Global drive component specialist Voith Turbo has received an order from pump manufacturer Sulzer for the supply of Vorecon drives to State-owned power utility Eskom’s Medupi power station. Sulzer will supply three boiler feed pumps for each boiler, with one as a standby for pumping water into the boilers at high pressure to generate steam for the turbines.
“The total value of the order is about R250-million and we expect this contract to increase spin-off potential for the supply of our products in the Voith stable,” says Voith divisional manager Martin Darrington.
The Vorecons will be built by Voith and will weigh about 50 t, 10 t of which is oil content. The Vorecon drives will have a power output of between 18 MW and 20 MW, and will drihow to crush rocks for gold miningve the Sulzer boiler feed pumps at the power station. The delivery of the first Vorecon drive to Medupi will take place in December 2009, with one unit being delivered every month thereafter. Each Vorecon drive will be delivered as a complete unit.
Darrington explains that this is what makes the high efficiency Vorecons ideal as high volumes of water generate more steam, increasing pressure for maximum power generation. He explains that high pres-sure is necesmagnetic separation for ilmenitesary to pump the required volumes of water into the boiler and, by adjusting the planetary gear, the input can be increased from 1 500 rev/min to 18 000 rev/min.
Darrington adds that Eskom analysed the feasibility of the Vorecon together with three other products, including a low-speed variable-frequency drive (VFD), a high-speed VFD, and an RK geared coupling to arrive at the best solution for the effective and efficient driving of the boiler feed pumps.
“When Esilver ore process equipmentskom’s senior management recognised and understood the significant benefits and feasibility of the Vorecon drives as the best solution, they specified the units for driving the boiler feed pumps,” he says.
He adds that industry reports that rigorous testing has shown that the Vorecon is unmatched for reliability, quality and longevity and that these three key elements are what identifies Voith as the preferred supplier of the variable-speed planetary gears.
The company reporprices of jaw crushers used in blue metal quarriests that, during a 12-month study, which monitored and projected maintenance and operating costs over a 30-year cycle, the Vorecon performed seamlessly and without any maintenance costs. Further, the monitoring period revealed that the Vorecon could even exceed the maintenance-free 30-year life expectancy. This, says Darrington, will deliver excellent return on investment, a fact that is recognised by Eskom.
Darrington reports that Voith is knownpineapple squeezing and crushing equipment for its hydrodynamic technology and the hydrodynamic Vorecon, which operates largely free of wear and offers unsurpassed efficiencies across wide speed ranges with a reliability rate of 99,97%. Voith has designed the Vorecon not to exceed noise levels of 95 dbA, while vibration levels of the rotating machinery will run at 2,5.
Voith specially developed the Vorecon variable-speed planetary gear in 1985 for power exceeding 1 000 kW and over 200 drives are in service worldwide. The Vorecon operates on the principle of power splitting, which permits high efficiencies over a wide range of speeds. Most of the power is trans-mitted hydrodynamically directly through the main shaft and the rotating planetary gear.
The Vorecon’s hydrodynamic torque converter and super-imposed gear ensure that only the power necessary for adjusting the speed of the driven machine is split off from the main shaft through the hydrodynamic torque converter and superimposed into the planetary gear. By using most of the mech-anically transmitted power, the overall unit efficiency exceeds 95% and is, therefore, ideal for the continuous speed regulation of heavy-duty machines, such as the control of pumps, fans and coal mills in power stations.