Process for dewatering sludges in filter presses
AssigneePassavant-Werke AG
InventorOswald Busse
Life of this patent
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Abstract
To improve the dewaterability of sludge, which is dewatered in a dewatering device, in particular a plate filter press, a polymeric filter aid is added to the sludge. Since the flocs require a certain ripening time to form, a part stream of the unfiltered sludge is to be taken off according to the invention at the point opposite the feed and recycled into the main stream. The recycled flocs serve as flocculation nuclei. A further advantage of the sludge recycle is that the floc structure and/or size can then be scanned in the recycled part stream. The representative measured results are utilized for changing parameters which determine the dewaterability.
Claims13
A process for conditioning and subsequent dewatering of sludges in a filter press comprising the steps of:
- feeding a feed stream of sludge to a feed point of the filter press;
- adding conditioning agents including polymeric filter aids to the feed stream to condition the sludge and form sludge flocs;
- taking off a part of the conditioned sludge stream including sludge flocs at an end of the filter press opposite the feed point before activation of the filter press;
- recycling the part of the conditioned sludge stream including sludge flocs to the feed stream;
- mixing said flocs in said feed stream to form floc nuclei which permit new floc formation and contribute to the formation of flocs which are stable in the filter press;
- and
- dewatering the feed stream of sludge including floc nuclei in the filter press.
Dependencies are inferred from the claim text.