| 摘要 |
Screened and drained used lubricating oil stock is predistilled in a steam stripping still for about 4 hours or more. The thus predistilled used oil then flows to an evaporator for a vacuum distillation at a temperature below the cracking temperature of the stock, about 480 DEG -650 DEG F., to effect an evaporation of the used lubricating oil and its separation from a concentrate by-product of heavy lube hydrocarbons and additives. |
