Differences between cold dryers and suction dryers

Air dryers have two categories: suction dryers and refrigeration dryers, what is the difference between refrigeration dryers and suction dryers?

1. The working principle is different

According to the principle of freeze dehumidification, the saturated compressed air from the upstream is cooled to a certain dew point temperature through the heat exchange with the refrigerant, and a large amount of liquid water is condensed, which is automatically discharged out of the machine after separation by the gas-liquid separator, so as to achieve the purpose of water removal and drying. According to the principle of pressure swing adsorption, the saturated compressed air from upstream is in contact with the desiccant under a certain pressure, and most of the water is adsorbed in the desiccant, and the dry air enters the downstream work, so as to achieve the purpose of deep drying.

2. The difference in the effect of water removal

Because the refrigeration dryer is constrained by its principle, if the temperature is too low, there will be ice phenomenon, so its dew point temperature is usually 2~10 °C. The dryer does not need to pass the temperature change, and the desiccant (alumina) can be deeply dried, so usually the dew point temperature of its outlet can reach -20 °C or less, that is, deep drying can be achieved.

3. The difference in energy loss

For the refrigeration dryer, because the work can be achieved by the refrigerant compression work, the power supply power will be high. Because the dryer only controls the valve through the electric control box, the electricity power is usually only tens of watts, which means that there will be no loss of electricity.

4. The gas volume loss is different

Because the refrigeration dryer achieves the purpose of removing water by changing the temperature, and the water is discharged from the machine through the automatic drainer, there is no loss of gas volume. The dryer needs to be regenerated after the desiccant is saturated with water absorption, because it requires a loss of about 6% of the regeneration gas. However, the JRR series waste heat regeneration adsorption dryer produced by Jiangsu Jiayu uses the waste heat generated during air compression to complete the regeneration of the adsorbent, so that the heating and regeneration does not consume compressed air, and only 1% of the dry compressed air is consumed during cold blowing, which almost reaches the standard of zero air consumption.