Appliance for heating an electroconductive material in the form of a continuous strand

A device for the manufacture of blanks (26) for building materials, in particular wall-building blocks, from a pourable raw mixture containing a binder which can be activated by heat, preferably a hydraulic binder, comprised by:

• a channel (14) receiving the raw mixture containing the binder at an entrance end and being formed by four synchronously-driven belts (10 to 13) made from an electrical insulating material for moving the material forward from the entrance end toward an exit end, a cutting apparatus (18) installed at the exit end of the channel (14), which cutting apparatus is synchronised with the speed at which the strand is fed through the channel and which is capable of being moved, in the forward-feed direction, from a starting position, and of being moved back into this starting position, and an appliance for heating the raw mixture within the channel (14), the appliance including a high-frequency generator (23), a first two capacitor plates (30) being arranged on two oppositely disposed sides of the channel (14), the plates (30) being staggered by at least their length and being connected to a non-earthed terminal of the high-frequency generator (23), and a second two capacitor plates (31, 32) arranged on each of the two sides of the channel and adjacent the first two capacitor plates (30), the second capacitor plates (31, 32) being connected to the earthed terminal of the high-frequency generator (23) and extending along the channel (14) for distance such that the strand outside the heating zone of the channel between the plates is no longer at a different potential from earth potential.