Dusty conveying job in quarry

Geared motors were selected for the conveyor system at the Gardanne quarry operated by Durance Granulats. Increasing the capacity by 25%, it takes the weight of ore processed from 400,000 tonnes to 500,000 tonnes a year. SMIL is a boiler making company which designs and installs heavy handling equipment, targeting three main markets: Quarries and Mines, Industrial Buildings and Aeronautical-Marine applications. The company was engaged to undertake the complete installation of an aggregate processing plant, including 25 belt conveyors, for Durance Granulats (part of the Eurovia group), in a quarry at Gardanne in the south of France. The old, now obsolete, plant has been part-dismantled and the equipment has been completely renewed. It means that three different sources of material can now be exploited, rather than just one: the first, on the site, and the second, 30 km from the quarry, are for the production of sand, gravel, ballast and mine run materials, intended primarily for roadworks (road base and subgrade layers), but also for industry, and particularly for removing sulphur emissions from the Gardanne power station. The third comes from a recycling facility, to recover materials from public works demolition rubble. The conveyors provide the link between the point of arrival of the raw material, the recovery equipment, and the point where it leaves the quarry. “For these new systems, Nord Drivesystems was of course one of the makes that interested us, both in terms of performance and resilience,” says Mathieu Kasprzak, Operations Manager for Durance Granulats. “Once we’d compared the specifications, Nord offered the best solution both technically and economically. We needed a robust, highly reliable solution which would fit into a very tight budget,” explains Mr Herry, Project Manager at SMIL. Nord’s SK90 bevel gear motors were chosen. They are sealed to IP55 standard, with an anti-run-back system. This is a mechanical system which operates when the conveyor is halted to prevent the belt from running backwards under the weight of the load. This device is incorporated into the gears. In all, 26 geared motors were acquired, rated from 2.2 kW to 22 kW. Six to eight months were needed to get the whole system with its 25 belt conveyors up and running. Pre-assembly was carried out in the workshop to fit the geared motors to the conveyor heads. Universal type motors with IEC flanges were chosen. In the case of a breakdown, other makes can be fitted as an emergency replacement. “We asked for universal fittings, so that the customer would be able to carry out quick repairs in the case of a breakdown, but Nord is also highly committed to after-sales service, with a fast on-site response within 2 days. In the preliminary study stages we also received good technical support from Nord’s teams, who helped us to select the equipment best suited to this application,” added Mr Herry. Alongside this, and for a different plant, a further dozen Nord Drivesystems geared motors have been chosen for 7 or 8 more conveyors, again for Durance Granulats. “Nord will be one of our partners in our forthcoming projects,” concludes Mr Herry.