Following an extensive trial at one of the largest waste processing plants in Europe, separators made by Borger are now playing a crucial role in improving the quality of the digestate used for land fertilisation in accordance with PAS 110 regulations.
The facility, which generates up to 5.9 MW of electricity from over 100,000 tonnes of food waste per year, had been looking to progress the way it removes contaminants such as plastic from the final digestate. Previously, the plant was using centrifuges to create a solid digestate, but felt that it could further improve the quality of its final product by producing a liquid digestate. RC 75 Separators from Borger were introduced, to see how they could deal with the significant challenges of hard-to-handle materials that come with food waste.
For a full 12 months, the Separators were put through their paces; monitored for their whole life performance and durability in an application that makes tough demands on wearing parts.
Designed with a leakproof rotating multi-disc, the energy efficient 75 m³/h Borger Separators benefit from having no metal-to-metal parts, with no abrasion between the auger and the wedge wire screen – and separation of the dewatering box and press channel to protect material.
“Our customer certainly found these new separators very suitable for the tough application”, said David Brown, Managing Director of Borger UK.
“They have enhanced the way that they filter out contaminants, separating solids 24/7 very effectively, which provides excellent peace of mind because it reduces the risk and the significant cost of any final product being sent to landfill”.
‘More capacity in the digesters’
He continued: “By improving the quality of the digestate, we have also helped the food waste/biogas facility reduce the cost and time of their chemical usage. For such sturdy pieces of equipment, the separators are simple to operate and maintain. The hire unit was a stand-alone, but the two separators are now fully integrated into the process. Another benefit is that with their capability in removing more solids, the separators provide more capacity in the digesters”.
Conveying the feedstock from the digester to the separators are self-priming Borger PL 400 rotary lobe pumps, which despite having had to fit into a confined space, have also proved very easy to maintain.
‘Pumps only need simple tools to service’
A spokesperson for the food waste/biogas facility, added: “The Borger pumps are very reliable and so much easier to strip down and rebuild than other pumps – some of which we know are going to be a very time-consuming job on the bench, whereas with Borger, we only need simple tools to carry out maintenance in place”.
He added: “These PL 400 pumps can, if necessary, be taken apart and put back together in just a couple of hours – and there’s never an issue getting parts. Borger are a very good and easy company to work with. They know what they’re talking about”.