Many types of buildings can be used to store cottonseed at gins. Most gins select common clear-span metal frame buildings, but quonset huts and Muskogee houses are also used. Metal frame buildings have a fairly low cost for 1,000-5,000 ton capacities. This type of construction is efficient and has other uses when not used for seed storage.
Quonset huts rely on formed panels for structural integrity and have no steel framework to support the outside skin. When constructed as a true quonset hut, the floor space is not efficiently used. Four to twelve feet vertical concrete wall/foundations are sometimes used to increase the storage volume and minimize wall damage from loading equipment. A quonset hut should be filled uniformly on each side to avoid building deflection.
Muskogee houses generally have roof slopes of 45° and a high ridge line to maximize storage volume while minimizing wall forces of seed “flowing” against the walls. The roof slope and height also require a greater steel superstructure. Muskogee houses are normally used for volumes greater than 6,000 tons. Seed depths of 40-75 ft and lower air flow rates are found in most Muskogee houses.
Cottonseed storage facilities should have moisture-proof concrete floors. Floor loads from seed alone will be approximately 500lb/ft2 for a 20 foot seed depth. Also, floors should have sufficient concrete and reinforcement to support a 60,000 lb truck and loader.
Buildings used to store cottonseed must be designed to withstand the lateral forces exerted by the cottonseed as it is loaded and unloaded. For vertical sided buildings, wall forces depend on seed depth and bulk density. Maximum force and wall failure usually occur at 10 to 20% of wall height above the floor. Forces will be higher during filling because the seed has not yet settled.
Several side and end wall failures have recently occurred in cottonseed storage facilities. Walls of existing buildings converted to cottonseed storage should be analyzed and strengthened as needed before filling with seed. Lining the interior walls with ¾-inch plywood helps prevent damage to the outside building walls, facilitates clean out, increases wall strength, and reduces settling pressure on otherwise exposed framework. The top of this inside wall should be sealed to prevent seed and lint from accumulating between the walls.