Company Announcement - FLSmidth has upgraded the latest generation of its Tailings Dewatering Press technology for coal tailings applications, Jefrey Pilusa, Filtration Technology Specialist, FLSmidth, says. FLSmidth’s experience with belt press equipment dates back to 1979 with its EIMCO® branded belt presses, which were instrumental in the original pioneering of this technology. “Combined with its long and successful track record in tailings management over many decades, we have now taken proven TDP technology to the next level,” Pilusa says.

The TDP design includes several enhancements which recognise critical design considerations that make a positive difference to the belt press operation, performance and operating expenditure. For example, the design incorporates perforated ‘S’-rolls in key areas to double the filtration area and ensure more efficient dewatering of the cake, which means a greater drainage capacity compared to other belt press designs in the industry.

Ricus van Reenen, Sales Manager: Products, FLSmidth, explains that belt press technology is used mainly for the mining, wastewater and pulp and paper industries. “Over the years we have noticed competitive designs that have emulated older FLSmidth designs. As part of FLSmidth’s global programme utilising its global resources and experience to review all of our products, we recently decided to take another look at the belt press technology and to upgrade it with the focus on the tailings market. By offering better performance, a user friendly design and more cost effective solutions, FLSmidth hopes to provide our customers with an enhanced ‘One Solutions’ total service offering for our diverse customer base.”

Pilusa says the most significant advantage of the TDP technology is that it offers maximum cake dryness due to the ‘S’-roll design. Traditional ‘S’-rolls are configured in a horizontal mounting arrangement, which leads to visually discernible water pooling between the ‘S’-rolls, resulting in rewetting of the filter cake. In order to avoid this issue, TDP S-rolls are configured in a vertical configuration. This means that the belt travels upwards, with the filtrate (which is now removed from each S-roll) going into its own drip trays, thereby avoiding pooling and rewetting. “This produces consistently drier cake than horizontal designs,” Pilusa confirms. Another significant advantage is increased safety and a more user friendly design due to the low location of the gravity drainage zone. “FLSmidth regards health and safety as one of its topmost priorities,” Pilusa says. The TDP design means it is no longer necessary to use a ladder or to build expensive platforms for the purpose of monitoring the gravity drainage zone – where 80% of the dewatering work happens, as was the case with traditional designs.

“This reduces working-at-height hazards by allowing operators to inspect and monitor such critical areas from a standing level,” Pilusa says.  Furthermore, as with any belt press, if the solids are not properly gravity drained, the performance of the whole machine is degraded.  “If the gravity drainage zone is ‘out of sight and of mind’, how can any operator do their job properly?” Pilusa asks.

Reducing the operating expenditure is always a priority. “One of the ways of doing just that is to focus on increasing the life of the belts, which is what the TDP press has done,” Pilusa says.  Therefore the TDP design includes three unique features: Firstly, a rack-and-pinion belt take-up arrangement ensures that each side of the belt travels the same distance each revolution so as to eliminate belt ‘biasing’ and belt misalignment problems that lead to premature belt failures.

Secondly, each TDP frame is a built-in structure to insure that the frame remains true and square. Thirdly, each bearing is located with locating stops to ensure that all rolls are parallel, both when leaving the factory and in the field when rolls are removed and reassembled. These features enhance belt life by eliminating belt ‘biasing’ and belt alignment problems, while reducing maintenance costs.

The TDP technology also features a high cake discharge, which reduces installation costs as the filter is placed on ground level along with the conveyor. Other designs call for special platforms for the filters and conveyors so as to accommodate any discharge below ground level. “The TDP technology obviates this additional capital expenditure, which lowers operating costs, as all areas of the filter and conveyor are easily accessible for any future planned maintenance,” Pilusa says.

Another advantage is that the TDP technology can be factory assembled and delivered to site as a single unit. “The frame provides a rigid structure that will withstand maximum anticipated stresses and provide the best geometry for cloth tracking, which extends cloth life,” Pilusa says. All support bearings are self-aligning and anti-friction, with triple-lip nitrile seals.

In terms of FLSmidth’s ‘One Source’ approach, van Reenen says it can provide automated solutions ranging from panels for controlling local dewatering equipment to large plant-wide control system solutions. “We deliver state-of-the-art technology solutions for cost effective operation and increased plant availability, accompanied by comprehensive modernisation, optimisation and maintenance services,” he concludes.