SU1707515A1 - Method of determination of liquid vapor concentration in atmosphere - Google Patents

Abstract

The invention relates to instrumentation engineering, in particular to methods for determining the concentration of liquid vapors in the atmosphere, and can be used in industry and scientific research. The purpose of the invention is to simplify the method. Non-volatile substances dissolve in the test liquid and organize its outflow through the capillary at a flow rate lower than the flow rate from the open mirror in this capillary due to evaporation. The frequency of flow rate pulsations is recorded, according to which the concentration of interest is judged.

Description

The invention relates to instrumentation technology and can be used to determine the concentration of liquid vapors in an atmosphere with any composition.

There are known methods for determining the concentration of gases in the atmosphere: chemical, photoelectric, thermochemical, electrochemical, ionization. emission, emission and others.

All these methods have considerable complexity.

The closest to the present is - with the method of qualitative and quantitative determination of the composition of gas mixtures by mass spectral analysis of complex mixtures, and: even their individual components after separation. The accuracy of the results is controlled using standard mixtures prepared from pure gases.

The method is complicated and requires the use of special technical means of measurement, since for preliminary separation of the gas mixtures being analyzed, rectification, sorption by solid or liquid absorbers, mass transfer through semipermeable partitions, centrifugation, and chemical reactions are used. For other analogues, the separated components, after their separation by chemical reaction, are determined by photometric, photometric and other methods. The gases under investigation are often absorbed by solutions, which are then analyzed numerically, potentiometrically and voltamperemetrically.

In addition, the method has a significant error.

In any case, there is a loss of the investigated gases.

J

about 1

SL

SL

In some cases, gas analysis can be based on differences in the physical properties of the components — density, thermal conductivity, refractive index, etc.

Volumetric (volumetric and gauge) methods are also used in which the change in the respective volume and pressure of the components of the gas mixture is determined during various chemical reactions.

The aim of the invention is to simplify the method.

The method is carried out as follows.

The capillary radius is determined to allow fluid to flow out according to the formula

 ; & P-S RT &

de

R

I

-R "M

fluid viscosity; capillary length; the depth of the fluid in the channel; pressure drop along the length of the capillary;

capillary cross-sectional area; liquid vapor pressure; molecular weight of the fluid;

35

- universal gas constant;

- temperature;

- diffusion coefficient of liquid vapors in the atmosphere. 4Q

o

five

0

five

thirty

35

4Q

For a given liquid, they select - non-volatile additives and dissolve them in a liquid ;; (for example, a liquid is supplied to a vessel connected to a capillary, the other end of which goes into the atmosphere) and, over the length of the capillary, creates a differential pressure differential pressure to a given value, (PЈ is the capillary pressure), but not more than a condition is provided - fluid flow due to

Claims (1)

P less liquid flow due to evaporation. At a given mode of fluid flow through the capillary, the phenomenon of flow rate pulsation occurs, the frequency of which pulsations are proportional to the concentration of liquid vapor in the atmosphere. The pulsation period of the fluid flow rate is recorded, compared with the previously obtained calibrated dependence, and the concentration of liquid vapor in the atmosphere is determined. Invention Formula The method of determining the concentration of liquid vapors in the atmosphere, including the flow of the test liquid into the atmosphere and the measurement of its physical characteristics, distinguished by the fact that, to simplify the determination, non-volatile substances in the test liquid feed it into the atmosphere through the capillary a lower flow rate of the liquid from an open mirror in this capillary is due to evaporation, and the vapor concentration of a given fluid in the atmosphere is judged by the frequency of the pulsation of the flow rate of the test liquid through the capillary.