REDESIGN OF AN EXISTING 5000 m3
CORN SILO

The problem: A concrete silo with six cells of 800m 3 capacity, was built in 1918 for storage of corn and grain. The silo either had to be redesigned or replaced by a new one, capable for storage of the common raw materials for animal food, such as soybean meal, maize gluten, tapioca etc. The decision, either to break down or redesign, depends upon the comparative costs and whether a redesigned silo would be reliable.

The solution: It was decided to redesign the silo. By cutting the cone up to a diameter of 4000 mm, a discharge opening was created.- large enough to prevent bridging. A controlled rate of flow was achieved by using the vibrating discharge bottom JUMBO SILETTA® UBL . By using controlled start/stop operation, the rate of flow is adjustable to any desired value. As the rate of product flow is controlled, the space in the hopper below the SILETTA® is free and unobstructed, the material slides towards the outlet. Therefore, the slope of the hopper walls could be less then the original design. This enabled the hopper to be connected at the same place where the outlet was originally located. Thus, this saved the cost for redesign of the transport equipment because it can be used in its original form.

The advantages of this solution are: the perfect operation of the silo, short redesign-time and a very low project price.

100 m3 SILO FOR STORAGE OF WASTE FUEL

The problem: A cement plant in Latin America was planning to use the enormous quantities of waste from agricultural products, such as milled palm-nut-shells, milled straw and other wastes that can be burned as secondary fuel for the cement kiln. The powder properties of these milled products exhibit different flow properties from extremely cohesive to free flowing and flooding, with all variations between these extremes.

The solution: By testing flow characteristics of all the products, the discharge opening for the most cohesive powders needed to be greater than 2 m. For the self fluidizing powders, the powder must be allowed chance to de-aerate in the silo before reaching the discharge opening. The consequence of this is that the silo has to be built twice as large as would be necessary for non-aerated powders. The decision was to build an IDEAL FLOW SILO - a silo without a cone. A JUMBO SILETTA®- UBL was chosen, with a diameter of 2.4m, equal to the silo-diameter.

For the proportioning, an IDEAL FLOW SILO of 2m3 and a SILETTA® of 1.2m diameter was chosen. Because of self-fluidization, 90 % of the content is used as buffer, a to prevent flooding.

The advantages: This solution allows the storage and proportioning of powders having the most extreme range of flow properties, and even those powders which were not known at the time the silo was designed. The installation was a success from the first minute. This installation saves fuel and this enabled reduction in the quantity of oil to be imported, which is very important for developing countries.

PROPORTIONING SYSTEM LR FOR FIBERGLASS

The problem: Chopped fiberglass with different lengths to be proportioned in to a water stream for production of fiberglass tissues. A second to second accuracy should be better than 1%.

The solution: In order to prevent bridging and rat holing, an IDEAL FLOW SILO - a silo without cone is the solution. For proportioning, a specially designed SILETTA® for fiberglass was chosen. Because the fibrous materials don't flow uniformly, a special proportioning program was developed.

The advantages: A simple solution was realized, easy to maintain and with a accuracy of 0.5%.