Holborne roll out the barrel in Belgium

HOLBORNE Engineering Group Ltd of Wem, in Shropshire, have recently supplied a new primary trommel screen through their sales agents P.W. Laver Equipment Sales Ltd. The BT212 trommel, featuring an 8m long x 2.1m diameter barrel, was commissioned in July 2009 at a large quarry in Fond des Valux, near Wellin, in south-east Belgium.

Used to reclaim and clean run-of-quarry limestone from some of the overburden as well as areas of clay/soil contamination in the quarry excavations, the trommel screen is located adjacent to the primary crusher haul road and fed via a 75-ton capacity feed hopper and 1.5m x 4m reciprocating tray feeder.

The barrel itself was created by the fabrication of four sections, each constructed from 75mm diameter high-grade steel bars welded to 30mm and 50mm support rings to give screen apertures of 100mm x 100mm over the first two sections, and 80mm x 120mm over the second two sections.

Barrel drive is via a heavy link chain and sprocket arrangement powered by a hydraulic geared motor, while the reciprocating feeder is powered by a single hydraulic cylinder. Both drive units are supplied by independent hydraulic pumps coupled to electric motors.

With the screen apertures being relatively small for this application, Holborne also supplied and installed their patented barrel-cleaning mechanism. This 2m long unit comprises a series of flame-cut sprockets mounted on a shaft supported above the barrel drum. The sprocket teeth engage with, and are driven by, the rotating barrel, forcing any sticky or pegged material out of the apertures. The barrel cleaner can be extended over further sections if required.

Any oversize from the screen is collected by loading shovel and dumptruck and fed back into the quarry’s crushing plant together with the clean rock feed. Meanwhile, the undersize is utilized within the quarry or marketed as fill material, depending on the rock content and quality.

According to Holborne Engineering, investment in the heavy-duty trommel screen will guarantee its Belgian owner higher-grade/quality aggregate sales as well as reclaiming material that would otherwise be discarded.