JPS62147362A - Measuring device of slow-speed and flow direction of ground water - Google Patents

Abstract

PURPOSE:To improve accuracy of measured values, by constructing the device with an inner tube with an inlet port retractable toward an electrode chamber by a cylinder mechanism and a means of supply of a constant volume of solution into the inner tube. CONSTITUTION:When ground water is introduced into an electrode chamber 20 through a guard mesh 23, distilled water existed in the special electrode 21 at the center id diluted by in-coming ground water by replacement and distilled water is gradually pushed outward of the chamber 20 through a number of through holes from the special electrode 21 located at the center of the chamber 20 and when reaching any of electrodes 22 arranged radially, as resistance values of the electrodes 22 are changed, slow-speed and flow direction of ground water corresponding to attitude and time of the change can be measured. Further, when the measuring operations of the flow speed and direction are finished and a renewed measurement is attempted, pressure liquid is introduced into the upper chamber 11 of the cylinder for lowering a cylinder 10 and insertion of an inner tube 15 into the electrode 21, a valve 18 is opened and a valve 19 is closed for filling distilled water in the tube 15 and allowing distilled water to remain in the electrode and thus, repeated measuring operations become available.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device for measuring minute flow velocity and flow direction of groundwater, and an object of the present invention is to improve the accuracy of measured values and simplify the measurement.

(Conventional technology) Regarding groundwater, which plays the most important role among water resources,
Various problems have been raised regarding its contamination.

Therefore, it is important to know the extent and extent of groundwater contamination and to accurately understand the movement of groundwater, and in particular, various studies have been conducted on methods for determining the flow velocity and direction of groundwater.

A typical method is to lower a current meter with a rotating propeller into a polling hole in flowing water and measure the flow speed and direction based on changes in the propeller rotation speed.
Further, as disclosed in Japanese Patent Publication No. 45-25029, an attempt is made to lower a disk into a poling hole and estimate the flow condition of groundwater from the pressure caused by the upward and downward flow of water in the hole acting on the disk, or There has been an attempt to measure the flow velocity and direction by injecting a radioisotope (R1) into flowing water and tracing changes in the radiation dose distribution caused by the flowing water.

However, with methods that drive mechanical measuring means with flowing water, it is extremely difficult to accurately measure flow velocities of less than 2 cm per second, and methods that use radioactive materials require a license to handle. Not only is this difficult, but the equipment becomes extremely expensive.

Therefore, in order to further solve these problems, the present inventors arranged a plurality of electrodes at equal intervals with respect to a specific electrode, and the potential difference (electrical resistance value difference) of each electrode between the specific electrode and the change developed a method to measure groundwater trends,
It has already been put into practical use.

(Problems to be Solved by the Invention) However, in the case of the above method, a NaCl solution or a solution containing a radioactive substance such as RI is used as the tracer material (tracking agent) to be first injected between the electrodes, which may cause environmental pollution. Not only are there problems, but there is also the problem that the accuracy of test values cannot be accurately confirmed, especially since the tracer material is only installed once and cannot be set repeatedly.
In addition, the equipment for injecting the tracer material between each electrode installed in a well is complicated and inevitably large-sized, which results in a large loss of measuring instruments and is not only uneconomical, but also makes it difficult to inject the tracer material between each electrode. Since it is actually extremely difficult to accurately supply a fixed amount during the measurement period, there is a limit to the accuracy of the measured values, and a certain amount of measurement error is considered to be unavoidable.

(Means for Solving the Problems) In order to solve the problems of the prior art described above, the present invention significantly improves measurement accuracy. It consists of an outer shell and an electrode chamber suspended at the lower end of the outer shell.The electrode chamber has a plurality of electrodes arranged opposite each specific electrode at equal intervals, and the outer shell is filled with a solution. It has a tank chamber and a spouting part that supplies a fixed amount of solution from the solution tank chamber into the electrode chamber, and the cough spouting part has an inner tube that can freely extend and retract toward the electrode chamber by a cylinder mechanism, and The device is characterized by comprising a solution supply means for supplying a fixed amount of solution into the tube.

(Embodiment) An embodiment of the present invention will be described below based on the illustrated embodiment. Reference numeral 1 denotes a hollow cylindrical outer body, and 8 a spouting part installed at the lower part of the inner part of the outer shell. , 20 denotes an electrode chamber suspended from the lower end of the outer shell.

The outer shell 1 has a solution tank chamber 3 above, a flexible thin film 4 made of rubber stretched over the outer opening of the solution tank chamber, and a pressure balance room between the thin film 4 and the outer shell 1. Furthermore, a plurality of through holes 6 communicating inside and outside are provided on the peripheral surface of the outer body 1 corresponding to the pressure balance room 5, and a balance filter is interposed in the through holes. Note that the solution tank chamber 3 is filled with distilled water.

The electrode chamber 20 is suspended below the lower end bottom plate 1a of the outer body l so as to be movable downward by a fixed distance with respect to the lower end bottom Fj-1a by a long bolt or the like. A cylindrical strainer with a cylindrical shape and a number of holes bored on its circumferential surface, the upper end of which is fixed directly below the pouring hole 1b bored in the center of the electrode holding plate 24, and the lower end fixed to the center of the electrode holding plate 24. - a specific electrode 21 which also serves as the center, and a plurality of electrodes 22) provided between the bottom plate 1a and the electrode holding plate 24 at equal intervals around the specific electrode, and their peripheral edges. It is composed of a fixed cylindrical guard mesh 23 having a large number of through holes around the entire circumference, which is interposed between the bottom plate 1a and the electrode holding plate 24 at a certain distance from each electrode. Furthermore, a large number of particles 25 are filled between the outside of the specific electrode 21 and the inner surface of the guard mesh 23, and a flexible part is provided on the outer periphery of the guard mesh 23 to cover the particles. A sex net 27 is set up, and the net 2
A large number of back beads 28 are filled between 7 and the guard mesh 23.

On the other hand, the spouting part 8 is fitted into a cylinder 9 which is located inside the lower part of the outer shell 1 and is fixed to the center of the upper surface of the bottom plate 1a, and is fitted into the cylinder so as to be movable in the vertical direction, and when it is lowered, from the spouting hole 1b. A piston 10 integrally has an inner tube 15 that enters into the specific electrode 21 and is movable upward from the specific electrode 21 when rising.The upper end is fixed to the upper center of the cylinder 10 and the tip is connected to the upper surface of the piston 10. Hollow chamber 10a of piston 10 through
a fixed tube 16 facing inside, and a hose 17 communicating between the fixed tube 16 and the solution tank 3;
A liquid supply/drainage pipe 13 that communicates with the upper chamber of the cylinder 9;
It is composed of a liquid supply/drainage pipe 14 that communicates with the lower chamber of the cylinder 9.

Note that opening/closing valves 18 and 19 are attached to the distal ends of the fixed tube 16 and the inner tube 15, respectively. Further, above the outer shell 1, a gyro device 26 is installed, which is an ultra-miniaturized version of the gyro commonly used for attitude control of aircraft and ships.

(Function) In the configuration of the embodiment described above, the first
The device shown in the figure is lowered to the measurement depth. At this time, the pack beads 28 in the electrode chamber and its surrounding surface are stretched downward due to the weight of the lower packer and cylinder (both not shown) suspended below the electrode holding plate 24. When the strainer reaches a predetermined depth and is fixed to the inner wall surface of the strainer 29 by expanding the lower part, the piston (not shown) moves downward inside the cylinder due to the weight of the measuring instrument body. As the bank beads 28 are moved, the bank beads 28 provided around the electrode chamber 20 are compressed from above and below. The packed beads 28 gradually become thicker as they are compressed in the vertical direction, expand in the radial direction, and are pressed against the inner wall surface of the strainer 29. In addition, pressure liquid is fed into the upper chamber of the cylinder 9 in advance, and the piston 10 is lowered to lower the inner tube 1.
5 inserted into the specific electrode 21, the valve 1
8 is opened, and with the valve 19 kept closed, a certain amount of distilled water is poured out from the solution tank 3 into the inner tube 15 through the hollow chamber 10a of the piston.

Thereafter, while closing the valve 18 and keeping the valve 19 open, the pressure liquid is fed into the lower chamber 12 of the cylinder, and the pressure liquid in the upper chamber 1) is drained. The inner tube 15 is pulled up from within the specific electrode 21, and only distilled water (test solution) remains within the specific electrode 21 without causing any volume change.

In this state, a constant weak current is applied between the specific electrode 15 and each electrode arranged radially around the specific electrode 15, and the change in resistance between each electrode is measured by a voltage indicator (not shown) installed on the ground. ) to know the flow velocity and flow direction of groundwater.

Specifically, when groundwater flows into the electrode chamber 20 through the guard mesh 23, the distilled water that was in the central specific electrode 21 is replaced and diluted with the inflowing groundwater, and the distilled water gradually flows into the center of the electrode chamber 20. When the specific electrode 21 is pushed outward from the electrode chamber 20 through a large number of through holes and reaches one of the radially arranged electrodes, the resistance value of the electrode changes. The minute flow velocity and flow direction of groundwater can be measured depending on the mode and time.

In the case described above, groundwater constantly flows in and out of the pressure balance room 5 via the balance filter 6, and the water pressure can be directly transmitted to the distilled water in the solution tank 3 via the thin film 4, so that the groundwater is not connected to the groundwater. The water pressure in the electrode chamber 20 and the water pressure in the solution tank 3, which are in contact with each other, are always kept in equilibrium.

Furthermore, when the flow velocity and direction measurement work is completed and the measurement is to be performed again, pressurized liquid is fed into the upper chamber 1) of the cylinder, the cylinder 10 is lowered, and the inner tube 1
5 into the specific electrode 21, open the valve 18, close the pulp 19, fill the inner tube 15 with distilled water by the same operation as described above, and further leave this in the specific electrode 21. Therefore, it is possible to continue the repeated measurement work.

Further, by utilizing the gyro device 26, it is possible to immediately know the orientation of a specific part of the measuring device.

(Effects of the Invention) As described above, the present invention has a solution tank chamber in the outer shell and a pouring section for supplying a fixed amount of solution from the solution tank chamber into the electrode chamber, and the pouring section is provided with a cylinder mechanism. Since it is composed of an inner tube that can freely extend and retract toward the center of the electrode chamber and a solution supply means that supplies a certain amount of solution into the inner tube, when supplying the solution to the center of the electrode chamber, the As a result of the solution being constantly supplied in a fixed amount to the correct position without causing any volume change, not only the accuracy of the measured values is significantly improved, but the entire device can also be made smaller, making it even more convenient to handle. It can be done.

In addition, the electrode chamber is surrounded by a mesh-like guard mesh, and the inside of the electrode chamber is filled with a large number of granules, and a large number of puncture beads are also arranged and covered on the outer periphery of the mesh-like guard mesh. Because of this structure, the streamlines of the groundwater flow are not distorted (and the natural flow of the groundwater flow within the electrode chamber can be maintained).

In addition, a flexible watertight sheet is attached to at least a portion of the solution tank chamber, and one or more balance filter holes are formed on the circumferential surface of the outer body in correspondence with the exposed position of the watertight sheet. Groundwater pressure is transmitted to the solution in the solution tank chamber through the balance filter, and the solution and the water pressure in the electrode chamber can always be maintained in equilibrium, contributing to further improvement of measurement accuracy.

Furthermore, since a miniaturized gyro device is built into the outer shell, the orientation of a specific part of the measuring device can be immediately known even at a deeper position than before, making it possible to easily align the measuring device as in the past. Inconveniences and inaccuracies can be resolved.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a main part of an apparatus for measuring the minute current velocity and flow direction of underground water, which is an embodiment of the present invention. 1...Outer body 3...Solution tank chamber 4...Flexible thin 1)! 5... Pressure balance room 6... Through hole 8...
... Pour part 9 ... Cylinder 10 ...
... Piston 15 ... Inner tube 16 ... Fixed tube 18.19 ...
・Opening/closing valve 20... Electrode chamber 21...
...Specific electrode 22... Electrode 23
... Guard mesh 25 ... Particulate matter
26... Gyro device 27...
Flexible net 28...Inventor of pack beads
Hajime Kawanishi

Claims (6)

[Claims] (1) Consists of a hollow cylindrical outer shell and an electrode chamber suspended from the lower end of the outer shell, and the electrode chamber has multiple electrodes facing each specific electrode at equal intervals. In addition, the outer body has a solution tank chamber and a spouting part for supplying a fixed amount of solution from the solution tank chamber into the electrode chamber, and the spouting part is directed into the electrode chamber by a cylinder mechanism. What is claimed is: 1. A device for measuring minute flow velocity and flow direction of underground water, comprising an inner tube that can be freely moved in and out, and a solution supply means that supplies a certain amount of solution into the inner tube. (2) In the device described in claim 1, the electrode chamber is surrounded by a mesh-like net, and the inside of the electrode chamber is filled with a large number of granular materials. Microflow velocity and direction measurement device. (3) In the item set forth in claim 1, the specific electrode within the electrode chamber is located in the inner tube provided at the center of the chamber and at the retractable position of the inner tube that protrudes and retracts into the chamber. A groundwater microcurrent velocity and flow direction measurement device that is a somewhat larger diameter electrode strainer. (4) In the device described in claim 1, the solution supply means for supplying a certain amount of solution into the inner tube recessed and recessed into the electrode chamber is configured to move the inner tube forward and backward within the cylinder that moves the inner tube forward and backward. A groundwater microflow velocity and flow direction measurement device that is a fixed tube that is inserted airtight from the direction. (5) In the product as set forth in claim 1, a flexible watertight sheet is attached to at least a part of the solution tank chamber, and a flexible watertight sheet is attached to the periphery of the outer body in correspondence with the exposed position of the watertight sheet. A device for measuring the microflow velocity and flow direction of underground water, which has one or more balance filter holes in its surface. (6) A device for measuring the minute current velocity and flow direction of underground water according to claim 1, which comprises a gyro built into the outer shell.