Bolton Clinical Waste Incinerator
Clinical Waste Incinerator operated by Sericylce (SRCL) Ltd and based at the Royal Bolton Hospital.
Summary
The Clinical Waste Incinerator is located at the Royal Bolton Hospital and is operated by Stericycle (SRCL) Ltd. The plant consists of a single stream, rated at 750 kg per hour or 6570 tonnes per annum of solid wastes[1]. The Primary Chamber operates a rotary kiln design to provide good mixing of the waste coupled to sufficient retention time to burn the wastes to a high quality ash[1].
Plant
Waste is loaded mechanically into the Primary Chamber using a hydraulic lift and tip arrangement, to avoid any manual handling of the waste ,ref name="SRCL" />. The rotating action of the kiln provides good mixing of the waste, exposing fresh surfaces to combustion conditions. The combustion process is operated slightly in the sub-stoichiometric or starved air mode to produce volatile gases to fuel the Secondary Chamber while providing good burnout of the fixed carbon in the waste to produce bottom ash,ref name="SRCL" />. The bottom ash is discharged from the end of the rotary kiln into an ash quench system to cool it rapidly, and from the ash quench pit it is discharged into storage skips. The skips of bottom ash are taken to a licensed Landfill Site for disposal as non-hazardous waste[1].
The combustion gases produced in the Primary Chamber then pass into the Secondary Chamber, which operates at a minimum temperature of 850°C during start-up using non-hazardous wastes; and at a minimum temperature of 1000°C when hazardous waste may be loaded[1]. The Secondary Chamber provides a minimum of two seconds residence time under oxygen-rich conditions to combust any Carbon Monoxide and volatile organic compounds produced in the Primary Chamber[1].
The hot gases then pass through a boiler and dilution air system, which reduce the temperature from above 1000°C to around 160°C, before the gaes pass on to the flue gas treatment (FGT) system[1].