JP2014240044A - Sludge scraping machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sludge scraping machine capable of securing tension necessary for an endless chain even if elongation occurs in the endless chain while low cost is achieved by a simple configuration.SOLUTION: While a low cost is achieved by a simple configuration that a support part 11A which movably supports an endless chain 2 from below is provided between a wheel 3A on the uppermost stream side of a bottom 1B of a vessel 1 in the revolving direction of the endless chain 2 and a wheel 6A which is closest to the wheel 3A and positions near a water surface 1A, and a catenary part 15 is formed between the wheel 6A and the support part 11A of the endless chain 2. Even if elongation occurs in the endless chain 2, the endless chain 2 only becomes slack at the catenary part 15, a catenary length L is always maintained at a constant length comparing to a conventional case where the catenary length becomes shorter with the elongation of the endless chain 2, reduction of tension caused by the self-weight of the endless chain 2 is eliminated in the catenary part 15, and tension necessary for the endless chain 2 is secured.

Description

  The present invention relates to a sludge scraper.

  A so-called 4-axis type chain flight type sludge scraper is known as a device for scraping sludge. This four-axis type chain flight type sludge scraping machine has an endless chain that wraps around a plurality of sprockets and moves around in a tank facing the width direction of the tank as described in Patent Document 1 below. A pair of endless chains are attached to the pair of endless chains in a circumferential direction, and the pair of endless chains are moved around by the rotation of the sprocket. Move along the water surface. Then, as the flight moves along the bottom of the tank, the deposits such as sludge accumulated on the bottom of the tank are scraped together.

  In this sludge scraper, the upstream sprocket in the circumferential direction of the endless chain located near the water surface is used as the driving sprocket, and the driven sprocket located near the water surface and located downstream of the driving sprocket in the circumferential direction of the endless chain. A catenary portion of the endless chain is formed between the driven sprocket located downstream of the driven sprocket and upstream of the bottom of the tank in the circumferential direction of the endless chain. In this catenary part, the endless chain hangs down from the upstream driven sprocket that constitutes the catenary part toward the downstream driven sprocket, and in the horizontal direction from the downstream driven sprocket to the sludge collection pit side. By placing the flight on the extending guide rail, the suspended endless chain becomes almost horizontal and reaches the downstream driven sprocket.

  The catenary part is widely used in 4-axis type chain flight type sludge scraping machines. In this catenary part, the tension | tensile_strength by the chain's own weight generate | occur | produces in the slack part to the position where an endless chain hangs down while tilting and begins to become horizontal. Therefore, in the sludge scraper having a catenary part, even if the endless chain is extended, the tension on the loose side of the drive sprocket (downstream side of the drive sprocket: the delivery side) is caused by the tension of the catenary part due to its own weight. Insufficiency is solved, and as a result, it is possible to prevent skewing and wheel removal due to tooth skipping.

  In this catenary section, as the endless chain grows larger, the endless chain begins to drop and become horizontal while tilting from the upstream driven sprocket constituting the catenary section (the flight is placed on the guide rail). The catenary length, which is the horizontal length until it is placed and started to be supported, becomes shorter (in contrast, the length of the flight placed on the guide rail becomes longer). Therefore, as the endless chain extends, the tension due to the endless chain's own weight at the catenary portion decreases, and the necessary tension cannot be secured. In particular, in the light-weight resin chain that has been recently adopted, it is more difficult to secure the necessary tension because the tension due to its own weight at the catenary portion is smaller than that of a conventional iron chain.

  Therefore, in the following Patent Document 2, a flight passage type rotating body having a plurality of fork portions extending radially and a space portion that is formed between the fork portions in the circumferential direction and can store a flight passing therethrough is provided. A swing member which is supported at one end side so as to be swingable and rotatably supports the flight-passing rotator at the other end side. When the flight on the endless chain reaches the flight passing rotator, the flight can be passed by the rotation of the flight passing rotator while being stored in the space of the flight passing rotator. A 4-axis type chain flight type sludge scraper is described. In this sludge scraping machine, an appropriate tension can be applied to the endless chain regardless of the elongation of the endless chain by the flight passage type rotating body and the swing member.

JP 2013-10085 A JP 2013-22571 A

  However, Patent Document 2 has a problem that the structure is complicated and the manufacturing cost is very high. Here, without providing such a complicated configuration, it is necessary to periodically drain all the sewage in the tank, adjust the take-up at the bottom of the tank, or reduce the number of links of the endless chain. Although tension can be secured, it is not preferable because maintenance costs are significantly increased.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sludge scraping machine capable of ensuring the necessary tension for an endless chain even when the endless chain is elongated while achieving cost reduction with a simple configuration.

  The sludge scraper according to the present invention includes a pair of endless chains that are wound around a plurality of wheels and move around in a tank, and a plurality of flights are attached to the pair of endless chains along the circulation direction. The endless chain of the endless chain moves around, and the flight moves along the bottom of the tank to scrape the sediment deposited on the bottom of the tank. A support portion that supports the endless chain from below is provided between the wheel and the wheel that is closest to the wheel and near the water surface.

  According to such a sludge scraper, the endless chain can be moved between the wheel on the most upstream side of the bottom of the tank in the circulation direction of the endless chain and the wheel closest to the wheel and located near the water surface. By providing a support part to be supported from below, a catenary part of an endless chain is formed between the wheel and the support part, and even if the endless chain is elongated, the endless chain is only loosened in the catenary part, The catenary length is always kept constant as compared with the conventional case where the catenary length becomes shorter as the endless chain grows. For this reason, in the catenary part, there is no decrease in tension due to the weight of the endless chain, and the tension necessary for the endless chain is ensured. In this way, the tension required for the endless chain can be ensured even if the endless chain is elongated, while reducing the cost with a simple configuration.

  Here, specifically as a support part which show | plays the said effect | action effectively, the rotatable wheel which supports an endless chain from the bottom so that a movement is possible is mentioned. Another example of the support portion is a chain guide that supports the endless chain from below so as to be movable and guides the side of the endless chain.

  According to the present invention, it is possible to secure the necessary tension for the endless chain even when the endless chain is elongated, while reducing the cost with a simple configuration.

It is a schematic side view which shows the sludge scraping machine which concerns on embodiment of this invention.

  Hereinafter, a preferred embodiment of a sludge scraper according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic side view showing a sludge scraper according to an embodiment of the present invention.

  As shown in FIG. 1, the sludge scraper 100 is a 4-axis type chain flight type sludge scraper, and is installed inside the tank 1 including a settling basin of a sewage treatment plant, for example.

  The tank 1 is configured to be horizontally long, and sewage is supplied from the left side of FIG. A sludge collection pit 1C is provided at the end of the tank 1 on the sewage supply side, and a discharge pipe 1D for discharging the sludge to the outside is provided for the sludge collection pit 1C. A scum pipe 9 that is rotatable about an axis is provided over the entire width direction of the tank 1 at a substantially central portion of the tank 1 near the water surface 1 </ b> A of the tank 1. The scum pipe 9 includes an opening that extends in the axial direction (perpendicular to the plane of FIG. 1) on the circumferential surface and opens upward, and has a C-shaped cross section. Then, the scum pipe 9 is repeatedly rotated counterclockwise in FIG. 1 so that the opening is positioned below the water surface 1A in order to collect the suspended matter (scum) floating on the water surface 1A, and then repeatedly returns.

  The sludge scraper 100 includes an endless chain 2 that circulates in the longitudinal direction in the tank 1, and the endless chain 2 is provided in a pair facing the width direction (perpendicular to the paper surface) of the tank 1. The flight 10 is configured in a channel shape extending in the width direction of the tank 1, and a plurality of flights 10 are arranged along the circumferential direction of the endless chain 2. These flights 10 are attached so that both ends thereof are respectively stretched over a pair of endless chains 2 (is laid horizontally). The both ends of the flight 10 extend from the endless chain 2 to the outside in the width direction of the tank 1 and are located in the vicinity of the side wall of the tank 1.

  In the sludge scraper 100, the first driven shaft 3 is provided on the bottom 1B of the tank 1 on the side opposite to the sludge collection pit 1C (the right side in the figure), and is close to the sludge collection pit 1C on the bottom 1B. A second driven shaft 4 is provided at the position. A pair of first driven sprockets 3A are attached and fixed to both ends of the first driven shaft 3, and a pair of second driven sprockets 4A are attached and fixed to both ends of the second driven shaft 4. Yes.

  Further, in the sludge scraper 100, a drive shaft 5 is provided below the water surface 1A of the tank 1 and above the second driven shaft 4, and is located slightly upstream (left side in the drawing) below the scum pipe 9 below the water surface 1A. A third driven shaft 6 is provided. A pair of drive sprockets 5A are attached and fixed to both ends of the drive shaft 5, and a pair of third driven sprockets 6A are attached and fixed to both ends of the third driven shaft 6. The drive shaft 5 and the driven shafts 3, 4, 6 are rotatably supported.

  Here, the endless chain 2 is a resin chain and is wound around each of the sprockets 3A to 6A, which is a kind of wheel, and a part of the endless chain 2 is stretched along the water surface 1A. A part of 2 is stretched along the bottom 1 </ b> B of the tank 1. The endless chain 2 may be, for example, an iron chain.

  Further, in the sludge scraper 100, a motor sprocket 5B is attached and fixed to one end of the drive shaft 5 on the outer side in the axial direction (outer in the width direction of the tank 1) than the drive sprocket 5A. A motor 7 for rotationally driving the drive shaft 5 is installed on the upper tank upper wall. A drive chain 8 is hung between a motor sprocket 7 </ b> A attached and fixed to the output shaft of the motor 7 and a motor sprocket 5 </ b> B of the drive shaft 5.

  Here, particularly in the present embodiment, a support portion 11A is provided between the first driven sprocket 3A and the third driven sprocket 6A so as to be in contact with the endless chain 2 and movably support the endless chain 2 from below. .

  Here, the support portion 11 </ b> A is a kind of wheel and is a sprocket that can mesh with the endless chain 2. The support portion 11A is attached and fixed to both ends of the fourth driven shaft 11 that is rotatably supported, and rotates according to the movement of the endless chain 2.

  The support portion 11A is not limited to a sprocket, and may be a roller that is a kind of wheel. Further, the support portion 11A may be a chain guide that is a fixing member that contacts the endless chain 2 and supports the endless chain 2 from below so as to be movable and guides the side of the endless chain 2.

  And by providing the support part 11A which supports such an endless chain 2 from below, a catenary part 15 of the endless chain 2 is formed between the third driven sprocket 6A and the support part 11A. .

  In addition, between the drive shaft 5 and the 3rd driven shaft 6, the flight 10 which moves toward the 3rd driven shaft 6 side from the drive shaft 5 side is mounted, and it guides while sliding in a horizontal direction A pair of return rails R is provided, and a flight 10 moving from the fourth driven shaft 11 side toward the first driven shaft 6 side is provided between the lower position of the fourth driven shaft 11 and the first driven shaft 6. A pair of guide rails G is provided for placing on the first driven shaft 6 side and guiding while sliding in the horizontal direction. The return rail R and the guide rail G are provided so as to face each other in the width direction at a position outside the endless chain 2 in the width direction of the tank 1 and to extend in the horizontal direction. Incidentally, when the distance between the fourth driven shaft 11 and the first driven shaft 6 is short, the guide rail G may be omitted.

  According to the sludge scraper 100 configured as described above, the drive shaft 5 rotates in the clockwise direction in FIG. 1 through the motor sprocket 7A, the drive chain 8, and the drive motor sprocket 5B. As a result, the endless chain 2 orbits the orbit in which the sprockets 5A and 6A, the support portion 11A, and the sprockets 3A and 4A are arranged in this order (see arrows). The sludge accumulated in the bottom 1B of the tank 1 is scraped and collected in the sludge collection pit 1C, and the suspended matter floating on the water surface 1A is scraped and collected by the scum pipe 9. it can.

  In particular, according to the sludge scraper 100 of the present embodiment, the first driven sprocket 3A, which is the most upstream sprocket on the bottom 1B of the tank 1 in the circumferential direction of the endless chain 2, and the closest to the first driven sprocket 3A. A support portion 11A is provided between the third driven sprocket 6A and the support portion 11A so as to support the endless chain 2 from below so as to be movable between the third driven sprocket 6A that is a sprocket located near the water surface 1A. Since the catenary portion 15 of the endless chain 2 is formed, even if the endless chain 2 is stretched, the catenary portion 15 is simply loosened by the catenary portion 15 and the catenary length is shortened according to the elongation of the endless chain 2. Compared with the prior art, the catenary length (horizontal length of the catenary part 15) L is always maintained constant. For this reason, in the catenary part 15, the tension | tensile_strength required for the endless chain 2 is ensured, without the tension | tensile_strength reduction by the dead weight of the endless chain 2. FIG. As described above, according to the present embodiment, it is possible to secure the necessary tension for the endless chain 2 even if the endless chain 2 is elongated while reducing the cost with a simple configuration.

  In this embodiment, for the purpose of reducing driving force, the endless chain 2 is a resin chain that is lighter than an iron chain. However, since the support portion 11A is provided, a lightweight resin is used. Necessary tension can be secured even with chains.

  As described above, the present invention has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment. For example, in the above embodiment, it is particularly preferable that the position is near the water surface 1A. The upstream shaft and sprocket in the circumferential direction of the endless chain 2 are the drive shaft 5 and the drive sprocket 5A. However, the third driven shaft 6 and the third driven sprocket 6A are the drive shaft and the drive sprocket. It can also be applied to.

  Further, the present invention can also be applied to a sludge scraping machine in which a chain is a notch type chain, a driving sprocket is a pin wheel, and a driven sprocket is a sheave wheel.

  Further, in the above-described embodiment, the application to the 4-axis type chain flight type sludge scraping machine is described as being particularly suitable, but the application to the 3-axis or more chain flight type sludge scraping machine is described. it can.

  DESCRIPTION OF SYMBOLS 1 ... Tank, 1A ... Water surface, 1B ... Bottom of tank, 2 ... Endless chain, 3A ... First driven sprocket (wheel on the most upstream side of the tank), 4A ... Second driven sprocket, 5A ... Drive sprocket, 6A 3rd driven sprocket (wheel located near the water surface and closest to the 1st driven sprocket), 10 ... flight, 11A ... support part (sprocket; wheel), 15 ... catenary part, 100 ... sludge scraper.

Claims (3)

A pair of endless chains that hang around a plurality of wheels and move around in the tank are provided, a plurality of flights are attached to the pair of endless chains along the turning direction, and the pair of endless chains move around by the rotation of the wheels. In the sludge scraping machine that scrapes the sediment deposited on the bottom of the tank as the flight moves along the bottom of the tank,
A support portion for supporting the endless chain from below so that the endless chain is movable between a wheel on the most upstream side of the bottom of the tank in a circumferential direction of the endless chain and a wheel that is closest to the wheel and near the water surface. A sludge scraping machine characterized by the installation.   The sludge scraping machine according to claim 1, wherein the support portion is a rotatable wheel that supports the endless chain from below so as to be movable.   The sludge scraper according to claim 1, wherein the support portion is a chain guide that supports the endless chain from below so as to be movable and guides a side of the endless chain.

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