Coffee roaster upgrades 25-year-old flexible screw conveyor
Machine still meets company's needs despite length of service
Coffee connoisseurs in the San Francisco Bay area often source their favorite brews from a famed local roaster called Mr. Espresso. The company, which opened in 1978 selling Italian espresso machines to restaurants and cafés, has supplied gourmet coffee, including espresso blends, since 1982.
The family-run business, founded in Oakland by Carlo Di Ruocco, promotes traditional Italian coffee making through the artisanal nature of its operations. One example is an innovative oak wood fire roasting technique that releases robust coffee flavor.
“We are the first and only roaster in the United States to roast coffee beans over a fire fueled exclusively by wood,” says John Di Ruocco, operations manager and grandson of the founder.
Another example of Mr. Espresso’s commitment to doing things its own way is a company culture that values old, reliable machines. One of these is a flexible screw conveyor from Flexicon Corporation that Mr. Espresso purchased in 1991. The conveyor and hopper transport ground coffee to a packaging machine from two grinders, each of which also has at least a quarter-century of service, says Di Ruocco.
A rugged, flexible spiral is the only moving part that contacts the ground coffee. As it rotates, the spiral self-centers within a flexible plastic tube, providing uniform wall clearance that eliminates or minimizes grinding or clogging of the material.
“This is a problem-free way of transporting ground coffee,” Di Ruocco notes. “Any other conveying option would entail higher cost with no additional benefit. When a machine works as well as this one does, there is no need to replace it.”
However, the company recently required the addition of a stainless steel hopper cover and asked Flexicon to provide a solution. The cover measures 36 by 36 in., says Di Ruocco. Flexicon customized the cover with two inlets that mate with each grinder discharge chute. For easy access to the interior of the hopper, a hinge runs the length of the lid creating a 36-in. long door that swings up.
An operator manually loads roasted beans into the hoppers of the grinders, which are positioned on either side of the 8-cu.-ft. capacity hopper. Ground coffee flows from the grinders into the hopper, which charges the three-in. diameter flexible screw conveyor. The coffee is then conveyed 10 ft. at a 45° incline to a filling machine for two-and-three-quarters- or seven-oz. packages.
Flexicon also supplies tubular cable conveyors (TCCs) for large-scale coffee manufacturing. TCCs (also known as disc conveyors and drag conveyors) gently slide bulk materials through smooth stainless steel tubing using low-friction polymer discs attached to stainless steel cable. The discs and cable are driven by a wheel at one end of the circuit and put under tension by a wheel at the other end.
This design allows single or multiple inlets and outlets, and the routing of conveyor tubing horizontally, vertically or at any angle. Because the components are modular, inlets and outlets can be added, removed or relocated, and the circuit lengthened, shortened or re-routed as needs change. The conveyors handle friable materials gently, efficiently and dust-free.
But for Mr. Espresso, sticking with the flexible screw conveyor is the solution. Despite its age and lack of modern controls, the conveyor continues to reliably and automatically deliver ground coffee to the filling machine for a quarter-century of productivity for Mr. Espresso.
“With the new stainless steel cover in place, the conveying system has many years of service ahead,” Di Ruocco says.
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