SU1620931A1 - Device for determining content of gas in gas-liquid medium - Google Patents

Abstract

The invention relates to measuring technique and can be used to determine the concentration of gas in gas-liquid environments, for example, in the study of the cavitation properties of machine motors, in solving problems of applied hydrodynamics. The aim of the invention is to improve the accuracy of determining the gas content in gas-liquid environments by accounting for gas dissolved in a liquid. The device performs irradiation of the investigated volume of gas-liquid among ultrasonic focused waves, which ensure the release of dissolved gas in a free form, and irradiation of the resulting two-phase medium simultaneously with two ultrasonic waves at different frequencies. Using the receiver, the signal of the difference frequency is extracted, according to the level of which a controlled parameter is judged. 2 Il. with Ј

Description

The invention relates to instrumentation and can be used to determine the concentration of gas in gas-liquid environments, for example, in the study of the cavitation qualities of hydraulic machines, in solving problems of applied hydrodynamics.

The purpose of the invention is to improve the accuracy of determining the gas content in gas-redic acid media by accounting for gas dissolved in a liquid.

FIG. 1 shows a block diagram of a device for determining the gas content in gas-borne media; in fig. 2 - timing charts of the device.

The device contains sequentially connected oscillator 1 of video pulses and delay circuit 2, series-connected crystal oscillator 3, modulator A, power amplifier 5 and first acoustic emitter 6 of sound, serially connected second crystal oscillator 7, second modulator 8, second power amplifier 9 and a second acoustic emitter 10 in series connected receiving acoustic transform

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The receiver 11, the selective amplifier 12, the third modulator 13 and the recorder 14, connected to the generator clock 1 of the video pulses, are connected in series to the second delay circuit 15 and the driver of the 16 square pulses, whose output is connected to the control inputs of the first and second modulators 4 and 8, a third crystal oscillator 17, a fourth modulator 18, a third power amplifier 19 and a focusing acoustic emitter 20, and a second and third formers 21 and 22 rectangular pulses, the outputs of which are connected, are connected in series the control inputs are the fourth and third modulators 18 and 13, respectively, and the inputs are to the outputs of the video pulse generator 1 and the first delay circuit 2, respectively.

The device works as follows.

The generator 1 video pulses generates clock pulses 23 (Fig. 2). Continuous harmonic oscillations with frequencies E. and fn with high

of the quartz oscillators 3 and 7 are fed to the signal inputs of the modulators 4 and 8, the outputs of which form radio pulses that are amplified by the power amplifiers 5 and 9 and are emitted into the liquid under study by the radiators 6 and 10, the tracking period and the duration of the probing signals are determined the period of the clock pulses 23, delayed by the second delay circuit 15 by time C3ad, (24). At the output of the first generator of 16 rectangular pulses, a pulse of 25 duration is formed. At the beginning of the measurements, the back edges of the clock pulses 23 start the second generator of 21 rectangular pulses, at the output of which pulses 26 of duration and under the influence of which are generated from continuous harmonics with frequency f -. A personal generator 17, at the output of the fourth modulator 18, radio pulses 27 are formed, which are amplified by a third power amplifier 19 and are fed to the input radiating its focusing emitter 20. Under the influence of acoustic oscillations in the focal ob region of the focusing emitter

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20, dissolved gas is released. B

The next moment of time gas bubbles released during liquid degassing are simultaneously irradiated with signals 28 and 29 with frequencies f and f, emitted by radiators 6 and 10. The level of the scattered acoustic signal in a liquid with bubbles released during degassing is detected at a difference frequency (f) with the help of receiving a transducer 11 installed outside the zone of acoustic oscillations with frequencies Ј and fg, and a selective amplifier 12 connected via a third modulator 13c with a recorder input 14. To reduce the noise level received signals are gated over time. The selection of signals in time is carried out using the first circuit 2 delays triggered by the falling edges of the clock pulses 23 and generating video pulses 30 of duration t-hp and falling edges of which triggers the third shaper 22 of the square pulses. The latter generates video pulses 31 of duration, controlling the operation of the third modulator 13, which passes to the recorder 14 the signals of the 32 difference frequency, the levels of which carry information about the concentration of the dissolved gas in the liquid. The concentration of the dissolved gas in the liquid is determined from the recorded level of the received signals using a calibration curve.

The use of the invention in comparison with the known device provides an increase in the accuracy of determining the concentration of gas in a gas-liquid medium, since the proposed device, in addition to free gas, makes it possible to take into account gas dissolved in a liquid. The ability to determine the concentration of a gas dissolved in a liquid makes it possible, for example, to refine the methods for determining the cavitation properties of hydromayin.

Claims (1)

Invention Formula A device for determining the gas content in gas-liquid environments, comprising a series-connected video pulse generator and a delay circuit, a series-connected crystal oscillator, a modulator, 51 a power amplifier and a first acoustic sound emitter connected in series a second crystal oscillator, a second modulator, a second amplifier and a second acoustic emitter, and a receiving acoustic transducer in series, a selective amplifier, a third modulator and a recorder, characterized in that accuracy of determining the content of gas in gas-liquid environments, it is equipped with connected to the output of the generator of video pulses erzhki and 0 five sixteen a square pulse shaper whose output is connected to control inputs of the first and second modulators connected in series by a third quartz oscillator, a fourth modulator, a third power amplifier and a focusing acoustic emitter and a second and third shaper of the rectangular pulses whose outputs are connected to the control inputs of the fourth and third modulators, respectively, and the inputs are connected to the outputs of the video pulse generator and the first delay circuit, respectively. U bhjl U6 6 Ud 911 Phage. one Thebes. 2