Mixer/heat exchanger

Static mixer/heat exchanger comprising a housing (6) having a product flow space for a product to flow through, said product flow space being provided with an inlet and an outlet, at least two tubes (1) which enter the product space and are open at both ends to the exterior of the housing and are adapted to receive heat transfer media within their interior, to heat or cool a product flowing through said product space, a multiplicity of heat exchanger fins (2a, 2b) distributed over the circumference of the tubes (1), arranged in at least two parallel layers (7, 8) along the tubes (1), and wherein the fins (2a) end (2b) belonging to adjacent layers (7, 8) are rotated through an angle α of 45° to 135° with respect to one another about the axis of the tubes (1), and wherein the fins (2a, 2b) are disposed at an angle β of ±10° to 80° with respect to the main direction of flow (21) of the product through the housing (6).