Dynamic vacuum evaporation system

摘要

An ultraclean evaporation system which includes a vessel formed of a fluoropolymer inert to hydrogen peroxide and having an impurity level less than the impurity level of samples to be analyzed therein, preferably perfluoroalkoxy (PFA). A radiant heater is spaced from the vessel for uniformly heating the contents of the vessel. A shield, manufactured of aluminum and coated with a fluoropolymer encases the vessel alone or in conjunction with the heater. An inert gas supply is coupled to the vessel with a coupler of fluoropolymer inert to hydrogen peroxide, preferably PFA. An output is provided from the vessel formed of a fluoropolymer inert to hydrogen peroxide, preferably PFA. An orifice is provided which is formed of a fluoropolymer inert to hydrogen peroxide, preferably PFA, for controlling the flow rate of the inert gas supply. The tubing has a length of at least about 3 meters. The vessel has a side wall and a bottom forming a corner and is disposed so that the corner is the lowest region of the vessel. A vacuum pump is coupled to the outlet of the vessel for creating a dynamic vacuum in the vessel to maintain the mole percentage of hydrogen peroxide vapor in the vessel below 26 mole percent. The vacuum pump is preferably a Venturi vacuum pump with the inert gas supply also directly coupled to the Venturi vacuum pump to create the dynamic vacuum conditions in the vessel. The dynamic vacuum is preferably about 100 Torr.