• 2024/12/10 11:10:48

Working Process of Adsorption Dryer

Overview of adsorption dryer

The adsorption dryer mainly uses adsorbents (such as activated alumina, molecular sieves, etc.) to adsorb moisture in humid air to obtain dry air. It usually adopts a double-tower structure, that is, the two drying tanks A and B are filled with adsorbents respectively, and continuous air drying is achieved by alternating work.

Detailed explanation of the work process

1. Adsorption stage

During the adsorption stage, humid air enters the A drying tank (or B drying tank, depending on the current working status) through the air inlet valve. The humid air enters from the lower pipe system and passes through the adsorbent bed from bottom to top. The adsorbent has extremely strong hydrophilicity and can adsorb moisture in the humid air to obtain dry air. The dried air is discharged from the upper pipeline for subsequent use.

During the adsorption process, the following points should be noted:

• Inlet pressure and temperature: The air inlet pressure should be controlled within a certain range, usually not exceeding 1MPa, and the inlet temperature should also be kept within the specified value to ensure the adsorption effect.

• Adsorbent saturation: As the adsorption time increases, the saturation of the adsorbent will gradually increase. When the adsorbent reaches saturation, its adsorption capacity will drop significantly, and it needs to be regenerated in time.

2. Regeneration stage

The regeneration stage is a key link in the work process of the adsorption dryer. During the regeneration stage, part of the dry air (usually about 10%) enters the B drying tank (or A drying tank, opposite to the adsorption stage) through the upper pipe system regeneration gas regulating valve. This part of the air is called "regeneration gas".

After the regeneration gas enters the B drying tank, the adsorbent is purged from top to bottom to remove the moisture and impurities adsorbed in the adsorbent. The decompressed dry air (i.e., regeneration gas) gradually heats up during the purge process, further improving the regeneration effect. The regenerated regeneration gas is discharged into the atmosphere through the lower pipe system B2 valve and muffler.

During the regeneration process, the following points should be noted:

• Regeneration gas volume: The size of the regeneration gas volume directly affects the regeneration effect. Too small a regeneration gas volume may lead to insufficient regeneration, while too large a regeneration gas volume may waste energy.

• Regeneration temperature: The regeneration temperature is an important factor affecting the regeneration effect. Appropriate regeneration temperature can accelerate the desorption process of moisture in the adsorbent and improve the regeneration efficiency.

• Regeneration time: The length of the regeneration time should be flexibly adjusted according to the saturation of the adsorbent and the regeneration effect.

3. Pressure equalization stage

The pressure equalization stage is carried out after the regeneration stage. During the pressure equalization stage, the B2 valve is closed and the B drying tank begins to increase the pressure to the online pressure, which is consistent with the working pressure of the adsorption stage. The purpose of the pressure equalization process is to balance the pressure in the B drying tank with the working pressure of the adsorption stage to prepare for the subsequent switching stage.

The pressure equalization process is usually faster, but it is also necessary to ensure the stability of the pressure balance. If the pressure equalization is insufficient or unstable, it may cause pressure fluctuations during the switching process and affect the drying effect.

4. Switching stage

The switching stage is the last link in the workflow of the adsorption dryer. During the switching phase, the B1 valve of the lower pipe system is opened, the A1 valve is closed, and the A2 valve is opened at the same time. In this way, the A and B drying tanks are switched: the B tank enters the adsorption phase and begins to adsorb moisture from the humid air; while the A tank enters the pressure relief regeneration phase and prepares for the next regeneration process.

The switching process needs to be carried out quickly and accurately to ensure the continuous and stable operation of the dryer. At the same time, the pressure fluctuation during the switching process also needs to be controlled within a certain range to avoid damage to the equipment or affect the drying effect.