2 Sisters do the Double


Location: North Lancs., UK

Installation Date: 8th August 2008

Industry Sector: Chicken Roasting (120 tonnes per week)

Pre-install Issues: The client site has a central collection pit for all effluent which was emptied utilising high shear chopper pumps. The effluent was then passed over a wedge wire screen to remove solid debris before passing to a bio nutrient plant, from where the treated effluent was pH balanced and fed through a DAF plant to remove oils and excess biomass. The high content of chicken fat present caused untold problems with all stages of the process, the screen would blind with semi solid fat causing a large proportion of the effluent to simply run into the solids collection pit (30 mі) resulting in the requirement for this to be pumped 3 times per week at a cost of Ј400 each time. The bio nutrient plant, which is designed to remove sugars present in the coatings, could not operate efficiently as the fats were clogging up the system. The DAF plant could not cope with the strength of effluent being passed through it. As a consequence the Water Authority was regularly assessing the site and applying surcharges to the normal water charges. There was also a considerable odour problem from decaying fats, as the site is adjacent to a residential area, so the site was subject to pressure from the City Council and local resident pressure groups to improve the situation. Water disposal costs were around Ј25,000 per month with tankering costs of around Ј5,000.

2 Sisters PhotoSolution: The site was fitted with a Recoil 18 system, complete with solids removal augers and low shear pump systems. Additional heat sources were utilised due to the fast solidifying nature of the chicken fat and the exposed location of the equipment.

2 Sisters PhotoResult: The effluent is now initially treated by the Recoil system which efficiently removes the solid debris before de-oiling the effluent. As a result the wedge wire screen now works as designed to remove fine solids and carbon from the ovens. The bio nutrient plant is also now fully operational with the DAF system being used solely to remove the biomass carryover at the end of the process. Consequently the site is now compliant with the effluent standards required, the smell issue has abated and the sludge haulage costs are sunstantially reduced. Moreover, the site’s water charges have reduced to Ј5000 per month with Recovered Oil sales yielding approx Ј3-4000 per month.