It is proposed that the heat transfer body (2) is arranged inserted into an accommodating recess (9) provided for the heat transmission body (2) in the prefabricated plastic sheath (8).

Heat is transferred by the convection from the heated heat-transmitting conveyor (6) to the material that is being transported.

The heating device (100) comprises an electrically operable heating apparatus and a liquid chamber for accommodating a heat-transferring liquid.

The heat spreader comprises a base plate adapted to be thermally connected to the power semiconductor device, and a heat transmitting element, which is mounted on the base plate and adapted to dissipate the generated heat.

The surface of the heat transmitting element is dimensioned so as to extend at least over the entire surface of the at least one power semiconductor device.

The invention relates to a rod-shaped ultrasonic resonator which comprises a heat-transfer element that is coupled to the piezoelectric transducer in a thermally advantageous manner.

According to the method, rock material is heated by the combined action of a heating unit (7) located above the conveyor and a heated heat-transmitting conveyor (6).

Like iron, it is a good conductor and transmitter of heat, for that reason those utensils do not require thermal bottom or an internal layer of another metal.