Process and apparatus for re-refining used petroleum products

摘要

Used petroleum products, such as crankcase oils, are reclaimed by an initial treatment step consisting of flash vaporization with continuous recirculation of a substantial portion of the unvaporized liquid. At atmospheric pressure and 210 DEG -240 DEG F, water comprises substantially all of the overhead product and this may be vented to the atmosphere. The unvaporized liquid product is mechanically filtered through a vibratory filter and then successive cannister filters to produce a product which may be used as a fuel oil or further refined into various fuel and/or lubricant products in successive flash distillation stages. In the preferred embodiment, three such stages are operated, respectively, at 300 DEG -400 DEG F and 24-28 inches mercury, 600 DEG -650 DEG F, and 7 torr, and 630 DEG -680 DEG F and 11/2-3 torr.