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 and parallelly to said axis, and 2. at least one pair of generally opposed blade members, each blade member projecting generally radially from said shaft, each blade member axially extending generally continuously, except that such pair of blade members is slotted in the region of one pair of their respective diagonally opposite outside corners so that the effective total slot crosssectional area in each blade member of such pair ranges from about 1 to 50 percent of the total effective surface area of such blade member, the unslotted corner portion of each blade member being circumferentially disposed angularly from the soslotted corner thereof, both blade members of said pair having a similar angular disposition which extends generally in the same direction relative to said shaft, the angular displacement ranging from 0* to about 90*, the radially outer tip region of each blade member at any given location axially along said shaft together with the adjacent wall of said housing at about the same location forming a gap which is not more than about 5 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.