JP2002219307A - Scraper for sand sedimentation basin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce load at a time when a reciprocating type scraper is provided in a sand sedimentation basin. SOLUTION: In the scraper for the sand sedimentation basin having the scraping member provided on the bottom surface of the sand sedimentation basin and scraping up sand sedimented on the bottom surface of the sand sedimentation basin using the scraping member, pressure water is ejected to sedimented sand accumulated in the sand sedimentation basin from the pressure water supply device provided to the scraping member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scraper for a sand basin (hereinafter referred to as a scraper) provided in a water treatment facility such as a sewage treatment plant.

[0002]

2. Description of the Related Art Conventionally, this type of scraping machine has attached a large number of scraping plates at predetermined intervals to a chain that is driven to rotate between the underwater of a sand basin and the surface of the sand, and the sand scraping plate is used to set up the sand. There is known a chain drive system in which sediment deposited on the bottom of a pond is raked.

[0003] However, this chain-driven scraping machine is of a reciprocating type in which the size of the apparatus is increased and the chains and sprockets are liable to be worn. A scraper has been proposed.
This reciprocating scraper has the advantages that the size of the apparatus can be reduced and the cost can be reduced.

[0004]

However, in the reciprocating scraper according to the above proposal, when the reciprocating drive is started in a state where the scraper plate is swallowed by the sand, or when the accumulation of the sand is abnormal. When it is large, a large force is required to drive the scraping plate, and there is a disadvantage that overloading occurs. In order to eliminate such disadvantages, it is conceivable to prepare a large driving source in advance, but in this case,
A new problem arises in that equipment costs and power costs are increased.

The present invention has been made to solve the above-mentioned drawbacks, and an object of the present invention is to provide a scraping machine which can reciprocate a scraping member with a small driving force.

[0006]

The scraper according to the present invention comprises:
In order to achieve the above object, it has a scraping member provided on the bottom surface of a sand basin, a sand basin scraping machine for scraping the sand on the bottom surface using the scraping member, It is characterized in that the pressurized water is jetted from the pressurized water supply device provided on the scraping member toward the settling sand deposited in the sand basin. Further, the pressure water supply device is characterized by comprising a hollow portion formed in the scraping member and a hole communicating from the hollow portion to the outside.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a scraper according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a cross section of a sand basin to which a scraper according to the present invention is applied, and FIG. 2 is a cross-sectional view of a scraper plate corresponding to a scraper member of the present invention. The sedimentation basin a has a raw water inflow pipe 1a from one end side (the left side in FIG. 1).
And has the shape of a well-known horizontal flow type sand basin configured to receive treated water (supernatant water) through a treated water outflow pipe 1b provided on the other end side. .

The bottom surface 2 of the sand basin a is formed in a substantially horizontal surface, and a pit 3 is provided on the raw water receiving side of the bottom surface 2.

The scraper 4 is movably mounted on the bottom 2 of the sand basin a, and is provided with a plurality of scrapers 5a, 5a,. ing.
Have a length substantially equal to the width direction of the sand basin a (direction orthogonal to the flowing direction of the raw water), similarly to the well-known reciprocating rake plate. The cross-sectional shape (vertical cross-sectional shape along the direction in which the raw water flows) has a substantially triangular shape as shown in FIG.
The side has a concave rake face 51 which is almost vertical and has a flank 52 which is inclined or curved on the side opposite to the pit 3 so as to taper in a direction opposite to the scraping direction. And
The upper portions of the raking plates 5a, 5a,... Are integrated via a connecting rod 6 and an assembling material 9 described later to form a raking machine 4.

The link mechanism 7 converts the rotational motion of the motor M into a reciprocating motion of the scraper 4. The upper end of the connecting rod 7a of the link mechanism 7 controls the rotational speed of the motor M at a predetermined rate. The lower end of the connecting rod 7a is rotatably connected to the first end of a triangular conversion part 7b provided on the side wall of the sand basin a. It is connected to. The second tip of the conversion part 7b is rotatably supported by the side wall of the sand basin a, and the third tip of the conversion part 7b is
A connecting rod 7c whose one end is rotatably connected to the connecting rod 6a of the scraper 4 is rotatably connected to the distal end.
Therefore, when the connecting rod 7a moves up and down, the scraper 4
As shown by the arrows, it is possible to reciprocate on the bottom surface 2 of the sand basin a. The interval between the reciprocating motions is determined to be slightly larger than the interval between the scraping plates 5a.

Although not shown, the pit 3 is provided with a pump for discharging sand. The sand settled by the pump is configured to be conveyed to a sand settling device (not shown) via a discharge pipe P. In addition, the sediment in the pit 3 can be pumped and discharged by a bucket.

The scraper 4 provided in the sand basin a having the above structure.
In the forward movement in which the scraper 4 moves to the pit 3 side (see arrows in FIGS. 1 and 2), the sediment is moved forward (pit 3 side) by the rake face 51 of the scraper 5a. In the return movement in which the concession 4 moves away from the pit 3 side (refer to the arrows in FIGS. 1 and 2), the resistance that the flank 52 of the scraping plate 5a may receive from the sedimentation can be reduced, and the sedimentation is moved. The scraper 4 is moved back without any action. Therefore, the sediment on the bottom surface 2 of the sand basin a is efficiently scraped to the pit 3 by the reciprocating motion of the scraper 4.

FIG. 3 is a view showing the scraper 4, in which FIG. 3 (a) is an enlarged perspective view of a part thereof, and FIG. 3 (b) is an enlarged sectional view taken along line AA of FIG. 3 (a). It is.

The plurality of scraping plates 5a, 5a,.
As shown in FIG. 2A, a plurality of assembling parts are provided on the bottom side of the scraping plates 5a, 5a,..., Other than the connecting rod (see FIG. 1, 6) connected to the link mechanism (see FIG. 1, 7). Lumber 9, 9
Assembled with That is, these assembly materials 9, 9
Are fixed to the bottom surfaces of the scraping plates 5a, 5a,... By welding at predetermined intervals in a direction orthogonal to the longitudinal direction of the scraping plates 5a, 5a,. That is, the scraping machine 4 is configured by combining a plurality of scraping plates 5a, 5a.

In FIG. 2A, 10, 10,...
A receiving member made of a synthetic resin provided at a position corresponding to each of the assembling members 9 on the bottom surface 2 of the base member 2, and is provided so that the reciprocating movement of the scraping machine 4 can be performed smoothly.

As shown in the enlarged view of FIG. 2A, each scraping plate 5a has a hollow portion 5a 'formed therein, a rake face 51 of the scraping plate 5a and a relief surface. A plurality of holes 5a ", 5a",... Are provided on the surface 52 at predetermined intervals in communication with the hollow portion 5a '. This hole 5a ″ may be provided on the bottom surface of the scraping plate 5a.

In FIG. 3A, reference numeral 11 denotes a header tube which constitutes a part of the pressure water supply device of the present invention. This header tube 1
1 is configured so that a part of the treated water (see 1b in FIG. 1) is supplied via a pump (not shown). The pressurized water in the header pipe 11 is connected to the connecting pipes 12 and 12.
Through the hollow portions 5a ', 5 of the scraping plates 5a, 5a,.
a '... are supplied. Since the supply of the pressurized water to the header pipe 11 also moves via the link mechanism 7, the header pipe 11 and the pump (not shown) are connected by a flexible tube (not shown).

The hollow portions 5a ', 5 of the scraping plates 5a, 5a,.
are supplied into the sand basin a via the holes 5 ", 5a"... The blast of the pressurized water loosens the sand deposited on the bottom surface 2 of the sand basin a. Therefore, it becomes possible to drive the scraper 4 with a small driving force.

The supply of the pressurized water to the raking plate 5a is performed at least for a predetermined time immediately before the driving of the raking machine 4 is started. That is, the supply of the pressure water is performed by the sand basin a.
The process is performed until the sand deposited on the bottom surface 2 is loosened. Of course, the supply of the pressurized water can be carried out continuously or intermittently during the operation of the scraping machine 4, but when the sand deposited on the bottom surface 2 of the sand basin a becomes loose, the scraping machine 4 is supplied. It is advisable to stop when the sedimentation is loosened because the load on the sand decreases.

[0020]

The scraping machine according to the present invention has a hollow portion formed in the scraping member and has a plurality of holes communicating with the hollow portion, and pressurized water supplied to the hollow portion is supplied to the holes. Since the blasting is performed toward the sand deposited in the sand basin deposited in the sand basin, the load on the scraper can be reduced, and the power cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a sand basin using a scraper according to the present invention.

FIG. 2 is a sectional view of a scraping plate corresponding to the scraping member of the present invention.

FIG. 3A is a perspective view of a part of the scraper according to the present invention, and FIG. 3B is an enlarged cross-sectional view taken along line AA of FIG.

[Explanation of symbols]

 Reference Signs List 1a Raw water inflow pipe 1b Treated water outflow pipe 2 Bottom surface 3 Pit 4 Settling machine for sand basin (Scraping machine) 5a Scraping member (Scraping plate) 5a 'Hollow portion 5a "Hole 9 Assembly material 10 Receiving material 11 Header tube (Pressure water supply device) 6a Connecting rod 7 Link mechanism a Sand basin

Claims (2)

[Claims] 1. A sand basin raking machine having a raking member provided on a bottom surface of a sand basin and using the raking member to crawl the sediment on the bottom surface, wherein the raking member is provided. A crusher for a sand basin, wherein pressure water is ejected from a pressure water supply device provided in the sand pit toward the sand deposited in the sand basin. 2. The sand raking machine according to claim 1, wherein the pressure water supply device comprises a hollow portion formed in the raking member and a hole communicating from the hollow portion to the outside.