Four Landia GasMix systems are close to completing their first year of uninterrupted operation at Eco Sustainable Solutions' award-winning 1.6MW AD facility in Piddlehinton, near Dorchester, Dorset. Externally-mounted with no moving parts inside the tank, the Landia GasMix systems serve two 2500m3 digesters that primarily contain household food waste.
Utilising 18.5kW chopper pumps to generate a total of 700m3 gas per hour, GasMix ensures that total mixing is achieved via specially angled recirculation nozzles. Compared to many energy-burning systems that have to run flat-out, 24/7, Landia's GasMix at Piddlehinton only needs to operate for approximately 10 to 20 minutes per hour. Food waste from around 60,000 Dorset households, plus liquid waste from milk and cheese production, is kept at 410C inside the digesters, with a retention time of 40 days.
Stephen Harman, Operations Manager at Eco Sustainable Solutions, said: "Since the installation of the four Landia GasMix systems, we have had absolutely no performance or reliability issues. Eco choose the Landia GasMix system because all the pumps and pipe-work parts are on the outside of the digesters, so importantly, can be maintained without interruption to our 24/7 process".
Initially, Eco had employed standard rotary submerged equipment for its first digester, but opted instead for Landia's GasMix when the second digester was built. Such was its efficiency, reliability and ease of access for servicing that the first digester was then retrofitted with Landia's GasMix.
The 2.5 acre site, which was Eco's first move into renewable energy, supplies 60% of its power to Mole Valley Farmers' neighbouring Dorchester Feed Mill, the first feed mill in the UK to be powered completely by renewables. The remaining 40% generated is sold on to the National Grid. PAS 110-approved digestate is also sold on as fertiliser to two local farms. Trelawney Dampney, Eco's Managing Director, added: "Completed on time and within budget, our AD facility at Piddlehinton is proving itself as a highly efficient plant and I believe will act as a blueprint for future resource projects".