Answer: Compared with adsorption dryers, freeze dryers (referred to as cold dryers) have the following characteristics:
① No gas source consumption. For most gas source users, using a cold dryer saves energy more than using an adsorption dryer;
② No valve wear;
③ No need to add or replace adsorbent regularly;
④ Low operating noise;
⑤ Daily maintenance is relatively simple, just clean the automatic drain filter on time;
⑥ There are no special requirements for the pre-treatment of the gas source and the matching air compressor. The general oil-water separator can meet the requirements of the cold dryer for the intake quality;
⑦ The cold dryer has a "self-cleaning" effect on the exhaust, that is, the solid impurity content in the exhaust gas is less;
⑧ While discharging the condensate, part of the oil vapor can also condense into liquid oil mist and be discharged with the condensate.
Compared with adsorption dryers, the "pressure dew point" of compressed air treated by cold dryers can only reach about, so the drying depth of the gas is far less than that of adsorption dryers. In quite a few application fields, the use of cold dryers cannot meet the process requirements for the dryness of the gas source. Therefore, when the "pressure dew point" is required to be above, cold dryers are preferred; when the "pressure dew point" is required to be below, adsorption dryers are the only choice.
