SU783654A1 - Method of measuring liquid surface tension - Google Patents

Description

one

The invention relates to the field of measurement technology, in particular, to aerohydrodynamic methods for measuring the surface tension of liquids, and can be used in various industries to measure the composition and properties of liquids by the magnitude of their surface tension.

A known method for measuring surface tension is based on measuring the maximum gas pressure during the formation (and subsequent tearing) of a bubble at the end of a capillary tube lowered into a liquid, to which 15 gas is supplied. The disadvantage of this method is its unsuitability for measuring the surface tension of viscous liquids.

The closest technical solution is a method for measuring the surface tension of liquids, which consists in that a nozzle at a nozzle located above the surface of the liquid in the measuring tank is measured with a constant flow rate formed by the action of a gas jet in a liquid, and judging by the height of the wake, the surface tension of the liquid is judged.30

The known method allows the measurement of the surface tension of viscous liquids.

Its disadvantage is the difficulty of measuring the height of the trace in opaque liquids and, as a consequence, the accuracy of the measurement is low.

The aim of the invention is to improve measurement accuracy.

For this, the nozzle is installed in the bottom of the measuring capacitance, which is filled with a controlled fluid until a gas oscillation, a self-oscillation fluid, occurs in the system, after which the volume of the supplied fluid is measured, judging by the magnitude of which the surface tension of the fluid is judged.

To clarify the method, the drawing shows an installation diagram for its implementation.

The installation includes a measuring burette 1 filled with a controlled / liquid. bone, with a tap 2, measuring tank 3, in the bottom of which a nozzle 4 is installed, at the entrance of which through the flow meter 5 and the gearbox 6 compressed air or inert gas is fed.

Claims (1)

To measure the surface tension of the liquid, compressed air is supplied to the nozzle 4. The flow rate is fixed, the value of which is determined with the aid of radar 6 and monitored by the flowmeter 5. The initial volume of liquid in the measuring burette 1 is recorded. From burette 1 by turning the tap 2 When a liquid flows, its level in the measuring tank 3 increases. Gazov. The jet coming out of the nozzle 4 forms a trace 7 in the incoming liquid. A gas jet transition — a liquid from a steady state, when the surface of the trace is not subject to a periodic change, into the self-oscillating mode starts when the liquid reaches a certain value in the measuring capacitance associated with noaepxHOC HfcJM tension. Thus, during the implementation of the process, the liquid is supplied to the burettes 1 in the measuring tank 3 until the next 7 formed by the gas branch in the incoming liquid retains its stable shape. ; It is possible to detect the moment of the beginning of self-oscillations S to the system-gas jet-liquid bone by indicating the start of pulsations of gas flow at the outlet of the gas channel formed by a gas jet through a layer of liquid or by means of indicating the start of pulsations of gas flow in the gas supply tube the sensitive element, for example, the microphone, into the zone of action of the jet coming out of the gas channel. In the second case, oscillations are easily detected by a change in the readings of the flow meter with variable or constant erepada pressure. gas stream As soon as a liquid in the system oscillates, the flow of the liquid is stopped by turning the crane 2, after which the volume of liquid supplied to measuring tank 3 from measuring burette 1 is measured. In terms of volume, the liquid contains about its surface tension. Using the proposed method of measuring surface tension will allow the rG15} to improve the measurement accuracy of viscous liquids. The measurement process can be easily automated. Claims The method of measuring the surface tension of liquids by applying a gas stream / outlet with a constant flow from the nozzle onto the fluid in the measuring tank and measuring the height of the wake formed by the gas jet in the fluid, in order to increase measurement accuracy, the nozzle is installed in the bottom of the measuring tank, which is filled. the controlled fluid until a gas jet appears in the system is a self-oscillating fluid, after which the volume of the supplied fluid is measured, the magnitude of which determines the surface tension of the fluid.