Abstract: A diffusion pump capable of separating impurities from its pump fluid during operation is disclosed. Skimming drains are provided in the pump's boiler for periodically skimming the evaporative surface of the working fluid. This eliminates nearly all contaminants of higher molecular weight than the pump fluid. In the foreline of the pump, a series of peripheral gutters are provided for trapping, separating and draining off condensates. The gutters facilitate the removal of impurities of lower molecular weight than that of the pump fluid. Means are also provided for further removing trace quantities of residual volatile impurities which tend to backstream up the diffusion pump barrel. The highly purified pump fluid allows for a more vigorously working evaporative surface, thereby increasing the throughput of the diffusion pump. Together with the elimination of volatile impurities from the pump barrel, this facilitates the attainment of significantly higher ultimate chamber vacuum.

Abstract: Apparatus for effecting heat interchange of fluids, at least one of the fluids containing dispersed or dissolved solids, said apparatus having one or more fluids contacted surfaces which are (1) preferentially oil wettable and (2) substantially zero water adsorbent, wherein the contacted surface or surfaces comprise fluorocarbon polymers, preferably FEP fluorinated hydrocarbon resin, and (3) means for supplying oil or the like to said contacted surface or surfaces, to prevent adherence of solids thereto.

Abstract: A method of growing silicon carbide whiskers from a gaseous phase by means of a vapor-liquid-solid mechanism on a substrate using iron in a finely divided state as a solvent for the silicon carbide.