AD operators wrong to run pumps into the ground – say Landia
“Mass-produced, bog-standard propeller mixers don’t last very long at all in AD environments”, says Landia’s Paul Davies. “We now see some operators just running their pumps into the ground because it’s actually cheaper to replace them completely than get at them to carry out maintenance. This can be the case for any type of mixing system that doesn’t allow you to carry out a service from outside the tank. Externally-mounted units have huge operational and safety benefits. Everything is at ground level, so there’s no working at heights. Nothing is in the gas-zoned area, so there’s no need for breathing apparatus. To maintain equipment such as submersible mixers, there’s no option other than to climb up, peel back the lid of the digester and purge the tank, which is extremely costly and time-consuming”.
He added: “Small submersible mixers will often be running flat out, lasting two years or much less - compared to a chopper pump that can last 25 years. You’d think energy savings would be at least part of most AD operators’ decision making, but that’s not always so. Three 30kW pumps doesn’t automatically mean 90kW hours because they might only need to run for a maximum of fifteen minutes per hour”.
Davies also points to the rising amount of acidic food waste being used as feedstock that corrodes cast iron equipment – and food waste that contains plastics from packaging that can also cause problems without the right processing or sufficiently strong pumps and mixers to handle it.
“Over-shredding of plastics will make particles too small to be screened out”, he says, “But under-shredding can create a floating mattress of plastic in the digester, which will see gas production reduce and then eventually have to stop so that someone has to go in manually and remove it all. AD downtime isn’t something you want. Lost revenue can amount to thousands of pounds per day - and a problem with fulfilling your contract to the energy provider”.
Founder ADBA members Landia will be promoting their externally-mounted GasMIx system during UK AD & Biogas at the NEC (July 2 & 3). GasMix is already in use at Cory’s first AD plant.
01948 661 200
No comments posted yet. Be the first to post a comment
Please enter your name
Please enter your comment
Your comment submitted successfully.Please wait for admin approval.
Some error on your process.Please try one more time.
Butchers in the UK are losing a generation through lack of training opportu...
NASA research has revealed how dust blown from the Sahara desert helps supp...
“In the run up to the Budget 2015 most commentators were predicting that th...
The UK’s first fully operational floating solar panel system has been unvei...
Axing the badger cull in England and Wales will save more than £120 million...
By 2025, solar power could become one of the cheapest forms of energy in ma...
Demand for Scottish farm land remains strong and continues to be better val...
The Welsh red meat industry should aim to increase sales by at least 34 per...
Fears about the impact that a proposed transatlantic trade agreement could ...