Modern Mining May 2017

PRODUCT News

Trend towards vertical turbine pumps

capabilities including three-dimensional solid modelling; hydraulic design; com- putational fluid dynamics (CFD) analysis; stress and deflection analysis using finite element analysis (FEA) and lateral and tor- sional rotor dynamic analysis. Weir Minerals Africa also offers the African market a recent Floway® innova- tion – the vertical turbine slurry pump (VTSP) – launched two years ago to serve the industry’s need to pump dirty water with specific gravity ratings of up to 1,2. “It is not common for vertical turbine pumps to be employed in applications of this range of specific gravity, so this prod- uct is a real pioneer,” Roelofse says. “The VTSP is particularly successful because it addresses and is designed to eliminate the two key contributors to the failure of cen- trifugal pumps: the mechanical seals and the line shaft and bowl bearings.” Rene Calitz, Weir Minerals Africa, tel (+27 11) 929-2622

A trend towards the use of vertical turbine pump (VTP) technology – which is gaining momentum in sectors including petro- chemical, mining and bulk water – is based on a number of valuable benefits over tra- ditional options. According to Kevin Roelofse, Weir Minerals Africa’s Dewatering Product Manager, Floway® vertical turbine pumps have particular advantages for applica- tions such as booster pumps in bulk water applications and for condensate extrac- tion in facilities that operate boilers, such as power stations. The release of a Floway® vertical turbine slurry pump (VTSP) also represents a technology breakthrough that is being well received. “In booster pump stations, VTPs allow savings on civil engineering infrastruc- ture as they have a smaller footprint, but more significantly they offer important operational cost efficiency related to reli- ability and lower maintenance,” Roelofse says. “The VTP can be multi-staged, with numerous impellers in the column, for large volume and discharge pressure applications.” While the traditional horizontal pump can offer up to a two-stage horizontal split casing configuration in a large-volume application, the impeller needs to be of a substantial size. “This means that the impeller tip speed will be high, so it will wear quicker and require more maintenance,” he says. By contrast, the VTP achieves lower wear and less maintenance by incorporat-

ing a number of smaller impellers along its column, so the speed at the impeller tip is lower. The operators of any facility that includes boilers – common in the energy generation, paper and petrochemical sectors – will know the challenges facing condensate extraction pumps. This equip- ment, vital to the movement of condensed steam, faces the danger of cavitation or pit- ting of impellers leading to inconvenient and costly downtime for replacement. “If there is insufficient suction pressure on the hot condensate then the vacuum existing at the suction of the impeller can exceed the water vapour pressure and can cause it to vaporise, imploding onto the impeller vanes and causing consider- able erosive wear on these impeller vanes due to cavitation,” Roelofse says. “This is devastating for the longevity of a centrifugal pump.” The VTP comes into its own

in these condensate extraction applications because the vertical column length can be designed in such a way that there is suffi- cient downward pressure of the condensate, restricting its abil- ity to vaporise and damage the impeller vanes. Floway® pumps are designed and manufactured under one roof at Weir’s state-of-the-art facility in Fresno, California. All the products embody a high level of in-house engineering

The Floway® VTP during installation at a customer’s site.

Specialised dewatering solutions from Franklin Franklin Electric is utilising its commit- ment to – and understanding of – complex dewatering applications together with cut- ting-edge scientific methodologies to offer specialised dewatering solutions in South Africa that it claims are 40 to 80%more cost effective than others on the local market. Application Engineering Manager for Franklin Electric SA, Lyon van der Merwe, says the company’s specialised dewater- ing solutions represent a problem-solving approach that offers durability and ease of repair resulting in increased uptime and an overall reduction in cost of ownership.

information can be accessed remotely via satellite (BGAN), cellular (GSM), Wi-Fi or radio systems. The VFD system is pre-programmed to manage and protect the motor and pump, accept transducer signals to ensure that the operation is controlled as well as collect all information and link it to the Remote Terminal Unit (RTU). The SCADA control system developed by Franklin Electric for dewatering monitoring and control applicationsmakes use of an RTU strategically placed in the mine dewatering field that is configured to collect direct and indirect VFD data such as voltage, current, frequency, torque, consumed power, operat- ing time, pressure and flow rates. Gideon Swanepoel, Franklin Electric, tel (+27 11) 723-6500

hostile conditions and are often situated deep underground, which can adversely affect their operation and make servicing difficult and time consuming, negatively affecting the viability of the mine. Franklin Electric has incorporated spe- cially developed and patented technology into its pumps, motors and control systems to ensure that repairs are quick and cost effective while a state-of-the-art moni- toring and control centre uses a Variable Frequency Drive (VFD) system to integrate water flows, levels and measurements. All parameters are recorded, logged and made available for operational and man- agement purposes. Data and operational

The pumps that are used for mine dewa- tering must be able to operate in extremely

May 2017  MODERN MINING  53