JP7499213B2 - Viscosity and density measuring device - Google Patents

Description

The present invention relates to an apparatus for measuring the viscous density of a suspended fluid material.

In the construction field, suspended fluid materials such as cement milk, grout, muddy water, bentonite solution, and liquefied treated soil are sometimes used as ground improvement materials, backfill materials, and filling materials for cavities (see, for example, Patent Document 1). In addition, suspended fluid materials may be injected to stabilize the ground during tunnel excavation or drilling of a vertical hole (see, for example, Patent Document 2). In order to ensure the performance quality according to the intended use of the suspended fluid material, such as the fluidity required during construction and the strength after construction, it is necessary to manage the density and viscosity of the suspended fluid material so that they are within a predetermined range. For example, by keeping the viscosity of cement milk and liquefied treated soil at an appropriate level, the material separation resistance during the process from transportation, injection or casting to curing is ensured, and by keeping the density at an appropriate level, the necessary strength after hardening is ensured. In addition, bentonite solutions used in tunnel construction and excavation work are adjusted to a viscosity that does not permeate or infiltrate the ground in contact with the excavation surface, and a density higher than the density of groundwater, thereby preventing outflow into the surrounding ground and inflow of groundwater.
The viscosity and density of suspended fluid materials usually require samples to be collected on-site and then taken to a testing laboratory for measurement, which means it takes time and effort to calculate the viscosity and density.

JP 2019-027134 A JP 2015-086535 A

An object of the present invention is to provide a viscosity and density measuring device that makes it possible to easily specify the viscosity and density of a suspension fluid material at the production site.

To solve the above problem, the viscosity density measuring device of the present invention comprises a hollow reservoir having an inlet formed at the top and an outlet formed at the bottom, a plurality of pressure gauges arranged in parallel along the height direction of the reservoir to measure the pressure of the suspended fluid material stored in the reservoir , and a distance gauge to measure the liquid level of the suspended fluid material in the reservoir .
The viscous density measuring method using the viscous density measuring device of the present invention includes a material storing step of storing a suspended fluid material in a reservoir, a material discharging step of discharging the suspended fluid material from a lower part of the reservoir and measuring the flow rate of the suspended fluid material, and a viscous density calculating step of calculating the viscosity and density of the suspended fluid material. A plurality of pressure gauges are disposed at different height positions in the reservoir, and the viscous density calculating step calculates the viscosity and density of the suspended fluid material using the pressure distribution measured by the plurality of pressure gauges and the flow rate.
According to this viscous density measuring method, the density can be calculated using the pressure distribution measured by a plurality of pressure gauges, and the degree of viscosity can be grasped from the flow rate of the material. The viscous density measuring device is a relatively simple device, and can be installed, for example, near the manufacturing tank of the suspension fluid material. Therefore, the suspension fluid material can be manufactured while checking the properties on-site.

Since the viscous density measuring device is equipped with a range finder that measures the liquid level of the suspended fluid material in the reservoir, the range finder can be used to measure the change in the liquid level of the suspended fluid material over time when the suspended fluid material is discharged from the reservoir without the need for a flow meter or the like, making it easy to implement the viscous density measuring method.
The viscosity density measuring device preferably further comprises an inlet pipe extending from the sludge tank to the inlet, a discharge pipe extending from the discharge outlet to the sludge tank, an inlet valve provided at the inlet, and a discharge valve provided at the discharge outlet. With such a viscosity density measuring device, the viscosity and density of the suspension fluid material supplied through the inlet pipe can be measured, and then the suspension fluid material can be returned to the production tank through the discharge pipe. At this time, the supply and discharge of the suspension fluid material are performed by operating the inlet valve and the discharge valve.

The viscosity and density measuring device of the present invention makes it possible to easily determine the viscosity and density of a suspension fluid material at the manufacturing site, and by using the results, it is possible to improve the quality of the suspension fluid material.

FIG. 2 is a schematic diagram showing a usage state of the viscosity density measuring device according to the present embodiment. FIG. 1 is a schematic diagram showing the configuration of a viscous density measuring device. 1 is a flowchart showing the steps of a viscous density measuring method. FIG. 11 is a side view showing an overview of a material storing process. FIG. 5 is a side view showing an outline of the material storage step following FIG. 4 . FIG. 4 is a schematic diagram showing pressure distribution within a reservoir. FIG. 11 is a perspective view showing an overview of a material discharging process. 1 is a graph showing an example of the relationship between flow velocity and flow value, which is created based on the results of laboratory tests and measurements in a plant. 1 is a graph showing an example of a method for displaying the measurement results of viscosity and density. FIG. 11 is a schematic diagram showing a usage state of a viscosity density measuring device according to another embodiment.

In this embodiment, a viscous density measuring device 1 for measuring the density and viscosity of a suspension fluid material W, and a viscous density measuring method using the same, are described, with the aim of ensuring performance and quality (e.g., fluidity and strength after hardening) that are appropriate for the intended use of the suspension fluid material W. Here, the suspension fluid material W is a material having fluidity used for ground improvement and the like, and corresponds to, for example, muddy water, grout, mortar, fluidized treated soil, etc. Figure 1 shows the usage of the viscous density measuring device 1 of this embodiment.
As shown in Fig. 1, the viscosity density measuring device 1 of this embodiment is provided near a production tank (sludge tank) T for producing a suspension fluid material W. The production tank T is a metal box-shaped container. The top surface of the production tank T is open so that a stirring means (e.g., a backhoe bucket) for stirring the stored matter (suspension fluid material W), materials, etc. can be introduced. The production tank T of this embodiment has a rectangular parallelepiped shape.

2 shows the viscous density measuring device 1. The viscous density measuring device 1 includes a reservoir 2, a pressure gauge 3, a distance meter 4, an inlet pipe 5, an inlet valve 6, a discharge pipe 7, and a discharge valve 8.
The reservoir 2 is made of a hollow member. The main body (upper part) of the reservoir 2 has a uniform cylindrical cross-sectional shape, and the lower part 21 of the reservoir 2 is tapered in an inverted truncated cone shape, with an outlet 22 formed at the center of the lower end of the lower part 21. In addition, the upper surface 23 of the reservoir 2 in this embodiment is open, and an inlet 24 is formed on the upper side surface of the reservoir 2 (a position a predetermined height lower than the upper end). The reservoir 2 is installed so that the central axis is vertical (including approximately vertical).

The pressure gauge 3 is provided inside the reservoir 2. The pressure gauge 3 measures the pressure of the suspended fluid material W stored in the reservoir 2. In this embodiment, a plurality of pressure gauges 3, 3, ... are arranged in parallel at a predetermined interval along the height direction of the general part (part with a constant cross-sectional area above the lower part 21) 25 of the reservoir 2. The number of pressure gauges 3 and the interval between the pressure gauges 3 are not limited and may be determined appropriately. The height position of the pressure gauge 3 is a known distance from the lower end (discharge port 22) of the reservoir 2. In other words, each pressure gauge 3 is arranged vertically in a state where the height from the lowest point of the suspended fluid material W stored in the reservoir 2 is known. The pressure gauge 3 in this embodiment is connected to a data processing means (e.g., a personal computer, etc.) 9 (not shown) by wire or wirelessly, and the measurement data of the pressure gauge 3 is transmitted to the data processing means 9.

The range finder 4 is provided above the reservoir 2 and measures the liquid level of the suspended fluid material W in the reservoir 2 from the upper surface 23 (opening) of the reservoir 2. The range finder 4 is fixed at a position at a preset distance from the upper end of the reservoir 2. The range finder 4 may be fixed to the reservoir 2 or to another member (e.g., the manufacturing tank T or a separately provided support member, etc.). The range finder 4 in this embodiment is a laser range finder, which is a type of non-contact range finder, and calculates the distance to the suspended fluid material W from the time it takes to irradiate a laser beam to the liquid level (upper surface) of the suspended fluid material W and receive the reflected laser beam. The range finder 4 in this embodiment is connected to a data processing means (e.g., a personal computer, etc.) 9 (not shown) by wire or wirelessly, and the measurement data of the range finder 4 is transmitted to the data processing means 9. The range finder 4 may be fixed to the side of the manufacturing tank T or may be supported by a separately provided support member.

As shown in Fig. 1, the inlet pipe 5 is a pipeline leading from the production tank T to the reservoir 2. As shown in Fig. 2, the inlet pipe 5 is connected to an inlet 24 via an inlet valve 6. The inlet pipe 5 transports the suspended fluid material W in the production tank T to the reservoir 2. As shown in Fig. 1, the inlet pipe 5 is provided at a position lower than the liquid level of the suspended fluid material W at the top of the production tank T so that the suspended fluid material W in the production tank T flows down into the reservoir 2.
2, the inlet valve 6 is provided at the inlet 24 and controls communication between the reservoir 2 and the inlet pipe 5 (opening and closing the inlet 24). When the inlet valve 6 is opened, the suspended fluid material W transported via the inlet pipe 5 is supplied into the reservoir 2. On the other hand, when the inlet valve 6 is closed, the supply of the suspended fluid material W to the reservoir 2 is stopped.

As shown in Fig. 2, the discharge pipe 7 is a pipeline for transporting the suspended fluid material W discharged from the reservoir 2. The discharge pipe 7 is connected to a discharge port 22 via a discharge valve 8. In this embodiment, as shown in Fig. 1, a temporary receiving tank T2 is provided below the reservoir 2, and the suspended fluid material W discharged from the reservoir 2 flows down through the discharge pipe 7 to the temporary receiving tank T2.
2, the discharge valve 8 is provided at the discharge port 22 and controls communication/non-communication between the reservoir 2 and the discharge pipe 7 (opening and closing the discharge port 22). When the discharge valve 8 is opened, the suspended fluid material W in the reservoir 2 is discharged from the discharge port 22 of the reservoir 2 and transported to the production tank T via the discharge pipe 7.
In this embodiment, a return pipe 71 is installed from the temporary receiving tank T2 to the production tank T. The return pipe 71 pumps the suspension fluid material W discharged from the reservoir 2 and stored in the temporary receiving tank T2 via a pump 72 provided in the temporary receiving tank T2 to the production tank T.
In this embodiment, the inlet valve 6 and the outlet valve 8 are opened and closed by control signals from a control means 91 .

Next, a viscous density measuring method using the viscous density measuring device 1 will be described. The steps of the viscous density measuring method are shown in Fig. 3. The viscous density measuring method includes a preparation step S1, a material storage step S2, a pressure measurement step S3, a material discharge step S4, a viscous density calculation step S5, and an adjustment step S6.
In the preparation step S1, first, the viscosity density measuring device 1 is installed at a predetermined position. The viscosity density measuring device 1 is installed near the production tank T so that the central axis is vertical. In addition, one end of the inflow pipe 5 is connected to the production tank T, and the other end of the inflow pipe 5 is connected to the inlet 24 of the reservoir 2 via the inflow valve 6 to ensure a path for the suspension fluid material W to flow into the reservoir 2. In addition, one end of the discharge pipe 7 is connected to the production tank T, and the other end of the discharge pipe 7 is connected to the outlet 22 of the reservoir 2 via the discharge valve 8 to ensure a discharge path for the suspension fluid material W.

In the material storage step S2, the suspended fluid material W is stored in the storage body 2. The material storage step is shown in FIG. 4 and FIG. 5. As shown in FIG. 4, in the material storage step S2, the discharge valve 8 is closed and the inlet valve 6 is opened to supply the suspended fluid material W into the storage body 2. When the liquid level of the suspended fluid material W in the storage body 2 reaches a predetermined height, the inlet valve 6 is closed as shown in FIG. 5 to stop the supply of the suspended fluid material W. In this embodiment, the suspended fluid material W is supplied until the liquid level of the suspended fluid material W reaches a position between the pressure gauge 3 arranged at the highest position and the upper surface 23 of the storage body 2. The supply of the suspended fluid material W to the storage body 2 is performed at a timing when the production of the suspended fluid material W in the production tank T progresses and the suspension fluid material W is stirred so that the concentration of the suspended fluid material W becomes uniform in the production tank T. In this embodiment, the opening and closing of the inlet valve 6 and the outlet valve 8 is automatically controlled by the control means 91. That is, when the viscosity density measuring device 1 is started, the control means 91 sends a signal to close the discharge valve 8 and a signal to open the inlet valve 6, and also sends a signal to start measurement by the range finder 4. When the range finder 4 confirms that the liquid level of the suspended fluid material W in the reservoir 2 has reached a predetermined height, the control means 91 sends a signal to close the inlet valve 6.

In the pressure measurement process S3, the pressure of the suspended fluid material W in the reservoir 2 is measured by the pressure gauge 3. Figure 6 shows the pressure measurement process S3. By simultaneously measuring the pressure using multiple pressure gauges 3, 3, ... arranged in a row in the height direction, the pressure distribution in the depth direction within the reservoir 2 is identified, as shown in Figure 6. Measurement by the pressure gauge 3 begins when the control means 91 sends a measurement start signal when the inlet valve 6 is closed. The measurement results of the pressure gauge 3 are sent to the data processing means 9.

In the material discharge step S4, the suspended fluid material W is discharged from the storage body 2. FIG. 7 shows the material discharge step S4. As shown in FIG. 7, the suspended fluid material W is discharged from the discharge port 22 formed in the lower part 21 of the storage body 2 by opening the discharge valve 8. When the measurement of the pressure of the suspended fluid material W in the storage body 2 by the pressure gauge 3 is completed, a signal to open the discharge valve 8 is sent from the control means 91, and the discharge of the suspended fluid material W from the storage body 2 is started. The suspended fluid material W discharged from the discharge port 22 by natural flow is transported to the temporary receiving tank T2 via the discharge pipe 7 (see FIG. 1). At this time, the distance meter 4 is used to measure the change over time in the height of the liquid level of the suspended fluid material W. The flow rate can be calculated from the change over time in the liquid level and the internal shape of the storage body 2. The measurement data of the distance meter 4 is transmitted to the data processing means 9 along with the elapsed time. The suspended fluid material W discharged into the temporary receiving tank T2 is pumped to the production tank T via the return pipe 71 as appropriate.

In the viscosity density calculation step S5, the viscosity and density of the suspension fluid material W are calculated. The viscosity and density are calculated or estimated using the pressure distribution and flow rate measured by the multiple pressure gauges 3, 3, .... The calculation of the pressure distribution and flow rate begins at the stage when the data processing means 9 receives data from the pressure gauges 3 and the distance gauge 4.
When calculating the density of the suspended fluid material W, first, the pressure difference between the measurements of the pressure gauges 3 arranged above and below is divided by the elevation difference to calculate the unit volume weight of the suspended fluid material W, and then this is divided by the acceleration of gravity (9.81) to calculate the density. The density of the suspended fluid material W is calculated for each layer, assuming that the space between each pair of pressure gauges 3 is a layer.

When calculating the viscosity of the suspended fluid material W, first, the flow rate of the suspended fluid material W is calculated based on the change in the liquid level over time. In this embodiment, since the internal space area of the main body (part other than the lower part 21) of the reservoir 2 is constant, the flow rate (change in the liquid level per unit time) is calculated by dividing the change in the liquid level by time. In this embodiment, the relationship between the flow rate of the suspended fluid material W and the flow value is determined in advance based on indoor tests and past data (see FIG. 8). FIG. 8 is a graph showing an example of the relationship between the flow rate and the flow value created based on the results of indoor tests and measurements at a plant. The flow value corresponding to the flow rate of the suspended fluid material W can be obtained by applying the measured value of the flow rate to the graph (approximation formula) in FIG. 8. Note that the flow rate is affected by the frictional force generated between the inner surface of the reservoir 2 and the suspended fluid material W, so it is preferable to measure the liquid level in a section with a constant internal cross section (cylindrical part in this embodiment) so that the effect of the frictional force is constant.

In the adjustment step S6, the suspension fluid material W is judged to have a predetermined quality based on the measurement results (calculation results) of the density and viscosity (flow value) of the suspension fluid material W, and the density and viscosity of the suspension fluid material W are adjusted as necessary. FIG. 9 shows an example of a method for displaying the measurement results. In the adjustment step S6, the target values of the density and viscosity of the suspension fluid material W (the range surrounded by the dotted line in FIG. 9) are set in advance, and it is judged whether the density and viscosity of the manufactured suspension fluid material W are within the target values. In this embodiment, as shown in FIG. 9, the relationship between density and viscosity is plotted, and the amount of water or the amount of soil or solidification material is increased so that the density and viscosity are within the target values. That is, if the measured density (density calculated in the viscous density calculation step S5) is excessively large compared to the target density, water is added to the manufacturing tank T to reduce the deviation. Also, if the measured viscosity (flow value calculated in the viscous density calculation step S5) is excessively small compared to the target value, soil or solidification material is added to the manufacturing tank T. In this embodiment, the addition of water to the production tank T or the addition of soil and solidification materials is performed automatically. That is, the data processing means 9 stores the target values for the density and viscosity of the suspended fluid material W in advance, and the data processing means 9 automatically compares the measurement results with the target values and transmits a signal to the control means 91 based on the comparison result.

According to the viscous density measuring device 1 of this embodiment and the viscous density measuring method using the same, the density can be calculated using the pressure distribution measured by the multiple pressure gauges 3, 3, ..., and the viscosity (flow value) can be grasped from the flow rate of the material. Therefore, the properties of the suspension fluid material W in the production tank T can be grasped in real time, and the quality of the material can be improved.
Furthermore, the viscosity density measuring device 1 is a relatively simple device and can be installed in the vicinity of the production tank T, so that the suspension fluid material W can be produced while checking its properties in real time on-site.
The viscosity/density measuring device 1 is capable of automatically measuring the properties of the suspension fluid material W, thereby reducing the effort required of the person performing the measurement.
Furthermore, by measuring the liquid level of the suspension fluid material W in the reservoir 2 using the distance meter 4, the flow rate of the suspension fluid material W can be measured without using a flow meter or the like.

Although an embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and each of the above-described components can be appropriately modified without departing from the spirit of the present invention.
In the above embodiment, the case where the storage body 2 has a cylindrical portion is described, but the shape of the storage body 2 is not limited and may be, for example, a square cylinder or a truncated cone.
In the above embodiment, the reservoir 2 is provided vertically, but the reservoir 2 may be inclined.

In the above embodiment, the pressure gauge 3 is provided inside the reservoir 2, but the installation location of the pressure gauge 3 is not limited. For example, only the sensing portion of the pressure gauge 3 may be provided facing the inside of the reservoir 2, and the main body of the pressure gauge 3 may be provided outside the reservoir 2.
In the above embodiment, a case has been described in which multiple pressure gauges 3 are arranged in a vertical row at a predetermined interval, but the arrangement and installation method of the pressure gauges 3 are not limited as long as the height position of each pressure gauge 3 is known.
The number of pressure gauges 3 is not limited as long as it is plural, and may be determined appropriately.

In the above embodiment, a laser range finder is used as the range finder 4, but the range finder 4 is not limited to a laser range finder, and for example, an ultrasonic range finder may be used.
Further, distance meters 4 may be provided as necessary. For example, the flow rate may be calculated based on the measurement results from a plurality of pressure gauges 3. That is, by determining that the liquid level of suspension fluid material W has passed through pressure gauge 3 at the time when the pressure of pressure gauges 3 arranged above and below becomes zero, the position of the liquid level of suspension fluid material W at each time can be grasped, and the flow rate can be calculated based on this.

In the above embodiment, the suspended fluid material W is supplied to the reservoir 2 through the inlet pipe 5, and the suspended fluid material W after measurement is returned to the production tank T through the outlet pipe 7, but the inlet pipe 5 and the outlet pipe 7 may be installed as necessary. That is, the supply of the suspended fluid material W to the reservoir 2 may be performed manually. Also, the suspended fluid material W in the reservoir 2 may be discharged into another container and then returned to the production tank T manually.
In the above embodiment, the inlet valve 6 and the outlet valve 8 are automatically controlled, but the inlet valve 6 and the outlet valve 8 may be opened and closed manually.

In the above embodiment, measurements are performed on suspended fluid material W that has been stirred to a uniform concentration in the manufacturing tank T, but the timing of the measurement (the timing of supplying the material to the storage body 2) is not limited, and may be performed, for example, before uniform mixing (immediately after the material is added to the manufacturing tank T or during the material mixing operation in the manufacturing tank T).
In the above embodiment, the spaces between pressure gauges are treated as layers and the density is calculated for each layer. However, the method of calculating the density is not limited to this. For example, an approximation curve may be obtained from the measurement values of multiple pressure gauges, and the density may be calculated from the slope of the approximation curve.

In the above embodiment, the reservoir 2 is connected to the side of the production tank T, and the suspended fluid material W in the production tank T is allowed to flow into the reservoir 2 by gravity, but the positional relationship between the reservoir 2 and the production tank T is not limited. For example, as shown in FIG. 10, the reservoir 2 may be disposed at a higher position than the production tank T, and the suspended fluid material W discharged from the reservoir 2 may be allowed to flow down into the production tank T via the discharge pipe 7 leading from the reservoir 2 to the production tank T. In this case, the supply of the suspended fluid material W from the production tank T to the reservoir 2 may be pressure-fed through the inlet pipe 5 by a pump 51 provided in the production tank T. It is preferable that the pump 51 is driven in conjunction with the opening and closing operation of the inlet valve 6.

Reference Signs List 1 Viscosity density measuring device 2 Reservoir 3 Pressure gauge 4 Distance meter 5 Inlet pipe 6 Inlet valve 7 Discharge pipe 8 Discharge valve T Production tank W Suspended fluid material

Claims (2)

A hollow reservoir having an inlet formed at an upper portion and an outlet formed at a lower portion;
a plurality of pressure gauges arranged in parallel along a height direction of the reservoir for measuring a pressure of the suspended fluid material stored in the reservoir;
and a distance meter for measuring the liquid level of the suspended fluid material in the reservoir . An inlet pipe extending from the mud storage tank to the inlet;
A discharge pipe extending from the discharge port to the mud storage tank;
an inlet valve provided at the inlet;
The viscosity/density measuring device according to claim 1 , further comprising: a discharge valve provided at the discharge port.

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