SU1431818A1 - Method and apparatus for wetting gaseous mixtures under dynamic conditions - Google Patents

Abstract

The invention relates to a gas analytical technique and can be used in any area of the national economy by controlling the air environment. It provides a simplification of the process of moistening gas mixtures while maintaining the quantitative composition of the mixture. Device for wet- No gas mixture contains a flow booster 1, a desiccant column i (L

Description

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2, a filter 3, a dispenser 4 and a humidification system. The latter includes a thermostatic mixing chamber, a container 7 with water, a pump 8 and a humidifier 9. The humidifier is made in the form of a heated metal tube 10 ,. in which, with a gap of 0.05-0.10 mm, the markers are a solid rod 11. The open end of the tube is placed in the mixing chamber. The method of wetting gas mixtures is carried out as follows.

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The dried air flow in the dispenser is mixed with the dosed micro-amounts of gases. The resulting mixture is fed to a humidifier, in which dry, saturated steam is obtained. Steam is supplied in quantities corresponding to the moisture content of the mixture. A mixture with a gas concentration of almost the same in dry and wet mixtures is obtained. 2 sec. f-ly, 1 ill., 2 tab.

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j The invention relates to gas-jet technology, namely to methods of preparing gas mixtures for checking methods and means of measuring air pollutants, and can be used in any branch of the national economy that carries out air monitoring.

The purpose of the invention is to simplify the process of wetting the mixtures by eliminating the operation of controlling the humidity and concentration of the dosed gases and vapors during - (maintaining the quantitative composition of the mixture.

; The drawing shows schematically a device for moistening gas mixtures.

The device contains a flow booster 1, combined with a drying column 2, a dust filter 3, a dispenser 4. The humidification system includes a mixing chamber 5 placed in a thermostat 6, a water tank 7, a pump 8 for supplying it, a humidifier 9 including a heated metal tube 10 in which a solid rod is placed with a gap of 0.05-0.10 mm .11. The tube is heated by a heater 12. The opposite end of the tube is placed and the mixing chamber.

The location of the open end of the metal tube in the mixing chamber of the air flow stub prevents it from cooling and condensing the dry steam escaping from the humidifier leading to a decrease in the concentration of the dosing component and water vapor in the gas mixture.

Example 1 With the aid of the booster 1, the flow through the drying column 2 and the dust filter 3 supplies air with a velocity of 2 dm / min through the metering device 4, in which acetone vapors are continuously metered into the air. The mixture of gases enters the displacement chamber 5, placed in a water thermostat 6 with a temperature, and at the outlet to

to the consumer. The flow path of the gas mixture is indicated by arrows in the drawing.

To wet dry gas mixture

supply water from tank 7 by pump 8 at a rate of 54.0 mg / min to humidifier 9 through a brass tube 10 (inner diameter 1.0 mm, outer 2.0 mm) with a continuous rod of soft copper wire (diameter 0 , 80 mm). A 6 W electric heater 12 powered by a 28 V mains is used. Dry gas formed in the gap (0.10 mm) when steam enters chamber 5 where it is mixed with a dry gas mixture containing acetone at a temperature of a water thermostat - 30 + 0,

The concentration of acetone in dry and moistened gas mixtures is determined by the spectrophotometric method, and the content of water vapor is determined by the gravimetric method. J

Concentrations of acetone in dry and humidified to 90% with gas mixtures are almost the same and are 97.8 and 97.5 mg / m, respectively.

Similar results are obtained when dosing, instead of acetone, other volatile substances whose concentration

determined by photocolorimetric methods.

At the specified water supply to the coagulant 9 (54.0 mg / min) in a 2 dm gas mixture, it was determined to be 54.3 mg and 53.8 mg with a gap of 0.05 mm after inserting copper wire with a diameter of 0 into the tube 10, 90 mm.

The uniformity of boiling water in the humidifier 9 and the continuity of the jet of dry saturated steam are observed to direct the steam to the glass. At the same time, the fogging spot remains fixed.

An increase in the gap results in an uneven jerky nature of the boiling and discontinuity of the jet of outgoing steam. Reducing the gap is undesirable in the form of increased resistance to the flow of water entering the humidifier.

The test results are summarized in table. one.

Example 2. Conditions are the same as Example 1.

The pump 8 smoothly regulates the flow of water to the humidifier 9 (a gap of 0.05 mm) in accordance with the different moisture content installed in the dry gas mixture passing through the thermostatically controlled mixing chamber at its flow rate 2.

The test results are presented in Table. 2, from which it can be concluded that the quantities of water vapor introduced into the dry gas mixture, determined by the gravimetric method, differ from the specified humidity by no more than 2%.

Claims (2)

Invention Formula 1, Method for moistening gas mixtures under dynamic conditions, including-45 0 five 0 0 Drying the air stream, mixing it with metered micro-quantities of gases and moistening the mixture, characterized in that, in order to simplify the process of moistening gas mixtures by eliminating the operation of controlling humidity and concentrations of metered gases and vapors while maintaining the quantitative composition of the mixture, the moistening of the mixture is carried out by supply of dry dried steam in quantities corresponding to the established moisture content of the mixture. 2. A device for moistening gas mixtures under dynamic conditions, comprising a flow booster, a drying column, a metering unit and a moistening system in the form of a container with water, a pump for supplying it, a humidifier, a mixing chamber, characterized in that, in order to simplify the moistening process gas mixtures, the humidifier is made in the form of a heated metal tube with a solid rod inserted into it, the gap between the tube and the rod being 0.05-0.10 mm, and the open end of the tube is located in the mixing chamber. Table 1 Note, Average data from 4 determinations of the amount of water vapor in the gas mixture. Table 2