Continuous operation was a priority. “We didn’t want to be stuck with a problem that would cause us to be shut down,” says Falcucci. Faced with an emergency situation, they might have been pressured to make a quick and potentially expensive decision for the sake of convenience.
Because they were prepared, Falcucci and Mion we were able to spend eight to 10 months planning for the new bin and soliciting multiple bids.
Understand your needs
With time to plan, the managers considered how the new aggregate bin could improve the plant’s efficiency. “We jotted down every idea, and asked as many questions as possible to improve on what we had and decide exactly what we wanted to build,” says Falcucci.
Capacity was an obvious place to start. They upgraded from an eight-compartment bin that held 330 tons to a bin with 12 compartments and a 385-ton capacity. A larger, faster bucket elevator delivers aggregates up to the bin at a rate of more than 75 tons per hour. Workers now spend a quarter of the time refilling aggregates compared to before; loading once a day rather than several times, without fear of running empty.
The new bin is configured with compartments ranging from 22 to 55 tons to optimize storage space for an average of 14 different kinds of aggregates and sand. It includes bins for small quantities of specialty aggregates that used to be stored in bags and added to the concrete by hand, in a tedious and expensive process.
The bin is also filled more accurately. Each compartment is covered and has a 30x30-inch opening for the conveyor. The design keeps aggregates separated, and eliminates waste caused by mixing and contamination of materials. If an aggregate is not frequently used, the opening can be completely covered.
USI also requested a design change to prevent corrosion. Inside the original bin, wet sand would settle on support channels and corrode them. They hope to avoid this with new sloped channels inside the new bin.
Other time-saving adjustments included adding plates to the bottom of each bin compartment to accommodate vibrators for individual aggregates. Each bin has a moisture probe opening, so probes can be moved as needed.
BMH also built a 38-ton capacity truck hopper with steam pipes to thaw and warm aggregates. Materials can sit in the hopper overnight to dry before being stored. USI worked with the equipment designer to design this system, instead of using heating pipes that release steam and unwanted moisture.