Mixer

Claim 1

A mixer adapted for use in processing highly viscous fluids comprising: A. a housing enclosing an interior chamber whose walls are generally radially symmetrical with respect to a longitudinal axis extending therethrough, said housing having defined therein port means adapted for input and output of material into and from said chamber, B. a paddle assembly positioned generally within said housing and comprising: 1. a shaft rotatably mounted at its opposite end portions in said housing and extending generally longitudinally through said interior chamber parallelly to said axis, and 2. at least one pair of diametrically opposed blade members, each blade member radially projecting from said shaft, each blade member axially extending generally continuously along said shaft, each such pair of blade members being slotted in the region of their respective diagonally opposite outside corners, the effective total slot cross-sectional surface area in each blade member ranging from about 3 to 50 percent of the total effective surface area of such blade member, the diameter of each such pair of blade members at any given location along said shaft except in slot locations being not less than about 90 percent of the diameter of said interior chamber measured at about the same location, C. bearing means functionally located between said housing and said shaft and adapting said shaft for rotational movements, and D. sealing means for said shaft adapted to prevent fluid leakage between said shaft and said housing.