| 摘要 |
An improved method for heating the aqueous slurries of soils contaminated wi th tarry/oily organics and volatile compounds. The method includes the steps of heating the slurry (containing inorganic and carbonaceous solids below 1/8 inch) with atmospheric pressure steam in a specially designed slurry heater(s), contacting the hot (95-99.degree.C) slurry with the contaminated feed soil (top size 5 inch) in a hydraulic feeder, processing the resultant slurry in a tumbler at temperatures up to 90.degree.C, separating the -1/8 inch solids from the slurry exiting the tumbler and recycling a portion of the -1 /8 inch solids in slurry back to slurry heater(s). In order to reach the required temperature in the tumbler, the -1/8 inch slurry has to travel through the tumbler at mass flow rates 1. 5- 4.0 times higher as compared to those for the soil feed stream. Under such conditions, the find (-1/8 inch) components of the soil are processed under more rigorous conditions (steam, high temperature, residence time, agitation) compared to large (1/8-5.0 inch) mineral components of the soil. This results in further improvement of thermal efficiency of the process.
|
