JPH0726926B2 - Device for measuring the concentration of snow in snow-water mixtures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is used in the technical field of snow and snow, or the technical field of air conditioning and refrigeration.

[Conventional technology]

Examples of conventional snow concentration measurement techniques include “Fluid engineering problems in hydraulic transport of snow”, Proc. Of the 6th Multiphase Flow Symposium, Flow mechanism and flow characteristics of multiphase flow, P62
~ 63, the calorimetric method, the centrifugal dehydration method, the single tube method, the stirring resistance method and the like were used.

[Problems to be Solved by the Invention]

Conventionally, the above-mentioned various methods have been used, but each has a characteristic that is not practically convenient.

That is, since the calorimetric method and the centrifugal dehydration method are methods of collecting a sample, continuous measurement is impossible and at the same time, a lot of time and effort are required for the measurement. The single pipe method is a method in which the hydraulic gradient in a vertical pipe is measured in the middle of a pipe that transports a mixture of snow and water, so continuous measurement is possible to some extent, but the magnitude of the flow velocity in the pipe can be measured. There was no choice but to be restricted by the location and the shape of the measurement part. The agitation resistance method allows continuous measurement and is less restricted in terms of measurement location, but due to the structure that rotates the ring in the snow-water mixture, it is necessary to take measures so as not to cause blockage in the pipeline. Met.

The inventor has found a practical and applicable method that solves the difficulties inherently associated with these conventional methods.
That is, the present invention is capable of continuous measurement in real time, measurement at any place regardless of whether it is in a pipe or in a tank, and may cause a blockage in a pipe line. By not reducing the shape of the electrode of the detection part without having a protrusion, it is possible to measure the local concentration,
An apparatus for measuring the concentration of snow in a snow-water mixture is provided.

[Means for Solving the Problems]

The present invention will be described below with reference numerals attached to the drawings for easy comparison with the drawings showing an example.

In a measuring device for measuring the concentration of snow or ice pieces in a snow / water mixture in which natural or artificial snow or ice pieces are mixed with water, a first electrode 1 for detecting the conductivity of the snow / water mixture is used. The conductivity detection device A, which is installed oppositely, the conductivity detection device B, which is provided with the second electrode 2 for detecting the conductivity of only the water or liquid phase in the snow water mixture, and the conductivity detection device A, The ratio of the conductivity of the snow-water mixture to the conductivity of the water or liquid phase detected by the conductivity detector B is calculated, and the concentration of snow or ice pieces in the snow-water mixture is calculated from this ratio. The present invention relates to a device for measuring the concentration of snow in a snow-water mixture, which comprises a concentration output device 3 using a conductivity method for calculating and displaying or outputting.

Further, the present invention relates to a device for measuring the concentration of snow in a snow-water mixture, characterized in that the second electrode 2 is housed in a case 5 provided with a net, a grid, a slit or a perforated plate 4 on at least one side. is there.

In the concentration output device 3, the ratio of the conductivity of the snow water mixture detected by the conductivity detecting device A to the conductivity of only the water or liquid phase detected by the conductivity detecting device B is converted into an analog circuit or a digital circuit. And the concentration value of the snow or ice pieces in the snow-water mixture calculated from this ratio, and displaying or outputting in real time the concentration output device 3 using the conductivity method. The present invention relates to a device for measuring the concentration of snow in a mixture.

[Work]

The present invention utilizes the so-called conductivity method, and the principle and main points when this conductivity method is used for measuring the concentration of snow in a snow-water mixture are as follows.

The water in the snow-water mixture should be natural water,
Its conductivity is of the order of 10-100 μS / cm. On the other hand, snow or ice pieces are solids that are almost non-conductive, and their conductivity is on the order of about 10 ^-3 μS / cm, and their ratio is extremely large. From this, the conductivity of the snow-water mixture becomes smaller as the concentration of snow becomes higher, and conversely, the conductivity becomes closer to that of water only as the concentration of snow becomes smaller. Therefore, if both the conductivity of water alone and the apparent conductivity of the snow-water mixture can be measured, the snow concentration can be determined by comparing them.

In the present invention, the electrical conductivity of the snow-water mixture is detected by the electrical conductivity detecting device A provided with the first electrode 1, and the electrical conductivity of the water or liquid phase is obtained by the electrical conductivity detecting device B provided with the second electrode 2. Only the conductivity of the snow is detected, and the concentration output device 3 calculates the ratio of these two to convert it to the concentration of snow, and the concentration of snow in the snow-water mixture is displayed or output.

When the second electrode 2 is housed in a case 5 provided with a net, a grid, a slit or a perforated plate 4 on at least one side and the snow-water mixture is dipped or brought into contact with it, snow or the like will be removed from the case 5.
Since it does not enter inside and does not intervene between the second electrodes 2, the conductivity of only the water or liquid phase can be detected.

〔Example〕

It is an example of measuring the concentration of snow in the middle of the flow path,
FIG. 1 shows an example in which the conductivity detecting device A and the conductivity detecting device B are provided in the concentration output device 3. First electrode 1
Is a metal plate that is installed so as to face the inner wall 6 of the flow path, and enables measurement without providing protrusions that may obstruct the flow in the pipeline. It is an electrode for detection. The second electrode 2 is an electrode for detecting the conductivity of only water or a liquid phase, and is installed in the vicinity of the electrode shown in FIG. A structural example of the second electrode 2 is shown in FIG.

The conductivity detecting device A having the first conductivity measuring circuit 7 as a main part and the conductivity detecting device B having the second conductivity measuring circuit 8 as a main part in the concentration output device 3 respectively include the first electrode 1 and By passing an alternating current of a certain magnitude between the electrodes of the second electrode 2, the electrical resistance of only the snow-water mixture or the water or liquid phase present between the electrodes is measured, and the magnitude of each conductivity is measured. It has a function to obtain the output corresponding to.

The calculation / output / display circuit 9 also has a function of calculating the ratio of the two outputs, calculating the concentration of snow or ice pieces, and outputting or displaying the result.

The cross section of the measuring duct 10 of the embodiment shown in FIG.
The first electrode 1 has a size of × 50 mm, and is composed of two 50 mm × 50 mm stainless steel thin plates, and the electrode constant is about 0.14 cm ⁻¹ . The second electrode 2 has an area of about 2 cm ²
The stainless steel plates are placed facing each other at an interval of 5 mm, and the electrode constant is about 0.22 cm ^-1 . A 5 kHz, 25 μA sine wave current is applied to each electrode to measure the electrical resistance.

FIG. 3 shows the relationship between the concentration of snow in a snow water mixture obtained by mixing tap water and rough snow and the ratio of electrical conductivity. Second electrode 2
The resistance value of the liquid phase measured by 26KΩ, the conductivity is 8.6μS / cm,
When the snow concentration is, for example, 57%, the resistance value measured by the first electrode 1 is 45.8 KΩ, the conductivity is 3.0 μS / cm, and the conductivity ratio is 0.35.

Further, FIG. 4 shows a state in which a snow-water mixture in which the concentration of snow continuously changes is flown through the measuring duct 10.

If the electrodes are small and portable, the local concentration in the snow-water mixture can be measured. An example of the structure of the electrode in that case is shown in FIG. In this example the first electrode 1 has a diameter
The electrode constant is about 0.42 cm ^-1 with 30 mm stainless plates facing each other at intervals of about 30 mm. Further, in this embodiment, the second electrode 2 has an inner diameter as shown in FIG.
A stainless steel rod with a diameter of 0.9 mm is installed inside a stainless steel tube with a length of 4 mm and a length of 9 mm, and the electrode constant is about 0.23 cm ^-1.
Is. With this electrode, it is possible to measure the concentration distribution of snow with a resolution equivalent to the volume between the first electrodes 1.

In the figure, reference numeral 11 is a connector pin, 12 is an electrode plate support,
13 is a stem, 14 is a cable, and 15 is a mounting bracket.

〔The invention's effect〕

Since the present invention is configured as described above, the concentration of snow in the snow-water mixture can be continuously measured in real time. Therefore,
When combined with other control equipment, more rational handling of snow and ice chips becomes possible than in the prior art. Furthermore, in the field of research, development, and design of the transportation equipment, it is possible to measure the local concentration, and it is possible to measure the concentration of snow in the snow-water mixture, which has an excellent effect not seen in the prior art. It becomes a device.

[Brief description of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic configuration diagram showing a basic configuration showing the principle of the present invention.
The figure is a perspective view in which the details of the second electrode of FIG. 1 are cut away, and FIG. 3 shows that the ratio of the conductivity of the snow-water mixture to the conductivity of its liquid phase corresponds to the concentration of snow. FIG. 4 is a measured graph when the concentration of snow continuously changes, FIG. 5 is a perspective view showing another example of the electrode configuration for measuring the local concentration, and FIG. FIG. 6 is a perspective view in which a detail of a second electrode in FIG. 5 is cut away. A ... conductivity detector, B ... conductivity detector, 1 ...
1st electrode, 2 ... 2nd electrode, 3 ... concentration output device,
4 ... Net, grid, slit or perforated plate, 5 ... Case

Claims (3)

[Claims] 1. A measuring device for measuring the concentration of snow or ice pieces in a snow / water mixture in which natural or artificial snow or ice pieces are mixed with water. 1
Conductivity detector A having the electrodes of FIG. 2 installed, a conductivity detector B having a second electrode for detecting the conductivity of only the water or liquid phase in the snow water mixture, and the conductivity detector A The ratio of the conductivity of the snow water mixture detected by the conductivity detector to the conductivity of only the water or liquid phase detected by the conductivity detector B is calculated, and the snow or ice in the snow water mixture is calculated from this ratio. A device for measuring the concentration of snow in a snow-water mixture, comprising a concentration output device that uses a conductivity method to calculate and display or output the concentration of a piece of snow. 2. A net, a grid, and a second electrode on at least one side.
The device for measuring the concentration of snow in a snow-water mixture according to claim 1, which is housed in a case provided with a slit or a perforated plate. 3. A ratio between the conductivity of the snow-water mixture detected by the conductivity detector A and the conductivity of only the water or liquid phase detected by the conductivity detector B is calculated by an analog circuit or a digital circuit. 2. A concentration output device using a conductivity method for calculating the concentration of snow or ice pieces in a snow-water mixture from the value of this ratio and displaying or outputting in real time. A device for measuring the concentration of snow in a mixture of snow and water.