Wiped thin film evaporation and treatment apparatus

Claim 1

A wiped thiN film treatment apparatus, especially for treating viscous materials, comprising means defining a rotationally symmetrical treatment chamber, heating or cooling jacket means encircling said treatment chamber, rotor means within said treatment chamber, said rotor means comprising a rotor shaft, material conveying means and wiper means, said material conveying means comprising a plurality of vane stubs arranged in at least one row extending in axial direction along said rotor shaft and being supported thereby, each vane stub having a conveying surface inclined with respect to the axis of rotation of said rotor shaft at an angle of less than 90* with respect to said axis, each vane stub further having a leading edge and a trailing edge, each trailing edge of one vane stub of said row being spaced from the leading of the succeeding vane stub of said row as viewed in the axial direction to form a respective axial gap between adjacent vane stubs in said row, which is not swept by any vane stubs in said row, said wiper means comprising at least one wiper member extending substantially over the length of the treatment chamber said wiper member being angularly retarded in immediate trailing fashion with respect to said row of vane stubs, said vane stubs forming ridged circumferential arcs of the material being treated on the chamber inner surface of substantially shortened circumferential extent relative to the circumferential extent and width of the continuously wiped film formed by said wiper member, said ridged arcs being sheared and spread upwardly and downwardly substantially immediately by said wiper member after being formed, thereby minimizing the gravitational effects on said ridged arcs and increasing the wiped film residence time with the heat exchange surface contacted.