According to the classification of adsorbent regeneration, it can be mainly divided into two kinds: non-thermal regeneration adsorption dryer and thermal regeneration adsorption dryer. Since the non-thermal adsorption dryer is based on isothermal adsorption, also known as "pressure swing adsorption", the thermal adsorption dryer is based on isobaric adsorption, also known as "variable temperature adsorption". In actual use, there is also a kind of micro-thermal dryer, from a formal point of view, micro-thermal regenerative dryer is also a regenerative gas heating, but because it makes the regenerative gas is from its own water content is very low dry air, so it is also a "pressure swing adsorption" dryer.