June 17, 2011
OVERLINE: Supply Lines
Down to the Last Drop
Drain as much water as possible out of your aggregate materials with this line-up of dewatering screens and screws.
by Kerry Clines, Senior Editor
Dewatering screens increase production while removing water.
Metso Mining & Construction says the first section of its high-capacity dewatering screen is constructed with a sharp 45-degree slope to remove water during the initial screening process. The remaining reverse-incline sections retain material and compact particles into a “filter cake” where most of the remaining moisture is removed.
The G4 dewatering screen from Linatex features a curved, sieve-like feed section and upward-inclined main deck for increased dewatering. The company says the use of centrifugal force allows a larger total screening area without increasing the size of the machine.
Derrick Corp. says its new W56 dewatering screen features true-High G force linear motion coupled with a high-open-area urethane screen surface to allow water removal at up to 300 tons per hour. The unit is operated by two vibratory drives and can be outfitted with spray bars for a cleaner end product.
GreyStone, Inc. offers three dewatering screen models — the 4- by 8-foot DS-488, the 5- by 10-foot DS-6010, and the 6- by 12-foot DS-7212. The units produce a dense, compact cake that rides up the belt to form a pile with no runoff or water pools. The high-frequency separators have an adjustable bed depth, table tilt, and vibrator variables.
The reverse-angle deck, VDS dewater screens from Sizetec, Inc. are available in many sizes — 2 by 7 feet, 3 by 8 feet, 3 by 10 feet, 4 by 10 feet, 5 by 12 feet, 6 by 12 feet, and 7 by 14 feet. All screens are equipped with either 1,200- or 1,800-rpm motors; the largest screen can dewater sand at up to 300 tons per hour.
Screen and screw combinations offer double-duty dewatering.
Trio Engineered Products
Trio offers a range of dewatering screens that can work along or in series with screws to provide additional dewatering when lower moisture content is desired. The company also offers fine material washers and log washers.
McLanahan manufactures dewatering screens and screws that can be used in combination to supplement existing screw installations, depending on design criteria and particle size. A double-wash process can be performed by using the screw for de-silting and adding sprays on the screens.
GreyStone, Inc. says its Aggre-Dry Washer combines a fine material screw and dewatering screen to reduce moisture content in material to as low as 8 to 13 percent, while using only 30 horsepower to wash and dewater up to 100 tons per hour. The unit’s 0.25-mm screen opening allows material to build to a depth of 14 inches on the screen to squeeze out additional moisture.
From single to double and from fine to coarse, screws offer options that meet plant needs.
KPI-JCI’s fine material washers are engineered with high-efficiency drives, resulting in low-horsepower requirement and reduced operating costs, while increasing throughput.
Eagle Iron Works
Both single and double screws are available from Eagle Iron Works. Single-screw sizes range from 20 inches by 22 feet to 72 inches by 38 feet; double-screw washers range from 36 inches by 25 feet to 72 inches by 38 feet.
KPI-JCI says its 500-ton-per-hour, coarse material washers are engineered to adapt to changing needs. Both single and twin-spiral designs can be reconfigured with numerous bolt-on paddle and flight arrangements to meet specifications.