JP3054000U - On-site automatic pumping test equipment using weir type flow meter - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide an on-site automatic pumping test apparatus using a weir type flow meter, which is used for a pumping test performed for drafting a drainage plan for a site where ground excavation is performed. An on-site automatic pumping test apparatus for measuring the flow rate of groundwater pumped through a pumping pipe of a pumping well provided in the ground of a site by a flow rate measuring means and inputting the measured value to a record display means. The flow rate measuring means has a configuration in which a weir is provided in a receiving tank of groundwater to be pumped, and a differential transformer type float type water level meter for measuring a water level overflowing to the weir is provided. Is input to the recording and display means in real time.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 This invention belongs to the technical field of an automatic pumping test device used for a pumping test that is performed to formulate a drainage plan for a site where excavation (root cutting) of the ground is performed. The present invention relates to an on-site automatic pumping test apparatus using a slab.

[0002]

[Prior art]

 The on-site pumping test is one of the very important tests when planning a drainage plan when excavating the ground at the site where groundwater exists. In a normal on-site permeability test, a single-hole type casing is used to determine the permeability from the water level recovery situation, etc., but it is not possible to estimate the amount of water that will spring out during actual excavation. It is understood that the drainage volume is often low or abundant during drilling, and the importance of pumping tests is high. However, in the on-site pumping test, a large number of pumping wells and observation wells are installed, so the number of measurement personnel is required according to the number of wells. In addition, a large number of people and labor are required to summarize the measured results in numerical tables and calculate constants (permeability coefficient, storage coefficient, etc.), which is reflected in the high cost of pumping tests.

[0003] Conventionally, there have been proposed some automatic pumping test apparatuses that can automate the on-site pumping test and can be performed with a small number of people and little labor.

As an example, FIG. 4 shows a conventional on-site automatic pumping test apparatus. In this on-site automatic pumping test apparatus, water level gauges 9, 9 'are installed in one pumping well 1 and a plurality of observation wells 10 provided in the ground E, respectively. , 9 ′... Are sent (collected) and input to the recording recorder 11 in the observation room K, respectively. Further, an electromagnetic flow meter P is installed in the pumping pipe 1a of the pumping well 1, and the measured value of the flow rate measured by the electromagnetic flow meter P is sent to the recording recorder 11 also in the observation room K and input. The data such as the measured water level and the measured flow rate are calculated by a terminal device such as a notebook computer 4 serving as a recording and displaying means connected to the recording and recording device 11 to obtain hydraulic constants. The plan is to formulate an appropriate drainage plan. Symbols a to d in FIG. 4 are codes that connect each device to the recording and recording device 11. Reference numeral 2 ′ denotes groundwater in the observation well 10.

[0005]

[Problems to be solved by the present invention]

 Since the conventional on-site automatic pumping test apparatus illustrated in FIG. 4 is an automatic pumping test apparatus using an electromagnetic flowmeter, there is a serious problem in practicality.

That is, when using the electromagnetic flowmeter P, in order to maintain the accuracy of the flow measurement, an electromagnetic flowmeter appropriate for the thickness of the pumping pipe 1a is used, or an appropriate thickness for the electromagnetic flowmeter is used. Must use a water pipe. However, in pumping tests on site, pumping wells are prepared in advance, and pumping tests often need to be performed on the assumption of existing pumping pipes. Electromagnetic flowmeters must be prepared for pumping pipes of various thicknesses, which cannot be met at all, making it impractical. Furthermore, a flow meter with an appropriate capacity according to the amount of pumped water must be used. Therefore, if a large-capacity flowmeter is used for an extremely small flow rate, the measurement error increases, and there is a possibility that a highly accurate pumping test may not be performed.

An object of the present invention is to use a low-cost weir-type flow meter that can be implemented without any problems corresponding to existing pumping pipes of various thicknesses, is practical, and easy to visually observe. It is to provide an on-site automatic pumping test device.

[0008]

[Means for Solving the Problems]

 As a means for solving the above problems, an on-site automatic pumping test apparatus using a weir type flow meter according to the present invention according to claim 1 is used for pumping water through a pumping pipe of a pumping well provided in the ground at the site. In the on-site automatic pumping test apparatus which measures the flow rate of groundwater by a flow rate measuring means and inputs the measured value to a record display means, the flow rate measuring means is provided with a weir in a receiving tank of the groundwater to be pumped. A differential transformer-type float-type water gauge for measuring the water level overflowing to the weir is provided, and the measured value of the float-type water gauge is input to the recording and display means in real time. .

The invention according to a second aspect is characterized in that, in the automatic on-site pumping test apparatus using the weir type flow meter according to the first aspect, the weir provided in the receiving tank is a triangular weir.

[0010]

Embodiments and Examples of the Invention

 An embodiment and an example of an on-site automatic pumping test apparatus using a weir type flow meter according to the present invention will be described below with reference to FIGS.

[0011] The on-site automatic pumping test apparatus using the weir type flow meter according to the present invention, as shown in the overall system in Fig. 1, passes through the pumping pipe 1a of the pumping well 1 provided in the ground E at the site. The flow rate of the groundwater 2 pumped by the submersible pump 8 is measured by the weir type flow meter 3, and the measured value is input to the recording and display means 4 in real time.

As shown in detail in FIGS. 2A and 2B, the weir type flow meter 3 first divides a water receiving portion into a water receiving tank 5 for the groundwater 2 pumped from the water pumping pipe 1a and controls the water surface to sway. There is provided a dive weir plate 12 for prevention, followed by a weir plate 6 which rises from the bottom of the water receiving tank 5 in a watertight manner, and the weir plate 6 is formed with a triangular weir 6a. As the water receiving tank 5, notch tanks usually prepared at many sites may be used. A differential transformer type float type water level meter 7 for measuring the water level H overflowing to the triangular weir 6a is installed on the downstream side of the submerged weir 12. The float type water level meter 7 grasps the vertical displacement (change of water level) of the float 7b by the magnitude of the current value as described later, and the measured value is inputted to the recording and display means 4 in real time. .

As shown in detail in FIG. 3, the differential transformer type float type water level gauge 7 has a core rod (steel rod) 7 a and a spherical float which is passed through the core rod 7 a and movably mounted. 7b, and a support portion 7c to be installed on the dive weir plate 12. The spherical float 7b has a hollow inside and serves as a float floating on water, and is displaced along the core rod 7a with a change in the water level H overflowing to the triangular weir 6a. As a result, the entire electric resistance value changes, and the change in the current value flowing in the core rod 7a is measured as a change in the water level. In the present embodiment, the support portion 7c is fixed and installed on the downstream side surface of the dive weir plate 12 so that the core rod 7a faces the vertical direction. However, the present invention is not limited to this. May be installed on the inner surface of the water receiving tank 5 between them. The support section 7c has a built-in section for transmitting measured values and the like.

The operation of the on-site automatic pumping test apparatus using the weir type flow meter according to the present invention will be described below with reference to FIG.

[0015] Water level gauges 9, 9 '... are respectively installed in one pumping well 1 and a plurality of observation wells 10 ... provided in the ground E of the site, and the water level gauges 9, 9' ... The measured values of the measured water level are sent (collected) and input to the recording recorder 11 in the observation room K, respectively. The water level measured by the float type water level gauge 7 of the weir type flow meter 3 installed below the drain port 13 of the pumping pipe 1a of the pumping well 1 is also sent to the recording recorder 11 in the observation room K. It is sent and input. The data of the measured value of the float type water level meter is converted into the following formula for calculating the flow rate Q of a known triangular weir by a terminal device such as a notebook personal computer 4 serving as a record display means connected to the record recorder 11. Apply to [1] and calculate the flow rate in real time.

[0016]

Q = 0.0084H ^5/2 Q: m ³ / min H: cm The data of the flow rate Q obtained from the water level H and the data of the water level measurement values of the water level meters 9, 9 ′... By calculating the hydraulic constants, an appropriate drainage plan can be formulated. Reference numerals a to e in FIG. 1 are codes for connecting each device to the recording and recording device 11. Reference numeral 2 ′ is groundwater in the observation well 10.

[0017]

[Effects of the present invention]

 According to the on-site automatic pumping test device using a weir type flow meter according to the present invention, the flow measurement means uses an existing notch tank or the like as a water receiving tank, and uses a differential transformer type float type water level meter. Since it can be implemented with a configuration that installs water pipes, it can be implemented extremely easily at each site in response to existing pumping pipes of various thicknesses, and it is practical and low cost. In addition, since visual observation is easy, there is no large measurement error.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an embodiment of an on-site automatic pumping test apparatus using a weir type flow meter according to the present invention.

FIG. 2A is a perspective view showing a weir flow meter used in the present invention, and FIG. 2B is a longitudinal sectional view showing a weir flow meter used in the present invention.

FIG. 3 is a front view showing a float type water level meter used in the present invention.

FIG. 4 is a system diagram showing an embodiment of a conventional on-site automatic pumping test apparatus.

[Explanation of symbols]

 E Ground on site 1 Pumping well 1a Pumping pipe 2 Groundwater to be pumped 3 Flow rate measuring means (weir type flow meter) 4 Record display means 5 Receiving tank 6a Weir H Overflowing water level 7 Float type water level meter

Claims (2)

[Utility model registration claims] An on-site automatic pumping test apparatus for measuring the flow rate of groundwater pumped through a pumping pipe of a pumping well provided in the ground of a site by a flow rate measuring means and inputting the measured value to a recording and displaying means. The flow rate measuring means has a configuration in which a weir is provided in a receiving tank of the groundwater to be pumped, and a differential transformer type float type water level meter for measuring a water level overflowing to the weir is installed. An on-site automatic pumping test apparatus using a weir type flow meter, wherein a measured value of a meter is inputted to the recording and displaying means in real time. 2. The on-site automatic pumping test apparatus using a weir type flow meter according to claim 1, wherein the weir provided in the water receiving tank is a triangular weir.