Patent ID: 6914226

Claim:
An oven for heating a product, the oven comprising: a conveyor apparatus to convey the product through the oven; one or more first electrodes; one or more second electrodes, the one or more second electrodes disposed relative to the one or more first electrodes to form a heating path between the one or more first electrodes and the one or more second electrodes through which the product is conveyed on the conveyor apparatus; one or more variable impedance devices, each of the one or more variable impedance devices having an adjustable impedance, and an input and an output, the output of an each one of the one or more variable impedance devices exclusively connected to at least one of the one or more first electrodes; an at least one adjustable length electrode feeder connecting the output of at least one of the one or more variable impedance devices to at least one of either the one or more first or second electrodes, whereby the distance between the at least one of either the one or more first or second electrodes and the product can be adjusted as the impedance of the adjustable length feeder is changed; one or more power sources, each of the one or more power sources having an RF power output, the RF power output of each one of the one or more power sources exclusively connected between the input of at least one of the one or more variable. impedance devices and at least one of the one or more second electrodes, the RF power output of each of the one or more power sources supplying RF power with a potential difference between the one or more first electrodes and the one or more second electrodes to radiate a RF energy between the one or more first electrodes and the one or more second electrodes, the RF energy to heat the product as the product is conveyed through the heating path; and whereby heating of the product is controlled by varying the adjustable impedance of each of the one or more adjustable impedance devices in an each circuit formed by one of the one or more power sources, one of the one or more variable impedance devices or the at least one adjustable length electrode feeder and the one of the one or more variable impedance devices associated with the at least one adjustable length electrode feeder, one or more first electrodes and one or more second electrodes, as the product is conveyed through the heating path.