(EN) The device comprises a two-layer plate (1) which is provided with a low heat conducting layer (2) and a highly heat conducting layer (3). At least two metal tubes (4) are arranged in said plate (1). Cooling tubes (4) are arranged in the plate (1) with a gap appearing therebetween so that a boundary surface (5) of the layers (2) and (3) of the plate intersects a hollow of said tubes (4) lengthwise essentially in parallel to the plane of the plate (1). According to the invention the boundary surface (5) of the layers (2) and (3) of the plate (1) is displaced in relation to the longitudinal central plane of the tubes (4) towards the low heat conducting layer (2).
