I had a discussion with another consultant recently and thought it may be helpful to convey some thoughts about the growing use of compressed air material dryers…
Compressed Air Dryers
The compressed air dryer uses air that is provided from an existing air compressor. The air passes through a heater before reaching the pellets. At the compressor, the air loses moisture and the dewpoint typically drops 25 degrees Celsius or 45 degrees Fahrenheit below the dewpoint of the ambient air within the room. Since the dewpoint is not as low that of a desiccant dryer, they are not commonly used for highly hygroscopic materials such as nylon and acrylic.
These dryers are growing in popularity with respect to two purposes:1) Small Batch Drying – although these dryers are not the most effective method of drying, they can be used to dry virtually all materials, but they often take as much as 50% more time to accomplish the task. 2) Supplemental Drying – although many molders are trending towards large centralized material delivery systems, the material resides at the hopper for a period of time. Small capacity, compressed air dryers are a helpful method of maintaining a dry material at the hopper, especially during a process interruption.