| 摘要 |
<PICT:1037683/C1/1> Raw sludge is delivered to digester 31 in which sludge is already undergoing digestion. Partially digested sludge is withdrawn and separated for example with a solid bowl type centrifuge 37 into a dilute fraction containing mostly undigested gasifiable matter and a concentrated fraction largely non-digestible solids which is disposed of in a suitable manner by conveyer 44. The dilute fraction is thickened or dewatered in nozzle type bowl centrifuge 38 and at least a portion of the thickened material is returned to the digests while the rest may be returned for primary clarification. |
