Carbon Molecular Sieve (CMS) is the core adsorption material of PSA (Pressure Swing Adsorption) high-purity nitrogen generators, and standardized filling technology directly determines the nitrogen purity, gas production stability and service life of the equipment. High-purity nitrogen production (99.9%–99.999%) puts forward stricter requirements for CMS filling uniformity, compactness and sealing performance, which is different from ordinary industrial nitrogen generator filling operations. Before formal filling, comprehensive pretreatment of the adsorption tower is essential. Operators need to thoroughly clean the inner wall of the tower to remove welding slag, dust, rust and residual oil stains, as these impurities will cause local poisoning and failure of CMS, reducing adsorption efficiency. Meanwhile, it is necessary to check the integrity of the tower bottom filter screen, air distribution plate and sealing gasket to avoid sieve leakage and air channeling caused by damaged accessories.

The layered quantitative filling method is the key skill for high-purity CMS filling. It is forbidden to fill the CMS in one time, which will lead to loose accumulation and uneven gaps. The standard operation is to divide the total CMS dosage into 4-6 equal parts, fill each part evenly and vibrate the tower body moderately with a professional vibration tool for 3-5 minutes to eliminate internal gaps. The vibration intensity should be controlled moderately to avoid crushing CMS particles and damaging the structural pore channels. During the filling process, the flatness of the CMS material surface must be kept consistent, and the height error of the material surface in all areas of the adsorption tower shall not exceed 5mm, so as to ensure that the compressed air can fully contact the CMS in the adsorption process and avoid partial short-circuit air flow that affects nitrogen purity.

Post-filling sealing and aging treatment cannot be ignored. After filling to the standard height, install the tower top pressing plate and sealing device tightly to prevent the CMS from floating and fluidizing during frequent pressure switching. Then carry out 2-3 times of pressure maintaining and purging tests with dry compressed air to remove fine powder generated during filling and vibration. Finally, let the standing machine age for 24 hours to stabilize the CMS stacking structure. Standard filling skills can effectively extend the service life of CMS by 1-2 years, maintain stable high-purity nitrogen output, and reduce the failure rate of equipment caused by adsorption failure.