RU80007U1 - GAS SIGNAL OF INCREASED SPECIFICITY - Google Patents

Abstract

A gas detector of high specificity relates to measuring equipment - devices for analyzing gas in the environment, namely, to the device of gas analytical devices. It can be used to quantify the gas content in ambient air and to signal if its limit values are reached. The objective of the utility model is to expand the list of defined compounds in various multicomponent gas mixtures by increasing the specificity of the gas detector. The technical result that can be obtained using the utility model is to expand the number of detected harmful substances by introducing into the device a multicapillary gas chromatographic column connected to a gas sensor made in the form of an ion mobility spectrometer. The task is achieved in that the gas detector of high specificity contains the gas sensor itself, a flow restrictor, a pump, an information processing unit, an analog-to-digital converter, and indication and signaling devices. Moreover, the device is characterized in that a multicapillary gas chromatographic column is placed at the inlet of the gas sensor itself, made in the form of an ion mobility spectrometer, the gas flow inducer is a pump installed at the device inlet, and two two are formed between the pump inlet and the multicapillary gas chromatographic column parallel air branches, in one of which a gas flow restrictor and a filter are installed, and in the other, a controlled gas flow restrictor having a device in for discharge into the atmosphere, while the input of the information processing unit is connected to the database unit of the determined harmful substances. The proposed gas detector has industrial applications in enterprises of the chemical and processing industries, in metallurgy and other industries, where the operation of the sensor is important when the environment contains a large number of different compounds. In addition, it can be used as an autonomous means of chemical control of air in industrial and other premises, at facilities for the storage and destruction of chemical weapons, mobile laboratories. 1 ill.

Description

The utility model relates to measuring technique - devices for analyzing gas in the environment, namely, to the device of gas-analytical devices. It can be used to quantify the gas content in ambient air and to signal if its limit values are reached.

Known gas analyzer (RF patent No. 2094794 from 09/27/1997, IPC G01N 27/407). It contains a voltage source, a solid electrolyte sensing element with electrodes and a heater connected to the output of the temperature controller, an amplifier, an indication unit and a multiplexer, it is also equipped with two adders, a division unit, a memory unit, a control unit and a linearization unit. The disadvantage of such a gas analyzer is its use only for the quantitative determination of one substance - fluorine.

An analyzer of the EUK-565 type Japanese company RUKEM KEUKU is also known. However, it has limited use due to its low specificity.

Known gas analyzer (RF patent No. 2091781 from 09/27/1997, IPC G01N 27/00, G01N 27/12). It contains a sensor head including a sensing element, and a measuring circuit, a load resistor and power lines, and a measuring and signaling device comprising a measuring circuit, power lines, a current-voltage converter, and a compensating stage. This device was used in the development of gas analyzers for hydrogen sulfide 666 EX15, 666 EX16, sulfur dioxide, carbon monoxide, methane 604 EX07, ammonia 342 EX03, 342 EX04, 342 EX05, chlorine 662 EX05.

The closest in technical essence and the achieved technical effect to the proposed technical solution is the "Gas analyzer" (RF patent for the invention No. 2209419, G01N 27/00). The gas analyzer contains the actual gas sensor, flow restrictor, gas flow inducer, information processing unit,

analog-to-digital converter, digital indicator of gas content, light signaling of limit contents, sound buzzer of limit contents. The gas analyzer operates as follows. The input gas flow of the surrounding gas is driven by the flow sensor through the specific gas sensor and the gas flow restrictor and is released into the environment by the output gas. The output of the gas sensor is fed to the information processing unit and, through an analog-to-digital converter, is fed to a digital gas content indicator, as well as to the signaling of the limit gas contents, light and sound. However, this gas analyzer can be used to determine the content of only a certain gas in ambient air.

The objective of the utility model is to expand the list of defined compounds in various multicomponent gas mixtures by increasing the specificity of the gas detector.

The technical result that can be obtained using the utility model is to expand the number of detected harmful substances by introducing into the device a multicapillary gas chromatographic column connected to a gas sensor made in the form of an ion mobility spectrometer.

The task is achieved in that the gas detector of high specificity contains the gas sensor itself, a flow restrictor, a gas flow inducer, an information processing unit, an analog-to-digital converter, and indication and signaling devices. Moreover, the device is characterized in that a multicapillary gas chromatographic column is added, located at the inlet of the gas sensor itself, made in the form of an ion mobility spectrometer, the gas flow inducer is a pump installed at the inlet of the device, and two parallel air columns are formed between the pump inlet and the multicapillary gas chromatographic column branches, in one of which a gas flow restrictor and a filter are installed, and in the other, a controlled gas flow restrictor having a device for discharge into the atmosphere, while the input of the information processing unit is connected to the database unit of the determined harmful substances.

The gas detector is shown in figure 1:

1 - pump;

2 - throttle gas flow;

3 - controlled throttle gas flow;

4 - filter;

5 - polycapillary gas chromatographic column;

6 - the actual sensor for a specific gas;

7 - information processing device (microprocessor);

8 - the device database of the determined harmful substances;

9 - analog-to-digital Converter;

10 - digital indicator of the content of a certain gas in the air;

11 - light alarm about the gas content;

12 - sound alarm about the gas content;

13 - timer.

The gas detector can be represented in the form of two blocks: measuring A and alarm B and a stimulator of the flow of gas stream 1. (figure 1).

The measuring unit A is designed to transmit service information to the signaling unit B, which displays it.

Measuring unit A can be in the following modes:

- training mode;

- Work mode;

- diagnostic mode;

- training mode;

In the future, only the first two modes will be considered.

In the preparation mode, heating, temperature control of the units, diagnostics and adjustment of parameters are performed.

In the operating mode, a cyclic input, analysis and identification of air occurs in accordance with the table of measured components.

Measuring unit A consists of a pump 1, a gas flow throttle 2, a controlled gas flow throttle 3, a filter 4, a multicapillary gas chromatographic column 5, a specific gas sensor 6, an information processing unit (microprocessor) 7, and a database of detected harm

data of identified harmful substances 8.

Alarm block B is designed for:

- output of light signals DANGER, READY, MALFUNCTION, and INPUT and NETWORK;

- issuing a dry contact type information signal;

- issuing a sound signal;

- changes in the operating modes of the device;

- display the current operating mode of the device:

- output of the self-diagnosis malfunction code of the device;

- display of service information during the maintenance of the device.

- communication control with the measuring unit.

The alarm unit B consists of an analog-to-digital converter 9, a digital indicator of the content of a certain gas in the air 10, a light alarm about the gas content 11, an audible alarm about the gas content 12, a timer 13.

The device operates as follows.

Preparation mode.

The flow of ambient air under the action of the pump 1 is fed to the input of a gas detector of high specificity. Next, the stream is divided.

One part of it through the gas flow restrictor 2 and filter 4 provides a continuous supply with a predetermined flow rate and is fed to the input of a multicapillary gas chromatographic column 5. Filter 4 provides for the cleaning of impurities (organic and non-organic compounds) of ambient air.

At the same time, another part of the ambient air inlet stream is supplied to a controlled gas flow choke 3, which is preliminarily adjusted to a predetermined value of the ambient air flow rate due to its further discharge into the atmosphere, and then it is shut off. Thus, at the inlet of the multicapillary gas chromatographic column 5, purified ambient air is supplied as a carrier gas.

Next, the cleaned ambient air is supplied to the actual gas sensor 6, which is performed in the form of an ion mobility spectrometer and then is released into the environment.

At the output of the information processing device 7, there is no signal, which indicates that the gas detector is ready for operation.

Work mode.

The principle of operation of the device is based on gas chromatographic separation of the analyzed sample of ambient air, subsequent ionization by a radioactive source of the sample and registration of the ion current.

At the command of the control system, the controlled throttle of the gas stream 3 supplies a strictly dosed portion of the input stream of the analyzed ambient air pulsed to the multicapillary gas chromatographic column 5. In it, a gas-chromatographic separation of the sample (sample) of the input stream of the analyzed ambient air into components that depending on the retention time in the multicapillary gas chromatographic column 5, at the output of which there is a chamber with a radioactive source, under the influence of which It is ionized sample sequentially fed into an ion mobility spectrometer type sensor 6.

In the sensor 6, the components of the input stream of the analyzed ambient air are registered and identified in accordance with their nature.

In this case, the obtained ions are pulsed into the drift zone, where under the influence of a weak constant electric field, ions are separated in accordance with their mobility. At the end of the drift zone there is a collecting collector connected to an electrometric amplifier. Next, the analog signal is amplified by an electrometric amplifier and converted to digital.

The output from the gas sensor 6 is supplied to the information processing unit 7 simultaneously with the information from the database device of the determined harmful substances 8, where it is identified with the extracted components of the measured gas and compared with their maximum permissible concentrations.

Further, the final information is fed to the signaling unit B. In this case, through the digital-to-analog converter 9, it is supplied to the digital gas content indicator 10, as well as to the signaling of the limit gas contents, light 11 and sound 12 with the simultaneous start of the timer 13.

Thus, high specificity is achieved through the use of a multicapillary gas chromatographic column 5 in combination with a sensor 6, made in the form of an ion mobility spectrometer.

In it, the sample of the studied medium is divided into component components

and subsequent registration and identification of these components in the sensor 6, made in the form of an ion mobility spectrometer, which together allows you to register and identify the required components of the ambient air.

Each new measurement cycle begins with a sample input.

At the identification stage, in addition to the main program for identifying the substance and changing the signal DANGER, the degree of purity of the sensor 6 is analyzed. Depending on the results of the analysis, the cycle repeats with a satisfactory sensor purity. If there is contamination, the sample is not taken and the measuring unit is automatically cleaned. In operating mode, parameters that affect the operation of the unit are monitored and supported.

The use in the proposed gas detector of a multicapillary gas chromatographic column 5 connected to a sensor 6 made in the form of an ion mobility spectrometer can significantly increase its specificity in the analysis of gas flow from the environment, and also allows the analysis of gas media containing a wide range of different compounds.

The proposed gas detector has industrial applications in enterprises of the chemical and processing industries, in metallurgy, gallurgy and other industries, where the operation of the sensor is important when the environment contains a large number of different compounds. In addition, a gas detector can be used as an autonomous means of chemical control of air in industrial and other premises, at chemical weapons storage and destruction facilities, and mobile laboratories.

Claims (1)

A gas detector of increased specificity, comprising a gas sensor itself, a gas flow restrictor, a gas flow inducer, an information processing unit, an analog-to-digital converter, and indicating and signaling devices, characterized in that a multicapillary gas chromatographic column is placed at the input of the gas sensor itself, made in in the form of an ion mobility spectrometer, the gas flow inducer is a pump installed at the inlet of the device, and between the pump inlet and the multicapillary two parallel air branches are formed by a gas chromatographic column, in one of which a gas flow restrictor and a filter are installed, and in the other, a controlled gas flow restrictor having a device for discharge into the atmosphere, while the input of the information processing unit is connected to the database unit of the determined harmful substances.