Patent ID: 8215899

Claim:
A vertically mountable shaft and bearing assembly for imparting rotary motion to a rotatable device submerged in a process fluid at a high temperature, the assembly comprising: a shaft having a proximal end to which rotation can be imparted, and a distal end which is attached to the rotatable device; a lower mechanical bearing rotatably supporting the shaft near its distal end; a shaft housing which contains the lower mechanical bearing and at least a portion of the shaft proximal to the lower mechanical bearing, the shaft housing including a layer of thermal insulation proximal to an inward-facing surface of the shaft housing which is capable of inhibiting conduction of heat from process fluid surrounding an exterior of the shaft housing into an interior of the shaft housing, the thermal insulation including at least one of vacuum, air, nitrogen, insulating foam, and glass wool, the interior of the shaft housing being a reservoir which is able to contain a lubricant that lubricates the lower mechanical bearing; and a lower mechanical seal allowing the distal end of the shaft to rotatably extend beyond a distal end of the shaft housing while preventing entry by the process fluid into the interior of the shaft housing when the distal end of the shaft housing is submerged in the process fluid.