooth portion 26 is located higher than the upper surface T2 of the guide rail 19 (for example, H1). By setting the position higher by a distance (see FIG. 2)), the traveling flight 12 is lifted by the driven sprocket 7.

In order to smoothly move the flight 12 traveling on the guide rail 19 from the upstream side diagonally downward on the downstream side, FIG. 2 is shown so that the traveling track R does not become a discontinuous track in the driven sprocket 7 portion. It is better to arrange the driven sprocket 7 slightly lower than the position, but as described above, the radial tooth tip T1 of the driven sprocket tooth portion 26 is intentionally placed on the upper surface of the guide rail 19 so that the flight 12 can be lifted once. The driven sprocket 7 is arranged so as to be higher than T2.

According to the above configuration, the hooking range between the driven sprocket 7 and the endless chain 10 (chain link 11) can be widened. As a result, the number of chain links constituting the endless chain 10 meshing with the driven sprocket 7 can be increased as compared with the conventional case, and the time during which the chain link 11 to which the flight 12 is attached and the driven sprocket 7 are meshed with each other. Can be made longer than before, and it is possible to further prevent the endless chain 10 from falling off from the driven sprocket 7 due to the occurrence of sloshing or the like.

The same applies to the drive sprocket 6 portion. As shown in FIG. 3, the drive sprocket 6 is composed of a drive sprocket main body 27 and a plurality of drive sprocket teeth 28 projecting radially outward from the drive sprocket main body 27, and the drive sprocket teeth 28 are formed. And the chain link 11 constituting the endless chain 10 mesh with each other. More specifically, the side surface of the drive sprocket tooth portion 28 in the rotational direction and the outer peripheral surface of the tubular portion 11b provided between the barrel portions of the chain link 11 come into contact with each other to engage with each other.

As shown by the alternate long and short dash line in FIG. 3, the traveling track R at the upper end of the flight 12 is formed by the drive sprocket 6 and the guide rail 19 so that the ascending flight 12 falls on the guide rail 19 at the drive sprocket 6 portion. The relative position in the vertical direction of is adjusted. Specifically, when the rotating drive sprocket tooth portion 28 is located at the highest position, the radial tooth tip T1 of the drive sprocket tooth portion 28 is located higher than the upper surface T2 of the guide rail 19 (for example, H1). By setting the position higher by a distance (see FIG. 3)), the ascending flight 12 is made to fall onto the guide rail 19 at the drive sprocket 6 portion.

In order to turn the ascending flight 12 by about 90 degrees and smoothly guide it onto the guide rail 19, the traveling track R does not become a discontinuous track in the drive sprocket 6 portion, so that the position shown in FIG. 3 is higher than the position shown in FIG. It is better to arrange the drive sprocket 6 slightly lowered, but as described above, the radial tooth tip T1 of the drive sprocket tooth portion 28 is intentionally set to the guide rail 19 so that the flight 12 falls on the guide rail 19. The drive sprocket 6 is arranged so as to be higher than the upper surface T2 of the above.

According to the above configuration, the engagement range between the drive sprocket 6 and the endless chain 10 (chain link 11) can be expanded even in the drive shaft 2. As a result, the number of chain links constituting the endless chain 10 meshing with the drive sprocket 6 can be increased as compared with the conventional case, and the time during which the chain link 11 to which the flight 12 is attached and the drive sprocket 6 are meshed with each other. Can be made longer than before, and it is possible to further prevent the endless chain 10 from falling off from the drive sprocket 6 due to the occurrence of sloshing or the like.

As shown in FIG. 4, the bracket 29 is fixed to the side wall 1b (1a) of the settling basin 1 with anchor bolts 22. The upper wheel derailment prevention rail 31 is fixed to the lower surface of the bracket 29 arranged above the bracket 23 via the support member 30. The upper derailment prevention rail 31 is a pair of left and right rails arranged above the flight 12 traveling between the drive sprocket 6 and the driven sprocket 7 of the intermediate shaft 3, and is a pair of left and right rails arranged above the flight 12 when sloshing occurs. Is provided to prevent the rail from shaking significantly in the vertical direction. The upper derailment prevention rail 31 of the present embodiment is composed of an upper derailment prevention rail main body 32 made of angle steel (equal angle steel) and a flat bar (flat steel) welded and fixed to the upper derailment prevention rail main body 32. It is composed of a rail contact plate 33.

As shown in FIG. 2, the upper derailment prevention rail 31 extends to the downstream side of the axis of the intermediate shaft 3. The extended downstream side portion is referred to as a downstream side extension portion 31b. Further, as shown in FIG. 3, the upper wheel derailment prevention rail 31 extends to the upstream side of the axis of the drive shaft 2. The extended upstream side portion is referred to as an upstream side extending portion 31c. The portion between the upstream extending portion 31c and the downstream extending portion 31b is referred to as an intermediate portion 31a.

The lower surface S1 (= surface facing the flight 12) of the intermediate portion 31a, which is the longest portion arranged between the drive sprocket 6 and the driven sprocket 7, is horizontal like the upper surface T2 of the guide rail 19 below the lower surface S1. Be placed. Therefore, the distance between the lower surface S1 and the upper surface T2 is constant.

As described above, since the radial tooth tip T1 of the driven sprocket tooth portion 26 is positioned higher than the upper surface T2 of the guide rail 19, the traveling flight 12 is lifted by the driven sprocket 7 portion. The lower surface S2 (= surface facing the flight 12) of the downstream extending portion 31b so that the flight 12 does not get caught between the driven sprocket 7 and the upper derailment prevention rail 31 when the flight 12 is lifted. ) Is set higher than the lower surface S1 of the intermediate portion 31a to prevent the distance between the flight 12 and the upper wheel derailment prevention rail 31 from becoming narrower in the driven sprocket 7 portion.

In the present embodiment, in order to further prevent the traveling flight 12 from swinging in the vertical direction, a part of the lower surface S2 (the boundary portion with the intermediate portion 31a) is formed on an arc surface along the traveling track R of the flight 12. By using S2a (curved surface), the distance between the upper derailment prevention rail 31 and the traveling flight 12 is always constant.

Further, as described above, since the radial tooth tip T1 of the drive sprocket tooth portion 28 is positioned higher than the upper surface T2 of the guide rail 19, the ascending flight 12 is above the guide rail 19 at the drive sprocket 6 portion. Move to fall to. The lower surface S3 (= surface facing the flight 12) of the upstream extending portion 31c is the lower surface S1 of the intermediate portion 31a so that the flight does not get caught between the drive sprocket 6 and the upper derailment prevention rail 31. It is set to a higher position to prevent the distance between the flight 12 and the upper wheel derailment prevention rail 31 from becoming narrower in the drive sprocket 6 portion.

In the present embodiment, in order to further prevent the traveling flight 12 from swinging in the vertical direction, a part of the lower surface S3 (the boundary portion with the intermediate portion 31a) is formed on an arc surface along the traveling track R of the flight 12. By using S3a (curved surface), the distance between the upper derailment prevention rail 31 and the traveling flight 12 is always constant.

As shown in FIG. 4, the lower surface S (= wide surface facing the flight 12) of the upper derailment prevention rail 31 and the surface 12a facing the upper derailment prevention rail 31 of the flight 12 are parallel to each other. According to this configuration, damage to the flight 12 when the flight 12 collides with the upper derailment prevention rail 31 due to sloshing or the like can be suppressed.

In the present embodiment, the side derailment prevention rail 34 is fixed to the upper surface of the bracket 23 to which the guide rail 19 is fixed. The side derailment prevention rail 34 is a pair of left and right rails arranged on the wall side of the settling basin 1 of the flight 12 traveling between the drive sprocket 6 and the driven sprocket 7 of the intermediate shaft 3, and is sloshing. It is provided to prevent the flight 12 from swinging significantly in the left-right direction when it occurs. The side derailment prevention rail 34 of the present embodiment is made of a long steel material having an L-shaped cross section. The inner side surface 34a (= wide surface facing the flight 12) of the side derailment prevention rail 34 and the surface 12b facing the side derailment prevention rail 34 of the flight 12 are parallel to each other. According to this configuration, damage to the flight 12 when the flight 12 collides with the side wheel derailment prevention rail 34 due to sloshing or the like can be suppressed. FIG. 4 shows the water level (W.L.) of the settling basin 1. The side derailment prevention rail 34 is arranged so as to be located below the water level of the settling basin 1.

Further, in the present embodiment, the distance between the lower surface S (= wide surface facing the flight 12) of the upper derailment prevention rail 31 and the surface 12a facing the upper derailment prevention rail 31 of the flight 12 and the lateral derailment. The distance between the inner side surface 34a (= wide surface facing the flight 12) of the wheel prevention rail 34 and the surface 12b facing the lateral derailment prevention rail 34 of the flight 12 is the same.

The support plate 29a constituting the bracket 29 to which the upper derailment prevention rail 31 is fixed has a hole 36 into which the anchor bolt 22 is inserted, and the hole 36 is a long hole or an anchor that is long in the vertical direction. The circular hole is sufficiently larger than the diameter of the bolt 22 (bracket fixing member). That is, the bracket 29 has a height adjusting portion in the vertical direction. With this configuration, the position of the bracket 29 can be adjusted in the vertical direction, and the lower surface S of the upper derailment prevention rail 31 (= wide surface facing the flight 12) and the upper derailment prevention rail 31 of the flight 12 face each other. The distance from the surface 12a can be easily adjusted.

The above embodiment can be changed as follows.

Regarding the drive sprocket 6, the drive sprocket 6 may be arranged slightly lower than the position shown in FIG. 3 so that the traveling track R does not become a discontinuous trajectory in the drive sprocket 6 portion. In this case, the lower surface S3 of the upstream extending portion 31c is also lowered in the same manner, such as making the height level of the lower surface S3 of the upstream extending portion 31c of the upper derailment prevention rail 31 the same as that of the lower surface S1 of the intermediate portion 31a. Position.

Regarding the upper derailment prevention rail 31, the upstream side extension portion 31c and the downstream side extension portion 31b may be omitted.

The arc surface S2a may not be provided on the lower surface S2 of the downstream extending portion 31b of the upper wheel derailment prevention rail 31, and the lower surface S2 may be a straight line from the upstream end to the downstream end in a side view. The same applies to the upstream extending portion 31c. The arc surface S3a may not be provided on the lower surface S3 of the upstream extending portion 31c, and the lower surface S3 may be a straight line from the upstream end to the downstream end in a side view.

The distance between the lower surface S (= wide surface facing the flight 12) of the upper derailment prevention rail 31 and the surface 12a facing the upper derailment prevention rail 31 of the flight 12, and the inside of the side derailment prevention rail 34. The distance between the side surface 34a (= the wide surface facing the flight 12) and the side surface 12b facing the side derailment prevention rail 34 of the flight 12 may be different.

In addition, it is of course possible to make various changes within the range that can be assumed by those skilled in the art.

1: Sedimentation pond 2: Drive shaft 3: Intermediate shaft 6: Drive sprocket 7: Driven sprocket 10: Endless chain 11: Chain link 12: Flight 19: Guide rail 25: Driven sprocket body 26: Driven sprocket tooth 27: Drive Sprocket body 28: Drive sprocket tooth 31: Upper derailment prevention rail 34: Side derailment prevention rail 100: Sludge scraper T1: Radial tooth tip T2: Top surface of guide rail

Claims (5)

Multiple flights to scrape sludge from the bottom of the settling basin,
A pair of left and right endless chains to which the plurality of flights are attached, and an endless chain in which a plurality of chain links are connected.
A drive shaft having a pair of left and right drive sprockets on which the endless chain is hung, and a drive shaft arranged at the upper part in the settling pond.
An intermediate shaft having a pair of left and right driven sprockets on which the endless chain is hung, and an intermediate shaft arranged on the downstream side of the drive shaft and above the sedimentation pond.
A pair of left and right guide rails that support the flight traveling between the drive sprocket and the driven sprocket from below, and a guide rail arranged at the upper part in the settling pond.
A pair of left and right upper derailment prevention rails arranged above the flight traveling between the drive sprocket and the driven sprocket , and
Equipped with
The drive sprocket is
Drive sprocket body and
It has a plurality of drive sprocket teeth that protrude radially outward from the drive sprocket body portion, and has a drive sprocket tooth that meshes with the chain link.
When the rotating drive sprocket tooth is located at the highest position, the radial tooth tip of the drive sprocket tooth guides the raised flight onto the guide rail at the drive sprocket. It is said to be higher than the upper surface of the rail,
The guide rail is not inclined upward on the drive sprocket side, and the upper surface of the guide rail is the drive when the rotating drive sprocket tooth portion is located at the highest position over the entire length thereof. It is located lower than the radial tooth tip of the sprocket tooth,
The driven sprocket is
With the main body of the driven sprocket,
It has a plurality of driven sprocket teeth that protrude radially outward from the driven sprocket body portion, and has a driven sprocket tooth that meshes with the chain link.
When the rotating driven sprocket tooth is located at the highest position, the radial tooth tip of the driven sprocket tooth is above the top surface of the guide rail so that the traveling flight is lifted by the driven sprocket. It is said to be in a high position,
The upper derailment prevention rail is extended to the downstream side of the axis of the intermediate shaft, and the surface of the extended downstream side portion facing the flight is the upper derailment prevention rail. By setting the position higher than the surface facing the flight in the middle portion, it is possible to prevent the distance between the flight and the upper derailment prevention rail from becoming narrow in the driven sprocket portion .
The boundary portion of the surface facing the flight on the downstream side portion with the intermediate portion is an arc surface along the traveling trajectory of the flight.
Sludge scraper. In the sludge scraper according to claim 1 ,
The upper derailment prevention rail is extended to the upstream side of the axis of the drive shaft, and the surface facing the flight in the extended upstream portion is the flight in the middle portion. By setting the position higher than the facing surface, it is possible to prevent the distance between the flight and the upper derailment prevention rail from being narrowed in the drive sprocket portion.
Sludge scraper. In the sludge scraper according to claim 1 or 2 .
The wide surface of the upper derailment prevention rail facing the flight and the surface of the flight facing the upper derailment prevention rail are parallel to each other.
Sludge scraper. In the sludge scraper according to any one of claims 1 to 3 .
Further provided with a pair of left and right lateral derailment prevention rails arranged on the settling basin wall side of the flight traveling between the drive sprocket and the driven sprocket.
The wide surface of the lateral derailment prevention rail facing the flight and the surface of the flight facing the lateral derailment prevention rail are parallel to each other.
Sludge scraper. In the sludge scraper according to claim 4 ,
The wide surface of the upper derailment prevention rail facing the flight, the distance between the surface of the flight facing the upper derailment prevention rail, and the wide surface of the lateral derailment prevention rail facing the flight. And the distance between the side facing derailment prevention rail of the flight and the facing surface are the same.
Sludge scraper.

Images