JPH074488B2 - Backwash device for jet pump and backwash method thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a backwash device for a jet pump and a backwash method thereof.

2. Description of the Related Art Jet pumps can be used to lift up objects that are pumped up, such as sand that has settled at the bottom of a sand basin or sludge in a pit. A conventional jet pump is, for example, as shown in Japanese Utility Model Application No. 60-152620, a receiving pipe that opens toward the pump-up target such as sand and sludge, and jet water to the receiving pipe to pump up. It is common to provide a jet nozzle for sucking an object into the receiving pipe.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the conventional jet pump as described above, impurities mixed in the object to be pumped up enter into the receiving pipe together with the object to be pumped up, and then, in the receiving pipe and this receiving pipe. There is a problem that the inside of the lifting pipe to be connected may be blocked.

Therefore, an object of the present invention is to surely prevent such blockage.

Means for Solving the Problems In order to solve the above problems, the device of the present invention includes a receiving pipe that opens toward the pump-up target, and jet water into the receiving pipe to receive the pump-up target. A jet nozzle that sucks into the pipe, a lifting pipe that is connected to the receiving pipe, and a first backwash pipe that is in communication with the vicinity of the open end of the receiving pipe and that is capable of ejecting first backwash water into the receiving pipe. , A second backwash pipe that is in communication with the lift pipe and is capable of ejecting second backwash water from the lift pipe toward the receiving pipe.

In addition, the method of the present invention includes a first backwash which is opened to face the object to be pumped up and which receives the water jetted from the jet nozzle and is capable of sucking the object to be pumped up, the first backwash being communicated with the tube. The first backwash water is ejected from the pipe, and then, into a lifting pipe connected to the receiving pipe, from a second backwash pipe communicating with the lifting pipe, via the lifting pipe and the receiving pipe, The second backwash water is ejected toward the open end of the receiving pipe.

Action According to the above-mentioned device of the present invention, the first backwash water ejected from the first backwash pipe into the receiving pipe backwashes the foreign substances present in the vicinity of the open end in the receiving pipe, and the foreign substances Is discharged from the open end of the receiving pipe. Further, the second backwash water ejected into the lifting pipe backwashes the foreign substances present in the pipe path from the lifting pipe to the receiving pipe, and discharges it from the opening end of the receiving port as described above. . For this reason, it is possible to prevent the second backwash water from blocking the inside of the lifting pipe and the receiving pipe with foreign matters, and particularly, the vicinity of the open end of the receiving pipe in which the foreign matter is apt to be blocked by foreign substances causes the first backwashing. It is reliably blocked by water.

Further, according to the method of the present invention, the vicinity of the open end of the receiving pipe, which is likely to be clogged, is first backwashed with the first backwash water, and then the lifting pipe and the entire receiving pipe are turned into the second backwash water. As a result, good backwashing can be performed, so that efficient backwashing is possible.

Embodiment 1 In FIG. 1, reference numeral 1 is a sand basin, and a pit 3 for sinking sand 2 as a pump-up target is provided at the bottom thereof. As shown in FIG. 6, a jet pump 4 is provided at a position corresponding to the pit 3 from above the water surface in the sand basin 1 toward inside the sand 2.

3 to 6 show the detailed structure of the jet pump 4. Here, 5 is a relatively large diameter driving water pipe,
As shown in the figure, it is supported by a floor 6 located above the pit 3. 7 is a support support. The lower end of the driving water pipe 5 is closed by a closing plate 8, and the closing plate 8 has
A receiving pipe 9 having an open lower end is attached downward. On the other hand, inside the driving water pipe 5, a sand lifting pipe 10 as a lifting pipe that communicates with the receiving pipe 9 is passed, and this sand lifting pipe 10 penetrates the upper end of the driving water pipe 5 to be described later by a sand lifting machine. 37 (see Fig. 1). Similarly, a first backwash pipe 11 is passed through the inside of the drive water pipe 5, and the first backwash pipe 11 is located in the vicinity of the open end 12 of the receiving pipe 9 (to be exact, the open end 12 and the closing plate). 8 is in the middle position).

A branch pipe 13 is connected to the lower end of the drive water pipe 5, and a J-shaped connecting pipe 14 is connected to the branch pipe 13 via a closing plate 8. As shown in detail in FIG. 3, a check valve 15 and a jet nozzle 16 are provided at the tip of the connecting pipe 14. The jet nozzle 16 is a throttle for jet water generation.
It has 17 and is arranged at a position facing the open end 12 of the receiving pipe 9. An air pipe 18 is connected to the jet nozzle 16 at the tip end side of the throttle portion 17. This air tube 18
Like the fried sand pipe 10 and the first backwash pipe 11, is passed through the inside of the drive water pipe 5. As shown in FIG. 4, the air pipe
The 18 and the first backwash pipe 11 are mounted and supported on the sand lifting pipe 10 by a bracket 19 inside the driving water pipe 5.

7 to 8 show the detailed structure of the check valve 15. Here, 20 and 20 are upper and lower mounting flanges, and a # -digit-shaped frame 21 is provided between both mounting flanges 20 and 20. A pair of flap valves 23, 23 that open and close around a support shaft 22 using bolts are provided in the frame 21, and these flap valves 23, 23 are tubular members 24 formed on the lower flange 20. Can be blocked by its own weight. The frame 21 comes into contact with the flap valve 23.
A stopper bolt 25 for adjusting the opening degree of 23, 23 is attached.

FIG. 9 shows another example of the check valve 15. In this example, a spherical body 29 is provided in the water passage 28 provided between the upper and lower mounting seats 26, 27, and the weight of the spherical body 29 is used to close the opening 30 of the lower mounting seat 27. . Reference numeral 31 is a stopper that hits the sphere 29 and prevents the sphere 29 from rising.
Reference numeral 32 is a guide for guiding the sphere 29 to the center of the opening 30.

Next, the pipeline system will be described in detail with reference to FIG. 33
Is the drive water pump, the first pressure sensor 34 and the drive water valve
A drive water supply pipe 36 having 35 is connected to the drive water pipe 5 described above. The sand lifting pipe 10 is extended from the driving water pipe 5,
It is guided to the cyclone 38 of the lift sand separator 37. 39 is a discharge valve, 40 is a discharge valve, and 41 is a second pressure sensor provided near the cyclone 38. The sand lifter 37 includes a sand settling pocket 42 connected to the cyclone 38, a settling sand unloader 43 for receiving sand from the sand settling pocket 42, and a settling hopper.
44 and a drainage pit 45 that receives the separated water from the cyclone 38
And have.

The first backwash pipe 11 is branched from the drive water supply pipe 36, and is used as a backwash valve.
Equipped with 46. 47 is the second backwash pipe, the first backwash pipe 11
In the same manner as in (1), the drive water supply pipe 36 is branched, and the backwash main valve 48 is connected to the sand lifting pipe 10 portion between the discharge valve 39 and the drainage valve 40. The air pipe 18 is the driving water pipe 5.
It has been extended from and is open to the atmosphere.

A stirring water injection nozzle 49 is provided in the pit 3, and a stirring water supply pipe 51 from a stirring water pump 50 is connected to this nozzle 49. The stirring water supply pipe 51 includes a third pressure sensor 52 and a stirring valve 53.

Next, the operation based on the above configuration will be described with reference to FIG. That is, when the sand 2 has settled and accumulated in the pit 3 of the sand basin 1, first, the start switch 54 shown in FIG. 2 is operated to start the driving water pump 33 and the stirring water pump 50.
At this time, all the valves 35, 39, 40, 46, 48, 53 are closed. Both pumps 33, 50 are timer-operated for about 1 minute or less, and the first and third pressure sensors 34, 52 determine whether or not the discharge pressure has reached a set value.

When this discharge pressure reaches the set value, discharge valve 39, discharge valve 4
0 and the stirring valve 53 are opened, and if the discharge valve 39 and the discharge valve 40 are opened, then the driving water valve 35 is opened. Then, the stirring water is jetted from the nozzle 49 in the pit 3, and the sand 2 is stirred by the stirring water.
Is stirred and sand is gathered in the center of the pit. Further, by opening the drive water valve 35, the drive water from the drive water pump 33 enters the drive water pipe 5 through the drive water supply pipe 36, passes through the branch pipe 13 and the connection pipe 14, and the check valve 15 The flap valves 23, 23 are pushed open to be jetted from the jet nozzle 16 into the receiving pipe 9. Then, the jet water 55 jetted from the nozzle 16 sucks the sand 2 around the receiving pipe 9 which has been stirred by the stirring water from the nozzle 49 into the receiving pipe 9 from the opening end 12 together with the water. Rarely, it flows in the sand-lifting pipe 10.

Therefore, when the driving water pump 33 is operated by a timer for a certain period of time after opening the valves 39, 40, 53, and 35, if the receiving pipe 9 and the sand lifting pipe 10 are not blocked by foreign substances, the cyclone 38 The pressure (P) in the sand blasting tube 10 in front of is larger than the set pressure (P ₀ ), and this is detected by the second pressure sensor 41. The timer operating time required for this pressure detection varies slightly depending on the type of piping system.
Seconds are common.

If the pressure is detected, it is determined that the pipeline is not blocked, so the jet pump 4 is put into actual operation. This main operation is also performed by the timer operation. The operating time at this time varies depending on the capacity of the pit 3, but is generally about 5 to 10 minutes.

At this time, the sand 2 and the water sucked into the receiving pipe 9 by the jet water 55 are sent to the lifted sand separator 37 through the lifted sand pipe 10.
Here, the sand 2 separated from the water by the cyclone 38 is carried out to the settling hopper 44 through the settling pocket 42 and the settling unloader 43. On the other hand, the water separated by the cyclone 38 is discharged to the drainage pit 45.

When the jet water 55 is jetted from the nozzle 16, air 56 is sucked into the nozzle 16 from the air pipe 18 which is open to the atmosphere, and the air 56 is jetted into the receiving pipe 9 together with the jet water 55 described above. It In this way jet water 55 and air 56
By injecting and in a mixed state, cavitation can be prevented from occurring in the receiving pipe 9.

When the main operation by the timer is finished, the driving water valve 35 is closed, and the discharge valve 39 and the discharge valve 40 are closed to finish the work. At the same time, the stirring valve 53 is closed and the stirring water pump 50 is stopped. Further, when the jet of the jet water 55 from the nozzle 16 is stopped due to the end of the operation of the driving water pump 33,
The flap valve 23 of the check valve 15 is closed by its own weight, which prevents sand from entering the connecting pipe 14.

On the other hand, if the receiving pipe 9 and the sand lifting pipe 10 are blocked by foreign matters, even if the timer operation is performed after opening the valves 39, 40, 53, 35, the sand inside these pipes 9, 10 will not be discharged. Since it does not flow, the internal pressure (P) of the sand lifting pipe 10 detected by the second pressure sensor 41 does not exceed the set pressure (P ₀ ).

In this case, first, the backwash valve 46 is opened while the drive water valve 35 is kept open, and the drive water pump 33 is operated by the timer. Then, the jet water 55 from the nozzle 16 and the first backwash water 57 from the first backwash pipe 11 backwash the vicinity of the open end 12 of the receiving pipe 9. As a result, the clogging of the portion close to the open end 12 where clogging is likely to occur is first cleared. The timer operating time at this time is preferably about 30 seconds.

When this timer operation is completed, the drive water valve 35 and the backwash valve 46 are then closed, the discharge valve 40 is closed, and the backflow main valve 48 is closed.
Open and restart the timer. Then, the water from the drive water pump 33 reaches the sand lifting pipe 10 through the second backwash pipe 47, flows backward through the discharge valve 39, and is pushed toward the receiving pipe 9. As a result, the second backwash water 58 pushed into the sand pump
The inside of the pipe 10 and the inside of the receiving pipe 9 are backwashed, and this second backwashing water 58 is received in the receiving pipe 9 together with the impurities that have blocked the inside of the pipes 10 and 9.
It is discharged into the sand basin 1 from the open end 12 of the. About 30 seconds is also appropriate for the timer operating time at this time.

As described above, the vicinity of the open end 12 of the receiving pipe 9 which is apt to be clogged is first backwashed with the first backwash water, and then the sand lifting pipe 10 is used.
Since the back pipe 9 and the receiving pipe 9 are back-washed with the second back-washing water 58 over substantially the entire length, efficient back-washing is possible. When the backwash with the second backwash water 58 is completed, the discharge valve 40 is opened, the backwash main valve 48 is closed, the driving water valve 35 is opened, and the pressure at the second pressure sensor 41 is set by the timer operation. Repeat detection.

As the means for detecting the occurrence of blockage, in addition to the one provided with the pressure sensor 41 as described above, one provided with a flow sensor such as a flow relay in the sand lifting pipe 10 can be used.

Further, in the above-mentioned embodiment, the description has been given of the case where the sand 2 in the pit 3 of the sand basin 1 is lifted, but the present invention can also be applied to a jet pump for lifting sludge accumulated in the pit.

Further, as in the above embodiment, the sand lifting pipe 10, the first backwash pipe
By arranging 11 and the air pipe 18 in one drive water pipe 5, the pipes can be efficiently arranged and used. It is not necessary to provide a support support for each pipe. It is possible to prevent clogging of residue on the pipes. Noise It is possible to obtain effects such as reduction of

EFFECTS OF THE INVENTION As described above, according to the present invention, the first and second backwash water can efficiently and reliably backwash the inside of the receiving pipe and the lifting pipe, so that blockage occurs in these pipes. Can be prevented.

[Brief description of drawings]

FIG. 1 is an overall schematic view of an embodiment of the present invention, FIG. 2 is a diagram showing an operation flowchart, FIG. 3 is a detailed view of a jet pump, and FIG. 4 is a sectional view taken along line IV-IV in FIG. 5, FIG. 5 is a sectional view taken along line VV in FIG. 3, FIG. 6 is a front view around the jet pump, FIG. 7 is a plan view showing an example of a check valve, FIG. 8 is its front view, and FIG. The figure is a front view showing another example of the check valve. 2 ... sand (object to be pumped up), 9 ... receiving pipe, 10 ... sand sand pipe (lift pipe), 11 ... first backwash pipe, 12 ... open end, 16 ... jet nozzle, 47 ... second reverse Wash pipe, 55 ... Jet water, 57 ... First backwash water, 58 ... Second backwash water

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Nagasaku Yamaguchi, Inventor, Nagasaku, Osaka, Osaka City, Naniwa-ku 1-47, Shikazu East Kubota Iron Works Co., Ltd. (72) Inventor, Mikifumi Watanabe Naniwa-ku, Osaka 1-27 Tsuto, Kubota Iron Works Co., Ltd.

Claims (2)

[Claims] 1. A receiving pipe that opens toward a pump-up target, a jet nozzle that jets jet water into the receiving pipe to suck the pump-up target into the receiving pipe, and a lift connected to the receiving pipe. A pipe, a first backwash pipe that is in communication with the vicinity of the open end of the receiving pipe and is capable of ejecting first backwash water into the receiving pipe, and a pipe that is in communication with the lifting pipe and is connected from the lifting pipe to the receiving pipe And a second backwashing pipe capable of ejecting a second backwashing water toward the backside of the jet pump. 2. A first backwash pipe, which is opened to face the object to be pumped up, and which is capable of receiving water jetted from a jet nozzle and sucking in the object to be pumped up, the first backwash pipe being in communication with this object. Spout the first backwash water from
In the pump connected to the receiving pipe, a second backwash water is communicated from the second backwash pipe communicating with the lifting pipe to the open end of the receiving pipe through the lifting pipe and the receiving pipe. A method of backwashing a jet pump, which is characterized by jetting.