The suction dryer, that is, the adsorption dryer, is mainly used to reduce the moisture content in the compressed air and ensure the dryness of the compressed air. Its working principle is based on the principle of pressure swing adsorption, the following is a detailed explanation:
working principle
adsorption process:
- when the compressed air enters the dryer, it passes through a container (usually called a tower or a cylinder) containing an adsorbent.
- Adsorbents (such as molecular sieves, activated alumina, silica gel, etc.) have the ability to adsorb moisture and can adsorb moisture in compressed air on its surface or inside.
- In this way, the compressed air after the adsorbent treatment becomes relatively dry, and its dew point (I. e., the temperature at which water vapor in the air condenses into liquid water) is significantly reduced.
regeneration process:
- with the continuous use of the adsorbent, its ability to adsorb moisture will gradually decrease, and regeneration is required to restore its adsorption performance.
- The regeneration process is usually achieved by means of decompression expansion. A portion of the compressed air that has been dried (called regeneration gas) is decompressed and expanded to atmospheric pressure. This pressure change makes the expanded air drier.
- This drier regeneration gas is then directed through a layer of desiccant to be regenerated (I. e., a drying tower that has absorbed sufficient moisture). In the circulation process, the regeneration gas will absorb the moisture in the desiccant and carry it out of the dryer.
- In this way, the desiccant completes the regeneration process, regains its ability to adsorb moisture, and can continue to be used in the next adsorption cycle.
Classification
according to the adsorbent regeneration method, the suction dryer can be divided into two main types: no heat regeneration adsorption dryer and heat regeneration adsorption dryer:
- no heat regeneration adsorption dryer: The drying effect is achieved through "pressure change" without consuming additional heat source. A part of the dried air (regeneration gas) is expanded to atmospheric pressure under reduced pressure, and then flows through the desiccant layer to be regenerated for regeneration.
- Adsorption dryer with heat regeneration: The drying effect is achieved by "temperature change. This type of dryer is usually built-in or external heater, the regeneration gas is heated to produce high temperature air, so as to more effectively absorb the moisture in the desiccant.
Application
drying machine is widely used in new energy, biopharmaceutical, electronic chip, food chemical industry, high-end spraying, medical equipment, precision instruments and other industries. In these industries, there are high requirements for the dryness of compressed air. The suction dryer can ensure that the dryness of compressed air meets the production requirements, thereby ensuring product quality and production efficiency.
Advantage
- low dew point temperature the suction dryer can ensure that the dew point of the compressed air reaches a very low level, usually up to -20 ℃ to -70 ℃.
- Good stability: The suction dryer adopts the principle of physical adsorption for drying, and does not need to use chemical reagents or produce harmful substances, so it has good stability and is environmentally friendly.
- Environmental protection and energy saving modern suction dryers mostly adopt energy-saving designs, such as intelligent control, energy recovery and other technologies, which further reduce energy consumption and reduce the impact on the environment.
In summary, the suction dryer effectively reduces the moisture content in the compressed air through the pressure swing adsorption principle, and ensures the dryness of the compressed air. Its unique working principle and wide application fields make it an indispensable equipment in many industries.
