The air separation cold box is generally filled with pearlescent sand as thermal insulation material, and the pearlescent sand particles are filled with air. After the air separation unit is operated, the volume of insulation material and air will be reduced due to the temperature greatly reduced. If the cold box is well sealed, negative pressure will be formed in the cold box. Under the effect of internal and external pressure difference, the cold box may be compressed. However, if the cold box is poorly sealed, the moisture outside the cold box will enter the cold box again, which will make the insulation material damp and greatly increase the cold loss of the equipment. Therefore, in order to maintain a slight positive pressure in the cold box, the cold box is generally filled with dry nitrogen or dirty nitrogen after the equipment is operated.
The scientific research innovation of the liquefied air upper rectification tower independently developed by Kaifeng DEAR air separation has been successfully applied in the production of Shandong Kenli kdon-300 / 3000 high-purity nitrogen hanging oxygen tower and the manufacturing equipment of energy-saving and environment-friendly industrial gas, which has solved the problem of heat loss caused by heat transfer of accessories, strengthened the thermal insulation effect of the upper rectification tower, reduced the temperature drop of the rectification tower, and is very effective in ensuring the thermal insulation effect of the upper rectification tower, The anti-skid layer composed of polytetrafluoroethylene is used to improve the friction force of the inner wall of the clamp ring, so that the clamp ring can be more firmly fixed to the rectification tower body, and the service performance of the device is improved.
