#Industry News
Precautions for the selection and use of gas analyzer under different industrial operating conditions
With the people's increasing demands on living environment, environmental protection has attracted high attention, and the country's regulation on emissions from factories has been strengthened day by day. Gas analyzer is widely used in petroleum gas
1.Monitor location and situation
1.1Online gas analyzer
The online gas analyzer is widely used in industrial equipment and production process, and can be installed at specific monitoring points to monitor specific gas. In the process and technology of online gas analyzer, it is more suitable for the characteristics of continuous, long time, online and stable required by monitoring. It needs to be selected according to the type and concentration of field gas, and the location of installation is also one of the selection factors of online gas analyzer.
1.2Portable gas analyzer
The portable gas analyzer is easy to operate and small in size, and can be carried to different production sites for monitoring.
Portable gas analyzers are often used in open situations such as open workshops.
2.Types and characteristics of gases under test
In the process of industrial production, a large number of combustible, toxic and harmful gases will be produced, among which combustible gases are mainly H2, CH4, CnHm (C2H2, C2H4, C2H6), and toxic and harmful gases are mainly CO, CO2, SO2, NOX, H2S, etc. When the mixture of CO, H2S, H2 and air reaches the limit value, fire and explosion accidents will occur easily, resulting in casualties and equipment damage. Emissions of CO2, SO2, NOX and other gases not only harm the human body, but also cause air pollution. Therefore, gas monitoring in industrial processes is very necessary.
2.1Oil and gas
In the production process of oil and gas, a large amount of hydrocarbon gases and CO, H2S etc. will be produced, and the accident probability is high. Therefore, in order to protect the health of field workers and the safety of production, the oil and gas industry generally adopts the method of gas detection and analysis to control, installs the gas analyzer to detect whether the flammable gas and toxic gas leak, and monitors the flammable and toxic gas content in the environment around the process equipment or storage and transportation facilities.
2.2Coal chemical industry
In the process of coal chemical production, gas is an inevitable product. Gas contains toxic gas. When the toxic gas concentration of coal chemical plant reaches or exceeds the safe value, accidents will occur. The gas analyzer can send out alarm signal through real-time detection, and can start solenoid valve, exhaust fan and other external equipment to automatically eliminate hidden dangers.
Monitoring application: coking, coal gasification - synthesis ammonia, coal based methanol, coal synthesis oil, coal chemical industry and other industries.
Gas monitoring: O2、CO、CO2、CH4、H2、CnHm(C2H2、C2H4、C2H6) etc.
2.3 Power plant
The main fuel of power plant in China is coal. The combustion of boiler in power plant produces a lot of toxic and harmful gases, which not only pollutes the environment, but also affects the combustion efficiency of boiler.
Monitoring application: furnace, combustion furnace, flue gas emission test behind the flue gas cleaning device, coal bunker and coal mill, etc.
2.4 Waste-water treatment
Many cities and towns use waste-water treatment facilities to treat their sewage, because the waste water will cause a bad smell which is pungent and unpleasant. In recent years, the production of biogas by anaerobic fermentation of waste water has become one of the ways of utilization of waste water resources.
Monitoring application:
1.sewage treatment equipment -- digester, sewage tank and hydrogen sulfide scrubber, etc.
2.sewage biogas project - anaerobic fermentation equipment outlet, desulphurization tower export.outlet
2.5 Iron and Steel Metallurgy
In the production process of iron and steel metallurgy industry, a large amount of flue gas and syngas will be produced. Some components of flue gas and syngas will have an impact on the environment and resource recovery. Therefore, real-time monitoring of its e gas and syngas components must be carried out.
Monitoring application: blast furnace gas, coking furnace gas, converter gas and flue gas emissions.
Gas monitoring: O2, CO, CO2, CH4, H2, SO2, NO etc.
2.6 Cement
The cement plant is a highly polluting industry with large smoke and dust emissions. Some waste gas of the kiln end of the cement plant adopts bag dust collection and dust removal. Due to the high temperature in the bag dust collection, the mixture of CO gas and air in the air mixture of bag dust collection gas is easy to generate explosion and is of high risk.
Monitoring application: bag dust collection outlet, coal dust bin, coal mill, preheater outlet, smoke chamber or chimney, decomposition furnace outlet, etc.
Gas monitoring: CO, O2, NO, SO2.
3.Precautions for use of gas analyzer
3.1Calibration and Testing
The gas analyzer generally uses the method of relative comparison for measurement, that is, it first calibrates the instrument with a zero gas and a standard concentration of gas, and the standard curve is stored in the instrument. When measuring, the instrument compares the electrical signals generated by the gas concentration to be measured, and calculates the accurate gas concentration value.Therefore, it is necessary to adjust the instrument to zero at any time, and to calibrate the instrument regularly.
3.2 Detection interference between different sensors
Generally speaking, each sensor corresponds to a specific gas detection, but neither is absolutely effective.Therefore, when choosing a gas sensor, the detection interference of other gases should be known as much as possible to ensure its accuracy.
3.3 The service life of gas sensor
Gas sensor has a certain use age, that is, service life. Generally speaking, the sensor should be used within the validity period as much as possible.
3.4 Concentration measurement range
The gas analyzer has its fixed monitoring range.The accuracy of the instrument measurement can be guaranteed only when measuring within the range. Measuring beyond the range of measurement for a long time will cause damage to the gas sensor.
4.Conclusion
The monitoring and analysis of gas in industrial process can not only play the role of environmental monitoring, but also play a guiding and energy-saving role through the real-time detection of gas component in the process. It can be seen that the process of gas analysis is to strictly control various factors affecting the process on the premise of understanding and controlling the entire production process, so as to make the enterprise product efficiently and safely.