| 摘要 |
A vertically extending heat exchanger is provided in which an elongated dasher is rotatably mounted within an upright cylindrical chamber. The exterior surface of the dasher coacts with the interior surface of the chamber to form a product flow passage. The opposite side of the chamber interior surface is in contact with a heat exchange medium. The dasher is selectively movable longitudinally of the chamber between operative and inoperative modes. When in the operative mode, the dasher is fully assembled within the chamber and is supported at opposite ends by upper and lower endwall assemblies, the latter being mounted, respectively, on the upper and lower exterior end portions of the chamber. The dasher is movable to the inoperative mode when the lower endwall assembly is disassembled from the chamber and the dasher is lowered through the lower end portion of the chamber. The upper endwall assembly includes a static seal section disposed in an encompassing non-rotating relation with an upwardly projecting axial segment of the dasher, and a dynamic seal section encompassed by said static seal section and in sealing engagement therewith. The dynamic seal section encompasses the dasher axial segment and is rotatable therewith as a unit and moves longitudinally with the dasher when the latter is moved between operative and inoperative modes. The dasher axial segment has a portion protruding upwardly from the dynamic and static seal sections and is drivingly engaged by an external drive unit only when the dasher is in the operative mode. The dasher axial segment portion automatically engages with the drive unit when the dasher moves from the inoperative mode to the operative mode. |
