South West Water’s requirements were to find a more reliable and less labour intensive option to de-watering than a centrifuge with lowest Whole Life Costs, low operator attendance, simple odour control availability and simple operation.
HUBER worked closely with Kier Utilities, undertaking trials to demonstrate the HUBER Screw Press Q-PRESS® to South West Water operations who wanted to touch and feel the machine and satisfy themselves that the machine was simple, robust and easy to operate. The trial data not only satisfied South West Water that this, first of its kind in their region was what they needed but provided hard data to confirm Whole Life Costs in terms of power and chemical consumption as well as enabling accurate sizing.
South West Water now have an alternative to centrifuges with a demonstrable WLC benefit together with operators who have bought into the equipment and are supportive of the change.
- 40 % polymer saving
- 80 % power savings (typical)
- 50 % saving on annual operating costs
HUBER Technology have been working on establishing the Q-PRESS® as the go to technology for sludge dewatering.
Sludge dewatering works extremely well on primary sludge and on larger sites sludge dewatering helps achieve a dryer cake, typically 18%- 30% for transportation and storage.
When clients are looking at sludge dewatering, three technologies are generally considered:
- Screw Presses like the HUBER Q-PRESS®:
Provide efficient , fully automatic, mechanical dewatering of sludge, low polymer usage
- Belt Presses:
Although a well-established technology they are perceived to have high maintenance costs due to lots of moving parts, the belts are vulnerable to wear and blockage, spills are likely unless enclosed and they have a high wash water demand
Although again an established technology they tend to have high TOTEX although single units are capable of large throughputs which equals lower CAPEX, they have high power costs associated with them, high operator attendance is required, high wearing parts due to high rotation speeds and a single wash is required at the end of a shift which can overload the unit and spill out of the discharge end
The HUBER Q-PRESS® has been an established product for the HUBER group and now has 1633 installations worldwide and 21 of those are UK installations.
South West Water had identified sludge presses as an option to replace the centrifuge at Plymouth Central and compared HUBER’s Screw Press Q-PRESS® with another screw press technology, both technologies undertaking trials at Plymouth Central.
Plymouth Central serves a P.E of around 320,000 and, being on a coastal port receives higher proportions of saline and fat than other in-land works typically do. Maer Lane serves a small population on the outskirts of Exmouth.
On site previously was a 2002-centrifuge unit with 45 kW main drive and 7.5 kW back drive, which operated from around 6:30 AM to 9 PM as required, running at around 30 m³/h.
HUBER’s Screw Press Q-PRESS® was demonstrated to have:
- Lowest NPV and WLC
- Lowest whole scheme capital cost
- Lowest operating cost
- Best technical support
HUBER SCrew Press Q-PRESS® sludge dewaterers are designed to provide efficient, fully automatic, mechanical dewatering of sludge once the diluted polymer dose into the feed sludge has been adjusted correctly to provide a suitable flocc. The enclosed design serves to reduce the odours, noise and the potential requirement for operator attendance due to spills that can be associated with other dewatering technologies on some sites. The low operating speed of the screw presses reduces wear and energy demand.