A grain silo upgrade project usually has the main objective of increasing the overall capacity of the intake and storage capabilities of the plant. In this project, a maize and wheat handling plant needed to increase its operating capacity to 120 tonnes per hour.
A typical silo upgrade project usually starts from the grain intake section of the facility. The client’s existing intake pit was too small, resulting in very long offloading times. It would take an entire day for trucks to offload into the current intake system, which was very inefficient.
UPGRADED INTAKE SYSTEM
It was determined that to increase the capacity, the underground intake pit needed to be made wider and deeper. The structural changes had to be undertaken by civil contractors. We designed an upgraded intake system, based on the new requirements of the client, also considering the space limitations of the existing infrastructure and the product handling systems already in place.
The intake pit was re-designed to accommodate fully loaded delivery trucks, weighing up to 50 tonnes, that drive over the pit. The required reinforced steel beams were installed to carry the weight of the truck and its load. The delivery trucks drive onto the pit and offload the grain directly into the pit, either by sideways tipping of the loading bin, or via openings at the bottom of the bin. The grain flows out of the truck bin onto a grid and then falls into the underground intake pit.
GRAIN HANDLING CONVEYORS
A double deck drag chain conveyor was installed inside the bottom of the intake, running along the entire length of the intake pit. The double deck chain conveyor was selected to better manage the inflow of grain into the system. This configuration is more energy efficient way to control the feed of grain, and to avoid overloading the conveyor, and by extension, the entire intake system.
The grain moves along the second deck of the chain conveyor, which then feeds into a short, inclined tube screw conveyor. This in turn feeds into a 15m high bucket elevator and the grain is then moved to a grain cleaner or diverted to an outlet feed for collection.
Once the grain passed through the grain cleaner, the clean grain was fed into a second bucket elevator, 30m high, supported by steel cables for stabilization. A splitter or diverter at the top of the bucket elevator fed the grain to a series of chain conveyors, which were supported by a gantry, to feed into the client’s existing storage silos.
CUSTOM PLANT DESIGN
Maize and wheat are fairly abrasive products, and the overall design of the plant had to be adjusted to optimize operating capacities of all sections within the intake and handling system. As all equipment was exposed to the harsh elements, to ensure better durability and long-term wear these were all supplied with a galvanized finish.
Our process engineering division works extensively in the Agri-food industry, providing solutions for storage, conveying, cleaning, separating, grading, mixing, sorting and bagging of grain, seed and cereal products. Contact Us directly to discuss your handling and process capacity requirements.