Acetylene and other hydrocarbons, as well as the lubricating oil and light fractions of lubricating oil brought into the tower with the processing air. Among the hazardous impurities mentioned above, acetylene is the primary source of explosion formation. This is because the solubility of acetylene in liquid oxygen is extremely low, about 5.12cm3/1 liquid oxygen, and excess acetylene will be suspended in liquid oxygen as white solid particles. Acetylene is an unsaturated hydrocarbon with high chemical activity and extremely unstable properties. The explosion sensitivity of solid acetylene mixed with liquid oxygen is extremely high, and it is the most dangerous substance that can cause explosions in air separation towers. When liquid oxygen evaporates in the main condenser evaporator, the amount of acetylene carried away with gas oxygen is only about 1/24 of the total acetylene content in liquid oxygen. In this way, as liquid oxygen evaporates, the concentration of acetylene in liquid oxygen continues to increase. When acetylene exceeds its solubility, it precipitates in solid form. In liquid oxygen, solid acetylene is explosive. However, the actual situation often occurs when the content of acetylene in liquid oxygen does not exceed its solubility, or due to the unreasonable structure of the condenser evaporator, or due to blockage of certain channels, the local fluidity of liquid oxygen is poor, resulting in local concentration of acetylene and explosion. Therefore, it is necessary to strengthen laboratory analysis and strictly control the concentration of explosive substances in liquid air and liquid oxygen. Regularly analyze and monitor the content of liquid oxygen, acetylene in liquid air, hydrocarbons, and oil. Strictly control the carbon content and oil content in liquid air and liquid oxygen within the specified range. Among them, special attention should be paid to the control of acetylene content. To ensure the safe operation of air separation equipment, the warning values for the control indicators of acetylene and its hydrocarbons in the main cold liquid oxygen of industrial air separation equipment are: acetylene (0.1ppm, total hydrocarbons<100ppm (including ethane<15ppm, ethylene<10ppm, propylene<2ppm, propane<10ppm, n-butane+isobutane+butene+butadiene<1.5ppm), calculated by converting the total hydrocarbon content into methane. It is not difficult to see from the above analysis requirements that a general gas chromatograph cannot directly inject samples to determine<0.1ppm acetylene, and concentration technology needs to be usedWe need to use a large caliber to meet the above analysis requirementsPLOT Elastic Quartz Capillary Column and Programmed Temperature Analysis TechnologyJunqiGC9890The gas chromatograph has been modifiedAnd equipped with HPhigh sensitivityThe hydrogen flame detector (FID) (d>2.7 × 10-12g  s) has achieved a single injection and completed comprehensive analysis of methane, ethane, ethylene, acetylene, propane, isobutane, and other combinations, with satisfactory results.
Special gas chromatograph for acetylene detection in liquid oxygen, liquid oxygen gas chromatograph for detection

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Updated on September 2, 2020 at 10:22:27