Molecular sieve purifier in 0.5 ~ Regeneration should be carried out when the adsorption reaches saturation under 0.6MPa. Regeneration operation is divided into four stages: Pressure Relief, heating, cold blowing and pressure filling. Regeneration is generally 10 ~ Completed under 15kPa. During pressure relief, the moisture, carbon dioxide, acetylene and other molecules adsorbed by the molecular sieve will be partially desorbed. Because the release needs energy, it must absorb heat. This part of heat comes from the molecular sieve bed itself, so when the bed temperature decreases, the gas outlet temperature decreases accordingly.
In the heating stage, the heating gas usually uses dirty nitrogen. Sewage nitrogen passes through steam heater or electric heater. For monolayer molecular sieve purifier, the temperature of heating gas is 280 ~ 300℃; for double-layer molecular sieve purifier, the heating temperature is 200℃. The heating gas enters the molecular sieve bed, and the general gas enters from the upper part. The outlet side and the Middle bed are heated to make the absorbed impurities desorbed, and enough heat is stored in the bed. The outlet temperature of sewage and nitrogen serves as the basis of operation. At the beginning of the heating stage, the heating gas makes the temperature of the molecular sieve bed near the air outlet rise, and supplies water and carbon dioxide degassing energy, so the temperature itself decreases rapidly, the outlet temperature of sewage and nitrogen will even decrease to-10℃, and then gradually increase. Stop heating when the outlet temperature of sewage nitrogen reaches 100℃.
The gas used in the cold blowing stage is still dirty nitrogen, which is no longer heated. Obviously, the temperature of gas entering the molecular sieve bed will drop rapidly, and the bed temperature near the entrance side will also drop accordingly. As the heat goes to the outlet side of the dirt and nitrogen, the outlet bed will continue to rise, and this part of molecular sieve will continue to regenerate. The outlet temperature of sewage and nitrogen will also gradually increase, which can reach the peak temperature of 160℃, and then decrease until the normal temperature. This indicates that the molecular sieve has been regenerated and is ready for use. In the cold blowing stage, the outlet temperature of sewage nitrogen may also have two or three peaks, which is often caused by the unevenness, thinness and thickness of the molecular sieve bed of the purifier.
In the charging stage, air is introduced into the purifier, and the pressure inside the purifier rises. Because impurities, moisture, carbon dioxide and acetylene in the air are adsorbed by the adsorption bed, the temperature will rise, and the air outlet temperature will generally rise by 2 ~ 4℃.
