Nitrogen purification method

Abstract

The invention discloses a nitrogen purification method, wherein nitrogen and hydrogen both mixed with oxygen impurities are fed into a deaerator in which combustion reaction can be formed between the oxygen in the deaerator and the hydrogen to generate water, after the nitrogen mixed with steam is cooling-dewatered by a multistage cooler, freezing-dried by a freezing drier, dewatered by a gas-water separator and drying-dewatered by a multistage dryer, the dew-point temperature of the nitrogen can be lowered to about minus 80 degrees, in this case, the nitrogen hardly contains water, and in the end, the impurities like dust, particles, etc. in the nitrogen are removed by a filter to obtain nitrogen with the purity of 99.999%.

Description

technical field [0001] The invention relates to a nitrogen purification method. Background technique [0002] The nitrogen produced by compressed air through pressure swing adsorption is usually mixed with oxygen impurities. The purity of nitrogen is generally 97%-99.5%. The next two parts of hydrogen and one part of oxygen are combusted, and the reaction produces water, and then the reaction product water in the nitrogen is removed to obtain high-purity nitrogen. In the existing purification process methods, such as figure 1 As shown, the nitrogen and hydrogen mixed with oxygen impurities enter the premix tank 6' through the input pipeline, and the oxygen and hydrogen in the nitrogen in the premix tank 6' are fully mixed, and the amount of hydrogen added is controlled by manually adjusting the valve. There are flowmeters, pressure gauges, and oxygen content analyzers on the nitrogen input pipeline. According to the flow parameters, pressure parameters, and purity paramete...

AI Technical Summary

Problems solved by technology

The mixed gas obtained by fully mixing nitrogen and hydrogen mixed with oxygen impurities then enters the deaerator 1'. In the deaerator 1, the hydrogen and oxygen burn to form water, and the oxygen impurities in the nitrogen are removed by combustion, but in the nitrogen There is reaction product water in the water, and the water-containing nitrogen enters the cooler 2', because the hydrogen-oxygen reaction is exothermic, the temperature of the nitrogen is higher, and the cooler 2' cools the nitrogen to normal temperature, and can cool a part of the water in the nitrogen into The liquid state is removed, and then the nitrogen gas is sent to the cold dryer 3', and the cold dryer 3' freezes and dries the nitrogen gas for further dehydration to reduce the water content in the nitrogen gas, and then the nitrogen gas is sent to the dryer 4' to dry Adsorbent molecular sieves are used in the device 4' to absorb water to further reduce the water content in the nitrogen. After passing through the dryer 4', the water content or dew point temperature in the nitrogen is about -20 degrees. Finally, the nitrogen is filtered through the filter 5' to remove dust, Particle impurities, that is, purified nitrogen, the nitrogen produced by the above-mentioned existing method is insufficient for cooling, drying and dehydration, and its water content is still high, so high-purity nitrogen cannot be obtained

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