JPH0625727B2 - Fluid viscosity measuring device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a viscosity measuring device for a fluid, which is necessary for predicting a flow rate when pumping sand or sand by compressed air.

[Prior Art] Conventionally, for measuring the viscosity of a fluid, for example, as in the invention of JP-A-61-57833 relating to a continuous measurement method of coal / water slurry, a fixed section of a pipe for sending a slurry of coal and water is used. A pressure loss measuring instrument and a flow meter are placed, and the slurry is applied by applying the pressure loss detected by the pressure loss measuring instrument and the flow rate detected by the flow meter by circulating the slurry through the pipe to the Hagen-Poiseuille formula. There has been proposed a method for continuously obtaining the viscosity of.

Further, a method has also been proposed in which a bypass pipe having a thin pipe is provided from the pipe, a pressure loss measuring device and a flowmeter are installed in the thin pipe, and the viscosity of the slurry is obtained from the Hagen-Poiseuille equation.

However, in any of the above methods, the slurry is actually flowed in the laid pipeline for measurement, and there is a problem that the viscosity cannot be measured before laying the pipeline.

[Problems to be Solved by the Invention]

The present invention has been made to solve the above-mentioned conventional problems, and it is an object of the present invention to provide an apparatus capable of easily measuring the viscosity of a fluid before laying a pipeline for conveying the fluid. It was done.

[Means for Solving the Problems]

As a means for solving the above-mentioned problems, a fluid viscosity measuring device of the present invention comprises an open / close valve and a compressed air injection valve at both ends between two hermetically-sealed containers containing a sample whose viscosity is to be measured. And communicate with each other by a thin tube having a length of about 100 times the inner diameter, and a pressure gauge at each end of each end of the thin tube that is not affected, and the two pressure gauges A flow velocity meter or a flow meter is disposed between them, and compressed air injecting and exhausting valves are disposed above the respective containers.

It should be noted that each of the above-mentioned valves for injecting compressed air is connected to a compressed air supply source such as a compressor via a pipeline.

In the device having the above configuration, the sample to be measured is
It is possible to measure the viscosity of the fluid by repeating the operation of moving from one container to the other container by compressed air through a narrow tube and applying the obtained flow velocity and the pressure value at two points to the Hagen-Poiseuille equation. .

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a side view of a fluid viscosity measuring device according to an embodiment of the present invention, in which two sealed containers 11 and 12 for containing a sample whose viscosity is to be measured are provided. 12
The length l is between 100 times and 200 times the inner diameter D
It is communicated with a thin tube 13 having.

Next, pressure gauges 14A and 14B are placed at positions where there is no influence from the ends of the thin tube 13, that is, at positions away from each end by about 60 times or more of the inner diameter D of the thin tube 13, and these pressures are applied. Flowmeter 15 such as Doppler type between 14A and 14B in total
Or a flow meter is installed.

Further, the compressed air injection valves 3 and 4 and the compressed air discharge valves 5 and 6 are provided on the upper portions of the respective containers 11 and 12, and the opening / closing valves 1 and 2 and the compressed air injection valve 7 are provided at both ends of the thin tube 13. , 8 are provided.

Each of the compressed air injection valves 3, 4 and 7, 8 described above is provided with a line 9
Compressed air supply source such as compressor via
The compressed air injected into the thin tube 13 by opening the compressed air injection valves 7 and 8 provided at both ends of the thin tube 13 has a function of stirring the samples in the vessels 11 and 12 and the thin tube 13. To do.

Next, the procedure of using the fluid viscosity measuring device having the above-described configuration will be described. First, all valves, that is, the opening / closing valves 1 and 2, the compressed air injection valves 3 and 4, the compressed air discharge valves 5 and 6, and the compression valve are described. The air injection valves 7 and 8 are closed, a sample such as earth and sand whose viscosity is to be measured is put in the container 11, and both the containers 11 and 12 are closed with respective lids 11A and 11B.

Therefore, when the compressed air injection valve 3 and the opening / closing valves 1 and 2 are opened, the sample moves from the container 11 to the container 12 via the thin tube 13, but the flow velocity is changed while the sample is flowing through the thin tube 13. The pressure at two points on both ends of the thin tube 13 was measured with each pressure gauge 14A and 14B, recorded on a pen recorder, etc., and the flow velocity and pressure loss were applied to the Hagen-Poiseuille formula to determine the viscosity. calculate.

Next, close the open / close valve 2 and the compressed air injection valve 3,
Open the compressed air discharge valves 5 and 6 and containers 11 and 12 and thin tubes.
The compressed air in 13 is discharged as shown by arrow A.

Further, the compressed air discharge valves 5 and 6 are closed, the open / close valve 2 and the compressed air injection valve 4 are opened, and the sample is moved from the container 12 to the container 11 via the thin tube 13.

Therefore, the flow velocity of the sample while flowing through the thin tube 13
Then, the pressures at the two points are measured with the pressure gauges 14A and 14B, recorded on a pen recorder or the like, and the viscosity is calculated from the flow velocity and the pressure loss thereof in the same manner as described above.

The above operation is repeated until the viscosity of the sample becomes steady.

When the particle size distribution of the sample is wide, after opening the sample in the container 11 and before moving the sample, the open / close valve 1 and the compressed air injection valve 3 are closed, and the compressed air discharge valve 5 and the compressed air injection valve 7 are closed. It is necessary to stir and homogenize the sample by opening and and injecting compressed air into the container 11.

According to the above viscosity measuring device, it is possible to know the viscosity of the sediment when laying the pipeline for conveying the dredged sediment, and the calculation of the design such as the transportation distance and the volume of the sediment can be performed in advance. be able to.

In the Hagen-Poiseuille formula used to calculate the above viscosity, the viscosity η is the radius of the thin tube 13, the pressure loss of the thin tube 13 is ΔP, the length of the thin tube 13 is 1, and the flow rate in the thin tube 13 is Q. given that, , Where v is the flow velocity in the thin tube 13 and D is the inner diameter of the thin tube 13,
The flow rate Q in 13 is D = 2a, or Therefore, the viscosity η is Can be transformed into the above denominator On the X-axis, and the molecule Is plotted on the Y axis in FIG. 2, the viscosity η of the measured fluid can be obtained.

Here, in the case of Y = AX Newtonian fluid, since the Y intercept is 0, the viscosity diagram can be obtained by measuring once, while in the case of Y = AX + B non-Newtonian fluid, the above is repeated several times. A line diagram is obtained by measuring and plotting.

〔The invention's effect〕

According to the fluid viscosity measuring device of the present invention described above,
Since the viscosity can be measured without using the pipe line laid to convey the fluid, it is possible to easily predict the flow rate when the dredged soil is transported by the pump or the compressed air in the pipe. Has the effect of becoming.

Further, since compressed air is used, it is more economical than other means such as a piston pump, and there is an advantage that the compressed air can be used for stirring for homogenizing the sample.

Further, since the sample can be repeatedly measured, the time dependence of the sample can be obtained by measuring the time until the sample becomes stationary.

[Brief description of drawings]

FIG. 1 is a side view of the arrangement of a fluid viscosity measuring device according to an embodiment of the present invention, and FIG. 2 is a diagram of the viscosity obtained by measuring with the device of FIG. 1, 2 ... open / close valve, 3, 4 ... compressed air injection valve, 5, 6 ... compressed air discharge valve, 7, 8 ... compressed air injection valve, 11, 12 ... container, 13 ... thin tube, 14A, 14
B ... pressure gauge, 15 ... velocity meter, D ... inner diameter, l ... length.

Claims (1)

[Claims] 1. An open / close valve is provided at each end between two closed containers for containing a sample whose viscosity is to be measured, and a thin tube having a length of about 100 times the inner diameter or more is connected to each other. A pressure gauge is placed at a position where there is no influence from each end of the thin tube, and a velocity meter or a flow meter is arranged between the two pressure gauges, and compressed air is further provided above each vessel. Fluid viscosity measuring device with valves for injection and discharge.