摘要 |
<p>To separate unwanted matter from a mixed sludge, the settling sludge is constantly stirred and maintained at a dense suspension through the addn. of rinsing water. It is mixed intensively with the suspension at one or more mixing points with a rotating distribution through the cross-section and thickened. The water is directed against the sludge flow so that the light matter of low density, which settles more slowly, can be rapidly removed at the overflow. The suspension taken from the under flow contains a suspension with a min. grain size and high suspension density for removal. USE/ADVANTAGE - The method is for the sepn. of soot, heavy metals and organic impurities in fluids and mixed sludges such as sewage or the sludge from a wet exhaust gas desulphurising unit, with the recovery of useful material such as gypsum, silicic acid or suspended sludge free of heavy metals. The system cleans the sludge effectively with recovery of useful material.</p> |