Blue Air Compressed Air Dryers

Blue Air Compressed Air Dryers

Blue Air dryers dry the raw material with pre-dried air coming from the compressed air network in the plant. When dried compressed air expands to atmospheric pressure its dew point falls to a very low value; the air is heated to the required drying temperature and delivered to the chamber. The drying air is delivered at a dew point of −25 °C; drier air can also be produced if the application requires it.

The difference from a desiccant dryer

Dry air desiccant dryers hold the moisture in a desiccant material and have to regenerate that material regularly. In a compressed air dryer there is no regeneration circuit; the dry air already comes from the compressed air network. The number of moving parts is low and no cooling water connection is needed.

This design is particularly advantageous in three situations:

• Very small consumption: micro molding applications using less than one kilogram of material per hour.
• On-machine drying: the dryer sits directly on the feed throat; the dried material does not take up moisture again

in the conveying line.

• Blow molding plants: the very dry compressed air that an injection stretch blow molding machine discharges to atmosphere can be

reused in drying.

For central drying at high throughput, desiccant systems and the Digicolor Drywell family should also be assessed; the right choice depends on the compressed air capacity and the energy cost.

Models

How much the material has to be dried varies with the raw material; for details see our article on drying hygroscopic plastics, and for the chamber size the dryer selection tool.