It takes a mighty big conveyor to fill some mighty big tanks at Farmland Industries Inc.’s 9.8-million-bushel corn cleaning and distribution center in Hereford, TX (806-364-3811/www.farmland.com).
Farmland last year purchased the facility from Frito-Lay and upgraded it with a new rail loop track and 60,000-bph rail receiving system that can unload a 110-car unit train in 10 hours or less (as reported in the May/June 2000 issue of Grain Journal).
About 500 feet of conveyor, the first 100 feet at a 14-degree incline, was needed to deliver corn at a rate of 60,000 bph from the rail receiving facility to four 500,000-bushel welded steel tanks lined up in a row.
The conveyor would have to be equipped with four intermediate discharge gates capable of diverting a portion of the grain stream, and Farmland wanted to be able to specify the percentage of the stream passing through each gate.
According to Project Manager Larry Jackson, intermediate discharge gates typically are found only on drag conveyors, but it would take a massive amount of horsepower to run a drag conveyor for that length and capacity.
The general contractor on the project, Borton Inc., suggested bringing in The Rapat Corp., an enclosed belt conveyor manufacturer in Hawley, MN (800-325-6377/www.rapat. com), to devise a solution.
Belt Conveyor Features
Rapat suggested using its Model ETR-50054 60,000-bph enclosed belt conveyor with a 54-inch-wide belt and sealed CEMA C three-roll troughing idlers mounted at a 45-degree angle.
To meet Farmland’s requirements, Rapat designed a variety of special features for the conveyor. While none are brand new technology, this is the first time Rapat had incorporated all of these features into a single custom-designed conveyor.
Among them:
• Four electrically-operated rack-and-pinion intermediate discharge gates with proportioning capability. This allows a specified percentage of product to be drawn off at any tripper location.
• Because of its length and incline, the conveyor has two motors and speed reducers, 200-hp at the head end driving a 24-inch-diameter lagged pulley and 50-hp at the tail end on a 10-inch-diameter pulley. Fluid couplings prevent the two drives from “fighting” each other.
• The tail section is outfitted with an enclosed, suspended gravity takeup utilizing a 7,000-lb. counterweight. The counterweight maintains the correct tension on the belt at all times.
• The conveyor also is outfitted with long-lasting UHMW liner along the inside of the bottom cover and easy access top covers for routine maintenance.
“We are pleased with the performance of the conveyor so far,” Jackson comments. “We’ve met our capacity goals, and any glitches at startup have been worked out. It’s running quite well so far.”
Ed Zdrojewski, editor
