Radio Frequency Dryer

R.F. Technology

In a radio frequency heating system the RF generator creates an alternating electric field between two electrodes. The material to be heated is conveyed between the electrodes where the alternating energy causes polar molecules in the material to continuously reorient themselves to face opposite poles much like the way bar magnets behave in an alternating magnetic field. The friction resulting from molecular movement causes the material to rapidly heat throughout its entire mass.

The amount of heat generated in the product is determined by the frequency, the square of the applied voltage, dimensions of the product and the dielectric loss factor of the material, which is essentially a measure of the ease with which the material can be heated by radio frequency waves.

Advantages

For those applications that require uniform heating and precise temperature control RF offers many advantages over conventional drying methods.

• Uniform heating through entire thickness
• 2 to 20 times faster than conventional drying methods
• Energy efficient
• Uniform moisture profiling
• Low maintenance
• Eco-friendly process

What can I dry using RF?

Any product that is difficult to dry with convection heating is likely to be a good candidate for RF drying. Radio frequency heats all parts of the product mass simultaneously and evaporates the water in situ at relatively low temperatures usually not exceeding 80^oC (180^oF). Since water moves through the product in the form of a gas rather than by capillary action, migration of solids is avoided. Warping, surface discoloration, and cracking associated with conventional drying methods are also avoided.

Applications

• Textiles
• Paper
• Food Products
• Foundries
• Wood Products
• Rubber
• Chemicals and Pharmaceuticals
• Leather
• Ceramics