When using a compressed heat dryer as the post-processing equipment, the process flow of the air compressor station is changed to: air compressor - Dryer - After filter - After air storage tank - Compressed air network.

Whether the dew point of the compressed air after treatment by the compressed heat dryer can meet the requirements, from the equipment level, the type and filling amount of the adsorbent. From an operational perspective, this depends on the completeness of the adsorbent regeneration.  

Activated alumina has a fast desorption speed, a short adsorbent regeneration process, and a short dual-tower switching cycle, but its adsorption capacity is not as good as molecular sieve. Therefore, when the pressure dew point temperature is -40 ℃, the adsorption tower can only be filled with activated alumina as the adsorbent, while when the pressure dew point temperature is -70 ℃, a certain amount of molecular sieve must be filled. .  

The operating conditions of the compressed heat dryer will affect the heating process of the adsorbent. Since the high-temperature compressed air at the outlet of the compressor all enters the regeneration tower to heat the adsorbent, the flow rate and temperature of the compressed air will affect the heating time.

To ensure the stability of the outlet pressure dew point of the compressed heat dryer, combined with the process flow, the following principles should be followed in engineering applications:

(1) The air compressor and the compressed heat dryer should be in one-to-one communication. Each dryer is equipped with a corresponding air compressor. The connection between the air compressor and the dryer should not be a main pipe method, and the air compressor should be directly connected to the corresponding dryer. It avoids the hydraulic imbalance caused by too many equipment, and the low compressed air flow at the dryer inlet in unfavorable loops. The shorter the connecting pipe, the smaller the heat loss, and the compressed air temperature at the inlet of the compressed heat dryer can be guaranteed to meet the process requirements.

(2) Compressed heat dryers should not be used with variable frequency air compressors. Because the flow rate of the variable frequency air compressor is 60%~100% If the compressed air flow rate entering the dryer is too small, the heating cycle of the desiccant will be prolonged, and the regeneration effect of the desiccant will be poor. If an air compressor needs a variable frequency air compressor, a dew point control method for switching adsorption towers should be adopted.

(3) The compressed heat dryer's intake pipe and accessories should be insulated. The higher the compressed air temperature at the dryer inlet, the better the regeneration effect of the desiccant. If the intake pipe system is not insulated, the temperature of the compressed air will decrease during transportation, and the temperature of the compressed air pipe wall will rise to 60 ℃ or more, causing burns.

(4) For compressed air systems with large changes in gas load, the control method of the compressed heat dryer should be selected as dew point control and time control.

(5) When the dryer inlet temperature may be low, the dryer should be equipped with an electric auxiliary heating system to reheat the inlet compressed air.

In summary, compressed heat regenerative dryers are used in occasions with large air consumption and small load fluctuations. The traditional time control method can achieve ideal operation effect and significant energy saving effect.