JPS63165612A - Grout injection control system - Google Patents

Abstract

PURPOSE:To raise the efficiency of operations by a method in which a tightly closable three-way valve is used for a grout injection control system and an accumulator is also provided. CONSTITUTION:A grout injection control system consists of a storage tank 1, a grout pump 2, a tightly closable three-way valve 13, an accumulator 15, an injection port 12, and a return pipe 7. When a set injection pressure is higher than the sum of heads resulting from pressure loss of the return pipe 7 and also from difference in the levels of the injection port 2 and the tank 1, control is made to set flow rate and pressure by increasing the opening degree of the outlet 13c side of the valve 13 or making the outlet 13b side smaller. The injection under fine pressures and pressure pulsation by the pump 2 are eased by the accumulator 15. The construction cost can thus be cut down.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a grout injection control system that not only allows fine pressure adjustment during grout injection, but also allows efficient work.

In order to improve the ground during dam construction, cement or grout mixed with bentonite is injected into the ground. Conventionally, as shown in Fig. 3, the storage tank 1
The grout, which is constantly stirred, is sent to the three-way valve 3 by the grout pump 2, and the flow rate and pressure signals detected by the flow rate detector 4 and pressure detector 5 are sent to the flow rate pressure control device 6, and the detected values are sent to the three-way valve 3. The three-way valve was operated so that the flow rate and pressure approached the preset flow rate and pressure, and grout was injected into the ground 8 while returning excess grout from the return pipe 7 to the storage tank 1.

9 is a suction pipe, 10 is a supply pipe, 11 is an injection pipe, 12
3a is an inlet, 3b and 3c are discharge ports, and 16 is an injection pipe.

However, in the above-mentioned conventional injection control system, the three-way valve used is of a non-sealing type due to its structure due to wear caused by grout, etc. Therefore, as shown in FIG. If the location is higher and the return pressure due to the height difference is higher than the set injection pressure, the actual injection pressure will be higher than the set injection pressure even if you try to control it to the set injection pressure, so the storage tank 1 will be lowered. The injection pressure cannot be injected at the set injection pressure unless the return pressure is lowered by moving the tank, and there is the inconvenience of having to move the storage tank every time the injection location changes, resulting in inefficient work. It was hot.

This invention solves the above problems, and even if the return pressure is higher than the set injection pressure, it is not only possible to inject at the set injection pressure without moving the storage tank, but also allows fine pressure adjustment compared to the conventional method. An object of the present invention is to provide a grout injection control system capable of controlling the flow rate and pressure of grout in a storage tank through a grout pump and a three-way valve. In a grout injection control system that injects surplus grout while returning it to the storage tank, a sealable three-way valve is used as the three-way valve, and an accumulator or an air chamber is provided between the sealable three-way valve and the injection port. The invention is characterized in that it is configured to further control the pressure and inject.

Figure 1 is a system diagram of the grout injection control system of this invention.
An example is shown in which 1 is a storage tank in which grout is stored while constantly stirring, 9 is a suction pipe connecting the storage tank 1 and the grout pump 2, and 10 is the inlet port 13a of the sealable three-way valve 13 and the grout pump 2. A supply pipe line 7 connects the outlet, a return line 7 returns the grout discharged from the outlet 13b of the sealable three-way valve 13 to the storage tank 1, and 11 connects to the outlet 13c of the sealable three-way valve 13. The injection pipe 11 is connected to the injection port of the injection pipe 16 in a hole drilled in the ground, and the injection pipe 11 is equipped with an accumulator 15, a flow rate detector 4, and a pressure detector. A control device 14 compares the flow rate and pressure signals detected by the flow rate detector 4 and pressure detector 5 with preset flow rate and pressure set values, and detects the flow rate and pressure. The sealable three-way valve 13 is operated so that the value approaches the set value, and the accumulator 15 closes the discharge port 1 when the set pressure of the injection grout is a slight pressure.
It is configured to buffer and adjust pressure pulsations caused by slight repetitions of opening and closing of the valve 3c.

It goes without saying that the accumulator 15 is not limited to only when the set pressure is low, but also buffers pressure pulsations caused by the grout pump and smoothes not only the pressure but also the flow rate.

In the grout injection control system described above, when the injection pressure is higher than the sum of the head due to the pressure loss of the return pipe 7 and the head due to the height difference between the injection port 12 and the storage tank 1, the flow path on the discharge port 13c side is The opening degree is larger than the current one, that is, the discharge port 13
By making the opening degree of the b-side channel smaller than the current one, it is possible to control the flow rate and pressure to a set value, and the injection pressure is reduced by the head due to the pressure loss of the return pipe 7, the injection port 12, and the storage tank 1. If the grout flow rate is lower than the sum of the head due to the height difference between By making the opening degree of the flow path on the discharge port 13b side smaller, that is, making the opening degree of the flow path on the discharge port 13b side larger than the current value, the flow rate and pressure of the grout to be injected can be controlled to the set values. In the case of micro-pressure injection, the discharge port 13c is repeatedly opened and closed slightly as described above, but the buffering action of the accumulator allows injection without pulsation.

FIG. 2 shows an example of the grout injection control system system diagram of the present invention when an air chamber 17 is provided in place of the accumulator 15, where 17 is an air chamber provided in the injection pipe 11, and 24 and 24' are air chamber 1
A level switch attached to 7, 18 a pressure air source such as a compressor that supplies air to the air chamber 17 through a pipe 25, and 19 a level switch that controls the pressure air from the pressure air source 18 provided in the pipe 25 to a desired level. 20 is a pneumatically operated valve provided between the pressure regulating valve of the pipe 25 and the air chamber 17; 21 is a solenoid valve that opens and closes the pneumatically operated valve 20; 22 is a solenoid valve of the pipe 25; This check valve is installed between the pneumatic operation valve 20 and the air chamber 17, and when the lower limit level switch 24' attached to the air chamber 17 is activated, it sends a signal to the control unit 23 and operates the solenoid valve 21. The pneumatically operated valve 20 is closed to stop the supply of air, and when the upper limit level switch 24 is activated, a signal is sent to the control unit 23 to operate the solenoid valve 21 and open the pneumatically operated valve 20 to supply air. That is, the structure is such that the air in the air chamber is prevented from dissolving into the grout and the capacity decreases, so that the capacity does not change within a certain range. The grout injection control has been explained using the system shown in Figure 1, so it will be omitted here, but in addition to the effects of the system shown in Figure 1, the air pressure in the air chamber can be maintained at a desired level, further reducing pressure pulsations. It has the effect of being able to inject grout by adjusting the fine pressure.

Next, one example of a sealable three-way valve used in the grout injection control system of the present invention will be explained. Note that the sealable three-way valve described below can be used not only for grout but also for other fluids, and can also be used as a mixing valve, so it will be described in such a form.

In FIG. 5, the sealable three-way valve A has a valve case body 26, a cover plate 27 attached to one side of the valve case body 26, and a flow dividing tube 28 attached to the other side of the valve case body 29. two corresponding arc-shaped non-penetrating valve seat holes 30, 30' having a smooth surface and concentrically; and the two valve seat holes 30, 30'.
Two flow dividing holes 30a and 30'a that communicate with and penetrate through the
and a valve seat 31 shown in FIG. 6, which has a smooth surface in contact with the smooth surface of the valve seat 31 and corresponds to the valve seat holes 30, 30', and is further provided with a valve seat 31 shown in FIG. A valve body 33 having a long length (the opening degree is small, but the length may be short) shown in FIG. A rotating shaft 34 is attached to the body 33 so that the body 33 can be freely rotated in either the left or right direction. To explain in more detail, the valve seat 31 is connected to the valve case body 2.
It is held and fixed by a protrusion 26a protruding along the inner circumference of the valve case body 26 and a flow dividing tube 28 which is attached to the valve case body 26 by means such as screwing, and the flow dividing tube 28 has a flow dividing hole. 30a,
Diversion chambers 35, 35' communicating with 30'a and diversion chamber 35,
Discharge ports 36, 36' are provided which communicate with 35'. Further, an inflow chamber 37 is formed within the valve case main body 26.
An inflow port 38 is provided in communication with the inflow chamber 37, and the valve body 33
The tip of the rotary shaft 34 is inserted into a long recess 39 provided in the recess 39 . The rotary shaft 34 is rotatably fixed in position by a bearing 40 that is externally disposed and a nut 41 that is screwed into the inside of the case body 26. Nao 34
a is a flange protruding from the outer periphery of the rotating shaft 34; 42 is a nut 4;
The cover plate 27 is a locking bolt screwed through a notch 41a provided parallel to the end face of the case body 26, and the cover plate 27 is also attached to the case body 26 by screwing or the like, like the flow divider tube.

The sealable three-way valve configured as described above connects pipes to the inlet port 38 and the discharge ports 36, 36' to send fluid from the inlet port 38, and when the rotating shaft 34 is rotated by a drive source (not shown), the discharge port The flow rate of fluid discharged from 36, 36' can be changed at will, or the discharge amount from one of the discharge ports can be set to zero. That is why it is called a sealable three-way valve. Conversely, if different fluids are allowed to flow in from the discharge ports 36 and 36', the intended blended amount of fluid will be discharged from the inflow ports, and if a continuous mixer is connected to the inflow ports, they will be kneaded and discharged. It can also be used as a fluid mixing valve.

The arc-shaped through hole 32 of the valve body 33 includes a plurality of through holes 32'', 32''... (shown by dotted lines) arranged in an arc shape at intervals.
Instead of the valve body 33, a valve body 33' having an arc-shaped notch 32' shown in FIG. 8 may be used. Further, instead of fixing the rotating shaft 34 using the bearing 40 and the nut 41, the rotating shaft 34 may be fixed by being pressed by a spring disposed on the rotating shaft 34. Although the valve can be made of metal such as stainless steel, it will be even more durable if the valve body and valve seat are made of ceramics. In this case, valve body 3
3, as shown by the dotted line in FIG. 7, a reinforcing plate 43 made of steel or the like is provided with a through hole 43' or 43'' of the same shape that communicates with the through hole 32 or 32'', using an adhesive or the like. If the valve body is firmly fixed, the valve body will have excellent wear resistance and mechanical strength, and will also have excellent durability.

The above-mentioned valve can be used as a dividing valve or a mixing valve, but since it is a sealable type and has excellent durability, it is extremely suitable for use in the sealable three-way valve of the present invention. That is, the discharge port 36 or 36' is connected to the return pipe 7.
Alternatively, connect the inlet 38 to the injection pipe 11 and connect the inlet 38 to the supply pipe 1.
Use by connecting to 0.

Since the present invention is configured as described above, even if the return pressure is higher than the set injection pressure, injection can be performed at the set injection pressure without moving the storage tank, and therefore the installation location of the storage tank can be changed. Not only can you reduce the expense of moving the storage tank each time the injection location changes, but you can also shorten the time involved in moving it, making the work more efficient and economical, as well as maintaining a low pressure. It has extremely high performance compared to conventional systems, such as being able to inject grout using the system, and will greatly contribute to the industry.

[Brief explanation of the drawing]

Figure 1 is a system diagram of one example of the grout injection control system of the present invention, Figure 2 is a system diagram of another example, Figure 3 is a system diagram of one example of a conventional system, and Figure 4 is an example of on-site construction. Schematic diagram showing,
Figure 5 is a sectional view of an example of a sealable three-way valve, Figure 6 (A)
(B) and (C) are the front view, side sectional view, and rear view of one example of the valve seat, Figures 7 (A) and (B) are the front view and side sectional view of one example of the valve body, and Figure 8 is the valve seat. It is a front view and a side view of one example of a body. 1... Storage tank 2... Grout pump 12... Inlet 13
...Sealable three-way valve 15...Accumulator 17...
Air chamber A...Sealable three-way valve Patent applicant Isao Hachimaki, Representative Director of Front Engineering Co., Ltd.

Claims (1)

[Claims] A grout injection control system for injecting grout into a storage tank via a grout pump and a three-way valve while controlling the flow rate and pressure and returning excess grout to the storage tank,
A sealable three-way valve is used as the three-way valve, an accumulator or an air chamber is provided between the sealable three-way valve and the injection port, and the injection is performed while controlling the pressure. grout injection control system.