Bucket with rake and dust removal device equipped with same

Abstract

To provide a bucket with a rake capable of continuously and effectively removing shellfish adhering to a bar screen.SOLUTION: In a rake provided on a bucket 3 capable of moving upward by means of an endless carrying chain along an upstream surface of a bar screen installed across a water intake channel in the width direction, the rake has a structure in which a plurality of rake pieces 4 are arranged in the longitudinal direction of the bucket 3 over the entire width of the intake channel. The front shape of the rake piece 4 forms an acute angle in the traveling direction of the bucket 3. The cross-sectional shape of the width direction plane of the intake channel is such that the rake pieces 4 are convex toward the downstream side, and the portions between the rake pieces 4 are concave.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a rake used in a bar screen that is installed for the purpose of removing foreign matter such as dust from water when taking water from the sea or river or when purifying the water. [Background technology]

[0002] In power plants such as thermal power plants, water is taken from rivers and the sea at intake sites to be used as cooling water, but this water may contain dust and aquatic organisms and cannot be used as is. For this reason, bar screens are installed at intake sites as dust removal devices that capture dust and aquatic organisms in the water.

[0003] The bar screen (a vertical grid pattern made up of multiple bars arranged at equal intervals within a rectangular frame) is erected across the intake channel, either perpendicular to the water flow or at a specified inclination angle, and a rake attached to an endless carrying chain scoops up and removes debris that has adhered to the upstream surface of the bar screen.

[0004] In other words, multiple rake-equipped buckets provided for removing debris attached to the bar screen rise continuously as the carrying chain rotates, scooping up and removing the debris.

[0005] In this way, the rake can remove most of the debris that has adhered to the upstream surface of the bar screen, but it is very difficult to remove shellfish such as mussels that have attached and grown in the gaps in the bar screen using the conventional rake bucket structure.

[0006] Therefore, if shellfish that could not be removed are left behind, there is a risk that they will come into contact with the rake bucket and cause deformation. Therefore, in order to remove the shellfish that have become attached to the gaps in the bar screen periodically, such as during inspections of the power plant, the intake channel upstream of the bar screen is blocked off with a water stop gate to create a dry space without water, and then scaffolding is erected and the shellfish are removed by hand. Alternatively, a crane is used to lift the bar screen from the intake channel to ground level to remove the shellfish.

[0007] In addition, if the water flow area is reduced due to shellfish attached to the gaps in the bar screen, a difference in water level will occur between the upstream and downstream sides of the bar screen, making it necessary to shut down the power plant. As a temporary measure, divers are diving into the intake channel and manually removing the debris.

[0008] However, the above-mentioned method requires extensive work such as blocking the intake channel to drain the water, assembling scaffolding and setting up a crane, before the removal work can be carried out, which takes a long time, and during this work the power plant must stop operating because cooling water cannot be secured from the intake channel. Furthermore, the shellfish attached to the bar screen give off an unpleasant odor, making the removal work a bad environment.

[0009] Furthermore, when divers perform the removal work, there is a risk that they will be swept away by the flowing water and become trapped in the screen, so removal work cannot be carried out when the current is fast. In addition, due to issues with water transparency, the workable area is limited to a depth of 2m below the surface, so it is not possible to completely remove shellfish from the bar screen.

[0010] If these removal works were to cause power plants to have to suspend operations or reduce power generation during the summer when electricity supply is high, it would cause major disruption to our lives.

[0011] Therefore, as disclosed in Patent Document 1, a device has been proposed in which a nozzle header is attached to a bucket and high-pressure water is sprayed from this nozzle header onto the bar screen to clean it.This eliminates the need to block the water intake and drain the water, or the need for divers to do the work, and allows the bar screen to be cleaned safely and efficiently in a short amount of time. However, to use high-pressure water, a compressor or other device must be installed to apply enough pressure to remove the shellfish, which is costly, and it is very difficult to adjust the direction of the nozzle used, as it requires a great deal of precision.

[0012] Furthermore, as disclosed in Patent Document 2, by making the cross-sectional shape of the rake corrugated, the unevenness on the surface of the rake's scooping surface scoops up the debris and ensures that it is collected. However, since it is difficult to remove shellfish attached to the bar screen due to the unevenness of the rake in Patent Document 2, it is not possible to completely remove the shellfish. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Japanese Patent Application Publication No. 2-56208 [Patent Document 2] JP 2014-152547 A Summary of the Invention [Problem to be solved by the invention]

[0014] SUMMARY OF THE PRESENT EMBODIMENT In view of the above problems in the prior art, an object of the present invention is to provide a bucket with a rake that can continuously and effectively remove shellfish that have adhered to a bar screen. [Means for solving the problem]

[0015] As a first means for solving the above problems, the present invention provides a rake equipped on a bucket that can be moved upward by an endless carrying chain along the upstream surface of a bar screen installed across the width of an intake channel, The rake has a structure in which a plurality of rake pieces are arranged in the longitudinal direction of the bucket across the entire width of the intake channel, The front shape of the rake piece is such that Angle 10 to 60 degrees Forming an acute angle, A side of the rake piece including a vertex of the acute angle is inclined upward toward a downstream side of the bucket, The cross-sectional shape of the intake channel in a plane in the width direction is such that the rake pieces are convex toward the downstream side, and the areas between the rake pieces are concave. The rake pieces form an uneven shape toward the downstream side of the intake channel, The rake pieces cut and remove shellfish attached to the gaps in the bar screen. The object of the present invention is to provide a bucket with a rake. According to the first means, the shellfish adhering to the bar screen can be cut by the acute-angled convex rake pieces and collected in the scraping bucket.

[0016] As a second means for solving the above problem, the present invention provides a bucket with a rake as described in claim 1, characterized in that the front shape of the rake piece forms one or two acute angles in the direction of travel of the bucket. According to the second means, the shellfish adhering to the bar screen can be cut by the acute-angled convex rake pieces and collected in the scraping bucket.

[0017] As a third means for solving the above problems, the present invention provides a dust removal device characterized in that a plurality of rake-equipped buckets as described in the first or second means are provided in the vertical direction on an endless carrying chain. According to the third means, the shellfish adhering to the bar screen can be cut by the rake pieces having a continuous acute-angled convex shape and collected in the scraping bucket.

[0018] As a fourth means for solving the above problems, the present invention provides a bucket having at least one rake with a rectangular front shape of a rake piece attached to an endless carrying chain, The object of the present invention is to provide a dust removal device characterized in that at least one rake-equipped bucket as described in the first or second means is provided alternately on the top and bottom. According to the above-mentioned fourth means, by alternately providing a conventional rake bucket whose rake pieces have a rectangular front shape and a rake bucket whose rake pieces have a front shape that is a convex shape with an acute angle toward the direction of travel of the bucket, it is possible to cut off shellfish attached to the bar screen with the acute-angled convex rake pieces and then reliably scrape them off with the rectangular rake pieces. Effect of the Invention

[0019] According to the present invention, by making the front shape of the rake piece of the rake-equipped bucket into an acute convex shape toward the direction of travel of the bucket, shellfish attached to the bar screen can be continuously and effectively cut and removed from the bar screen. In addition, there is no need for new equipment such as a compressor, as is the case when using high-pressure water, and there is no need to take the time to fine-tune the direction of the nozzle used to spray the high-pressure water. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a top view of the rake bucket of the present invention. [Diagram 2] 1A and 1B are explanatory views of a rake-equipped bucket according to the present invention, in which (a) is a front view and (b) is a side cross-sectional view. [Diagram 3] 1A and 1B are explanatory diagrams of a conventional rake bucket, in which (a) is a front view and (b) is a side cross-sectional view. [Figure 4] FIG. 2 is a simplified cross-sectional side view of a bar screen apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

[0022] [Bar Screen Device 20] 4 shows the bar screen device 20. The carrying chain 29, which is endlessly wound around the upper sprocket wheel 21A and the lower sprocket wheel 21B, rotates to raise the rake-equipped bucket 22 and scrape out the garbage captured by the bar screen. The scraped-out garbage is collected in the bucket and then passed down the guide plate 27 in the housing 26 to be discarded in the trough 28.

[0023] [Conventional rake bucket 12] Figures 3(a) and (b) show a conventional bucket with rake 12, which is applied to the bucket with rake 22 in Figure 4. Figure 3(a) is a front view, and Figure 3(b) is a side cross-sectional view. As shown in Figure 3(a), the conventional bucket with rake 12 is provided with rollers 15 that act as rollers to reduce the impact and wear caused by collision with the tooth surface when the carrying chain rotates and engages with the sprocket. In addition, a bucket 13 is attached to each link plate 17 of the carrying chain, and the bucket 13 is provided with multiple rectangular rake pieces 14 at equal intervals in the width direction of the intake channel so that they can fit into the gaps of the bar screen, which has a comb-shaped front shape.

[0024] As shown in FIG. 3(b), the cross-sectional shape of the side surface of the rake piece 14 provided so as to protrude downstream from the bucket 13 is a rectangle with an upward slope to the right. A conventional rake bucket 12 equipped with this rake piece 14 can remove most of the debris, but shellfish such as mussels that grow in the gaps in the bar screen are firmly attached and are very difficult to remove.

[0025] [Rake-equipped bucket 2 of the present invention] Figures 1, 2(a) and 2(b) show the rake bucket 2 of the present invention, which is applied to the rake bucket 22 of Figure 4. Figure 1 is a top view of the rake bucket 2 of the present invention, Figure 2(a) is a front view and Figure 2(b) is a side cross-sectional view. As shown in Figures 1 and 2(a), the bucket with rake 2 of the present invention is provided with rollers 5 that act as rollers to reduce the impact and friction caused by collisions with the teeth of the sprocket when the carrying chain rotates and engages with the sprocket, and a bucket 3 is attached to each link plate 7 of the carrying chain. The bucket 3 has multiple rake pieces 4 that protrude downstream and are arranged at equal intervals, and the rake pieces 4 form an uneven shape toward the downstream side of the intake channel. The size of the bucket 3, the number of rake pieces 4, and the spacing between the rake pieces 4 can be changed depending on the width of the intake channel and the specifications of the bar screen.

[0026] As shown in Fig. 2(a), the front shape of the rake piece 4 forms an acute convex shape toward the traveling direction of the bucket 3. Also, as shown in Fig. 2(b), the cross-sectional shape of the side of the rake piece 4 provided to protrude downstream from the bucket 3 is a right-upward rectangular shape with non-right-angled diagonals. In Fig. 2(a), the front shape of the rake piece 4 is preferably an isosceles triangle or a right triangle with an acute apex angle, and the apex angle that is convex in the traveling direction of the bucket 3 is an acute angle of 10 to 60 degrees. Therefore, the blade width of the rake piece 4 shown in Fig. 2(b) increases as the apex angle of the rake piece 4 decreases.

[0027] In addition, the front shape of the rake piece 4 may be a shape having two acute angles formed by arranging the hypotenuses of two right-angled triangles to form a V shape, that is, a shape formed by cutting an isosceles triangle out of a rectangle. In this case, the base of the isosceles triangle in the cutout portion of the rake piece 4 is equal to the width of the rake piece 4, and the height can be changed as appropriate. By changing the height of the isosceles triangle in the cutout portion, the angles of the two acute angles formed in the rake piece 4 can be adjusted. Specifically, if the height of the isosceles triangle in the cutout portion is lowered, the angle of the two acute angles formed in the rake piece 4 becomes larger, and if the height of the isosceles triangle in the cutout portion is increased, the angle of the two acute angles formed in the rake piece 4 becomes smaller.

[0028] The material of the rake pieces 4 is preferably the same steel material as that used for the bar screen, etc. Furthermore, a cleaning brush may be provided below the rake pieces 4 to clean the gaps in the bar screen after the rake pieces 4 have removed debris such as shellfish.

[0029] In this way, the rake bucket 2 of the present invention can cut and remove shellfish that are firmly attached to the gaps in the bar screen. Therefore, the work of removing shellfish from the bar screen using the rake bucket 2 of the present invention can be carried out continuously and efficiently while the water intake operation is ongoing, without the need to block the water intake to drain water or for divers to perform the work. Also, by simply changing the shape of the rake pieces 4, there is no need to install a new compressor or the like, and there is no need to take the time to fine-tune the equipment.

[0030] Also, the bucket with rake 2 of the present invention may be configured in combination with a conventional bucket with rake 12. With this configuration, after the shellfish attached to the bar screen are cut by the rake pieces 4 of the bucket with rake 2 of the present invention, the rake pieces 14 of the conventional bucket with rake 12 can fit into the gaps in the bar screen and move upward, making it possible to more efficiently remove the cut shellfish.

[0031] For example, when there are many small shellfish attached to the bar screen, it is advisable to combine two of the rake buckets 2 of the present invention and one conventional rake bucket 12, one above the other, alternating between the top and bottom. With this structure, the multiple rake buckets 2 of the present invention can cut the shellfish continuously, and then the conventional rake bucket 12 can reliably scrape off the cut shellfish.

[0032] In addition to the above, the configurations given in the above embodiments can be selected or appropriately changed to other configurations without departing from the spirit of the present invention. [Explanation of symbols]

[0033] 2. Bucket with rake of the present invention 3, 13 Bucket 4, 14 Rake pieces 5, 15 Laura 6. Ribs 7, 17 Link plate 12 Conventional rake bucket 20 Bar Screen Device 21A Upper sprocket wheel 21B Lower sprocket wheel 22 Rake and bucket 26 Housing 27 Information Board 28 Trough 29 Carrying Chain

Claims

1. A rake is attached to a bucket that can be lifted by an endless carrying chain along the upstream surface of a bar screen installed across the width of the intake channel. The rake has a structure in which a plurality of rake pieces are arranged in the longitudinal direction of the bucket across the entire width of the intake channel, The front shape of the rake piece forms an acute angle of 10 to 60 degrees toward the traveling direction of the bucket, A side of the rake piece including a vertex of the acute angle is inclined upward toward a downstream side of the bucket, The cross-sectional shape of the intake channel in a plane in the width direction is convex toward the downstream side with the rake pieces and concave between the rake pieces, and the rake pieces form an uneven shape toward the downstream side of the intake channel, A bucket with a rake, characterized in that the rake pieces cut and remove shellfish attached to the gaps in the bar screen.

2. 2. A bucket with a rake according to claim 1, wherein the front shape of said rake piece forms one or two acute angles in the direction of travel of said bucket.

3. 3. A dust removal device comprising a plurality of rake-equipped buckets according to claim 1 or 2 attached to an endless carrying chain in the vertical direction.

4. At least one rake bucket with a rectangular front shape of the rake piece attached to an endless carrying chain; A dust removal device comprising at least one rake-equipped bucket according to claim 1 or 2, the bucket being provided alternately above and below the other.

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