Patents Assigned to Alameda Instruments
  • Patent number: 5061348
    Abstract: An apparatus and method for reprocessing waste piranha containing contaminated H.sub.2 SO.sub.4 from, for example, a semiconductor processing operation is described. The apparatus and method include a first distillation flask which is maintained under a substantial vacuum. The first distillation flask includes a first column packed with a column packing material and an input pipe for refluxing to retard loss of H.sub.2 SO.sub.4 in the first distillation. The second distillation flask boils off substantially pure H.sub.2 SO.sub.4 and provides for a continuous automatic purge of the contaminants from the second distillation flask thus improving the purity of the H.sub.2 SO.sub.4. The substantially pure H.sub.2 SO.sub.4 flows through a column which is coupled to a condenser which condenses substantially pure H.sub.2 SO.sub.4.
    Type: Grant
    Filed: February 15, 1990
    Date of Patent: October 29, 1991
    Assignee: Alameda Instruments
    Inventors: Marshall W. McCormick, Jesse C. Dobson