ENGINEERING: WMA Ships First Cavex Cyclone
Recent Western Cape Business News
FOLLOWING full implementation of its local fabrication capability for manufacture of its new Cavex ceramic dense media (DM) cyclones, Weir Minerals Africa (WMA) is now poised to ship the first orders for this innovative alternative technology specifically designed for dense media applications, with specific focus on coal processing.
A Cavex 650CVXT DM cyclone was dispatched at the end of November 2011 to a fluorspar operation, while a colliery on the Highveld has received eight 500CVXT and five 400CVXT units during the month of November.
The cyclone, that will be available in sizes from 250 mm up to 1450 mm, features a unique laminar spiral inlet geometry that delivers sharper separation, maximum capacity and longer wear life than conventional involute or tangential feel inlet DM cyclone designs.
“Our classification cyclones have earned a prominent place in the world market and, based on the success of this technology we took a strategic decision to enter the coal market with a premium brand Cavex DM cyclone for coal applications,” JD Singleton, cyclones and engineered systems product manager at WMA, says. “The coal sector is an exciting new growth area for us and we are entering it with a well-proven technology that has an innovative spin.”
Steel design for the new cyclone is being managed in-house and WMA has teamed up with a local ceramic tile fabricator to manufacture heavy duty alumina ceramic tiles. These are bonded onto prepared substrate using troweled-on, two-part epoxy adhesive for enduring strength.
“We believe our ceramic radius tiles offer the coal processing industry benefits which are not found anywhere else,” Singleton says. “Turbulence is reduced by the Cavex feed chamber design, where the tiles follow the same radius of the inner profile of the rubber feed chamber, achieving a monolithic wear rate that could significantly exceed wear capabilities currently possible in the industry.”
The design of the laminar spiral inlet geometry provides a natural flow path into the cyclone body, allowing the feed stream to blend smoothly with the rotating slurry inside the chamber. The result is greatly reduced turbulence throughout the entire cyclone, which boosts separation efficiency significantly.
DM cyclones are commonly used for separating coal from rock. Fine (minus 45 micron) magnetite is added to water to form a medium. Medium density is adjusted to a value between the density of coal and gangue rock. High density rock moves through the medium to the cyclone wall and out of the apex, while light coal particles enter the overflow stream.
The Cavex cyclone was initially developed in response to industry concerns relating to cyclone wear and reduced efficiencies in grinding circuits. Typical feed designs are 75° and 180° involutes. Existing designs were prone to wear near the inlet as a result of turbulence and coarse particle scouring.
“Our experts addressed this problem using years of slurry pump modelling design experience and the result was the Cavex cyclone, with a three-dimensional curvature along the inlet path,” Singleton says. “This curvature smooths the path of the fluid and reduces turbulence upon entry into the cyclone. The benefit is an improvement in the net inlet energy loss which increases the fluid tangential velocity and centrifugal force.”
Business News Sector Tags:
Fax 2 Email
Study IT Online
Work from Home