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.

在一個(gè)壓力容器中的干燥劑飽和之前，閥門(mén)控制系統(tǒng)會(huì)將未完全干燥的壓縮空氣輸送到另一個(gè)充滿(mǎn)干燥劑的壓力容器中。同時(shí)將前一個(gè)壓力容器置于大氣壓下，通入干燥過(guò)的壓縮空氣，帶走已飽和干燥劑中的水分，對(duì)干燥劑進(jìn)行再生。由于壓縮空氣在大氣壓下，露點(diǎn)會(huì)降低，因此其帶走水分的能力更強(qiáng)。兩壓力容器中的干燥劑像這樣交替干燥和再生，周期通常為10分鐘。這一循環(huán)再生過(guò)程消耗的壓縮空氣約為干燥機(jī)額定產(chǎn)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，這里的15%～20%是干燥機(jī)額定產(chǎn)量的15%～20%。在某些情況下，干燥機(jī)不會(huì)滿(mǎn)載工作。舉例來(lái)說(shuō)，當(dāng)干燥機(jī)半載工作時(shí)，這里用來(lái)帶走干燥劑中水分的壓縮空氣將是產(chǎn)量的30%到40%。在干燥空氣的過(guò)程中，此類(lèi)干燥機(jī)本身就將用掉大部分已干燥的壓縮空氣，這也是審計(jì)員不看好此類(lèi)壓縮機(jī)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.

為了彌補(bǔ)這一缺點(diǎn)，設(shè)計(jì)師們提出了不同版本的吸附式干燥機(jī)，其中之一就是有熱再生吸附式干燥的方法。類(lèi)似于無(wú)熱再生吸附式干燥機(jī)，仍要使用已經(jīng)干燥過(guò)的壓縮空氣來(lái)干燥已飽和的干燥劑，但壓縮空氣在通入壓力容器之前，會(huì)先用電加熱器進(jìn)行加熱。

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.

這一設(shè)計(jì)上的改變使消耗的壓縮空氣更少，大約為干燥機(jī)額定產(chǎn)量的7.5%，可以釋放更多的壓縮空氣滿(mǎn)足需求，并降低了總體電氣運(yùn)行成本。這種類(lèi)型的干燥機(jī)略大于無(wú)熱再生型干燥機(jī)，且周期變?yōu)榱?小時(shí)。

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.