Storage Facility

Patented Circ-A-Bin Bulk Storage & Transshipment Facility

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EMS-Tech Inc. conceived, designed, constructed and commissioned Wilmington's new bulk storage and transshipment facility. This unique structure consisting of five individual storage compartments was constructed on poor soil conditions and requires more than 360 12-inch, 65-foot long steel piles to support the walls of the structure. The pile caps and 20-foot high walls required 5,500 cubic yards of concrete and more than 700 tons of reinforced steel.

Five independent roofs comprise a 3/16" thick galvanized stressed membrane and an exoskeleton structure of galvanized fabricated and rolled shapes to contain the outward pressure of the stored material. The two are connected with 5/8" high-strength bolts spaced every 3 inches; more than 250,000 in all. The inside of the roof is completely smooth and free of ledges to prevent any build-up of material or dust.

Conveyors, loaded by traveling hoppers on the dock, feed a radial stacker that travels from compartment to compartment on a rail mounted on the inner wall of the Circ-A-Bin. An AC variable frequency controller powers two 5 hp travel drives to move the machine on four 21-inch diameter crane wheels. The stacker feeds the material through a hatched opening in the top of each roof at a rate of 1,000 tons per hour.

The material is reclaimed by gravity through 5 automatic long-slot scissor gates on each of 5 tunnel conveyors. A radial loadout conveyor travels around to each of the tunnel conveyors on rubber tires driven by electro-mechanical drives. Depending on the material being handled, approximately 60% can be reclaimed without assistance from the wheel loaders.

The loadout conveyor discharges onto a feed conveyor and then into a truck loading spout. Trucks enter the truck loading building onto a 90-foot long truck scale and advance forward as they are loaded.

An operator watches the truck loading via a closed circuit television camera mounted adjacent to the loading spout. The gates are opened and closed by the operator using the control computer's animated screens. During the gravity discharge portion of the cargo, the system can be operated by one person.


The truck loading cycle is 5 minutes, allowing more than 100 trucks to be loaded during daylight hours. The load out system is completely protected from the rain to enable truck loading in all normal weather conditions.