A 30-ton elevator will fill, or empty, sand stored in either silo in one hour.
Once Alpha Foundry Co. in Wright City, MO, realized that demand for its aluminum and zinc castings was rising and its production was increasing, it recognized it had problem: as output increased Alpha's operations required more and more foundry sand, which meant the facility needed a way to store sand in high volumes.
They presented the problem to Frazier Bulk Inc. (www.frazierbulk.com), which designs and installs bulk material-handling systems, including several types of storage, conveying, weighing, dust-collection, and inventory-control systems.
Alpha Foundry had been storing sand in 2,000-lb bags, inside the plant. Floor space became scarce, and the operators realized that by storing some of their sand outside, in a silo, they could free valuable square footage for production activity.
Last spring, Frazier Bulk visited the Missouri foundry and consulted with Alpha's owners, Emerson and Ryan Barron to determine how to address the problem. After a thorough evaluation of the operating requirements and facility layout, Frazier Bulk proposed a system involving two 30-ton silos and a 30-ton/hour bucket elevator to fill each silo. Equipment was delivered last summer and installed by Alpha Foundry's workers.
The silos were designed specifically for bulk sand storage. Each silo includes ladder access to the top, an inspection hatch, and "high" and "low" level indicators to alert operators when the silo is ready to receive another load of sand, as well as when the silo is full. The discharge outlet was positioned 4.5 ft above the ground to allow the operator to fill tote boxes and other containers that feed core machines. A convenient butterfly valve controls flow from the silo outlet.
Also, Frazier Bulk provided an anti-segregation baffle above the silo outlet to prevent fines from accumulating, and to allow first-in, first-out flow from the silo. Frazier Bulk also provided a "skid" base that spreads the loaded silo weight over a greater area, so the foundry could employ the existing concrete pad, rather than pour new footings.
Frazier Bulk used standard product designs for the bucket elevators, but with simple sand-handling modifications. Use-specific features include high-wear buckets, commercial bearings, urethane-lined boot and head sections, a self-cleaning boot pulley, and abrasion-resistant rubber spouting.
According to Emerson Barron, "it used to take two guys working 2.5 hours to unload a truck. Now, one guy can unload a truck in about an hour." The system has opened up floor space inside the foundry, making more room available to produce castings, and besides the labor and space savings the foundry's need for disposing of sand-storage bags has diminished. "They really worked with us to provide a system that performs well at a cost we could justify," Barron says of Frazier.