The difficulty of gas analyzer analysis and application is well understood by those engaged in automation applications. Especially in industry, there are many difficulties and problems in process analysis: high temperature, high dust, high moisture, negative pressure and crystallization, corrosive and other harsh gas conditions; poor effectiveness of pretreatment equipment; process, pretreatment and analysis, large lag caused by instruments and other links; high requirements for protection from dust, splashes, corrosion, etc .; higher degree of automation and less maintenance workload, etc. These have brought a lot of difficulties to the application of process component analysis and environmental monitoring analysis (system).
- The characteristics of gas composition analysis and the problems to be solved. The most important and most used in industry is the analysis and measurement of gas composition.
According to the different working principles of the gas composition analyzer, it can be roughly divided into two measurement methods: one is the direct measurement method, that is, the probe is installed in the process gas pipeline to directly measure (the measurement and transmission device is inside the probe), such as infrared, ultraviolet and laser gas analyzer, etc .; one is the indirect (sampling) measurement method, that is, the process gas is extracted for dust removal and then sent to the analysis for measurement (including measurement and transmission devices). For indirect analysis and measurement, due to the influence of harsh gas conditions such as high temperature, high dust, high moisture, negative pressure, and corrosiveness of industrial process gases, the biggest difficulty faced is how to obtain a sample gas suitable for the test conditions. The only method is to use a pretreatment device to process the sample gas. As some imported analyzers have matured in technology, they can meet the needs of industrial analysis.
Therefore, selecting (manufacturing) a pretreatment device that can adapt to the process conditions and has stable and reliable performance is the key to solving the problem of analysis and use. For the direct analysis measurement, because it uses the latest optical technology, it can measure without affecting the state of the measured gas itself. It has the advantages of accurate measurement and rapid response. In particular, it does not require a pretreatment device, which saves investment in an automatic purge device, and has a great advantage compared to traditional thermal conductivity gas analyzers.
However, there are also some problems: 1) expensive; 2) not suitable for gases with large dust particle sizes; 3) gas that is insensitive to working light waves cannot help.
- Part of the application of online analysis avcray is an enterprise that adopts closed blast furnace (ISP) process for lead and zinc smelting. Less process analysis, such as CO, CO2, SO2 gas analyzer, H2SO4 concentration meter and pH meter, infrared moisture meter, calorimeter, etc.