Although there are other less common types of adsorption dryers, they are not discussed in this article. All typical adsorption dryers have two pressure vessels filled with desiccant particles and a valve control system that directs compressed air from one pressure vessel to another. The ability of desiccant particles to remove water vapor (adsorption) in compressed air before saturation is limited. Once the desiccant is saturated, the moisture in the desiccant must be removed in the regeneration cycle, otherwise the dryer will not be able to absorb the moisture in the air and reduce the dew point of compressed air to a lower level.

在一个压力容器中的干燥剂饱和之前，阀门控制系统会将未完全干燥的压缩空气输送到另一个充满干燥剂的压力容器中。同时将前一个压力容器置于大气压下，通入干燥过的压缩空气，带走已饱和干燥剂中的水分，对干燥剂进行再生。由于压缩空气在大气压下，露点会降低，因此其带走水分的能力更强。两压力容器中的干燥剂像这样交替干燥和再生，周期通常为10分钟。这一循环再生过程消耗的压缩空气约为干燥机额定产量的15%到20%。

Before the desiccant in one pressure vessel is saturated, the valve control system will deliver the compressed air which is not completely dry to another pressure vessel filled with desiccant. At the same time, put the former pressure vessel under atmospheric pressure, pass in the dried compressed air, take away the moisture in the saturated desiccant, and regenerate the desiccant. Because compressed air at atmospheric pressure, dew point will be reduced, so its ability to take away water is stronger. The desiccant in the two pressure vessels is alternately dried and regenerated like this, and the cycle is usually 10 minutes. The compressed air consumed in this recycling process is about 15% to 20% of the rated output of the dryer.

需要注意的是，这里的15%～20%是干燥机额定产量的15%～20%。在某些情况下，干燥机不会满载工作。举例来说，当干燥机半载工作时，这里用来带走干燥剂中水分的压缩空气将是产量的30%到40%。在干燥空气的过程中，此类干燥机本身就将用掉大部分已干燥的压缩空气，这也是审计员不看好此类压缩机的原因。

It should be noted that 15% ～ 20% here is 15% ～ 20% of the rated output of the dryer. In some cases, the dryer will not be fully loaded. For example, when the dryer is working at half load, the compressed air used to remove moisture from the desiccant will be 30% to 40% of the output. In the process of drying air, this kind of dryer itself will use up most of the compressed air that has been dried, which is also the reason why auditors are not optimistic about this kind of compressor.

为了弥补这一缺点，设计师们提出了不同版本的吸附式干燥机，其中之一就是有热再生吸附式干燥的方法。类似于无热再生吸附式干燥机，仍要使用已经干燥过的压缩空气来干燥已饱和的干燥剂，但压缩空气在通入压力容器之前，会先用电加热器进行加热。

In order to make up for this shortcoming, designers have proposed different versions of adsorption dryer, one of which is the method of thermal regeneration adsorption drying. Similar to the heatless regenerative adsorption dryer, the saturated desiccant still needs to be dried with the dried compressed air, but the compressed air will be heated by the electric heater before it is introduced into the pressure vessel.

这一设计上的改变使消耗的压缩空气更少，大约为干燥机额定产量的7.5%，可以释放更多的压缩空气满足需求，并降低了总体电气运行成本。这种类型的干燥机略大于无热再生型干燥机，且周期变为了4小时。

This design change results in less compressed air consumption, which is about 7.5% of the rated output of the dryer. It can release more compressed air to meet the demand and reduce the overall electrical operation cost. This type of dryer is slightly larger than the heatless regenerative dryer, and the cycle is changed to 4 hours.