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Mixing system is key to Anaerobic Digestion efficiency

Regardless how many various technologies are used within an AD process, a thorough and efficient tank mixing system is absolutely fundamental to the success of its operation and output.

The drive for maximising efficiency, producing high yields and generating the best returns from the AD (Anaerobic Digestion) process is very much the focus for those who have invested in these renewable energy plants and is often a source of comment and opinion.

The reality for AD operators today is that not only is it vital to achieve maximum gas yields by perhaps reducing sludge foaming issues, or plant maintenance downtime, they also need to fully maximise the sustainability of their process. This means every section of the system is becoming the subject of ever closer scrutiny.

System Mix are the sole UK suppliers of their bespoke design Rotamix (Digester Mixing) and STM (Small Tank Mixing) tank mixing systems using the integral Vaughan chopper pump. These are operating successfully throughout the UK waste water industry, especially in Southern Water where they are now mixing in excess of 90 per cent of their digesters.

More recently the burgeoning market of private sector food waste AD plants are benefitting from their technology and experience and are involved in many 'retrofit' projects where existing mixing systems (or lack of them) were contributing to operational and biological issues. High grit deposition is commonplace which is reducing active digester volume and threatening a significant reduction in output, failing compliance requirements.

Also the compressors in 'traditional' gas mixing systems were requiring excessive maintenance with obvious process downtime and multiple costs. This of course all contributes to escalating problems further downstream because rag mass reweaving and settlement within the digester further impairs efficiency and output by causing blockages in the heat exchangers and other pumps and equipment.

"Many AD operators now need to maximise the sustainable credentials of their plant and equipment even further and we are confident that the benefits of our mixing systems are becoming even more important," Andy Parr, director at System Mix said.

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