The amount of gas an AD plant produces isn’t just down to the feedstock. The feed system can play just as much of a vital role, according to biogas machinery manufacturer, Vogelsang.
With its dedicated biogas engineering team in Essen, Germany, Vogelsang has produced what it believes is the ‘gold standard’ in feed systems for feeding solid matter into a mashed form that promotes easy access to the bacteria and microbiological process.
The PreMix feed system was introduced to the biogas market in 2015, and has since become the feed system of choice for AD plant operators due to its particular design and high material quality.
“We’ve found that the PreMix has become the favoured feed system in the UK because it’s a complete 4 in 1 feeding concept for separating heavy matter, mixing solids with liquids, chopping down fibrous and coarse matter mashing and pumping with just one unit,” said Jonathan Gutteridge, Managing Director of Vogelsang Ltd.
“It’s made life so simple for plant operators to have one complete, connected system for treating and pumping.”
One of the key functions of the PreMix is its ability to effectively reduce the particle size of the feedstock before it enters the digester. It comprises a progressive cavity pump and a Vogelsang RotaCut macerator. The feedstock is fed into the side of the system through a feed screw, whilst recirculated liquid material is added. In a single step, the PreMix (pictured below) turns this into a homogeneous organic suspension and pumps it into the digester.All floating and suspended substances within the medium (hair, fibres, bones, wood etc) are transported to the cutting screen by the liquid current and are reliably crushed by rotating, self-sharpening blades.
Another benefit of the company’s feed system is that maintenance and stoppage time is significantly reduced by preventing blockages at the source. An AD plant on the east coast suffered from daily stoppages due to food waste blockages, prior to the PreMix being installed. The plant manager stated:
“The PreMix feed system and XRipper grinder have reduced the stoppage time by over 90% as there are far fewer blockages in the machinery.”
“Before, it was hours of work to clear the blockages, but now we almost never have any problems with the equipment. It’s reduced our downtime massively. Vogelsang’s equipment has been working faultlessly and is straightforward enough that we can do the maintenance for ourselves.”
“We have a lot of future plans for our site, such as building an additional digester in the next 12 months, and Vogelsang is an integral part of this,” added the Plant Manager.