JP4916032B2 - Sludge scraping device - Google Patents

Description

  The present invention is used in a sludge treatment tank such as a sludge sedimentation basin, and reciprocates on the bottom surface of the sludge treatment tank with respect to the sludge pit, each extending in a direction perpendicular to the reciprocating movement, and spaced along the reciprocating movement direction. The present invention relates to a sludge scraping device composed of a plurality of scraping elements.

As a sludge scraping device for scraping sludge in a sludge sedimentation basin, stainless steel plate is used as a raw material, sliding on the bottom surface of the sedimentation basin, each extending in a direction perpendicular to the reciprocating movement direction, and spaced in the reciprocating movement direction It is known to have a plurality of scraping elements with a gap. The scraping element has a concave shape, and includes a scraping surface (front surface) facing the sludge pit, and an inclined surface (back surface) inclined toward the bottom surface of the sedimentation basin in a direction away from the sludge pit from the scraping surface. (Patent Document 1).
Japanese Patent Laid-Open No. 5-245308

  In this kind of sludge scraping device, a guide rail made of hard synthetic resin such as ultra high molecular weight polyethylene (UHMWPE) is provided along the entire length of the scraping element in the reciprocating direction of the scraping element to reduce friction. Each of the sliding plates made of stainless steel plates, which are spaced apart in the width direction so as to extend along the reciprocating direction of the scraping element, are welded and fixed to the lower surface of the scraping element and are in contact with the resin guide rail. It is made to reciprocate while doing. In other words, simply comparing the hardness of stainless steel and synthetic resin, because stainless steel is harder than synthetic resin, the resin guide rails wear out as they are used, and the resin guide rails are worn at the stage where wear has progressed to the limit. The original design philosophy was that if it was replaced, the sludge scraping device could be used for a long time.

  However, when examining the operation results of actual machines, it was often the case that the wear was caused by a sliding plate made of a stainless steel plate rather than a relatively soft resin guide rail. When the cause is investigated, the sliding plate has a welded structure on the lower surface of the scraping element, but at the time of scraping, the uneven load applied locally to the sliding plate at the connecting part with the drive link, etc. It was found that the sliding plate was deformed in a wavy shape due to welding defects and the like, and this was caused by uneven wear of the sliding plate. Since the guide rail is designed to be replaced by wear, the replacement work is easy, but the sliding plate is not considered to be worn and is designed on the assumption that it can be used permanently. Therefore, if wear occurs at one end, it is necessary to disassemble and reassemble the entire scraping device, and the efficiency of the replacement work is very poor. .

  The present invention has been made in view of the above problems, and an object thereof is to provide a novel structure capable of improving the workability of replacement at the time of wear.

The sludge scraping device of the present invention reciprocates on the resin guide rail on the bottom surface of the sludge treatment tank, each extending in a direction substantially perpendicular to the reciprocating direction, and spaced along the reciprocating direction. A sludge scraping device comprising a plurality of steel scraping elements, wherein a sliding body as a metal plate is installed on the bottom surface of the scraping elements along the reciprocating direction of the scraping elements, The sliding body is fixed to the bottom surface of the scraping element, and the scratching element is substantially disposed along the entire length of the scraping element in the reciprocating direction on the lower plate of the upper plate so as to be in direct contact with the upper plate and the guide rail. is composed of a reciprocation direction lower fixed along the plate, insignificant gaps in the lower plates adjacent in the series of the lower plate is characterized Rukoto been left behind.

Lower plate in comparison with the upper part plate are wide width, the fixation of the lower plate to the upper plate can be carried out by welding at intervals in the longitudinal direction of the upper plate.

  The sliding body is composed of a continuous upper plate fixed to the scraping element by welding or the like, and a series of lower plates fixed to the lower surface of the upper plate by welding or the like so as to contact the guide rail. Even if wear on the steel side occurs, it occurs on the lower plate that is in direct contact with the guide rail, and it is sufficient to remove the lower plate from the upper plate and install a new lower plate, leaving the remaining scratching device as it is. There is an effect that the efficiency of the replacement work can be remarkably improved.

  In FIG. 1, reference numeral 10 denotes a sedimentation basin (sludge treatment tank of the present invention) provided in a sewage treatment plant or a water purification plant, which is installed to precipitate and separate sludge contained in the sewage that has flowed in. That is, a water conduit 12 is opened at the top of the settling basin 10, and sewage and clean water to be treated are allowed to flow into the settling basin 10 from the top thereof as indicated by an arrow a. After the treatment in the sedimentation basin 10, it is discharged from the outlet 13 as shown by the arrow b.

  A sludge pit 14 is provided at the end of the inflow side at the bottom of the sedimentation basin 10, and the sludge deposited on the bottom surface 10A of the sedimentation basin 10 is scraped toward the sludge pit 14 by a reciprocating sludge scraping device as will be described later. And finally collected in the sludge pit 14. A sludge discharge passage 16 is opened in the sludge pit 14, and a sludge pump (not shown) is installed in the sludge discharge passage 16, and sludge collected in the sludge pit 14 by the operation of the sludge pump is placed outside the sedimentation basin 10. It can be discharged as shown by arrow c.

  The reciprocating sludge scraping device 18 includes a number of scraping elements 20 each extending substantially the entire width of the settling basin 10, and a plurality of sliding bodies 22 (described later) are provided on the lower surface of the scraping element 20. In the embodiment, three sliding bodies 22 are provided, each extending substantially the entire length along the longitudinal direction of the sedimentation tank bottom surface 10A, and a plurality of sliding bodies 22 (in this embodiment, as shown in FIG. 2) spaced in the width direction. 3) are arranged so as to be slidably guided on the synthetic resin guide rail 24 to be arranged.

  In FIG. 1, reference numeral 26 denotes a drive mechanism for reciprocating the scraping element 20 as a whole. The drive mechanism 26 is a rotary drive motor 28 such as an electric type, and a rotary drive motor 28 is not shown. A transmission (its output shaft is represented by 30), a swing arm 32 connected to the transmission output shaft 30, a reciprocating rod 34 pivotally attached to one end of the swing arm 32, and a lower end of the reciprocating rod 34 A triangular link 36 pivotally attached to the link, a link support 38 for rotatably supporting the triangular link 36, and a connecting rod 40 for connecting the triangular link 36 to the sludge scraping device 18. . The rotation drive motor 28 is controlled by an inverter so as to swing and rotate at a predetermined angle, the swing arm 32 connected to the transmission output shaft 30 swings at a predetermined angle as indicated by the arrow d, and the reciprocating rod 34 is moved to the arrow. The triangular link 36 swings as shown by an arrow f, and the swing of the triangular link 36 is converted into the reciprocating motion of the scraping element 20 in the direction of the arrow g via the connecting rod 40. The The stroke of this reciprocating motion of the scraping element 20 is set to be equal to or slightly larger than the pitch of the scraping element 20. Therefore, the sludge deposited on the bottom of the sedimentation basin is gradually sent to the sludge pit 14 by one stroke amount.

  Each scraping element 20 is formed by bending a stainless steel plate, and its cross-sectional shape is shown in FIG. 3 and FIG. 4 and is generally upright but somewhat rearward (direction away from the sludge pit). It comprises a scraping surface 20-1 having a concave surface and an inclined surface 20-2 toward the bottom of the settling basin behind the upper end of the scraping surface 20-1. When the scraping element 20 moves in the left direction in FIG. 3, that is, toward the sludge pit 14 in FIG. 1, the scraping surface 20-1 is engaged with the sludge accumulated on the bottom surface 10 </ b> A of the sedimentation basin 10. The sludge is transferred toward the sludge pit 14 for one stroke, and conversely, the inclined surface 20-2 is moved in the moving direction when the scraping element 20 moves in the right direction, that is, away from the sludge pit 14. Because it is tapered, it passes through the sludge squeezed during the previous trip, leaving the sludge substantially in its position. Therefore, the sludge on the bottom of the sedimentation basin can be transferred to the sludge pit step by step by repeating the going and returning of the scraping element.

  Next, the detailed structure of the sludge scraping device 18 will be described. Each of the scraping elements 20 extends in the width direction of the sedimentation basin (in the direction orthogonal to the paper surface of FIG. 1), along the length direction of the sedimentation basin, etc. Many are provided at intervals. The sliding body 22 provided on the lower surface of the scraping element 20 includes an upper plate 42 and a lower plate 44. Each of the sliding bodies 22 including the upper plate 42 and the lower plate 44 is installed on a corresponding guide rail 24. As described above, in this embodiment, three guide rails 24 each extending in the longitudinal direction of the settling basin are provided in the width direction of the settling basin, and three sets of sliding bodies including the upper plate 42 and the lower plate 44 are also provided. Will be. The upper plate 42 and the lower plate 44 are made of stainless steel plates having appropriate thicknesses. The upper plate 42 is a single plate of, for example, 40 meters extending substantially the entire length of the sludge scraping device 18 and is welded to the bent portions 20-3 and 20-4 on the bottom surface of each scraping element 20. The lower plate 44 is also formed of a stainless steel plate having an appropriate thickness. However, the lower plate 44 is not a single piece structure like the upper plate 42, and each of the lower portions has a divided structure such that each length L (FIGS. 2 and 3) is 4 m, for example. The plates 44 are arranged in series, ie in series, over substantially the entire length of the sludge scraping device 18. The lower plate 44 is directly opposed to the guide rail 24. That is, in the present invention, the sliding body has a double structure, and the single upper plate 42 functions for mechanical connection with the scraping element 20, and the short lower plate for sliding with the guide rail 24. The function sharing of making 44 function is performed. As shown in FIGS. 2 and 4, the width of the lower plate 44 is somewhat larger than the width of the upper plate 42, and the lower plate 44 is partitioned on the upper surface of the side plate of the upper plate 42 at intervals in the longitudinal direction. It is welded in the length region, so-called tap welding. The tap weld site is shown at 46 in FIG. The length and interval of the tap welded portion 46 ensure the necessary joint strength between the upper plate 42 and the lower plate 44, and the separation and disassembly work from the upper plate 42 when replacing the lower plate 44 is not so difficult. It is set to an appropriate interval and length. A small gap G of, for example, 5 mm is left between the adjacent lower plates 44. The size of the gap is as small as possible from the viewpoint of not impairing the smooth sliding movement with respect to the guide rail 24 regardless of the divided structure lower plate 44. However, the size of the gap is appropriate so as not to impair the assembly workability. Set to

  The sludge scraping device 18 according to the present invention is connected to the link mechanism in the same manner as in the prior art. As shown in FIGS. 2 and 3, the sliding body 22 composed of the upper plate 42 and the lower plate 44 each has a width direction. A pull rod 50, which is a stainless steel rectangular cross-section pipe, extends substantially the entire length of the sludge scraping device 18 on the upper surface of the intermediate sliding body 22. The connecting plate 51 (FIG. 1) is welded to the upper surface of the pull rod 50, and the connecting rod 40 is pivotally attached to the connecting plate 51, whereby the swinging motion by the drive mechanism 26 is transmitted to the sludge scraping device 18. It has become. The upper edge 20-5 of each scraping element 20 that crosses the lower surface of the pull rod 50 is welded, and the upper ends of the reinforcing plates 52 (FIG. 6) are spaced on both sides of the pull rod 50 in the longitudinal direction. Are welded, and the lower portion of the reinforcing plate 52 is welded to the upper plate 42 of the sliding body 22. FIG. 4 shows a connecting structure of the scraping element 20 to the sliding body 22 on both sides in the width direction where the pull rod 50 is not provided. 3 and 4, in the assembled structure of the sludge scraping device 18 of the present invention, three sets of sliding bodies 22 each extending in the longitudinal direction on the lower surface of the scraping element 20 and spaced apart in the width direction. (Each consisting of an upper plate and a lower plate) is welded, and the upper surface of the scraping element 20 is constructed by welding a pull rod 50 in the middle in the width direction. Omitted as shown in FIG. That is, since the rigidity is increased by the combined structure of the sliding body 22 composed of the upper plate 42 and the lower plate 44, the necessary strength as the sludge scraping device 18 can be secured even with a structure in which the bracing is omitted.

  In the present invention, the sliding body 22 is a joint structure of a single upper plate 42 in the longitudinal direction on the scraping element 20 side and a lower plate 44 having a divided structure in the longitudinal direction on the guide rail 24 side, and is in contact with the guide rail 24. Only the lower plate 44 is used. Even if the lower plate 44 is damaged due to uneven wear or the like, the lower plate 44 is simply removed from the upper plate 42 and replaced and welded to a predetermined portion of the upper plate 42. Therefore, the replacement workability can be improved.

FIG. 1 is a schematic cross-sectional view of a sedimentation basin equipped with the sludge scraping device of the present invention. FIG. 2 is a plan view of the sludge scraping device of the present invention. FIG. 3 is a cross-sectional view of the sludge scraping device of the present invention represented along line III-III in FIG. FIG. 4 is a cross-sectional view of the sludge scraping apparatus of the present invention represented along the line IV-IV in FIG. FIG. 5 is a partially enlarged view of FIG. 2 and shows a welded structure of the upper plate and the lower plate in the sliding body. 6 is a cross-sectional view taken along line VI-VI in FIG.

Explanation of symbols

10 ... Sedimentation basin (sludge treatment tank of this invention)
14 ... sludge pit 18 ... reciprocating sludge scraping device 20 ... scraping element 22 ... sliding body 24 ... guide rail 26 ... drive mechanism 42 ... upper plate 44 ... lower plate 46 ... tap weld 50 ... pull rod G ... lower plate Gap between

Claims (2)

A number of steel scraping elements that reciprocate on the resin guide rail on the bottom surface of the sludge treatment tank, each extending in a direction substantially perpendicular to the reciprocation direction, and spaced along the reciprocation direction A sludge scraping device comprising a sliding body as a metal plate along the reciprocating direction of the scraping element on the bottom surface of the plurality of scraping elements, wherein the sliding body is a bottom surface of the scraping element And fixed to the lower surface of the upper plate along the reciprocating direction of the scraping element so as to be in direct contact with the guide rail along the entire length in the reciprocating direction of the scraping element. A sludge scraping device , wherein a plurality of the lower plates are arranged in series, and a slight gap is formed between adjacent lower plates in the series of lower plates . Characterized in the invention described in claim 1, the lower plate as compared to the upper plate is wide width, that is fixing of the lower plate to the upper plate is made by welding at intervals in the longitudinal direction of the upper plate Sludge scraping device.

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