Following successful trials using the HUBER Technology pilot plant Screwpress Q-PRESS®, Dairy Crest Creamery in Davidstowe went ahead and purchased 2 off HUBER Screwpress Q-PRESS® units complete with polymer dosing, pumps and controls. This has now been followed by a third order to cover for expansion of the effluent plant which has now been successfully installed and commissioned.
Four different sludge streams arise from Dairy Crest’s modern effluent plant and it was initially thought they might behave differently with regards to polymer requirements and dewatering potential. Bench tests were carried out on all 4 streams individually and various combinations were followed by full scale tests and it was agreed that the 4 streams could be combined and an acceptable result could be achieved by combining all 4 streams. The DAF sludge aided the dewatering of the biological sludge and a suitable polymer was found to bind up the fines in all 4 feeds. By combining all 4 streams the system was simplified and a large saving in pipework and controls was made.
Originally the DAF sludge was dewatered on a Belt press and the other sludge’s were not possible to dewater efficiently on the belt press so they were taken away by tanker in a slurry form at ~4% Dry Solids. The belt press was awkward to use and the building required constant housekeeping to keep it clean and tidy. The totally enclosed HUBER Screwpress Q-PRESS® is much cleaner and reliable to operate.
On the permanent installation HUBER supplied all the pumps which pump the combined sludge into a common sump, 3 off Screwpress Q-PRESS®, the polymer dosing package, the conveyors and the control panel. Each Q-PRESS discharges the cake via a conveyor into a farm trailer for spreading by a solids muck spreader as opposed to liquid spraying. The volume reduction was 4 to 6 times the feed volume thus reducing transport and disposal costs.
Cake from Trials
HUBER Technology worked with Williams Industrial Services to install the 3rd Q-PRESS® and were pleased to of found the solution that Dairy Crests required.
The permanent Q-PRESS® units have now been running for over 6 months and consistently supply cake suitable for spreading by muck spreader and clean filtrate to return the flow to the effluent plant. The Q-PRESS® with its low power and volume reduction fit well in the ethos of Dairy Crest in reducing their environmental impact of running Europe’s largest mature Cheese production plant.
Trial plant on test at Dairy Crest
The above trial plant is supplied as a complete package and incorporates; the Q-PRESS®, the polyelectrolyte (poly) dosing unit, the sludge feed pump, the flocculation reactor and the control panel. The container also comes with a conveyor that is positioned under the discharge point from the Q-PRESS® and allows cake to be deposited outside the container.
Key benefits of the Q-PRESS®;
- Digestate volume reduction
- Reduced storage and transport costs
- High quality fertilizer
