A municipal waste processing plant in Poland faced a serious challenge with sludge dewatering. The sludge, a mixture of organic residues from the dry anaerobic digestion process, contained a high level of mineral substances – sand, silt, and glass powder – that proved too much for most dewatering equipment. These abrasive materials caused frequent blockages and significant damage to the machines. The situation seemed hopeless – until the inquiry reached the specialists at Esmil Group.
Sludge characteristics
The sludge generated at this facility is a byproduct of the dry anaerobic digestion of municipal waste with methane recovery. At the inlet stage, it has a dry solids content of 8-16% and an exceptionally high mineral content – reaching up to 64%. These parameters make the sludge particularly difficult to dewater effectively, posing a serious challenge for most technologies available on the market.
ESMIL Solution: Sludge Dewatering System with xJD Roller Press and Sand Separator
After thoroughly analyzing the challenges caused by the extremely high mineral content in the sludge, ESMIL specialists decided to implement not only the xJD-2000 roller press but also an additional unit – a sand separator.
The PT-100 sand separator effectively reduces the mineral content to a level that allows the sludge to be safely fed into the dewatering unit – without the risk of clogging or damage. The pre-treated sludge is then directed to the xJD roller press, where it undergoes mechanical dewatering.
The xJD/JD roller press is gaining increasing recognition among treatment plants dealing with difficult, abrasive sludges. It stands out for its high resistance to clogging – thanks to optimally spaced roller rows and a self-cleaning design, the dewatering process runs smoothly and without interruption.
As part of the order, we also supplied an automatic polymer preparation station, increasing the overall efficiency of the process.
Results achieved by the xJD roller press
Sludge characteristics at inlet:
- Dry solids content: 8–16%
- Mineral content: over 50% (up to 64%!)
xJD Roller Press Performance Results
- Dry solids content in dewatered cake: 25–35%
- Throughput: 380–920 kg/h (depending on polymer used)
- Suspended solids in filtrate: 1.5–3% (for comparison: previous solutions reached around 9–10%)
Summary
At Esmil Group, we approach every challenge comprehensively, going beyond standard solutions. In the case of this municipal waste processing facility, integrating a sand separator before the main dewatering stage effectively protected the roller press from potential damage caused by the extremely high mineral content in the incoming sludge. The system operates reliably, maintaining the target performance parameters – another success for ESMIL!
