Wileman Engineers of have recently played an important role in the supply of equipment for the independent, and privately owned Rotherham Sand and Gravel Co Ltd at their flagship site at Scrooby Top, near Bawtry.
Following continued company expansion over a period of 20 years which included an increase to the range of products and services available planning permission was sought to extend Scrooby Top Quarry.
Approval was eventually granted by Nottinghamshire County Council for an estimated 15 years of new reserves on the condition that a new access road was built and the processing plant re-sited at a lower level to reduce its visual impact.
Following the receipt of planning approval the company made the decision to invest in a new processing plant which included a complete new washing and grading plant and an associated sand processing facility, weighbridge, new ready-mixed concrete plant, pre-pack bagging facilities and a new office block. Including the Scrooby Top Quarry the total landholding of the company amounts to some 400 acres with a number of other RSG sites supplying sand and gravel which is stockpiled on site prior to processing.
As part of the new plant Wileman Engineers were successful in the manufacture and supply of Wileman designed and built washing and grading screens (both 1.5m wide x 3.6m long) and also a 1.5m diameter x 2.7m long Wileman scrubber barrel.
Additional Wileman products include a mechanical clay picker for the removal of large lump clay or stone at the feed end of a material handling process.
The process involves materials being discharged into a 3.6m long x 1.5m wide Wileman double-deck vibrating screen inclined at 15° and equipped with spray bars. The screen is fitted with modular polyurethane screen media with 20mm apertures on the top deck and 5mm on the bottom deck. Washed – 75mm +5mm material is then discharged directly into a Wileman 15M27 scrubber barrel, a 1.5m diameter x 2.7m long contra-flow unit that features perforated polyurethane elements to remove sand and dirty water at both the feed end and the discharge end of the barrel. This barrel is driven by a 30kW squirrel cage motor and directly coupled gearbox through standard pneumatic tyres.
The -5mm sand/water slurry from both the scrubber barrel and the preceding wet screen is flumed to a collection box and then piped to a Linatex sand classification and dewatering system. The coarse fraction from the barrel is then discharged into a Metso Aquamator which separates lower density material from the clean aggregate. The contaminant-free gravel is then fed onto an inclined conveyor , which discharges on to another Wileman double-deck sizing screen fitted with modular polyurethane screen media with 20mm apertures on the top deck and 10mm apertures on the bottom.
This dry screen and the previous wet version are the first screens to be designed and built by Wileman. Both screens feature an all-bolted design for easy maintenance together with a galvanized surface finish for maximum protection.
The dry screen separates the incoming feed into – 20mm + 20mm and -10mm +6mm gravel fractions, which are discharged to ground stockpiles via two 15m long x 600mm wide stockpile conveyors, each capable of handling 50 tonnes/h.
Any oversize off the dry screen is then fed into a 20 tonne capacity surge hopper.