Mixing Matters When You Need To Maximise the AD Process
Maximising the benefits of an anaerobic digestion system by achieving a higher gas yield, reducing foaming and eliminating the potential for maintenance problems, are among the important objectives for all AD plant owners.
However, in today’s climate AD operators are now seeking to fully maximise the sustainability benefits of their AD process plant which means each part of the process is coming under even closer scrutiny.
Mixing is a crucial part of the AD process and Huntingdon based System Mix LTD who market the Rotamix System incorporating the Vaughan chopper pump, are an established supplier of digester mixing systems at numerous installations across the UK. Andy Parr, Director of System Mix comments, “It is crucial to the AD process that suitable pre-conditioning of solids is carried-out prior to digestion and our system has been proven to be one of the most effective in achieving this”. He continued, “The Vaughan pump prevents re-accumulation of fibrous and fatty material in the digester and this means that material continues to pass through the nozzles. This in turn ensures that digestate is adequately conditioned and actually benefits all post-digestion equipment”. He concluded, “As many AD operators are now looking to maximise the sustainable credentials of their plant and equipment even further, we are confident that the benefits of our mixing systems are becoming even more important”.
Over last few years System Mix Ltd has been involved with ‘retrofit’ projects at existing AD plants where existing mixing systems were contributing to operational and biological issues.
For example, high grit deposition was reducing the active volume of digesters and threatening to significantly reduce output outside compliance requirements. Also, compressors were requiring high levels of maintenance and were proving costly to keep running. Furthermore, as deposition increased, the maintenance issues escalated because not only did the rag mass reweaving within the digester impair their efficiency, it also caused blockage problems in the heat exchangers and further downstream pumps and systems.