METHOD AND APPARATUS FOR THE CONVEYING AND RADIO FREQUENCY PROCESSING OF DIELECTRIC MATERIALS

摘要

Particulate dielectric material is processed by radio frequency (RF) energy while being simultaneously conveyed from an inlet to an outlet, by disposing the transmitting and receiving electrodes of an RF generator diametrically opposite each other on the outside of a conveyor tube containing a screw conveyor, both the tube and screw being made of dielectric material. A fiberoptic probe is located at one end to sense the temperature of the particulate material in the conveyor tube and is connected at the opposite end to an infrared sensor which provides an electric output signal proportional to the sensed temperature. This output signal is coupled to a set point controller which provides an electric output signal representing a small temperature range above and below a selected set point temperature, and the latter output signal is coupled to a duty cycle regulator which operates to regulate the "on" time of the RF generator.