Liquid/supercritical fluid carbon dioxide cleaning of stainless steel components.

摘要

A Development Job Order initiated a study for quantitatively determining effectiveness of Liquid/Supercritical Fluid Carbon Dioxide (LCO(sub 2)) cleaning for removing hydrocarbon and particulate from full-size stainless steel components. In the first part of the study, full-size bottles were doped with varying amounts of two types of hydrocarbons. After doping, the parts were LCO(sub 2) cleaned at 40(degrees)C using different pressures (1500 and 3000 psia) and flow rates (10 and 100 cm(sup 3)/min). Results of these tests showed that LCO(sub 2) effectively removed oil from stainless steel bottles doped to levels as high as 13,000 (mu)g, regardless of the cleaning process parameters. Oil dopant levels of 130,000 (mu)g required higher pressure for effective cleaning. LCO(sub 2) cleaning was less effective on the other hydrocarbon. The second part of the study involved coupling ultrasonics and LCO(sub 2) processing to determine whether ultrasonics would improve either the particulate or hydrocarbon removal abilities of LCO(sub 2). Aluminum foil erosion tests determined that cavitation definitely occurred in the 1200--1500 psia, 40--66(degrees)C range. Particulate removal tests showed that this cavitation aided in the removal of loose particulate from two different bottle shapes. Limited testing also showed that ultrasonically induced cavitation improves the ability of LCO(sub 2) to remove Trim Sol. 12 refs., 23 figs., 1 tab.