Add to favorites

#Industry News

The pre-treatment system plays an important role

The online analyzer pretreatment system removes and adjusts the gas to meet the conditions required for the analysis instrument. 

Some gas samples analyzed do not meet the operation requirements of the online analyzer under the working condition. There are also high pressure, high temperature and corrosive gases.The online analyzer pretreatment system removes and adjusts the gas to meet the conditions required for the analysis instrument. 

1. Remove corrosive gases


In the previous chemical online analyzer sample test, many of the components monitored contained highly corrosive gases, such as sulfur dioxide, hydrogen sulfide, and hydrogen chloride.These corrosive gases, once dissolved in water in the sample, will form acids or bases that not only increase humidity but may cause corrosion damage to the on-line analytical instrument.The online analysis table is a precision device, which has high requirements for the analysis of gas medium. Once corrosive gas occurs, it will have a direct impact on the analysis results and cannot guarantee the accuracy of the results.

The development of online analyzer complete sets of equipment has been able to provide the enterprise terminal with all anti-corrosion systems. First, the inner and outer coating of the probe is applied to prevent the corrosion of the corrosive gas. Secondly, the filter, valve, condenser and other important parts directly in contact with gas are designed and manufactured into anti-corrosion type to improve service life. Thirdly, the corrosion resistance of the analytical instrument also improves the applicability range of the analytical instrument. For the sample containing corrosive gas, a personalized analysis system has been designed for various corrosive properties and corrosive strength gas to meet different user demands.If the gas sample contains a small amount of corrosive components, it can be washed with water or removed by chemical method.In view of the corrosion gas is the most effective way is to keep the temperature above 135 ℃, the pipe heat preservation method is adopted, and effective measures of dehydration can effectively avoid corrosion gas analysis instrument damage caused by impact.

 2. Avoid interference between sample components

With the continuous development of society, the chemical industry is also changing with each passing day, and the products produced are more and more complex. Meanwhile, the process is also more and more complicated.The gas involved in the reaction process is abundant and easy to produce some by-products. Based on this, many types of gas mixture conditions must be faced during the operation of the online analyzer. The interference component can make the output signal produce a certain error, which will interfere the measured results and make the function cannot be fully developed.The pretreatment system can solve the negative effects of various components and obtain the best measurement results.

Firstly, all the interfering components should be removed by scientific and reasonable methods according to their chemical properties.

1)If it contains NH3, in this case it can be removed by washing;

2)If it contains SO2, it can be removed by alkali.

Secondly, Pretreatment system also can be mixed in the samples corrosive substance to shift.

1)For example, SO2 and SO3, both through conversion furnace heating method, has been to keep the temperature above 900 ℃;

2)For another example, in the case of NO and NO2, the transformation of both can be realized through MO/C catalysis.

The equipment required by this method is stable, relatively high efficiency and high reliability.

In addition, with the progress of science and technology, better instruments will be designed in the field of analytical instruments, and their selectivity will be improved day by day, so as to effectively solve the interference of various components, such as purple and infrared analytical instruments, and avoid errors caused by the influence of background components.、


3. Security of online analysis system

The safety of the online analysis system mainly includes electrical safety, airway tightness, explosion-proof safety and network information safety. The electrical safety of the system includes electrical safety such as electric shock, fire, lightning strike and electromagnetic interference.The seal of system gas path is to prevent the leakage of pipeline causing toxic gas crisis personal safety;The system explosion-proof safety is the level and ability of the explosion-proof design of the system in the explosion environment.The system network information security is the system output information in the transmission security, as well as the analysis instrument and the system specialized network security.The security of online analysis system can be divided into the security of hardware and software. The security of system hardware mainly refers to the security of each functional part of the system and the security of the system to the internal and external.

From a chemical perspective, most of the gases measured by the on-line analytical instrument have obvious chemical hazards, such as corrosivity and toxicity, etc. If not properly handled, it is bound to cause air pollution, human poisoning or even explosion, and endanger human safety.Therefore, most of the on-line analytical instruments have special protective measures.For example, most of the basic components of the explosion-proof on-line analytical instrument are equipped with obvious explosion-proof performance, which can ensure that there is no explosion accident, while the special pretreatment system is usually installed in the environment through pressurization and explosion-proof.

4 Adjust the pressure of the gas sample

The pretreatment system of the online analyzer can also adjust the pressure and temperature to a certain extent.Because for online analysis instrument, its special working environment is the need to have a certain pressure and temperature, and the pretreatment system can through the way of increase or decrease in pressure to make the external environment of pressure to achieve online analytical instrument, within the scope of the required to guarantee the normal work of the online analytical instrument can be, in general, general decompression under high pressure environment by the external environment will be able to achieve the online analytical instrument of pressure range.

 5 Remove the tar

In the chemical production process, the presence of tar will have an inestimable impact on the on-line analytical instruments, so some measures are often needed to remove the tar from gas samples. Although the electric capture method can effectively remove most of the tar, there are still some tar stubborn incorporation into the gas sample, which affects the data measured by the on-line analytical instrument. Therefore, the tar should be treated twice in the pretreatment system.In the pretreatment system, tar is generally treated by cooling method or water washing method.


  • Wuhan, Hubei, China
  • Ruiyi