JPH09170224A - Device for feeding liquid to ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the pressure of liquid such as water flowing out from the ground, by use of water hammer, so as to reduce affection upon the installation cost. SOLUTION: A device for feeding liquid into the ground, is composed of a liquid tank 10 from which liquid is fed into the ground 12, a pump 14 for pumping up the liquid from the liquid tank 10, and a pipe 16 inserted into the ground. The pipe is composed of a circulating passage 18 having an inlet port 26 connected to the pump and an outlet port 27 for discharging the liquid into the tank 10, a normally open shut-off valve which is located in the circulating passage 18 and which can be closed instantly through the manipulation on the ground, and an opening means for allowing the liquid to flow out from the circulating passage 18 by use of water hammer which occurs in the passage 18 when the shut-off valve is closed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for supplying a liquid to a ground, and more particularly, it allows water to flow into a sandy ground to compact the sandy ground, or to flow out a solidifying liquid to solidify the ground. A device suitable for.

[0002]

2. Description of the Related Art A plurality of drain columns are formed on the ground by using a drain material having a higher permeability coefficient than the soil of the ground, and water injection pipes are arranged at a distance from the drain pillars to pulsate water. A method of compacting the ground by press-fitting the above into the ground from the pipe (Japanese Patent Application Laid-Open No. 2-308007), or another application filed by the applicant (Japanese Patent Application No. 6-277192), In the method of compacting the ground by repeating water absorption from the ground, the higher the pressure of water flowing out to the ground, the more excellent the effect can be obtained.

[0003]

However, the pressure of water flowing out to the ground is determined by the capacity of a pump or other pressure source installed on the ground, and the piping of the equipment or other pressure resistant structure is determined based on the capacity of this pressure source. Since it is fixed, increasing the pressure of water flowing out to the ground causes a rise in equipment costs. Primarily for this reason, increasing the pressure of the water to flow to the ground is restricted.

The present invention provides a device for supplying a liquid to the ground, which can increase the pressure of water and other liquids jetted to the ground by utilizing the water hammer action and can suppress the influence on the equipment cost. provide.

[0005]

SUMMARY OF THE INVENTION The present invention is an apparatus for guiding a liquid from a liquid tank, ejecting the liquid to the ground to supply the liquid to the ground, and a pump for sucking the liquid in the liquid tank. And a pipe inserted into the ground. The pipe is a circulation passage having an inlet connected to the pump and an outlet for discharging liquid to the liquid tank, and a shutoff valve arranged in the circulation passage, and is instantaneously closed by an operation from the ground. A shutoff valve which is always kept open and an opening means for ejecting the liquid in the circulation passage to the outside by a water hammer action which occurs in the circulation passage when the shutoff valve is closed.

If the shutoff valve in the circulation passage is closed instantaneously, a water hammer action occurs in which the pressure rises rapidly in the circulation passage upstream of the shutoff valve. The liquid in the circulation passage is jetted to the ground because the opening means is opened due to the rise in the pressure of the water hammer action. With this, the ground is compacted, solidified, and other operations are performed.

Water and other liquids circulating in the circulation passage are pressurized by a pump and have a pressure. The pressure may be such that the liquid can be properly circulated in the circulation passage, and jetted to the ground. It is a low pressure compared to the pressure of the liquid to be made. Therefore, the capacity of the pump connected to the inlet of the circulation passage, and the circulation passage and other pressure resistant structures based on this capacity can be determined based on a low pressure except for the range where the water hammer effect is exerted. Since the pipe having a simple structure including the circulation passage, the shutoff valve, and the opening means is used, the facility cost can be suppressed. Further, since the water hammer force generated by the water hammer action can be adjusted in a wide range by changing the flow velocity of the liquid in the circulation passage by the pump, the pressure of the liquid to be jetted to the ground can be easily adjusted.

The present invention also relates to an apparatus for guiding a liquid from a liquid tank, ejecting the liquid to the ground and supplying the liquid to the ground,
It comprises a pump for sucking up the liquid in the liquid tank, a pipe inserted into the ground, and a vacuum pump. The pipe is
A circulation passage having an inlet connected to the pump and an outlet for discharging the liquid to the liquid tank, and a shutoff valve arranged in the circulation passage, which is instantly closed by an operation from the ground and is always open. Is connected to the vacuum pump and sucks up water from the ground. And a water absorption passage.

It is considered that the water ejected to the ground is discharged by the groundwater, such as when the ground has a flow of groundwater. However, if there is no groundwater flow, it is necessary to absorb water from the ground. The invention according to claim 2 of the present invention can be carried out on the ground that needs to absorb water.

According to the second aspect of the invention, in addition to the above-described action and effect, by positively absorbing water from the ground, the ground can be compacted, solidified, and other operations can be more effectively performed. Further, since the water absorption passage is provided in the pipe together with the liquid circulation passage, the shutoff valve, and the opening means,
The whole structure is simple.

[0011]

The pipe is preferably formed in the form of a double tube, in which case the outer tube is used for protection and the inner tube is used as a circulation passage. The inner tube is bent 180 ° at a portion corresponding to the lower end of the outer tube, and is formed to have substantially double the length of the outer tube. An electromagnetically actuated valve having two positions of open and closed, that is, an electromagnetic valve, is attached to the inner tube to serve as a shutoff valve. An opening means consisting of an auxiliary pipe and a valve is installed within the range of the water hammer effect upstream of the shutoff valve. The auxiliary pipe extends from the inner tube to the outer tube and connects the circulation passage and the ground. On the other hand, the valve can have the same structure as the safety valve. That is, although the liquid is closed under the pressure circulating in the circulation passage, it is opened by the pressure generated by the water hammer when the water hammer action occurs, and the liquid is ejected from the circulation passage toward the ground through the auxiliary pipe. . A plurality of combinations of shutoff valves and opening means are provided along the circulation passage. The inlet of the circulation passage is connected to a pump to suck water or other liquid from the liquid tank, and the outlet of the circulation passage is located in the liquid tank on the ground.

When the pipe is provided with a water absorption passage, the space between the inner tube and the outer tube of the double tube is used as a water absorption passage, or the pipe is formed into a triple tube, and the innermost tube and this inner tube are A space between the tube and the intermediate tube can be used as a circulation passage, and a space between the intermediate tube and the outer tube can be used as a water absorption passage.

[0013]

EXAMPLE An apparatus for supplying liquid to the ground according to the present invention is
Referring to FIG. 1 which is schematically shown, a liquid is introduced from a liquid tank 10 and ejected to a ground 12,
4 and a pipe 16 inserted into the ground 12. The pump 14 is a rotary type known per se. In the illustrated embodiment, the liquid tank 10 is filled with water, and the ground 12 is compacted by the water, but instead of water, a solidifying liquid or other liquid is put in and circulated to carry out the required work on the ground. can do.

In the embodiment of FIG. 2 showing the cross-sectional state, the pipe 16 has a water circulation passage 18, a shutoff valve 20 disposed in the circulation passage 18, and the water in the circulation passage 18 when the shutoff valve 20 is closed. Opening means 22 for ejecting to the protective tube 2
4 is provided.

In the illustrated embodiment, the circulation passage 18 is formed by bending a steel pipe 180 ° at the center. As shown in FIG. 1, the steel pipe has two ends, which are the inlet 26 and the outlet 27 of the circulation passage, projecting upward from the ground 12 when the pipe 16 is buried in the ground 12. The shutoff valve 20 is an open / close type solenoid valve, and a lead wire (not shown) is connected to an operation panel on the ground. The shutoff valve 20 is
Keep open during normal operation. Then, when the water hammer action should occur, the circuit is closed by energizing, and the circulation passage 18 is instantaneously shut off.

On the other hand, the opening means 22 is provided in association with the circulation passage 18 within the range where the water hammer effect is exerted. In the illustrated embodiment, the auxiliary pipe 30 which connects the circulation passage 18 and the ground 12 and the auxiliary It consists of an automatically actuated open / close type valve 32 located in the tube 30. The valve 32 is normally in the closed state, and is opened when the water pressure increases the water pressure. That is, when water circulates in the circulation passage 18, the valve 32 does not open due to the pressure of the circulation flow, but does open at a pressure increased by the water hammer action, which is much higher than the pressure of the circulation flow. Shut-off valve 20 and opening means 2
2 is provided at a plurality of locations along the steel pipe that is the circulation passage 18.

In order to secure sufficient strength, the reinforcing pipe 34 is press-fitted in the opening means 22 in the range upstream of the shutoff valve 20 where the water hammer action is exerted, and the portion of the steel pipe serving as the circulation passage 18, Reinforce by increasing the thickness of the plate compared to other parts.

The protective tube 24 is formed of a steel pipe, and a tapered bit 25 is provided at the tip thereof. The protective tube 24 has a hole for penetrating the auxiliary pipe 20 of the opening means 22 at a position corresponding to the auxiliary pipe 30, and the auxiliary pipe 30 penetrating the hole is welded. The steel pipe for the circulation passage 18 and the steel pipe for the protective tube 24 are fixed and maintained at a predetermined distance by a plurality of spacers 36 arranged at intervals in the axial direction.

At the place where the ground should be improved, the pipe 16
Is inserted into the ground 12 in a manner known per se, and the circulation passage 1
The inlet 26 of 8 is connected to the pump 14, and the outlet 27 of the circulation passage 18 is exposed to the liquid tank 10. When the pump 14 is driven, the pump 14 sucks the water in the liquid tank 10 and
The water that has been supplied to the liquid tank 8 and has entered the circulation passage 18 returns to the liquid tank 10. In this way, the water circulates in the circulation passage 18.

When water circulates through the circulation passage 18 in a steady flow as indicated by arrow A, as shown in FIG. 2B, the switch on the operation panel is manually operated or the CPU is controlled. When the shut-off valve 20 is energized and the shut-off valve is instantly closed to shut off the circulation passage 18, a water hammer action occurs and the water pressure rapidly rises. As a result, the valve 32 of the opening means 22 is opened, so that the water in the circulation passage 18 is in a high pressure state and the auxiliary pipe 30.
It spouts through the ground to the ground 12 and compacts the ground. Since the water hammer action naturally disappears after a short time, the pressure of the water in the circulation passage 18 drops to the pressure at which it was circulating, and the valve 32 of the opening means 22 closes. After that, shutoff valve 2
When 0 is opened, the water recirculates through the circulation passage 18.

In the embodiment shown in FIG. 3, the pipe 40 includes a water circulation passage 42 and a shutoff valve 44 arranged in the circulation passage 42.
An opening means 46 for ejecting the water in the circulation passage 42 to the outside when the shutoff valve 44 is closed, a water absorption passage 48, and a protection tube 50 are provided.

The pipe 40 is in the form of a triple tube,
A circulation passage 42 is formed by the thinnest tube 52 and a space between the tube 52 and a concentric tube 53 with a bottom lid. The shutoff valve 44 is an open / close type solenoid valve arranged at the lower end of the tube 52. The auxiliary pipe 54 and the valve 56 of the opening means 46 have the same structures as the auxiliary pipe 30 and the valve 32 of the opening means 22 of the above-mentioned embodiment, respectively. The auxiliary pipe 54 penetrates the tube 53 from the tube 52, further penetrates the protective tube 50, and connects the circulation passage 42 and the ground 12. In the illustrated embodiment, since the two opening means 46 are radially provided at the same level position of the tube 52, the water is radially ejected as shown by an arrow B.

A space between the tube 53 and an outer concentric protective tube 50 having a tapered bit 51 at the bottom serves as a water absorption passage 48. The water suction passage 48 is connected to a vacuum pump 58 on the ground and sucks water from the ground through a plurality of suction holes 60 provided in the protection tube 50 as shown by an arrow C. The three tubes 52, 53, 50 are
Fixed by a plurality of spacers 62, 64 with holes,
Maintains a predetermined interval.

In the pipe 16 shown in FIG. 2, the circulation passage 1
The space 38 between the steel pipe 8 and the protective tube 24 can be used as a water absorption passage. In this case, a hole is made in the spacer 36, and a hole is further made in a predetermined portion of the protective tube 24.

After inserting the pipe 40 into the ground, the inlet of the circulation passage 42 is connected to the pump 14, and the outlet of the circulation pump is exposed to the liquid tank. Furthermore, the vacuum pump 58 is set to the water intake channel 4
Connect to 8. When the pump 14 is driven to circulate the water in the circulation passage 42 and the shutoff valve 44 is instantaneously closed during the water circulation to shut off the circulation passage 42, a water hammer effect occurs. As a result, the valve 56 of the opening means 46 opens,
The water in the circulation passage 42 is jetted to the ground 12 through the auxiliary pipe 54 to compact the ground. After the water hammer effect disappears, the vacuum pump 58 is operated to suck up water from the ground 12. In this way, when water is jetted to the ground 12,
It is better to take a time lag than to take it up from the same time.

The water hammer force generated by the water hammer action can be theoretically obtained by the Zhukovsky formula given by h = cV / g when optimally controlling the blockage time of the flow. Here, h is the water hammer pressure head, c is the pressure propagation velocity, V is the flow velocity of the steady flow, and g is the acceleration of gravity. The pressure propagation speed is c ≈ 1000 for ordinary penstock
m / s. When the diameter of the circulation passage is 3 cm, the water hammer force and the flow velocity have the relationship shown in FIG. 4, when the water hammer force is obtained by converting the water head obtained from the above equation into the force per unit area. Therefore, if the flow velocity in the circulation passage is set to 10 m / s,
A water hammer force of 140 kgf / cm ² , or pressure, is obtained.

On the other hand, when the flow blocking time T satisfies T≤2L / c, the blocking time is optimally controlled. Here, L is the distance from the pressure source to the location where the water hammer effect occurs. For example, when a water hammer effect is caused 10 m below ground, the optimum blocking time T is 0.02 s or less. Since the response time of the solenoid valve is shorter than several ms, a sufficient water hammer effect can be caused by using the solenoid valve as in the above embodiment.

As can be seen from FIG. 4, the water hammer force is proportional to the flow velocity. Therefore, if a reducing portion 73 is provided upstream of the portion 74 of the circulation passage 70 where the water hammer action is generated and the flow velocity at the downstream is increased, the pump pressure is lowered. While keeping it, the pressure of water spouting on the ground can be increased. The circulation passage can be enlarged downstream of the location 74 where the water hammer effect occurs.

As shown in FIG. 6, the apparatus for supplying the liquid to the ground can be made movable by installing the pipe 16 or 40 together with the liquid tank 76 in a construction machine 80 such as a bulldozer.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an apparatus for supplying a liquid to the ground according to the present invention.

2 shows a lower portion of the pipe and the circulation passage shown by 2 in FIG. 1, (a) is an enlarged sectional view, and (b) is a schematic view showing a state in which circulating water is cut off. is there.

FIG. 3 is a schematic view of another embodiment similar to the part 2 in FIG.

FIG. 4 is a graph showing the relationship between water hammer force and flow velocity.

FIG. 5 is a schematic diagram showing a method of increasing the flow velocity.

FIG. 6 is a schematic view of another embodiment of the device for supplying liquid to the ground according to the present invention.

[Explanation of symbols]

 10 Liquid Tank 12 Ground 14 Pump 16, 40 Pipe 18, 42 Circulation Passage 20, 44 Shutoff Valve 22, 46 Opening Means 30, 54 Auxiliary Pipe 32, 56 Valve 38, 48 Water Absorption Passage

Claims (2)

[Claims] 1. A device for guiding a liquid from a liquid tank and flowing it out to the ground to supply the liquid to the ground, comprising a pump for sucking the liquid in the liquid tank and a pipe inserted into the ground. The pipe is a circulation passage having an inlet connected to the pump and an outlet for discharging the liquid to the liquid tank, and a shutoff valve arranged in the circulation passage, which is instantaneously closed by an operation from the ground. A liquid supply to the ground, which comprises a shutoff valve which is always kept open, and an opening means for ejecting the liquid in the circulation passage to the outside by a water hammer action that occurs in the circulation passage when the shutoff valve is closed. Device to do. 2. A device for guiding a liquid from a liquid tank and flowing it out to the ground to supply the liquid to the ground, a pump for sucking the liquid in the liquid tank, a pipe inserted into the ground, and a vacuum. The pipe is composed of a pump, and the pipe is a circulation passage having an inlet connected to the pump and an outlet for discharging the liquid to the liquid tank, and a shutoff valve arranged in the circulation passage, which is operated instantaneously by operation from the ground. A shut-off valve which is closed at all times and which is always kept open; an opening means for ejecting the liquid in the circulation passage to the outside by a water hammer action that occurs in the circulation passage when the shut-off valve is closed; and the vacuum pump. And a water absorption passage for sucking water from the ground.