The analysis of the sludges in the HUBER laboratory showed satisfactory guarantee values, e.g. cake DR contents > 28% with a throughput of 200 kgDR/h and a polymer consumption of 9 g/kgD. In addition, the numerous HUBER reference installations in Finland reinforced their decision to choose a ROTAMAT® Screw Press RoS 3Q size 620.
All guarantee values were met already during the first provisional start-up: With a polymer dose of 8 g/kgDR and a solids throughput of 280 kgDR/h DR contents of 33 % were measured. These values were even better than the performance data achieved by the six year old centrifuge on site with a low load and optimal settings. But whereas the centrifuge consumes 12 kW to achieve these performance data and shows a noise level in excess of 86 dB(A), the Screw Press needs only 1 kW with a noise level below 68 dB(A).
Besides, a performance test proved that the Screw Press achieves significantly higher dewatering results: We wanted to maximize throughput and minimize polymer consumption. In fact, the RoS 3Q 620 achieved an unbelievable cake DR of 38.5% with a solids load of 350 kgDR/H and a polymer dose of 6.5 g/kgDR – a far better result than that achieved by the centrifuge.
It remains to be seen in how far maintenance costs will decrease in Hämeenlinna which were the decisive factor for the customer to buy the HUBER product. On the basis of the experience we have made over many years with our ROTAMAT® Screw Press RoS 3Q units, however, we expect savings of 70 to 80% compared to the centrifuges.