The selection of the type of dryer is dependent on the application and the process. As a guide line the international standard ISO 8573.1 is used.

For semiconductor sector, Class 1 & 2 is preferred because of its low moisture, oil and dust content, while medical sectors uses Class 2 & 3, General Industry uses Class 4, 5 & 6. But in food industries especially for packaging, sometimes Class 2 is required to prevent food contamination.


Desiccant Dryers

Desiccant dryer is used when a low dew point is required.

The desiccant dryers are categorized into 2 types and is mainly the way the desiccant is regenerated. But VAPS Technologies together with our manufacturers Newgate Technologies, Inc from USA is offering a third option which will offer customers an even higher energy savings compared to both standard pressure swing and heat regenerative dryers. The new 3 main categories are as follows

•  Vacuum Assist Pressure Swing (VAPS) Dryers (ENERGY SAVING)

•  Pressure Swing Dryers

•  Heat Regenerative Dryers

As an operating standard for desiccant dryer, the wet air is flowed through a desiccant bed which can consist of either Silica Gel, Activated Alumina, Molecular Sieves or a combination of the latter 2 types. The desiccant has very fine capillary on its surface which makes it very Hygroscopic and will adsorb the water molecules from the compressed air. In the process of adsorbing it releases some energy in the form of heat which we call it Heat of Adsorption.

In the pressure swing dryer the heat of adsorption is needed later to be reabsorbed back into the desiccant to release the water molecules during regeneration, therefore the cycle time for pressure swing dryers are usually short.

For heat regeneration systems, since we are introducing heat into the system to regenerate the desiccant, we do not need to maintain the heat of adsorption in the vessel, thus the cycle time here is long.

Please call us for your requirements