Abstract: A method and apparatus for heating or drying material by applying radio frequency (RF) power to a material in a resonant cavity; wherein an RF power source is inductively coupled to a resonant cavity formed by distributed inductance in resonance with the applicator and material where the magnetic field established by the feed line(s) induces a voltage on the applicator permitting feed line voltages delivering said RF power to the cavity to be lower than those that would normally be encountered for equivalent RF heating using direct coupling.

Abstract: A vacuum drying system wherein the drying chamber is provided with at least two vacuum draw headers positioned one above and one below a median plane through a load being dried to draw gases substantially symmetrically from opposite sides of the load as it is being dried. Preferably the drying system is a dielectric drying system and headers are positioned on opposite sides of the load.

Abstract: A dielectric heating or drying system incorporating an electrode structure, which is provided with wings that projects toward the opposite electrode along each side of a planar central portion of the electrode and function to improve electric field uniformity through the load being dried.

Abstract: A dielectric drying kiln material handling system includes a bottom electrode incorporating a conveyor system for moving material along said bottom electrode for moving material on and off of the electrode. Conveyors are built into the electrode in a manner so that the electrode surface of the bottom electrode, i.e. the surface contacting material to be dried is configured with gaps having dimensions so that the gaps do not significantly affect the uniformity of the power distribution over the electrode surface. Various types of conveyors may be used such as slat conveyors, roller conveyors, belt conveyors and the like provided the gaps, i.e. between the slats receiving the rollers or for accommodating the return rollers belt type conveyor are configured with dimensions so that the gaps do not significantly affect the uniformity of electromagnetic field and power distribution over the effective surface of the bottom electrode.

Abstract: A dielectric drying kiln having a moveable electrode permanently electrically connected with a source of power via an electrical connector formed by a plurality of discrete interconnected electrically and mechanically interconnected conducting element that permit relative movement between the elements. One end of the electrical connector is connected to the moveable electrode and moveable therewith while said electrical connector maintains electrical connection with the source. The electrical connector has a minimum curvature on its outside surface having a radius of at least r to prevent arcing.