Compressed Air Dryers
The principle of compressing air in factories for power tools and other high-pressure uses has a side benefit for the world of resin drying.
A compressed air resin dryer is a type of dryer used to remove moisture from plastic resin using compressed air. The dryer uses a combination of heat and compressed air to dry the resin, which is important for maintaining the quality of the resin and preventing defects in the final product.
The compressed air resin dryer typically consists of a hopper, a heater, and a blower. The resin is loaded into the hopper, where it is heated to a specified temperature. The heated air is then circulated through the resin by the blower, removing any moisture present in the resin.
Compressed air, once “decompressed,” re-enters atmospheric pressure with less moisture than it contained prior to compression. By ‘less moisture’, we mean that the moisture level (dew point) of the decompressed air is reduced by about 40-50 degrees, usually to a level of between -10˚ to +10˚ F
Considerations for Investment in a Compressed Air Resin Dryer
Compressed air dryers are simple and relatively maintenance-free but they have some big drawbacks for several reasons:
- The process air NEVER attains a -40˚ dew point (-10˚ to +10˚ F. is typical)
- The dew point varies with the weather (rising in hot humid conditions)
- Lack of uniform drying results in rejected parts and taking the dryer offline
- Typical throughputs range up to only about 50 lb. /hr.
The energy usage of a compressed air dryer is very high compared to most other resin dryer types.
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