| abstract |
Process and apparatus for recovering clean water and solids from aqueous solids. Aqueous solids are mixed with a low viscosity, relatively volatile, water-immiscible light fluidizing oil to obtain a mixture which will remain fluid and pumpable after removal of essentially its entire water content. The mixture of solids, water and fluidizing oil is subjected to a dehydration step by heat evaporation whereby substantially all of the water and at least part of the light oil are evaporated and subsequently recovered. The light fluidizing oil is then largely separated from the solids. Those solids carrying residual light fluidizing oil are then brought into direct contact with steam, referred to herein as "blowing steam". The presence of the blowing steam reduces the boiling point of the water-immiscible light fluidizing oil to effect its more efficient removal from the solids. Effluent blowing steam and light oil vapor removed from the solids may be used to supply heat to the overall process. |