At the last bauma, the company Gebr. Siebers Tiefbau GmbH opted for a Sandvik QE341 heavy-duty scalping screen, a machine premièred at the trade fair. The 29-tonne screen is used primarily for mobile processing at Siebers’ construction sites and has proven efficient in solo operation as well as in combination with the Sandvik QJ241 jaw crusher acquired in 2011 from the Sandvik-Partner Trump Technik (Fig. 1).
Key focuses of the company founded in 2003 by the brothers Paul and Nicky Siebers near the German-Dutch border are all fields of civil engineering works including municipal supply and disposal systems, power and communications systems as well as earth moving for infrastructural projects or the development and preparation of plots for commercial and residential construction. Siebers was the first customer on the German market to buy a Sandvik QJ241 compact jaw crusher. The tracked 34 t crusher is impressive with quick set-up times and transportation between sites, good mobility on site and high crushing rates up to 150 t/h typically demanded in such applications. For screening, Siebers Tiefbau has so far used a compact scalping unit in the 20-t class. With a screening area measuring 1.20 x 2.70 m, it is able to handle the typical volumes of material (max 5000 t/construction site), but in larger projects or in combination with the Sandvik QJ241 jaw crusher, it soon came up against its limits.
“We needed a screen capable of handling larger feed sizes, with a better production rate, higher discharge belts for shorter set-up times for the crusher/screen combination and more flexible stockpiling capacities for one-man loader operation,” says Paul Siebers, running through the company’s various requirements. “And this if possible with a transport weight of around 30 t and screen performance that meets all demands for processing qualified material ready for use.“ Siebers Tiefbau finally decided to go with the scalping screen technology from Sandvik Construction. At the beginning of the year, the company took the Sandvik QE341, which perfectly meets the requirements listed above in terms of performance characteristics and capacity, for comprehensive performance trials as a long-term hire machine from Trump’s fleet of hire machines.
Key features of Sandvik’s QE series of scalping screens are the large screening areas of the double-deck screen boxes, which operate very efficiently thanks to the high throw. The transfers from the standard apron feeders and to the oversize discharge belts are designed to be especially wide to ensure trouble-free operation even when handling large feed pieces or very cohesive materials (Fig. 2). For duties as a scalping screen in quarries, the tracked chassis is designed to be extremely rugged, facilitating positioning and moving on construction sites. For rescreening of materials, the top and bottom decks of the QE models can be fitted with a wide range of screening media. High production rates with up to three final sizes are ensured by the wide transfers to the two side discharge belts, which with extensive horizontal and vertical reach also guarantee high stockpiling capacities for cost-efficient one-man loading operations (Fig. 3).
Built on a completely redesigned frame, the Sandvik QE341 is now even better equipped to handle high production rates. The rigid one-piece feed hopper is larger than before (7 m³), and thanks to an optional hopper extensions can be optimally loaded from the rear by wheel loader or excavator. The lengthened discharge belts are interchangeable for attachment to either side, and with adjustable discharge heights of over 4.0 m throughout, they enable much higher stockpiling volumes. The hydraulic system for lifting the screen box (1.5 x 4.70 m; screen angle 11°-17°) facilitates maintenance or changeover of the screen media in the lower deck (Fig. 4). Thanks to the hydraulically folding discharge belts and maintenance platforms, the 29 t Sandvik QE341 boasts compact transport dimensions – 14.84/3.00/3.40 m (Fig. 5). Once the screen is set up on site, the auto start/stop facility for all functions guarantees fast start-up. Smooth mobility even on difficult terrain (at quarries, construction sites) is ensured by the large clearance of proportionally driven crawler track with good traction and climbing ability (radio/cable remote control installed as standard).
The Sandvik QE341 now gleams in Siebers yellow livery and, transported on the also new 55-t low-bed loader trailer, is fully integrated in the company’s increasingly important recycling business (Fig. 6). “The machine delivers the expected performance in all areas. In standalone operation for separating building rubble or soil remediation we screen up to 200 t/h. As a scalping screen, its screening parameters and rate can be easily adjusted to a wide range of materials, optimizing the productivity of our crusher. The same applies to the production of final sizes, where the QE341 scores points with its wide flexibility and excellent performance.”