Patent ID: 7425090

Claim:
An apparatus for dispersing and melting flowable substances having at least two axis-parallel supporting shafts rotatable in the same direction on which screw elements with the same direction of thread are fitted so as to rotate in unison with said shafts, with which adjacent shafts intermesh, wherein for at least one pair of intermeshing screw elements, each said screw element comprises a plurality of screw portions that are disposed successively one next to the other along a length of said screw element, each said screw portion being disposed at a progressive angular offset from the next successive one of said screw portions, said screw portions having the same sense of rotation so as to form faces, wherein said faces of each said screw portion are at a progressive angular offset relative to said faces of said next successive screw portion and the pair of said screw elements are both of single-flighted or double-flighted form, wherein each said screw element comprises a monolithic screw element including the plurality of said screw portions at said progressive angular offset wherein said monolithic screw element is free of joints between said screw portions.