Abstract: A short path evaporator including a heatable double-walled evaporator pipe having an inner interspace, with a rotatable rotor system disposed within the evaporator pipe and with a condenser disposed centrally in the evaporator pipe, and with an inlet for a product leading into the evaporator pipe, an outlet for a concentrate of the product leading out of the evaporator pipe, and an outlet for distillate accumulating at the condenser, and an inlet and an outlet for supplying and discharging heating medium to or from the interspace of the evaporator pipe, wherein the evaporator pipe is formed by an outer pipe and an inner pipe which, leaving the interspace, is disposed within the outer pipe, which are fixed at their ends in a sealing manner between two flange plates clamped together, wherein an inlet channel for the inlet of the product and an outlet channel for the outlet of the concentrate, which communicate with the interior of the inner pipe, are formed in the flange plates, as well as inlet and outlet chan