Largest Hercules Trommel in the world

The largest HERCULES trommel screen in the world, operating at a quarry in England, has proved itself in boosting the quarry's production levels. Installed in June 2006, the 2.3 m diameter trommel screen, designed and manufactured by Stelex Engineering Limited. The barrel, which weighs 70 tonnes, is manufactured from round steel bars which are welded into support rings forming segments which make up the barrel. The unit can take a maximum feed size of 1.2 m3 and has a throughput capacity of up to 1000 tph. Its application is taking out the fines from the as-dug Kentish ragstone, a hard, fine-grained limestone with inter-bedded layers of a soft sandy material known as hassock, which the trommel separates out prior to primary crushing.

The 15.3 m long x 2.3 m inside diameter barrel is made up of three 4 m sections, two at 75 mm and one at 100 mm apertures. The clean +100 mm is fed to the primary crusher.

A variable speed reciprocating tray feeder, positioned beneath the hopper and supported on heavy duty rollers, gives the optimum feed rate of material to suit the quarry's daily production levels.

The feeder and screen are driven hydraulically from a electric hydraulic power pack located alongside the unit. Drive to the barrel is by a ‘live drive' system with hydraulic motors through steel support rollers, which are low maintenance and adjustable.

The trommel is self cleaning,due to the rolling action induced by the larger rocks,and offers the benefit of unmanned operation.