found that they can partially liquify the chocolate so that it can be pumped by heating it from 70 u00b0 to 85 u00b0 f in ten minutes at this time the chocolate was ready to be pumped out through the interior channel 21 that extends from product outlet 22 through the centre of the leg 10 that supports the heating elements and that is open at the bottom end the chocolate still had a high viscosity due to the fact that only a portion of the fat fractions in the material was liquified which was a requirement in this particular application because most or all of the heat transfer takes place at the heating element that consists of crossed arms 24 that are equipped with a number of vanes 25 to increase the surface area of the elements the transfer of heat mostly takes place in this leading plane the inventors describe this heating method as 34 progressive zone melting 34 a process whereby the heating element moves on through one zone to another once the desired amount of heat has been transferred for many materials the desired objective is to transfer a specific amount of heat and to avoid overheating any part of the material with the process and apparatus of the invention no local overheating takes place for three reasons first the temperature of the heating element is controlled by hot water that is pumped through the series of channels the water temperature can be controlled accurately second the element is only in contact with any portion of the material for a very short time because the rotation of the drum has the effect of moving the heated arms constantly through the material third the material is.