Abstract: A control system for controlling the heating of a product in a dielectric oven comprises at least one dielectric heating circuit including an electromagnetic energy source, such as a triode vacuum tube, having an anode and a resonant circuit including at least one inductor and at least a pair of capacitors. Each capacitor includes two capacitor plates and one of these capacitor plates is moveable, such that each pair of capacitors forms a variable capacitor in which the product to be heated is a dielectric. The system also includes at least one ammeter for measuring actual anode current at the anode. A motor is used to increase or decrease a distance between the plates of at least one of said capacitors, thereby adjusting the electromagnetic energy delivered to the product. A processor receives ammeter measurements, whereby the distance between the pair of capacitor plates is adjusted to increase or decrease the actual anode current.

Abstract: A removable tray holds a product for heating in a dielectric oven. The tray comprises at least one wall defining an interior, wherein the at least one wall is made from a non-electrically conductive material, such as a polycarbonate resin having a thickness in a range of about 0.08 to 0.09 inches (about 2.03 to 2.29 mm). The at least one wall includes at least a first and a second electrode. Each of the electrodes comprises a first portion and a second portion, wherein the first portion is separated from the tray interior by a thickness of polycarbonate resin in a range of about 0.01 to 0.03 inches (about 0.25 to 0.76 mm). The first portions bracket the product, are substantially parallel to each other, and are encased within the at least one wall. Each of the second portions has an exposed area which when the tray is placed in the oven is coupled with an electromagnetic energy source to produce an electromagnetic field between the electrodes.

Abstract: A reactor apparatus for production of Lunar oxygen uses feed stocks comprising a particulate hydrogen-reducible enriched feed in the size range from about 20-200 microns, containing 80-90% Lunar ilmenite (FeTiO.sub.3) and ferrous Lunar agglutinates. The reactor apparatus has three vertically spaced fluidized zones with downcomers from the upper to the central fluidized zone and openings for introducing a hydrogen-containing gas stream through the lower fluidized zone. A solid-to-gas RF-dielectric heater has a ceramic honeycomb with small parallel channels separated by thin, ceramic walls and electrodes surrounding the honeycomb connected to an external RF power source for heating the gas stream to a reducing reaction temperature. A top inlet introduces the enriched feed into the upper fluidized zone for fluidization therein and flow into middle and lower fluidized zones countercurrent to the flow of the gas stream.

Abstract: A dielectric oven for heating a product with a tray includes a housing having an access, wherein the housing defines a heating cavity. The oven includes an oven liner which substantially conforms to the interior shape of the heating cavity and forms a liner cavity within the heating cavity. The liner is made from a non-electrically conductive material which may have a low dielectric constant, a low dielectric loss tangent, and a melting point of at least about 225.degree. F. (107.degree. C.). The liner forms a vaportight boundary between the liner cavity and the heating cavity. The liner material may be a thermoplastic resin selected from the group consisting of polysulphone, polyester, and polycarbonate resins. The liner material may be reinforced with, for example, glass fibers, such as in fiberglass reinforced polyester resin. The housing and the liner may have at least one air intake port and at least one exhaust port. At least a pair of contacts may project into the interior of the oven liner.

Abstract: Slot interlock connectors for RF welding electrodes include an electrode having a working edge, at least two ends and an integral mounting block which has ends which overshadow the ends of the electrode and provide substantially flat alignment surfaces adjacent to the ends of the electrode. The electrode may have a curved or straight working edge and the integral mounting block may be disposed on the interior concave surface of the electrode or the exterior convex surface of the electrode. According to the invention, the electrode can have one, two, three, four, or more working edges with one, two, three, four, or more integral mounting blocks. The ends of the mounting blocks overshadow the ends of the electrodes and provide substantially flat alignment surfaces or alignment channels adjacent to the ends of the electrode. Several embodiments of connectors are disclosed, including connectors having L, T, +, and * configurations.

Abstract: An in-situ method of extracting contaminants from a soil volume comprises applying a radiofrequency (RF) excitation signal to heat the soil with an array of electrodes. The electrodes are inserted into the contaminated volume or inserted into a matrix of holes drilled into the volume. A first row of electrodes is electrically coupled to a shield of a coaxial cable, with a second row electrically coupled to the central conductor of the coaxial cable. RF energy is applied to pairs of electrode rows through the coaxial cable and a matching network is installed in front of the electrode-row pair to maximize power flow into the electrode-row pair. This results in very evenly distributed voltages which results in even heating. A balanced-to-unbalanced transformer (balun) is installed at the input to the matching network to prevent the deposition of RF energy outside the target volume and creation of voltages that could be hazardous to personnel.

Abstract: Improved methods and apparatus are disclosed for confining ohmic heating currents to a subsurface formation in the use of in situ ohmic heating for recovery of volatile and semi-volatile materials, such as hazardous waste, hydrocarbon-like materials, and valuable minerals having thermally responsive properties. Spacing between emplaced electrodes and the number of electrodes employed are controlled to cause coupling between electrodes for more uniform and higher temperature heating. Electrode designs are disclosed which suppress spurious earth currents which would heat other formations not of interest. Suppression of electrode end currents is accomplished by the use of distinct rings of insulation, control of the applied potential along the electrode, and injection or withdrawal of fluids at distinct locations along the electrode.

Abstract: An apparatus and method for drying, by heating, a continuous supply of dielectric material. A terminated, quarter-wavelength transmission line is used as a "traveling wave" applicator for transferring electromagnetic energy from a radio-frequency generator to the dielectric material as the material passes through the transmission line, preferably by gravity feed. The transmission line applicator is directly connected to the output of the radio-frequency generator, without any intervening feeding transmission line, so that the transmission line applicator becomes the resonant output tank circuit of the generator and thus determines the oscillation frequency of the generator. Forced air may be blown through the dielectric material as it flows through the transmission line so as to sweep moisture, driven to the surface of the dielectric material by heating, from the flowing dielectric material.

Abstract: The present invention relates to a joining method, a joining apparatus and a joining agent capable of joining two bodies to be jointed in a large size or in a complicated shape in a good joining condition. Specially, the present invention is to provide an improvement in a control of the current supplying method applicable for the electrically heating of the ceramic bodies or a joining agent in an electric conduction (a elecrode switching type due to a plurality of fixed electrodes and a switching control type between two kinds of the electric power sources), a control method of a auxiliary heating, a control of the holding apparatus (the control by the free thermal expansion at the pre-heating, a adaption of a balance mechanism and a measurement of the displacement), the adjustment of the shape at the butted portion (improvement of the pipe joint structure) and a joining agent superior in the joining strength.