SU491037A1 - Level meter for electrically conductive liquids - Google Patents

Description

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The invention relates to devices for controlling liquids and can be used in the mining, chemical and other fields of industry for measuring the level of conductive liquids with impurities that precipitate.

A level meter of electrically conductive liquids is known, comprising an excitation coil and a receiving circuit made in the form of rectangular frames in an insulating material body and spaced against each other.

However, such a device works only with high electrical conductivity of a liquid, is used only to control the level of liquid metals and is not applicable to work with solutions of salts and electrolytes, whose specific conductivity can vary over wide limits depending on concentration.

The aim of the invention is to expand the range of application and reduce the measurement error due to a change in the electrical conductivity of the medium.

This goal is achieved due to the fact that in the proposed meter, the receiving circuit is made in the form of electrodes, which are placed on the outside of the body forming the excitation coil and forming a closed coil with the liquid.

FIG. Figures 1 and 2 show variants of the layout of the proposed device.

In the reservoir 1 with the liquid, the excitation coil 2 is vertically placed. It is made in the form of a rectangular frame and placed in the casing 3 of insulated material, along the outer ones of which are mounted stainless steel electrodes 4 connected by insulating wires 5 to the indicator 6.

The device works as follows.

Variable magnetic notes created

coil 2, permeates the fluid contour bounded by the sections of supply wires a, b, c, scaled along the bottom of the reservoir, in a mist-plane, perpendicular to the plane of the drawing, (1, the bends and dj electrodes and the surface of the fluid

cf. Under the influence of this flow in the circuit, an induced emf arises, leading, in turn, to the appearance of alternating voltage on the electrodes 4, the effective value of which is indicated by U.

The value of U will be the greater, the larger the area of the circuit, t. C. volume: more liquid level / ;. Consequently, the proposed device realizes the value of li li in voltage /, measured by the indicator 6 with a large input :: s. resistance.

The magnetic field of eddy currents arising in the fluid enveloped in the circuit demagnetizes the field of the excitation coil. However, for the practical values of the electrical conductivity of liquids, the demagnetizing effect of these currents is insignificant, and therefore the output voltage of the proposed device over a wide range does not depend on the electrical conductivity of the controlled fluid.

FIG. Figure 2 shows another variant of the device that differs from the previous one in that the recording device is connected to the upper ends of the electrodes. In this case, the voltage will be the greater, the larger the contour area abefdc, i.e., the lower the level h.

The ratios on the electrodes of the receiving circuit and the change in the specific conductivity of the medium slightly affect the magnitude of the output voltage, which depends on the position of the liquid level and the input resistance of the indicator, the value of which should be much greater than the resistance of the liquid between the electrodes, which is easily achieved by using compensation-type devices.

Subject invention

A level gauge of electrically conductive liquids, comprising an excitation coil made in the form of a rectangular frame and placed in a vertically disposed case of insulating material, a receiving circuit and an indicator connected to it, characterized in that in order to extend the range of application and reduce the measurement error of variation the electrical conductivity of the medium, the receiving circuit is made in the form of electrodes placed along the outer forming of the housing of the excitation coil and forming a closed coil with the liquid .

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