16 Mar 2015
Hewitt Robins International (HRI) – a Tata Enterprise, have recently supplied four Quad-V screens for a new processing plant at Croft Quarry in Leicestershire.
Owned and operated by Aggregate Industries (AI), Croft is an established quarry covering an area of 89 hectares in total. The site has a significant history as the granite was first used by the Romans to construct the foundations of bridges on the Fosse Way. Today the quarry processes approximately 1.2 million tonnes of granite each year which is sold to an on-site concrete plant, asphalt plant and a block making plant. These sales are combined with local deliveries reaching as far as Redditch. Stone is also delivered via the on-site railhead to depots in the South East.
The new screening plant
With all the crushers located in the main process, the new 500tph processing plant consists of four Hewitt Robins screens, stocking out conveyors and a re-crush conveyor. Completed in July 2014, the whole project took six months to complete, with the plant being designed, specified and constructed by Roltech Engineering of Newcastle-under-Lyme, Staffordshire.
Brian Wiltshire – Works Manager AI, commented, “We looked very carefully at screen suppliers and eventually chose Hewitt Robins because of build quality and the ability to supply exactly what we wanted. An additional benefit has been the commonality of the vibrating pods, which are all interchangeable therefore we only need one spare set.”
Hewitt Robins supplied four screens in total; two – Quad-V14 – 2.7 x 8.4m inclined double-deck screens, one Quad-V14 – 2.7 x 7.2m inclined single-deck screen and one Quad-V11 – 1.6 x 4.8m inclined double-deck screen.
Each screen was supplied with 12.5mm thick side plates and 17.5mm thick doubler plates around the vibrator unit for extra strength and durability. The screens are of a bolted construction for ease of maintenance and incorporate bolted feed boxes and discharge lips. Support springs, spring base plates, pivoting motor base, complete v-belt drives and pullies complete the specification.
The screens were rubber lined with bolted liner rubbers with the cross members lined with 6mm thick rubber to provide complete protection. A rubber curtain in the back plate provides access to the bottom deck, at the feed end of the screens. The decks were fitted out with M.H.P rubber modular deck system. The screens were also supplied with complete dust encapsulation, which was imperative.
Hewitt Robins delivered the screens within 12 weeks of order with all screens being fully commissioned by Hewitt Robins engineers.
Brian, further commented, “After months of operation we have had consistent performance from the screens, Hewitt Robins have been very accommodating and supplied screens that are perfect for the application.”
HRI Quad-V Inclined Screens
Each one of the Hewitt Robins screens at Croft is fitted with the Quad-V14 vibrator mechanism. These are designed for exceptional reliability and low maintenance. The pod type vibrator unit consists of 2 bearings per pod (4 per machine) to give increased bearing life and less downtime.
Each Quad-V pod is connected through the centre of the machine using a Cardan shaft drive which can be disconnected, thus eliminating the issues of cumbersome heavy shafts that require craneage. Additionally, the Cardan shaft design also provides increased distance between the decks for maintenance and changing modules.
All Hewitt Robins Inclined Screens are custom designed to suit specific applications, with replacement screens engineered to fit into existing structures, saving valuable down time and money.
Hewitt Robin’s manufactures 100% in the UK and is known globally for producing superior quality equipment which operates in some of the toughest working environments to man. All equipment is backed up by exceptional customer service and parts support making Hewitt Robins the preferred supplier for mining, aggregates and steel producers around the world today.