When the air is compressed, the concentration of water increases. To avoid future problems in the installation of the compressor, it is necessary to treat the compressed air. In this article we will focus on drying by absorption and drying by adsorption (drying by desiccant). Demand of explosion proof compressed air dryer is very high.
What is absorption drying?
Absorption drying is a chemical process in which water vapor is bound to the absorption material. The absorption material can be solid or liquid. Sodium chloride and sulfuric acid are frequently used, which means that the possibility of corrosion must be taken into account. This method is uncommon and involves a high consumption of absorbent materials. The dew point is only reduced to a limited extent.
What is drying by adsorption or drying by desiccant?
As it is The universal in service code of adsorption dryers, also recognized as desiccant dryers, is easy: moist air flows over the hygroscopic material (the typical materials used are silica gel, molecular sieves, activated alumina) and, thus, it dries The exchange of water vapor from the moist compressed air to the hygroscopic material or “desiccant” causes the desiccant to be gradually saturated with adsorbed water. Therefore, the desiccant needs to be regenerated periodically to recover its drying capacity, and the desiccant dryers are usually built with two drying tanks for that purpose: the first tank will dry the incoming compressed air, while the second one will regenerate(similar to the operation of a nitrogen generator).
Each deposit (“tower”) changes tasks when the other tower is fully regenerated. The typical PRP that can be achieved is -40 ° C, which makes these dryers suitable for providing very dry air for more critical applications. There are four different ways to regenerate the desiccant and the method used determines the type of adsorption dryer. The types of higher energy efficiency are generally more complex and, therefore, more expensive.