RU2333480C1 - Tester for toxic gas control analytical instruments - Google Patents

Abstract

FIELD: metrology.

SUBSTANCE: tester for toxic gas control instruments incorporates a casing with a fastening, sealing and thermostating units, a cover, an inlet and outlet pipes with unions and a batcher. The said batcher represents a Petri absorber with its input pipe being terminated in an end face ball-like surface with through holes and connected with the inlet pipe, while the said absorber side pipe is connected, via a filter, with the outlet pipe.

EFFECT: compact, portable and safe device allowing testing gas analysers to be used at gas weapons destruction objects.

3 dwg

Description

The invention relates to measuring equipment, namely, to methods and devices for ensuring the operability of gas analyzers. In addition, it relates to the field of analysis of the air environment by determining its chemical and physical properties.

A device is known for ensuring the operability of a gas analyzer (RF patent No. 2221240 dated 01.10.2004 "A method for ensuring the operability of a gas analyzer", IPC G01N 27/00). In it, a Peltier thermoelectric module is fixed on the electrochemical sensor and temperature sensors are placed on the path of the gas air flow. At the same time, the temperature of the electrochemical sensor and gas are measured and, using the information processing device, controller and amplifier, a control effect is generated on the Peltier thermoelectric element proportional to the direction and current strength through the Peltier thermoelectric element, which, depending on the direction of the current, heats or cools the electrochemical sensor.

The disadvantage of this device and devices of this type is that the performance of gas analyzers is checked only during operation.

However, when working with toxic substances (OM), you must first verify the operability of the measured device, for example, using a simulator. As a rule, non-toxic compounds are used as a working fluid for simulators.

However, in order to reliably confirm the operability of gas analytical tools directly at the places of their placement at chemical weapons destruction facilities, it is necessary to use gas-vapor mixtures containing real OM samples.

A solution to this problem can be achieved by developing and creating a compact portable device capable of creating vapor-gas mixtures of organic matter of a given composition. In this case, the concentration of toxic substances in gas-vapor mixtures should correspond to threshold levels of concentration of the tested gas analytical devices.

In this regard, it is necessary to develop a device for confirming the operability of air pollution control devices immediately before taking measurements at the installation sites of chemical weapons destruction facilities in the working area. Dispensers using the method of uniform evaporation of the liquid into the carrier gas stream are most preferred for their purpose and the nature of the tasks to be solved.

As such a device, a dispenser can be proposed that provides prompt and high-quality control of changes in the properties of gas-vapor mixtures during the dosing of OV (RF patent No. 2280246 "Capillary batcher of gas-vapor mixtures", IPC G01N 1/22 from 07.20.2006).

This dispenser consists of a mixing chamber with inlet and outlet fittings, an evaporator chamber with a metered substance and a capillary. The evaporation chamber with the metered substance is made in the form of a cylindrical glass vial with interchangeable nozzles and capillaries of various flow cross-sections to create vapor-gas mixtures with different volatility in a wide concentration range and forms a detachable connection with the mixing chamber. The advantage of the proposed capillary dispenser of gas-vapor mixtures is the possibility of prompt and high-quality control of both changes in the properties of the substance during the dosing process and the amount of dosed substance per unit time for substances with a wide range of volatility.

However, to create a vapor-air mixture with a given concentration with other dosed substances, it is necessary either to connect another vial with this substance or pour a new dosed substance into the existing vial, while replacing the nozzle with the capillary required for this substance.

Obtaining gas-vapor mixtures of OM by evaporation of OM from its liquid phase into the carrier gas stream is undesirable. This is due to the fact that the use of OM in its pure form imposes special measures to comply with safety rules during operation of the device, and also significantly complicates the procedure for confirming the operability of OM control devices directly at the installation sites in the working area. In addition, upon the evaporation of OM from its liquid phase into a carrier gas, the resulting vapor – gas mixture will have a high concentration of OM, which entails the use of additional dilution systems. The release of OM into the environment even at a low concentration is harmful to others. In order to impart ejection properties to the dispenser, it is necessary to supply the carrier gas under high pressure, which is associated with the creation of a large volume of gas-vapor mixtures based on OM in the process of checking gas analyzers.

Therefore, the basis of the design of the device to confirm the operability of the OM control devices directly at the places of their installation in the working area should be the method of uniform evaporation of the liquid into the carrier gas stream. When using this method, a dynamic equilibrium is always established between the surface of the organic matter and the gas, ending with the creation of gas-vapor mixtures of a given concentration.

Closest to the principle of action and technical nature of the dispenser for gas-vapor mixtures to the claimed device is a dosing cell Camba, based on the evaporation of liquids from the surface, implementing a dynamic method for producing gas-vapor mixtures by carburetion (DKKolerov "Metrological foundations of gas analytical measurements." - M ., Publishing House of the Committee of Standards, Measures and Measuring Instruments, 1967, Fig. 77, p.227).

This method was developed by Camb, Labardine, Meir and Vaucher and consists in the evaporation of a certain amount of liquid into the carrier gas stream. The main part of the device is an evaporator. The device itself consists of a tube 600 mm high, in the lower part of which there is an evaporated liquid. Inside the tube is a cylinder made of thick and especially porous paper. The carrier gas flows through the central tube, the lower end of which is 1 cm above the surface of the liquid. The carrier gas from the tube passes along the walls of the porous paper, is saturated with vapor of its wetting liquid, and exits the tube. Thus, the operation of this dosing device is based on the evaporation of liquid from the surface into the flow of gas moving along this surface.

However, this device is characterized by the following disadvantages:

- the inconvenience of replacing filter paper and filling OB, which requires compliance with increased security measures;

- poor-quality mixing, tk. the wettability of the paper is variable in height.

In addition, the possibility of environmental contamination is characteristic of all of the listed devices.

The objective of the invention is to improve the quality of mixture formation during the preparation of a low concentration working mixture based on real OBs and to increase safety when working with OB.

The technical result that can be obtained by using the invention is to create a compact portable device for checking the serviceability and operability of gas analytical devices at chemical weapons destruction facilities.

This object is achieved in that the device for checking the operability of poisonous substances control devices comprises a housing with attachment points, seals and a cover, inlet and outlet pipelines with fittings and a dispenser. In this case, the dispenser is a Petri absorber, the inlet central tube of which ends with an end spherical surface with through holes and is connected to the inlet duct, and the side tube through the filter is connected to the outlet duct.

In Fig.1 shows a drawing of the device, Fig.2 is an external view of the dispenser and Fig.3 is a diagram of its connection and Fig.4 is an external view of the device,

where 1 is the body of the device;

2 - the base of the device;

3 - device cover;

4 - carrying handle;

5 - dispenser;

6 - fluoroplastic connecting tube;

7 - filter;

8 - input fitting;

9 - outlet fitting.

The device consists of a housing 1 with a base 2 and a cover 3 with a handle 4, a dispenser 5, fluoroplastic connecting tubes 6, a filter 7, a filter connecting pipe to the gas lines of the gas detector, input 8 and output 9 fittings.

The housing 1 of the device is designed to accommodate and protect the dispenser 5 from external mechanical influences. The dispenser 5 is a generator of a gas-vapor mixture and is intended to produce a gas-vapor mixture of OB. Obtaining a vapor-gas mixture of OM is carried out by passing the air flow through the dispenser 5, filled with a certain amount of working solution of OM. The base 2 of the housing is designed to provide reliable stability of the device, as well as for fixing some of its constituent elements. Cover 3 is designed to facilitate access to the internal elements of the device when performing operations on its equipment and unloading. The filter 7 is designed to absorb residual OM emitted by the device after analyzing the sample from the device. Fluoroplastic tube 6 is designed to connect the device to the tested gas detector. The carrying handle is designed to transport the device.

The principle of operation of the device is as follows. When connecting the device to the intake manifold of the gas detector, air sampling is carried out through the dispenser 5 of the device. In this case, the air flow entering the gas detector initially passes through the inlet nozzle 8 of the device and enters the dispenser 5. In the internal volume of the dispenser 5, the working solution of OB is barbated and, as a result, the formation of a vapor-gas mixture. The execution of the spherical surface with through holes on the end part of the Central tube contributes to an increase in air saturation with OM vapors, i.e. promotes mixing intensity.

Thus obtained vapor-gas mixture is sent to the outlet fitting 8 of the device and then through a fluoroplastic tube is supplied to the sampling lines of the gas detector.

The long life of the device is ensured by the fact that all the constituent elements of the device are made of chemically resistant materials, which allows for multiple degassing cycles of the device using degassing formulations used at the chemical weapons destruction facility. High safety of the device during operation is ensured by reliable protection of the dispenser 5 from damage, sealing of the internal volume of the device, as well as technical solutions used in the design of the device, which exclude the possibility of getting the working solution of OM both in the gas communications of the gas detector and in the external environment.

As follows from figure 1, the dispenser 5 is placed in the inner space of the device, which provides reliable protection of the generator from external mechanical influences. The free internal space of the device case is completely filled with activated carbon BAU. Activated carbon is designed to absorb the working solution in case of violation of the integrity of the dispenser housing 5. In addition, activated carbon fixes the dispenser housing 5 during operation of the device.

The absorption of residual OM emitted by gas detectors after analyzing the sample from the device was carried out by filter 7.

The tightness of the internal space of the device is achieved through the use in the design of the device of a gasket made of chemically resistant rubber, as well as input 8 and output 9 fittings of a special design, equipped with plugs.

Thus, the design of the device for confirming the operability of the OM control devices directly at the places of their installation in the working zone of chemical weapons destruction facilities meets the requirements for them. This device is compact, portable and safe to use.

Claims (1)

A testing device for gas analytical instruments for controlling toxic substances in the air, comprising a housing with fasteners, seals and a cover, an inlet and outlet piping with fittings and a dispenser, characterized in that the dispenser is a Petri absorber, the inlet central tube of which ends with an end spherical surface with through holes and connected to the inlet pipe, and the side tube through the filter to the outlet pipe.

Images