stand up to the demands of an international cheese processing line
Frequent stop and start operations, exposure to salt water and heavy loads are just a few of the challenges that the new hygienic Interroll motorised drum has had to undergo at a major Swiss cheese manufacturer.
At the Fromco SA cheese aging plant in Switzerland, Interroll drum motors had already been proven in reliably powering conveyors carrying thousands of heavy maturing cheeses in stop / start operations every week, since 1994. So when Fromco SA needed to almost double its storage and handling capacity, Interroll drum motors was a natural choice when it came to a new system design.
One of the best loved varieties of Swiss cheese – Gruyere AOC, is traditionally made in small villages in the Swiss cantons. At about three months old, these are delivered for maturing at the Fromco SA aging cellars in Moudon, eventually to be exported around the world. On arrival at the cellars, the cheeses are loaded onto a series of conveyors and transported to driven rollers, which automatically transfer them onto special fit wood pallets. Once stacked, the pallets are taken to storage areas by electric forklift trucks.
As part of the aging process, each cheese needed to be carefully brushed once a week with a special saltwater mixture based on a traditional Swiss recipe enhanced by Fromco. With a demand to increase the processing of cheeses from 90,000 per week, it was considered that this time honoured procedure must now warrant the introduction of modern automation technology.
Interroll drum motors at the heart of the automation system
The automation specialists, Patric concept SA based in Boudry, Switzerland, designed and implemented a tailor made conveyor system that automated the ageing process. Pallets of cheese are collected from the storage area by forklift trucks and delivered directly to a machine that automatically transfers them to a custom built processing line.
Once on the line, the cheeses are conveyed through a treatment machine that brushes them with the special saltwater mixture, after which they are automatically transferred to the pallets to be returned into store for maturing.
As a result, the output of the Fromco SA processing plant has recently been expanded from 90,000 to 160,000 cheeses – with the plant operating 17 hours a day, 5 days a week. With each cheese weighing 35kg the load on the drum motors driving the conveyor system is considerable, not to mention the wear demands of constant stops / starts within the process. If that isn't enough, the Interroll drum motors are exposed daily to corrosive salt water and high pressure cleaning that could damage exposed machine parts or ingress into the component.
These considerations had already led Fromco SA to opt for Interroll drum motors when the plant first went into operation in 1994 and having been so impressed with their durability, reliability and all-in-one hygienic sealed design, Interroll was the first choice for its expanded new process line.
Willy Correvon, technical director at Fromco SA reported, “With such high demands on the mechanical equipment, we place a lot of trust in the conveyor motors and need to be sure that they won't let us down. The original Interroll drum motors have been performing reliably ever since we started operation in 1994, so the decision to invest in further Interroll drum motors was easy.”
For the new expanded processing plant 165E and TM220M Interroll drum motors were selected. With a diameter of 165mm, the 165E drum motor is particularly robust and has a high radial load that makes it especially suitable for handling the heavy cheeses along the flat sections of the conveyor line. After analysing performance requirements, the 0.75kW version for conveyor speeds of 0.25, 0.32 and 0.4m/s was the ideal choice.
For transporting the cheeses down inclining and declining sections of the processing line, the TM220M drum motors provided a solution and greater performance with an output of 2.2kW at a conveyor speed of 0.32 m/s. To provide the extra friction needed between the drum motor and conveyor, a polymer covering is a standard add-on to the motor's stainless steel drum.
With 160,000 cheeses on four processing lines, the number of stops / starts is extremely high at 40,000 per motor every week, or over 2 million per year. This places a lot of mechanical stress upon the transmission and generates extra heat in the motor's electrical coil.
The investment in Interroll motorised drums have aided Fromco SA keep their electricity costs to a minimum, as conventional geared motors need to transfer energy and torque through a ninety degree angle, which necessarily wastes energy. Drum motors, on the other hand, optimise energy consumption, since energy transfer is in the direction of the motor only. This is particularly relevant for the Fromco plant with its heavy loads and large number of starts and stops.
To meet some of the very demanding environments, stainless steel drum motors are becoming more and more popular on food processing lines that require reliable operation under tough conditions.
To discuss possible drive solutions or for technical information covering the motorised drum range, contact Interroll or visit the website – www.interroll.com