Four Kinds of Treatment of Dampened 4a Molecular Sieve
How do you treat moisture absorption when the 4a molecular sieve is not tightly packed or the storage environment is damaged? Today we will discuss the adsorption capacity of molecular sieves and the treatment of moisture absorption.
It is widely known that molecular sieve has a highly strong adsorption. It can not only absorb moisture, but also adsorb impurities in the air. Therefore, people often take advantage of this quality to carry out adsorption work in industry in order to achieve good effects on separation and adsorption. What should we do when the 4a molecular sieve is improperly stored or is heavily damp after over-absorption while using?
1. How do you treat the damp 4a molecular sieve?
(1) First, close the master valve of the tower, and switch adsorption just between the molecular sieve of two cans, then regenerate the molecular sieve without moisture into the one with moisture by using the air inside it. When the moisturized molecular sieve comes into operation, the moisture in its back part will enter into the non-moisturized one. In this way, both molecular sieves store moisture, and regenerate each other with the adsorption,then the moisture content can be reduced. Finally, both of them are equipped with adsorption capacity.
(2) Directly heat and dry the 4a molecular sieve to dehydrate it as soon as possible and restore its adsorption capacity.
But adopting the above method to deal with the heavily damp molecular sieve will make the two sieves contain much moisture, and both will be ineffective in adsorption after regeneration. The reason is: The 4a molecular sieve will interact with moisture after it absorbs large amounts of moisture, and the water at the free state alters into the crystalline water of the molecular sieve. The crystalline water cannot be removed even with the temperature of 200 degrees, it should be delivered to the original manufacturer and sent back to furnace with 400 degrees so that the adsorption function of the molecular sieve will be restored.
Thus, when there is a large scale of damp , we should stop the operation at once and adopt regeneration method. If the adsorption still can not be restored, please contact with the manufacturer as soon as possible.
2. How do we send the heavily damp 4a molecular sieve back to the furnace for calcination?
(1) Put the molecular sieve in a drying cabinet for more than 4 hours at 250-300 degrees to remove most moisture. (Regeneration is not completely done.）
(2) Put the molecular sieve in a drying cabinet for another one hour at 150 degrees, then bake it in a high temperature muffle furnace for one hour at 500-550 degrees to remove the crystalline water. (Regeneration is completely done.)