System employs volumetric heating.

Click Image to Enlarge

The Macrowave RF Drying System from Radio Frequency Co., Inc. of Millis, Mass., is a new radio-frequency drying system for rapidly drying temperature-sensitive materials

The system employs volumetric heating, which keeps the temperature uniform throughout temperature-sensitive materials, reduces the moisture content to levels as low as 200 ppm, and eliminates the long dwell times required by conventional surface heating methods. Providing instant on/off control, this conveyor-fed drying system is billed as a suitable replacement for tumble, spray, tray, spin flash, and belt/tunnel dryers.

Rapidly removing water from material at bed depths up to 6 in., the system applies radio waves at a frequency of 40.68 MHz. Typically requiring one-fifth the floor space of conventional dryers, this system can reportedly reduce labor and energy costs by up to 60%. Applications include crystallization and the solid-stating of polymers. Company officials say the technology can be applied to all pelletized materials provided that carbon is not part of the formulation.  Carbon has a negative reaction to the RF which makes it arch.”  

The Macrowave RF Drying System is priced from $195,000 up, depending upon configuration