Patent ID: 8449245

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 that surrounds 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 that inhibits conduction of heat from process fluid surrounding the shaft housing into an interior of the shaft housing, the thermal insulation having a thermal conductivity below 1 W/(m° C.), the interior of the shaft housing being a lubrication reservoir containing a lubricant that lubricates the lower mechanical bearing; and a lower mechanical seal allowing the distal end of the shaft to rotatably extend into the process fluid beyond a distal end of the shaft housing while preventing entry of the process fluid into the interior of the shaft housing.