Moving Woodchips

Takraf Africa is handing over a complete woodchip conveying package as part of an expansion to a specialised cellulose production facility in South Africa. The facility produces Elemental Chlorine Free (ECF) dissolving wood pulp, mostly for the export market. The fast track contract covered the design, engineering, installation and commissioning of 24 trough conveyors, three Redler en-masse chain conveyors, transfer towers and related systems.

Increased production
Conveyors were integrated into both current and new lines to handle the increased production made possible by the expansion, with the conveyor system comprising three stockpiles fed by shuttle conveyors. With the new system, woodchips are conveyed from the existing and new chipping lines to the relevant stockpiles and then, using reclaim and associated conveyors, conveyed to existing infeed digester conveyors.

Various bypass systems have been planned and provided for, including that from the stacking route to the reclaim conveyors in the event that a reclaim machine is undergoing maintenance or unplanned downtime.

Controlling the dust
A set of Redler conveyors were installed for the conveying of fines generated by the screening system, which greatly assists in dust control.

“The Redler conveyors were selected for a number of the benefits they offer, including their ability to fit in with the current layout of the screening building, as well as space constraints within the plant,” says Richard Späth, General Manager for technologies, at Takraf Africa. “The Redler conveyor also boasts multiple discharges, facilitating the building of a “cone-shell type” stockpile, while also assisting in loading a truck evenly.”

Another uncommon feature designed and installed by the company is the four conveyor walk-in type gallery, with some of the conveyor gantries being required to span between 45m and 50m due to space constraints and existing infrastructure.

Since this was a brownfield project, the system was required to be installed in an operational plant where certain tie-ins had to be completed during limited shutdown windows. In addition, the fasttrack nature of the contract called for precise and tight planning of the in-house engineering, which was complicated by the challenges of interfacing with new and existing services on the plant.

“In total, approximately 1 700 tons of steel was required to be designed, fabricated and installed within 12 months, which included mechanical installation, commissioning and handover, without compromising on safety and the quality of the equipment provided,” Richard concludes.

Takraf Africa, Tel: (011) 201-2300