SCHENCK Australia's latest banana screens are especially designed for wet and corrosive applications. The screen side plates are extended below the bottom stiffener, doing away with bolt-on drip angles.
No internal ledges or crevices are located below the screen deck.
The new design allows the protective coating, applied to the inside of the side plates, to be carried around the bottom edge of the side plate and up the outside, to protect the bottom edge of the sideplates where corrosion can cause stress cracking.
No welding is carried out on the side plates, eliminating heat induced stresses, distortion and metallurgical discontinuities.
Cross members are stress-relieved rectangular hollow sections (RHS) which are sized with a significant safety factor to accommodate unexpected, but normal, overloads.
The end flanges are attached to the RHS by full penetration welds. The cleats for attaching the longitudinal deck supports are fully seal welded to the cross beam.
The longitudinal rails are Huck-bolted to the crossbeam cleats. The vertical portion of the cleat is rubber covered and the joint is wet sealed.
The drive beam is a torsionally rigid fabricated box beam specially designed to accommodate the forces generated by the exciters. The beam is stress-relieved and machined with particular attention paid to the exciter mounting pads.
This beam is critical to the performance of the screen, and all welding exceeds the requirements of AS1554 for special purpose welds.
High tensile precision bolts, with self-locking nuts, are used for connections, where replaceable parts are attached to the screen.
Critical parts that may require adjustment after assembly are also attached with high strength precision bolts, while the remainder of the connections are Huck-bolted. Prior to assembly, components are grit blasted and primed with structural grade epoxy primer.
Components are assembled with a 'wet sealing' technique that bonds the surfaces together using a high strength polyurethane compound. The screen is then finish painted in accordance with site-specific requirements.
The crossbeams and the cleat to rail connections are normally protected by rubber covering. Alternative coating systems can be provided to meet special requirements.