Once collected, Rabbit sorts waste removing all recyclable materials for reuse with non-recyclable biomass being used as fuel in Rabbit’s waste to energy facility. Ajax’s twin screw feeder supplies the combustion system via a chain and disk conveyor and two feeders. Constructed in mild steel, the twin screw feeder collects the fines and sawdust from a hopper, transferring the materials to the collecting conveyor.A previous feeder’s narrow inlet resulted in the fines and sawdust arching; arching occurs when the strength of a material allows it to form a stable structure over an outlet. As a result of bench scale and pilot plant testing Ajax recommended vastly increasing the size of the inlet and utilising large diameter screws to cover variability in material flow.“The original screw feeder provided by a different supplier was very problematic meaning our system was unusable. Ajax undertook tests on the material and came up with their recommended design, which they supplied; this is working very effectively,” said Mick Adams, managing director, Rabbit Waste Management.