JP2001129313A - Apparatus for pumping up sand and operation method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems that a large quantity of manual work is required to empty grit chamber by discharging water and to gather sand and that a large quantity of power is required to discharge the gathered sand by a jet pump at the time when sand deposited in the bottom of the grit chamber is gathered by water jet from nozzles and discharged by the pump. SOLUTION: The apparatus for pumping up sand comprises sand gathering pits installed at prescribed positions in a grit chamber and nozzles for jetting water toward an external sand gathering pit. A plurality of projected and recessed stripes are formed toward the sand gathering pits and troughs made of a metal are buried in the recessed stripes and nozzles are installed in the bottom parts. Water is supplied at 20-40 mAq to the nozzles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sand lifting device for removing sand deposited in a sand basin of a wastewater treatment facility.

[0002]

2. Description of the Related Art Conventionally, in order to remove sediment deposited in a sand basin, a nozzle is arranged at the bottom of the pond, and the deposited sand is jetted out by spraying pressure water from the nozzle and separately provided. A sand-lifting device is used, which collects sand in a sand-collecting pit, and discharges sand to the outside of the pond together with water by a sand-lifting pump arranged in the sand collecting pit. In Japanese Patent Application Laid-Open No. 7-100305 (known example), a trough is provided at the center in the width direction of a sand basin toward a sand collecting pit, and a number of small troughs are provided so as to be orthogonal to the trough. There is disclosed a sand lifting device in which a nozzle for ejecting pressurized water is disposed at an upper end portion between the nozzles and an underwater sand pump which is a sand pump for discharging sand collected in a sand collecting pit. When operating this sand-lifting device, after emptying the sand basin and exposing the bottom of the pond, pressure water is blown out from the nozzle, and the sand deposited on the bottom of the pond along with the water flow is passed through the small trough and trough. They are collected in a sand collecting pit and discharged from the sand basin by a sand pump.

Japanese Patent Application Laid-Open No. 8-229310 (known example) discloses that a bottom of a sand basin is formed to be inclined from upstream to downstream, a sand pit is provided at the downstream end, and a jet pump is provided in the sand pit. And a nozzle for discharging pressurized water in the direction of flow of raw water on the bottom surface of a sand basin is disclosed. When operating this sand lifting device, the inflow of raw water is stopped, and after the water level falls to a predetermined level, pressure water is ejected, and the other operations are the same as those described above.

[0004]

However, the above-mentioned known sand-lifting apparatus has a problem that it is necessary to empty the water to such an extent that the bottom of the sand basin is exposed, which requires a great deal of trouble. is there. Moreover, since the known sand lifting device uses a jet pump, there is a problem that a large power is required to operate the jet pump. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a sand-lifting device which can perform sand-lifting work relatively easily and has small power.

[0005]

According to a first aspect of the present invention, a sand collecting pit is provided at a predetermined position of a sand basin, and a plurality of nozzles are provided so as to jet water toward the sand collecting pit. In a sand-lifting device in which a sand-lifting pump is arranged so as to be located inside, a plurality of uneven strips are provided on the bottom of the sand basin toward the sand collecting pit, and a plurality of nozzles are arranged in each recess, The strip is characterized by being formed by embedding a metal trough. The second invention is characterized in that a sand collecting pit, a nozzle, and a pump well are provided in order from the inflow direction of sewage into a settling basin, and a part of the sewage in the pump well is supplied to the nozzle and jetted. . In the present invention, a nozzle, a sand collecting pit, a nozzle, and a pump well can be provided in order from the inflow direction of the sewage into the sand basin. In the above invention, a plurality of nozzles may be divided into a plurality of nozzle groups so that each nozzle group can independently discharge sewage. A third invention is a sand basin provided with a sand collection pit, a plurality of nozzles, and a pump well, wherein the plurality of nozzles are divided into a plurality of nozzle groups and arranged.
A sand pump is placed in the sand collecting pit so as to be able to move up and down freely, and water is ejected from the nozzle to transfer the sediment deposited on the bottom to the sand collecting pit, where it is discharged to the outside of the sand basin by the sand pump. A method of operating the apparatus, wherein a part of the sewage from a pump well is supplied to each nozzle group, and water is sequentially ejected from each nozzle group of each nozzle group.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the sand lifting device of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an overall system relating to the sand lifting device of the present invention. Reference numeral 1 denotes a sand basin, in which sewage flows in from the I direction, and a screen 2 is attached to the sewage inflow side, whereby relatively large suspended matter in the sewage flowing into the sand basin 1 is removed. A sand collecting pit 3 is provided at the bottom of the pond on the sewage inflow side, and a sand pump 4 is disposed in the sand collecting pit 3. Sand pump 4
Can be raised and lowered by a lifting device (not shown), and is usually lifted above the sewage level, and is lowered and placed in the sand collecting pit 4 only during sand lifting work. A plurality of nozzles 5 are disposed at the bottom of the pond so that the jetted water is directed toward the sand collecting pit 3. A pressure water pump 6 is connected to the nozzles 5 via a pipe, and a water tank 7 is provided. Supply pressure water to the nozzle 5.

A pump well 8 is provided on the sewage outflow side of the sand basin 1 to store sewage from which sand has been removed, and the sewage is transferred to the next step by a discharge pump 14, and a part of the sewage is supplied to a supply pump. At 9 the water is supplied to the water tank 7. By doing so, the pressurized water ejected from the nozzle 5 can use the sewage subjected to sand removal treatment, so that the amount of water used can be reduced. The solid-liquid separator 1 is connected to the discharge end of the above-mentioned sand pump 4 via a pipe line.
0 is connected, where sand and sewage are separated and appropriately treated.

FIG. 2 is a plan view showing an embodiment of the sand lifting device of the present invention, and FIG. 3 is a sectional view taken along line XX of FIG. Four rows of ridges 11 and 12 of mortar are formed at the bottom of the pond so as to have a downward slope toward the sand collecting pit 3 provided at the inflow end of the sand basin 1. S
A trough 13 made of US304 is laid, and six nozzles 5 are provided at the bottom of each groove 11 in a row toward the sand collecting pit 3.

By providing the ridge 12 and the ridge 11 and arranging the nozzle 5 at the bottom thereof, the water and sand ejected from the nozzle 5 are concentrated in a relatively narrow area within the ridge 11. In addition, the kinetic energy of the jet water can be used effectively. Regarding the point where the SUS304 trough 13 was laid in the concave strip 11, a sand flow experiment was conducted with the SUS304 trough and the concrete itself. And adopted. The resin trough also had good sand sliding, but did not reach the metal in terms of wear.

[0010] As shown in FIG.
A pipe is formed so that each of the groups can be independently selected at the time of jetting the pressure water. For example, first, pressure water is ejected from the nozzles 5 of the group C, and the sand deposited on that part is washed down to the part of the group B. Flush
Next, the pressure water of the nozzles 5 of the group A is blown out, and the sand in that portion is transferred to the sand collecting pit 3. By doing so, there is no great difference between the fact that the pressure water is ejected from the A, B and C groups at a time and the sand collecting effect, but the discharge amount of the pressure water pump 6 is 1 /
3, the required power can be reduced in this regard. Alternatively, as shown in FIG. 5, the nozzles 5 may be divided into nozzle groups D, E, F, and G in the inflow direction of the wastewater. In the embodiment shown in FIG. 1, the sand collection pit 3, the nozzle 5, and the
The reason why the pump well 8 is arranged is that it is difficult for sand that is washed away by the jet water to flow into the pump well 8.

FIG. 6 is an overall system diagram showing another embodiment. This is applied when the sand basin is long, in which a sand collecting pit 3 is provided in the center of the sand basin 1 and nozzles 5 are arranged from both sides toward the pit 3. The other configuration is the same as that shown in FIGS. Also in the embodiment shown in FIG. 6, the same consideration as in FIG. 1 is made so that the sand pushed by the jet water of the nozzle 5 is hard to flow into the pump well 8.

Next, an embodiment will be described. In the sand basin 1 having the configuration shown in FIG.
At m ³ / min, the head is 10 mAq, 20 mAq, 40
Using a pump of mAq, using a submersible sand pump having a discharge rate of 3 m ³ / min and a head of 10 m as the sand pump 4, the water level of the sewage in the sand basin 1 as a normal water level,
Sand collection and lifting operations were performed. As a result, the head is 20mA
In the sand collection operation using a q, 40 mAq pump, sand deposited on the bottom of the sand basin was substantially removed. However, with the pump having a head of 10 mAq, much of the deposited sand remained at the bottom, and the sand collection was insufficient. It is needless to say that sand collection can be performed even with a pump having a head exceeding 40 mAq, but this is not necessary because power is wasted.

[0013]

As described above, the present invention has the above-described structure, so that sand collecting and lifting operations can be performed efficiently even when the level of sewage in a sand basin is high, and the required power is reduced. I was able to.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an entire embodiment according to the present invention.

FIG. 2 is a plan view of a sand basin according to the present invention.

FIG. 3 is an enlarged cross-sectional view taken along line XX of FIG. 2;

FIG. 4 is a plan view showing an embodiment of a division state of a nozzle group according to the present invention.

FIG. 5 is a plan view showing another embodiment of the division state of the nozzle group according to the present invention.

FIG. 6 is a system diagram showing the whole of another embodiment according to the present invention.

[Explanation of symbols]

1 settling basin, 3 sand collecting pit, 4 sand pump, 5 nozzle, 6 pressure water pump, 7 water tank, 8 pump well, 9
Supply pump, 11 concave streak, 12 convex streak, 13 metal trough, A, B, C, D, E, F, G nozzle group

Claims (5)

[Claims] 1. A sand collecting pit is provided at a predetermined position of a sand basin, a plurality of nozzles are provided so as to jet water toward the sand collecting pit, and a sand pump is located in the sand collecting pit. In the arranged sand lifting device, a plurality of uneven strips composed of metal troughs are provided on the bottom of the settling basin toward the sand collecting pit, and a plurality of nozzles are arranged in each concave strip. apparatus. 2. A sand collecting pit is provided at a predetermined position of a sand basin, a plurality of nozzles are provided so as to jet water toward the sand collecting pit, and a sand pump is positioned in the sand collecting pit. A sand-lifting device, comprising: a sand-collecting pit, a nozzle, and a pump well, which are sequentially provided from a flowing direction of the wastewater into a sedimentation basin, and the wastewater in the pump well is supplied to the nozzle. 3. The pumping sand according to claim 2, wherein a nozzle, a sand collecting pit, a nozzle, and a pump well are provided in order from the inflow direction of the wastewater into the sand basin, and the wastewater in the pump well is supplied to the nozzle. apparatus. 4. The sand lifting device according to claim 1, wherein a plurality of nozzles are divided into a plurality of nozzle groups. 5. A sand basin provided with a sand collecting pit, a plurality of nozzles, and a pump well, wherein the plurality of nozzles are divided into a plurality of nozzle groups and arranged, and a sand pump is moved up and down in the sand collecting pit. A method of operating a sand pumping device that is freely arranged, ejects water from a nozzle, transfers sediment deposited on a bottom surface to a sand collecting pit, and discharges the sand out of a sand basin by a sand pump. The method of operating a sand lifting device, characterized in that the wastewater from the above is supplied to any one nozzle group, and the nozzle group that supplies the wastewater is changed.