SU957083A1 - Device for determination of impurity concentration in liquid - Google Patents

Description

The invention relates to an analytical technique and can be used when measuring the relative concentration of a mixture of liquids with a close dielectric constant value and different capillary properties, for example, when measuring the concentration of gasoline in kerosene.

A device is known for measuring the concentration of impurities in a liquid by measuring its density, which contains a floating element, pea. a guiding change in the density of the medium, and a position indicator of the floating element Cl.

A disadvantage of devices of this type is the difficulty of using temperature and pressure conditions in a controlled environment (additional devices must be created to compensate for density changes), the accuracy of measuring the concentration of a mixture of liquids with similar density values and different coefficients of volume expansion is low, as in this case If the temperature of the mixture changes, the density meter records the change in concentration.

The closest to the technical essence of the invention is a device for determining the concentration of impurities in a liquid, which contains a container with a mark of the level of liquid in it and a capacitive coaxial dielectric constant sensor with cylindrical coaxial electrodes 123.

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A disadvantage of the known device is the low accuracy of measuring the concentration of impurities with a close dielectric constant value, for example, impurities of gasoline in kerosene.

15 Dielectric constants of gasoline and kerosene differ by 5%, which is within the measurement error of existing industrial designs of capacitive sensors, i.e.

20 recognition of gasoline and kerosene by known capacitive devices is difficult.

The aim of the invention is to improve the accuracy of measuring the concentration of impurities at similar values of the dielectric constant, such as impurities of gasoline in kerosene.

Claims (2)

The goal is achieved by the fact that a device for determining the concentration of impurities in a liquid, containing a container with a level indicator of the presence of liquid in it and a capacitive coaxial dielectric constant sensor with cylindrical coaxial electrodes, is provided with a pressure source, with the capillary gap . The lower part of which is set at the level of the liquid in the tank, and the upper part is connected by non-capillary pipes with a pressure source and a tank. The arrangement of the elements, the capacitor of the sensor relative to each other with a gap forming a cylindrical capillary, and the described installation of the sensor result in liquids with a close dielectric constant, but differing in surface tension coefficient, rising in the capillary to a significantly different height. . The elevation ratio in the capillary of gasoline and kerosene is 1: 1.8. Since the degree of filling of the capillary corresponds to a certain value of the sensor signal, the measurement accuracy is significantly increased, the detection of liquids in the pipeline is simplified. The presence of shut-off organs and non-capillary pipelines will allow both to carry out repeated measurements and reduce the influence of previous ones by blowing the capillary with an inert gas from the pressure source. The drawing shows the proposed device. The device contains a coaxial sensor 1 dielectric constant with cylindrical coaxial electrodes 2 and 3 and a secondary device 4. The sensor is mounted vertically on the tank 5 with a mark of the presence of fluid 6 inside it. The electrodes of the sensor are located relative to each other with a capillary gap forming the annular capillary p 7, the lower part of which is installed at the level of the liquid in the tank 5, and the upper part is connected by noncapillary pipelines 8 and 9 through the locking bodies 10 and 11 to the container 5 and the source Full time pressure 12. The device works as follows. Prior to measurement, in order to reduce the effect of previous measurements, valve 10 opens and communicates the cavity of the capillary 7 with the pressure source 12, while valve 11 closes. At the end of the purge, the valve 10 closes and the valve 11 opens. The liquid b from the investigated container 5 under the action of capillary forces rises in the capillary 7 to a height depending on the concentration of the impurity in the liquid with a different surface tension coefficient. Concentration is judged by the magnitude of the coax sensor signal. The use of a device for measuring the concentration of impurities in a liquid will simplify the process of recognizing liquids with similar dielectric constant and various capillary properties, such as gasoline and kerosene, and improve the accuracy of measuring the concentration of impurities of these liquids in each other, which will improve the quality of petroleum products. Apparatus of the Invention A device for determining the concentration of impurities in a liquid, containing {capacitance with a level mark for the presence of liquid in it and a capacitive coaxial dielectric constant sensor for a liquid with cylindrical coaxial electrodes, in order to improve the accuracy of determining the concentration of impurities equipped with a pressure source, the sensor electrodes are placed relative to each other with a capillary gap, the lower part of which is set at the mark of the level of liquid in it bones, and the upper is connected by noncapillary pipelines with a source, pressure and capacity. Sources of information taken into account in the examination of the USSR Copyright Certificate No. 454484, c. 01 N 9/10, 1973. 2. USSR author's certificate No. 480006, cl. C 01 N 27/22, 1974 (prototype). / 7 // 7 /// 7 /// U // 1 //// at ////////// // l / 7 /