Compressed Air Dryers - DH-4 Series

Foremost Machine Builders makes compressed air dryers for drying hygroscopic and non-hygroscopic plastic resins. While our hot air dryers can handle hygroscopic materials with non-critical drying requirements, they are most frequently used for removing surface moisture from non-hygroscopic materials and as resin preheaters or processes that require controlled raw material temperature prior to processing. The DH-4 Hot Air Dryer is specifically designed to surface dry regrind material such as, polypropylene and polyurethane. Heating unit and hopper sizes will vary based on the particular application parameters.

Compressed Air Dryers

Our hot air dryers use warmed compressed air as a drying medium and are typically chosen for particulate materials that are non-hygroscopic, i.e., absorb moisture only on the surface, or for surface drying hygroscopic regrind material such as polypropylene and polyurethane.

How Compressed Air Desiccant Dryers Work

In the DH-4 series, heat is used to lower the relative humidity of the surrounding air which improves its drying ability. Our desiccant air dryers use a molecular sieve to dry compressed air at high pressure, where the air itself must loose moisture because it has been compressed and the free moisture created by the compressing of the air would damage equipment that used the air.  The moist air is expelled into the atmosphere while fresh ambient air is drawn in to continue the process.

Applications

Typically, compressed air dryers are used for stripping surface moisture from raw materials for maintaining relatively dry conditions in large storage vessels such as silos that maybe subject to a build up of condensation moisture when outdoors and subject to variations to day/night temperatures in humid environments. Also useful as a material preheater which maybe equally important where material is stored outside in colder conditions and then brought inside where it is warmer and more humid. A cold pellet brought inside where it is warmer will collect surface moisture on the pellet spoiling the process. A hot air dyer is an excellent choice for preventing this effect.