JPH07102283B2 - Sand basin structure - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sand basin structure in a water treatment facility such as a sewage treatment facility or a water purification facility.

2. Description of the Related Art Conventionally, in a sewage treatment facility or a water purification facility, a sand basin is provided as a facility for removing suspended solids such as sand from the influent sewage and the raw water taken. Then, the sand basin is provided with a device for scraping the sediment deposited at the bottom into the sand pit, and as the scraping device, a device for scraping the sand by mechanical operation such as a flight conveyor, a screw conveyor, and a feeder, In some cases, the settling sand was attracted by a jet stream of pressure water jetted from a cylindrical pressure water jet nozzle located at the bottom of the pond.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in a sand basin using a scraping device that performs the above-described conventional mechanical operation, when the amount of sediment deposited in the sand basin increases rapidly due to an increase in suspended matter during rainfall or the like. In some cases, the moving parts were buried in the sand and could not be driven. In addition, there is a problem that the mechanical operation causes severe wear and requires maintenance. Also, in a sand basin that uses a device that draws sand by a jet water flow, the pressure water injection nozzles are arranged at appropriate intervals in the channel width direction of the sand basin, but the intervals between the pressure water injection nozzles are widened. Although it is possible to reduce the cumulative amount of pressure water by reducing the number of pressure water injection nozzles, there is a problem that a region where the jet water flow does not influence occurs between the pressure water injection nozzles, leaving behind uncut sand. Further, if the number of pressure water injection nozzles is increased, it is possible to eliminate the residual sand, but there is a problem that the cumulative amount of pressure water and power consumption increase. Further, regardless of the number of the pressure water jet nozzles, there is a problem that a region where the jet water flow does not reach occurs in the immediate vicinity of the pressure water jet nozzles, and the settling sand remains. The present invention solves the above problems, and an object of the present invention is to provide a sand basin structure capable of transferring sand to a sand pit with a small amount of accumulated water without scratching the sand.

Means for Solving the Problems In order to solve the above problems, the present invention provides a flow path through which raw water flows from an upstream side to a downstream side, and a sand pit in a sand basin in which a sand pit is formed at the bottom. A pressure water injection nozzle for injecting pressure water toward the is located at the center of the flow path at the bottom of the flow path that continues to the sand pit,
The configuration is such that it is rotatably provided around a vertical rotation axis.

Action With the above-described configuration, the suspended matter that has flowed into the flow path of the sand basin together with the raw water sequentially settles according to the settling speed based on the specific gravity, and is deposited as sand on the bottom of the sand basin. Then, every appropriate period, or when an appropriate amount of sand is deposited on the bottom of the sand basin, pressure water is jetted from the pressure water jet nozzle, and the sand is transferred to the sand pit by the jet stream of the pressure water. At this time, by rotating the pressure water jet nozzle about the vertical rotation axis, the target region on which the jet water flow acts spreads over the entire width of the flow path, and the accumulated settling sand is transferred without remaining. For this reason,
It is possible to reduce the number of pressure water injection nozzles to be installed, and to reduce the cumulative amount of pressure water and the power consumption.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. First
1 to 2, a sand basin 1 forms a flow path through which raw water 2 flows from an upstream side to a downstream side, and a sand pit 3 is formed at the bottom of the sand basin 1 at the upstream side. ,
A sand pool 4 is formed at the bottom on the downstream side of the sand pit 3. A plurality of pressure water injection nozzles 6 for injecting the pressure water 5 toward the sand pit 3 are located near the bottom of the sand basin 4 at the center of the flow path of the sand basin 1 in the width direction, and the raw water 2 The pressure water jet nozzles 6 are provided at appropriate intervals in the flow direction of 1, and are respectively attached to a plurality of pressure water main pipes 7 arranged in the vertical direction. Further, each pressure water main pipe 7 is rotatably supported on the upper end side and the lower end side by the upper bearing 8 and the lower bearing 9 on the ceiling part and the bottom part of the sand basin 1, respectively. It becomes rotatable around the vertical rotation axis. Each pressure water main pipe 7 is connected to the rotary joint 10 and the on-off valve
A valve water hydraulic cylinder device 13 for opening and closing is connected to the pressure water supply pipe 12 via the valve 11. Further, the pressure water supply pipe 12 is provided with a pressure pump 14 on the base end side, and one end thereof is connected to an input side of a control circuit 15 formed of a solenoid valve as a control water pressure source.

A rotary drive hydraulic cylinder device 17 is connected to each pressure water main pipe 7 via a grip portion 16. The rotary drive hydraulic cylinder device 17 and the valve drive hydraulic cylinder device 13 are connected to the output side of the control circuit 15. It is connected to the.

The operation of the above configuration will be described below. The raw water 2 flowing into the sand basin 1 flows from the upstream side to the downstream side, and the sand settled 18 flowing into the sand basin 1 together with the raw water 2 sequentially from the one having a large specific gravity according to the sedimentation velocity based on the specific gravity. 3 and the sand settling pit 3 and settles and accumulates in a sand puddle portion 4 continuing to the downstream side.

Then, the sand sediment 18 is transferred at regular intervals or when an appropriate amount of sand sediment 18 is accumulated in the sand reservoir 4. This procedure will be described. First, the on-off valve 11 interposed in the pressure water main pipe 7 located on the most downstream side is opened by controlling the solenoid valve of the control circuit 15 to drive the valve drive hydraulic cylinder device 13, and the pressure pump 14 The supplied pressure water 5 is supplied to the pressure water jet nozzle 6 through the pressure water supply pipe 12 and the pressure water main pipe 7. Then, the pressure water 5 is jetted from the pressure water jet nozzle 6, and the settling sand 18 is transferred toward the upstream side by the jet water flow of the jetted pressure water 5. At this time, the solenoid valve of the control circuit 15 is controlled to rotate the hydraulic cylinder device for driving.
By driving 17 to rotate the main pressure water pipe 7, the pressure water jet nozzle 6 is rotated around the vertical rotation axis. As a result, the target area on which the jet water flow acts extends over the entire width of the flow path of the sand basin 1, and the accumulated sand 18 is transferred without remaining. Therefore, it is possible to reduce the number of the pressure water jet nozzles 6 installed, and it is possible to reduce the cumulative amount of the pressure water 5 and the power consumption. Also,
The settling water 18 does not remain even in the vicinity of the pressure water injection nozzle 6 due to the expansion of the target area due to the rotation of the pressure water injection nozzle 6.

After that, the on-off valves sequentially installed in the upstream pressure water main pipe 7
11 is opened, the pressure water 5 is jetted from the pressure water jet nozzle 6 provided in each pressure water main pipe 7, and the settling sand 18 is transferred to the settling pit 3. At this time, since the pressure water jet nozzle 6 is attached to the pressure water main pipe 7 provided in the vertical direction, it does not hinder the transfer of the settling sand 18. Furthermore, since the jet water flow is injected from the downstream side toward the upstream side, the sediment 18 suspended by the stirring by the jet water flow does not flow out to the downstream side, and the adverse effects on the downstream processes and equipment are prevented.
Further, the opening / closing valve 11 and the main pressure water pipe 7 are driven by using the water pressure of the pressure pump 14 to drive the valve hydraulic cylinder device.
Since it is performed by the rotary drive hydraulic cylinder device 17 and the rotary drive hydraulic cylinder device 17, it is possible to reduce the number of drive electric motors and to reduce the equipment cost and the power consumption cost as compared with the related art.

When the pressure water 5 is not jetted, the opening of the pressure water jet nozzle 6 can be directed to the downstream side to prevent the sand settling 18 from entering and to prevent the opening from being blocked.

Further, in this embodiment, the pressure water jet nozzle 6 attached to one pressure water main pipe 7 is a single body, but a plurality of pressure water jet nozzles 6 may be provided. Furthermore, the pressure water main pipe 7
As a structure for driving the gear, a structure using a chain and a sprocket or a structure using a spur gear and a rack and pinion may be used.

As described above, according to the present invention, by rotating the pressure water jet nozzle about the vertical rotation axis, the target region on which the jet water flow acts can be expanded over the entire width of the flow path, and The settled sand can be transferred without remaining, and the number of installed pressure water injection nozzles can be reduced to reduce the cumulative amount of pressure water and the power consumption.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention, and FIG. 2 is a plan view of FIG. 1 ... Settling basin, 2 ... Raw water, 3 ... Settling pit, 5 ...
Pressure water, 6 ... Pressure water jet nozzle, 7 ... Pressure water main pipe,
18 ... Settling sand.

Claims (1)

[Claims] 1. A pressure water injection nozzle for injecting pressure water toward a sand pit in a sand basin having a flow path through which raw water flows from the upstream side to the downstream side and having a sand pit at the bottom. The sand basin structure is characterized in that it is located at the center of the flow path at the bottom of the flow path following the sand pit and is rotatably provided around a vertical axis of rotation.