Heat producing device for e.g. heating water, has shaft guided in interior space of container, where shaft, disks connected with shaft, and interior side of container wall are coated with rigid, sturdy and open-porous foam material

摘要

The device has a container (10) comprising a closed interior space (11) containing fluid (20). A rotatable shaft (15) is guided in the interior space of the container. The fluid in the interior space of the container and the shaft are move relatively together, so as to develop heat in the fluid. The heat is directly dissipated as useful heat. The shaft and/or disks (17) firmly connected with the shaft and/or an interior side of a container wall (12) are coated with a rigid, sturdy and open-porous foam material e.g. metal foam material and ceramic foam material.