| 摘要 |
<p>The invention relates to a process for heat recovery during sludge treatment, especially in the hygienisation of sewage sludge, in which raw sludge is maintained at a temperature of about 60 to about 62 DEG C in a reactor 1. It is proposed, for preheating of the raw sludge and for cooling of the hygienised sludge drawn off from the reactor 1, that a heat exchanger 5, which has at least two chambers 8, 9, is charged in alternate periods with raw sludge and hygienised sludge. In the first period, the raw sludge is introduced into the first chamber 8 of the heat exchanger 5 and subjected to heat exchange with the precooled hygienised sludge present in the second chamber 9. Subsequently the hygienised sludge is drawn off and discharged, for example, into the digestion tank. In the second period, the hygienised sludge, which is at about 60 to about 62 DEG C from the reactor 1 is introduced into the second chamber 9 and subjected to heat exchange with the raw sludge preheated in the first period. Subsequently the raw sludge is discharged into the reactor 1. The first period then starts again.</p> |
