Screw-Based System Improves Solids Handling

Solids handling specialist Ajax Equipment has supplied renewable energy consultancy and technology developer Renewable Energy Technology with a screw-based handling system for ash and char produced as by-products of the NovaGen gasification process. As well as promoting reliable flow, the new system will allow the waste fly ash and char ash to be collected and reused in other applications.  

The gasification process converts wood into a mixture of carbon monoxide, carbon dioxide, and hydrogen, known as syngas, a source of renewable energy. In order to maintain the separate processing of ash and char, Ajax has provided four hopper screw feeders, a collecting screw conveyor and screw elevator for a new fly ash processing system, and four screw feeders for the existing char ash handling system.

Fly ash is collected from filters featuring improved hoppers and integral screw feeders. The smooth stainless steel hoppers transfer ash from the filters to a collecting screw feeder, all of which are gas tight. The filter screw feeders feature a steep-walled shape with diverging end walls, and feed ash into a larger-diameter screw with progressive extraction geometry better suited to the hopper’s long outlet slots, ensuring reliable flow. The smaller equipment previously used included a hopper shape too sensitive to variations in process conditions and unsuited to the ash’s arching capability, resulting in unreliable flow. A similar approach was adopted on the main char feed screws direct from the gasifiers.

“From our experience on other projects screw based technology has proved to be the safest and most reliable way of transporting the ash and char produced from gasification,” said Renewable Energy Technology technical director Peter Bellis. “Having worked with Ajax in the past on transporting these types of ash, we knew they would produce the high-quality of equipment Renewable Energy Technology requires”.

For more information on Ajax Equipment, call +44(0)1204 386723 or visit www.ajax.co.uk.

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