Combined heating and mixing apparatus

Claim 1

Apparatus for carrying out high-temperature processes, especially for the decomposition of high molecular compounds at temperatures of over 300* C., comprising elongated housing means having an axis, an inlet in the region of one end thereof and an outlet in the region of the opposite end; elongated screw means arranged in said housing rotatable about said axis, said elongated screw means comprising a first screw means portion having a first end in the region of said inlet and an opposite end between said inlet and said outlet end serving to knead and mix material fed through said inlet in said housing means to thereby heat the material due to the friction produced during said kneading and mixing and to transport the material in the direction toward said outlet, and a second screw means portion having a greater pitch but a smaller thread depth than said first portion; heating means surrounding at least said second screw means portion for applying heat to the thin layer of material surrounding said second screw means portion; adjustable throttling means in the region of said outlet; and discharge means connected to said outlet and comprising a tubular member extending transverse to said axis, a rotatable feed screw coaxially arranged within said tubular member and a cooling jacket surrounding said tubular member.