SU832398A1 - Device for sampling gas samples liberated from liquid and introducing them into analyzer - Google Patents

Description

(54) DEVICE FOR THE SELECTION AND INPUT OF SAMPLES OF GAS ISOLATED FROM LIQUID TO ANALYZER

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The invention relates to a technique for studying the physicochemical properties of liquids and can be used to conduct various studies to determine the effect of concentrations of gases dissolved in liquids on their physicochemical properties, as well as to control the composition and amount of gases dissolved in liquids.

During the operation of modern machines, especially supersonic aircraft, it is often necessary to control the composition and amount of gases dissolved in liquids. In addition, such a need arises in the study of the effect of dissolved gases on the properties of chemicals.

A device dp selection and entry of oxygen dissolved in the fuel in a analyzer containing a reaction cell, the dosing volume 111, is known.

The disadvantages of the known device are the low accuracy of the measurement, the considerable duration of the analysis.

The closest to the invention in its technical essence and the achieved result is a device for sampling and introducing gas samples emitted from the liquid into the analyzer, containing the dosing volume, sampler, fluid injection unit with a rubber membrane installed on the gas line in front of the analyzer and cranes G2 switches ..

The disadvantages of this device are the ineffective accuracy of measurement with due to the fact that dissolved gases in the excretory cell are not completely separated and the analyzed gas mixture is partially lost during sluicing and due to parasitic volumes in the gas mixture supply system from the excretory cell to the chromatographic columns.

In addition, it requires the use of an expensive and cumbersome vacuum assembly and control vacuum devices, which leads to an increase in analysis time (since the analysis is carried out at a well-defined vacuum pressure) and does not allow the creation of a portable device. The purpose of the acquisition is to accelerate the sampling and input. This is achieved by the fact that in the device dp of sampling and, injecting gas samples, a VBVdemog from a liquid, into the analyzer containing the dosing volume of the sampling unit, the sample input of the liquid with a rubber membrane, installed on the gas line and analyzers switches, dosing volume and fluid injection unit, installed in series on the bypass gas line, equipped with two switching taps at the inlet to the output of the third switching switch installed on the main gas line to meme by the specified switching taps l 1m, and the sampler is made in the form of a syringe with a needle bent at an angle of 90 ° with respect to the main axis of the body of liquid gases in the dosing volume. FIG. 1 shows a device for carrying out a method for determining the concentration of dissolved gases in a liquid, F1-p. 2 - the press of the precipitate and the entry of gases dissolved in liquids. A device for carrying out the method for determining the concentrations of gases dissolved in a liquid tank consists of an input sample from sample 1 of dispensing volume 2, taps 3 5, separation column 6, detector 7 and recording unit 8. The edge 4 of the curtain pipeline is the gas of the chromatograph carrier. The valve 5 connects the carrier gas pipeline, overlaps with the valve 4, with the input of the sample and the inlet of the dosing volume. A crane 3 connects the gas-gas pipeline, beyond the overlapping edge 4 to the outlet of the dosing volume. Valves 3-3 can be replaced with flexible hoses and clamped with Coca clamps. As a sampler, use a conventional medicine — a YUG syringe. The operation of the device is as follows. Carrier gas. Before the start of the analysis, it is passed through the dosing volume, clearing it of other gases. Crane 4 is closed, valves 3 and 5 are open, after this 1X1 valves 3 and 5 are closed at the same time and then valve 4 is opened, the iaa carrier passes along the main line. In the dosing volume there is a carrier gas under pressure equal to the operating pressure in the chromatograph line. With the help of a medical syringe, take a sample of the test liquid with a needle and pierce the flexible membrane of the sample introduction unit. The syringe is positioned vertically (Fig. 3, a). The pressurized carrier gas displaces the syringe piston and blows the fluid sample. By knowing the pressure of the gas-carrying l in the dosing volume and specifying the required amount of carrier gas for deep release of dissolved gases from the liquid, you can calculate the necessary volume of the dosing device where V is the volume of the dosing device, p is the atmospheric pressure, kg / cm,: Р working pressure in chromatograph system, kg / cm-; - the working volume of the syringe, cm. After the pressure in the dosing volume is equal to the pressure in. the syringe and is equally atmospheric, the sprits are rotated 9O (Fig. 3, b) to ensure that the liquid sample does not get into. dosing volume, and hold the gas mixture to equilibrium. At that, the syringe is turned 90 ° into the lower position (flash% 3, c), the valve 4 is closed, the valve 3 is opened (Fig. 2). The pressure in the system starts to decrease, and at that time the gas sample released is introduced into the carrier gas pkn1o, the sprays are removed from the sample introduction unit and the valve 5 is opened. The carrier gas carries the evolved gas CNjecb to the chromatographic column after which the composition and the quantity of (A) gases are determined, E1b1X is introduced into the chromatograph. A small part of the solution of the gases remains in the liquid (A / j), therefore the total amount of the dissolved gas can be determined by the formula A A. The amount of gas remaining in the liquid phase should be calculated using the formula of Henry A. g. K-P.,

where K is the solubility coefficient, P is the partial pressure of gas above the liquid in the syringe before entering the gas phase.

Partial pressure P is determined according to calibration schedules, knowing the amount of gas supplied to chromatograph A. Evaluation of the error of the method, after conducting a series of xperimen-Lev, shows 1 relative error in determining the concentration of gases, for example, in the fuel sample does not exceed 1.5 %

The use of the invention provides the following advantages:

a) the measurement accuracy is more than doubled;

b) the device is simplified by eliminating vacuum equipment with vacuum control devices and a number of elements (excretory cell, crane, parasitic volumes);

c) the analysis time is reduced to;

2 minutes;

d) it becomes possible to create a portable

concentrations of gases dissolved in the liquid. Formula and-a frenzy.

APV device for sampling and introduction of gas sampled from a liquid

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S analysis in Md containing D5xznrovyy volume, sampler, fluid injection unit with rubber membrane, mounted on. The gas line of the analyzer and the KpaHbt switches, characterized in that, in order to speed up the sampling input, the dosing volume and the taste sampling input unit are installed in series on the bypass gas line equipped with two input and output switches, the third crane switch installed on the main gas line between these two switch taps; and the sampler is made in the form of a syringe with a needle bent at an angle of 9 ° relative to the main axis of the body.

Sources of information taken into account in the examination

1. Astafyev, V.A., et al. Chemical method for determining fuel dissolved in oxygen. 3- scientific and technical science}))., Kiev, 1973.

2; USSR author's certificate N9 371510, Kn.QolN 1/22, 1971 (prototype).

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Claims (1)

Claims Device For sampling and sampling gas emitted from a liquid 33239S 6, into an analyzer containing a dosage volume, a sampler, a fluid sample inlet unit with a rubber membrane mounted on. analyzer gas line and switch taps, characterized in that, in order to accelerate sampling and injection, the dosing volume and the liquid sample inlet node are installed in series on the bypass gas line equipped with two switch taps at the inlet and outlet, a third * switch tap is installed on the main gas line between the two switch taps, · and the sampler is made in the form of a syringe with a needle bent at an angle of 9 O ⁴⁷ relative to the main axis of the housing.