Wiped film devolatilizer construction

Claim 1

A wiped film devolatilizer adapted for the processing of relatively viscous fluid, melt material comprising: A. a substantially gas tight and fluid tight, generally crosssectionally circular, elongated housing 1. said housing defining therewith at successive regions along a common axis extending therethrough a. an input chamber adjacent one end of said housing, b. an enlarged, elongated, cylindrical vapor separation chamber, c. a compression chamber, d. a pumping chamber, and e. a sealing chamber adjacent the other end of said housing, 2. said housing having defined therein a. an input port into said input chamber, b. a drive shaft entry port in either opposed end of said housing, c. a product output port from said pumping chamber adjacent said sealing chamber, and d. a vapor Take-off port in said separation chamber adjacent said compression chamber, B. a first shaft means generally positioned within said input chamber and generally coaxial with said axis, said first shaft means comprising: 1. a rotatably mounted central portion, and 2. journal means mounting said central portion for rotational movements, 3. said central portion and said journal means together being adapted to cause during rotational movements of said central portion in operation of said devolatilizer melt material in said input chamber to pass from said input port and enter into said separation chamber circumferentially about said central portion, and C. first sealing means generally associated with said input chamber and adapted to make sealing engagement between said first shaft means and said housing during operation of said devolatilizer, D. a rotatably mounted rotor assembly generally positioned wtihin said separation chamber and generally coaxial with said axis, said rotor assembly comprising: 1. an axially extending, generally enclosed, drum having cylindrical side wall portions and an end wall portion adjacent said input chamber, 2. a stub shaft means coaxial with said axis and interconnecting said first shaft means and said end wall portion of said drum, 3. a plurality of radially extending, raised rib members integral with said end wall portion and positioned between said stub shaft means and said side wall portions, 4. a plurality of blade members integral with, and radially extending outwardly from, said side wall portions and terminating in land regions at respective outer edge portions, all individual land regions being substantially equally radially spaced from said axis, said blade members being so arranged that substantially every inside cylindrical surface portion of said housing in said separation chamber adjacent said side wall portions is swept by at least one of said land regions during each revolution of said rotor assembly during operation of said devolatilizer, 5. said rotor assembly being adapted during operation of said devolatilizer to produce simultaneously a. movement of melt material through said separation chamber from said input chamber to said compression chamber, b. spreading in the form of a thin film of at least a portion of melt material over said inside cylindrical surface portions of said housing in said separation chamber, and c. cocurrent movement of vapors escaping from melt material with said melt material in said separation zone to said vapor take-off port, E. compression screw means generally positioned within said compression chamber, and generally coaxial with said axis, said compression screw means 1. having a shaft portion whose outside diameter is so interrelated to the inside diameter of said housing in said compression chamber along the axial length thereof that the radial distance between said shaft portion and the inside cylindrical surface portions of said housing in said compression chamber generally continuously declines in the axial direction from said separation chamber to said pumping chamber, said shaft portion adjacent said separation chamber being integral with side wall portions of said drum, 2. having a peripherally located, circumferentially located, radially projecting, helically extending rib integral with said shaft portion, the width of said radial projection bringing said rib proximately to the inside cylindrical surface portions of said housing in said compression chamber, 3. being adapted to collect, compress, and convey melt material from said separation chamber to said pumping chamber during operation of said devolatilizer, F. screw pump means generally positioned within said pumping chamber and generally coaxial with said axis, said screw pump means being adapted to pressurize and convey melt material from said compression chamber to said product output port, said screw pump means adjacent said compreSsion chamber being integral with said shaft portion, G. second shaft means generally positioned within said sealing chamber and generally coaxial with said axis including journal means mounting said shaft for rotational movements, said second shaft means adjacent said pumping chamber being integral with said screw pump means, H. second sealing means generally associated with said sealing chamber and adapted to make sealing engagement between said second shaft means and said housing during operation of said devolatilizer, and I. power transfer means functionally associated with either said first or said second shaft means and adapted to rotatably drive same in a direction to move melt material from said input port to said product output port in said housing responsive to a power source functionally interconnected therewith during operation of said devolatilizer.