A little more than 12 months ago, Tom White Waste (TWW) realised that it needed to develop significant additional waste processing capacity, both to service its present markets and to take the business into new sectors such as the production of refuse-derived fuel (RDF), while also keeping strict environmental control.
The new facility was conceived as a quantum leap in terms of the facilities available, the significant increase in waste handling capacity and, crucially, the equipment needed to provide the enhanced service levels.
The conclusion was simple: construct a high-specification building to house a high-performance recycling plant. The result of this major investment of around £10m can be seen as the plant opens for business.
Recycling machinery manufacturer Kiverco was involved in the project from its earliest days. TWW has used Kiverco sorting systems for nearly 10 years and it was the first choice for the upgrade. They worked extensively together to arrive at the best solution to handle the existing workload and ensure sufficient future capacity.
The plant has been designed to process up to 100,000 tonnes of mixed waste a year, with the option to recover key products for recycling and to process the residual waste into an RDF product, which can then be baled and wrapped before transportation to the end user.
The process for handling theincoming material and segregating it in order to be able to produce final products to the required specification is as follows:
1. Material is fed directly to a primary shredder to reduce volume and liberate material, giving a homogenous product of around 300mm particle size. From the shredder it is conveyed to a trommel with 40mm and 150mm screening apertures.
2. The fraction less than 40mm in size is collected under the trommel and conveyed beneath a Steinert in-line magnet to remove ferrous metals. From here material is fed directly to a Spaleck flip-flow screen to remove fines less than 10mm in size to a bay underneath.
3. The 10-40mm material is fed to a Kiverco density separator which produces a clean heavy fraction and a light fraction suitable for RDF.
4. The 40-150mm mid-size fraction from the trommel and the oversize fraction are conveyed in parallel to two Walair density separators. At this point there are a series of bi-directional conveyors which allow both sizes to be blended to run one line at a reduced capacity. This increases the availability of a customer’s facility during routine maintenance periods.
5. The heavy fraction from both density separators is combined and conveyed beneath a Steinert cross-belt magnet to remove ferrous metals. This fraction also goes through a sorting cabin where operatives can recover products or remove any remaining contaminants to leave a clean heavy fraction.
6. Finally, the light fraction from both density separators is conveyed through parallel sorting cabins, where operatives can recover products or remove materials unsuitable for the final RDF product.
The brief was a demanding one for Kiverco. The plant’s technology needed to ensure high throughput and maximum flexibility so the plant could operate according to changing market and customer requirements. In a business that cannot easily stop when work overwhelms, then robust and efficient plant is a must.
TOM WHITE WASTE
Tom White Waste was formed in 1981, when Tom White found it difficult to obtain waste management services for his other businesses and decided to start his own waste management operation.
Since then, the business has grown and, in 1988, Tom’s sons Ian and Paul joined. They now run the company as joint managing directors.
The firm operates in the commercial, industrial and domestic market sectors and covers an area of 30 miles radius from its facility in Coventry.
Ian White is a managing director of Tom White Waste and John Lines is marketing director of Kiverco