JP2001193700A - Blocking preventing device for sand raising equipment suction pipe, and driving method of sand raising equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a condition of sucking a relatively small size of can and the like and to block a suction pipe, in a sand raising equipment in a sand sinking pond using a jet pump, so as to eliminate the inconveneant condition to stop the operation and to dissolve and clean the jet pump every time. SOLUTION: A screen is provided to cover the periphery of a suction pipe of a jet pump, and a part of the screen is made open and close freely. When the suction pipe is blocked, the driving water of the jet pump is flown reversely to the suction pipe side, so as to exhaust the blocking articles out of the suction pipe, while a part of the screen is opened, so as to exhaust the above blocks to the outer side of the screen.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sand pumping facility in a sand basin of a sewage treatment plant, and more particularly to a sand pumping facility using a jet pump.

[0002]

2. Description of the Related Art Conventionally, a bucket conveyor system has been frequently used as sand-lifting equipment in a sedimentation basin of a sewage treatment facility. Is coming.
However, since the jet pump is generally arranged downstream of the coarse screen and upstream of the fine screen, suspended matter that has passed through the coarse screen, for example, cans and bottles, floats near the suction pipe of the jet pump, It is often sucked into the suction pipe as it is, and as a result, the suction pipe is often closed, and there is a problem that the operation is stopped and disassembled and cleaned each time. As means for solving the problem, Japanese Patent Application Laid-Open No. 63-240908 discloses an arrangement in which a coarse screen is arranged so as to cover a sand pit where a jet pump is installed.

[0003]

However, according to the above-mentioned prior art, there still remains a risk that a relatively small can or the like that has passed through the coarse screen and entered the sand pit is sucked into the suction pipe of the jet pump. An object of the present invention is to solve the above-mentioned drawbacks and to provide a sand-lifting facility with a low risk of blocking a suction pipe of a jet pump.

[0004]

SUMMARY OF THE INVENTION The present invention is directed to a suction pipe blockage of a sand pumping facility for sucking water and sand from a suction pipe by an ejector effect of driving water and discharging sand in a sand basin by a jet pump discharged from a discharge pipe. A prevention device, wherein a screen is provided so as to cover the periphery of the suction pipe of the jet pump, and at least a part of the screen is made openable and closable. In a method for operating a sand lifting facility that sucks water and sand from a suction pipe and discharges sand in a sand basin with a jet pump discharged from a discharge pipe, a screen is provided so as to cover around the suction pipe, and at least a part of the screen is provided. When the suction pipe of the jet pump that can be opened and closed is closed, the gate valve on the discharge pipe side of the jet pump is closed and driven. The allowed to flow back to the suction tube side occluder with discharged to the suction tube outside, in which to a part of the screen in the open, characterized in that discharging the obstruction on the outside of the screen.

[0005] It has been confirmed that when a can or the like is sucked into the suction pipe of the jet pump and gets caught in the pipe, the fiber or fuzz is entangled with the can and grows rapidly. At that time, the pumping amount of the jet pump decreases, but this is detected and as an abnormal situation, the gate valve connected to the discharge pipe is closed. Then, the high-pressure driving water of the jet pump flows back to the suction pipe side, and the obstruction is pushed out of the pipe by the water pressure. However, even if it is pushed out of the pipe, the obstruction remains in the area not far from the suction pipe due to the resistance of water, and when the sanding operation is restarted, it is sucked again, and the same as above is repeated The problem occurs.
To prevent this, a screen is installed under the suction pipe so as to cover it, and a part of the screen is made openable and closable. The opening and closing portion of the screen is also pushed out by the water pressure due to the backflow of the driving water, and the obstruction is removed out of the screen from the opening. When the driving water is stopped after confirming that, the screen is closed by its own weight without any remaining in the screen. Next, even when the sand-drying operation is started, the obstruction removed outside the screen cannot enter the screen again, and the above-described troubles when the screen is not present do not occur. Even if a fixed screen is installed, the same problem as the absence of the screen occurs because the obstruction discharged from the suction pipe is not removed outside the screen.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a suction pipe blockage prevention device of the present invention.
1 is an elevational view of an embodiment of the present invention, FIG. 2 is an enlarged view taken along the line AA in FIG. 1, and FIGS. 3 (A) and 3 (B) are explanatory views of opening and closing of a screen. A jet pump 2 is installed in a sand collecting pit 1 formed in a sand basin. The sediment accumulated in the sand basin is collected, for example, by a screw conveyor (not shown).
Collected within. The jet pump 2 is connected to the nozzle 3, a driving water pipe 4 for injecting high-pressure driving water into the nozzle 3, a suction pipe 5 connected to the suction side of the nozzle 3, and a discharge pipe 6 connected to the discharge side of the nozzle 3. And a gate valve 7.

At the end of the suction pipe 5, a divergent suction port 8 is provided.
Is formed, from which sediment is sucked together with water. A screen 10 is fixed to the outer periphery of the suction port 8 by a mounting bracket 9. The screen 10 is a first member 10
-1 and the second member 10-2.
1 is pivotally attached to the mounting bracket 9 so as to be openable and closable. First
The structures of the member 10-1 and the second member 10-2 are not particularly limited, and may be ordinary structures. The material is preferably stainless steel because it is used in polluted water and has movable parts.

When the normal sand lifting operation is performed, the gate valve 7
And the pressure from the driving water pipe 4 is 5 to 10 kgf / cm ²
The driving water is injected into the nozzle 3 and the sand is sucked together with the water from the suction port 8 by the ejector effect. The water and sand are sent to predetermined processing equipment via the nozzle 3 and the discharge pipe 6 together with the driving water. It is well known that the water flowing into a settling basin contains various substances such as sand, cans, fibrous paper waste, cloth, and hair. The jet pump used in the present invention has the advantage of being relatively insensitive to such contaminants due to the lack of rotating parts,
At times, some of them pass through the screen 10 and become trapped in the suction port 8 or the suction pipe 5. In this case, the fibrous material, the hair, or the like may become entangled with the material itself and become a lump in a short time, and the suction port 8 or the suction pipe 5 may be closed. At that time, since the amount of water in the discharge pipe 6 decreases, this is detected to determine that a blockage accident has occurred.

When it is determined that a blockage accident has occurred, the gate valve 7 is closed. Then, the high-pressure driving water injected into the nozzle 3 flows back to the suction pipe 5 side. The blockage of the suction port 8 or the suction pipe 5 is forcibly pushed out of the suction pipe 5 by the water pressure of the backflowing driving water. At the same time, the first member 1-1 and the second member
The member 1-2 is pushed upward by the pressure of the backflow driving water discharged from the suction pipe 5 around the pin 11 as shown in FIG. 3 (B) to form large gaps downward and sideways. The lump is discharged out of the screen 10 together with the backflow driving water.

When it is determined that the blockage of the suction port 8 or the suction pipe 5 has been released, the injection of the driving water into the nozzle 3 is stopped, and the gate valve 7 is opened. Then screen 1
Since the pressure of the backflow driving water applied to the first member 1-1 and the second member 1-2 of the first screen 1-1 disappears, the open screen 1
0 returns to the closed state as shown in FIG. Then, when the state is confirmed, the sand lifting operation is restarted. At that time, the lump discharged to the outside of the screen 10 is blocked by the screen 10 and again sucked into the suction port 8 or the suction pipe 5.
The normal sand driving operation can be continued without being sucked into the tank.

[0011]

Since the present invention has the above-described structure and operation, it is possible to minimize the stoppage of the sand pumping operation due to the blockage of the jet pump, and furthermore, it is possible to minimize the trouble of returning the sand pump. Sand facilities can be provided.

[Brief description of the drawings]

FIG. 1 is an elevation view of an embodiment of the present invention.

FIG. 2 is a view taken along the line AA in FIG. 1;

FIGS. 3A and 3B are explanatory diagrams of the operation of the screen of the present invention.

[Explanation of symbols]

1 Sand collecting pit, 2 jet pump, 3 nozzles, 4
Drive water pipe, 5 suction pipe, 7 gate valve, 8 suction port, 10 screen

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hiroshi Itakura 5200 Sankajiri, Kumagaya-shi, Saitama Hitachi Metals Co., Ltd.Environmental Engineering Division (72) Inventor Makoto Shibusawa 5200 Sankajiri, Kumagaya-shi, Saitama Hitachi Metals Environmental Engineering Business Department F-term (reference) 2D063 DB01 DB05 3H079 AA15 AA22 BB04 CC04 CC23 DD23 DD44 DD60 4D064 AA03 BB05 BB14

Claims (2)

[Claims] 1. A suction pipe blockage prevention device of a sand pumping facility for sucking water and sand from a suction pipe by an ejector effect of driving water and discharging sand in a sand basin by a jet pump discharged from a discharge pipe, comprising: A suction pipe blockage prevention device for sand pumping equipment, wherein a suction port of the suction pipe is covered with a screen whose part can be freely opened and closed. 2. A method for operating a sand pumping facility in which water and sand are sucked from a suction pipe by an ejector effect by driving water and sand in a sand basin is discharged by a jet pump discharged from a discharge pipe. At least part of the mouth is covered with a screen that can be opened and closed, and when the suction pipe is closed, the gate valve on the discharge pipe side is closed to drive the driving water back to the suction pipe side, and the screen is pushed open to close. A method for operating a sand-lifting facility, comprising discharging a material to the outside of a screen.