A hot new system for cold storage
When it outgrew its main production and distribution facility, Mydibel, a Belgian producer of frozen potato products, built an automated high-bay warehouse with a state-of-the-art storage and retrieval system.
The Walloon region of Belgium may be known to history for its battlefields, which include Waterloo and the World War I sites of Mons and Liege, but it is also the Idaho of Europe—in other words, it's an area ideally suited for growing potatoes. The region's "frites" are world-renowned. Legend holds that American servicemen stationed there in World War I called them "French" fries after the language spoken in the region and then brought a taste for the potato treat home with them.
Today, one of Belgium's leading providers of cut potato products is Mydibel. The family-owned company produces some 225,000 tons of potato products annually, shipping fries, hash browns, potato wedges and flakes, and more than 700 stock-keeping units (SKUs) of products to 120 countries worldwide. The company doesn't just process potatoes; it grows them as well, cultivating a significant share of the potatoes it sells.
The business has enjoyed tremendous growth in recent years—the kind of growth that's great for the bottom line but tends to put a strain on the back-end operations. By 2011, Mydibel had outgrown its main production and distribution facility in the Southern Belgian city of Mouscron and had resorted to renting four outside warehouses. But that arrangement was proving both costly and inefficient. "The problem was, we had to transport product back and forth between the facilities, and we did not have good visibility with all of the movement," says Fabian Leroy, Mydibel's maintenance and project engineer. On top of that, he says, the company was running up against the limitations of its warehouse management system (WMS), which could not be modified to accommodate the changes that were needed.
In order to consolidate all of those operations under one roof, the company began drawing up plans for the construction of a highly automated warehouse at the production site in Mouscron. Space was limited at the Mouscron property, however, which meant Mydibel would have to find ways to maximize the available footprint. It contracted with SSI Schaefer Systems to provide it with an automated storage and retrieval system (AS/RS) located in a large high-bay freezer. In addition to its Orbiter AS/RS, Schaefer supplied conveyors, shuttle systems, controls, and its Wamas warehouse management system to direct the distribution operations.TATER TOWER
In keeping with the goal of maximizing space, the new AS/RS is a deep-lane system designed to provide very dense storage, holding significantly more than the drive-in pallet racks located in the facility's existing storage areas. Not only has that allowed Mydibel to consolidate the former satellite operations in one place, but it has also reduced the company's cooling and electricity bills by minimizing the size of the area that requires refrigeration.
Today, the storage and retrieval processes unfold with minimal human intervention. As pallets of finished products arrive from the plant's processing and packaging areas, automatic readers scan their bar codes to determine whether they should go to a freezer with conventional racking, mobile racks, or the Schaefer AS/RS until ready to ship. Most finished goods are sent to the automated storage system, while goods that require client-specific packaging typically are directed to the conventional warehouse, where they're stored in drive-in racks and other pallet racks.
The pallets destined for the automated section are next measured and inspected to make sure that they meet the size and quality standards for pallets used within the system. Occasionally, products arrive in the staging area either without pallets or loaded onto pallets that aren't suitable for use in the AS/RS (although they might be perfectly adequate for shipping). These are loaded onto slave pallets for their sojourn in the AS/RS. The slave pallets are reserved for internal use and remain in the facility.
A chain conveyor then transports the pallets to the AS/RS, which is contained within the newly constructed rack-supported high-bay freezer building. The temperature in the high bay is maintained at minus 24 degrees Celsius (minus 11 degrees Fahrenheit), so pallets pass through an air lock first in order to transition to the ultra-chilled environment. To reduce the risk of fire, a low oxygen level is maintained in the racking.
The AR/RS contains five aisles that are 93 meters (305 feet) long. Eleven levels of deep-lane storage racks are arrayed along the aisles and stand 32 meters (105 feet) high. The racks are designed to hold 32,000 Euro pallets (a Euro pallet measures 800 by 1200 millimeters—about 31.5 by 47.2 inches). The system is also designed to accommodate wider industrial-sized pallets that measure 1000 by 1200 millimeters (approximately 39.4 by 47.2 inches). It can hold 25,600 of the larger pallets.
The deep-lane system stores pallets packed tightly together in long rows that run perpendicular to the aisles. Mydibel's system can hold 11 Euro pallets in each lane. Most of the racks (with the exception of those on the far left and far right) allow for pallets to be accessed from either of the adjacent aisles. In most cases, each lane holds pallets of a single SKU from the same production batch, with one aisle used for depositing pallets and the adjacent aisle used for removing them. This helps assure that in most instances, the first pallets to enter the system are the first to be retrieved.
Five storage and retrieval cranes travel up and down the aisles. Each crane carries an Orbiter transfer car that's used to move products in and out of the lanes. An Orbiter can transport a load weighing up to 1,360 kilograms (about 3,000 pounds). Once it reaches the assigned location, the transfer car undocks from the crane to carry the pallet to its destination on rails mounted within the lane. It uses light sensors and an incremental encoder to determine the position to place the pallet in, which is typically next to the most recently inducted pallet.
The Orbiter transfer car then returns to re-dock with the crane and prepare for the next move. The cars recharge while stationed at the crane, which means they don't require a cable to move down the lane as many similar systems do.
When products are required for orders, the cranes and transfer cars retrieve the pallets and take them to a lift that lowers the pallets to a conveyor that transports them to shipping. The slave pallets are removed automatically and returned to their origination point.
The shipping department contains a buffering system with 11 lanes that can hold nine pallets apiece. The WMS uses these buffer lanes to build truckloads. Two material shuttles gather the pallets for transport to truck lanes for actual loading.A PRODUCTIVE DESIGN
Combined, the five cranes and their Orbiters can store up to 52 pallets per hour and retrieve 126 pallets per hour. Both material flows are controlled by the Wamas WMS. The system can run one flow first and then the other, or run both functions simultaneously.
The WMS continuously tracks the location of products within the AS/RS. Cameras are located within the system to allow for visual inspection throughout, and computer displays show managers which positions are occupied and which are available for product storage.
The swift automated system has proved to be more productive than previous manual systems while requiring only half the labor. This allows Mydibel to deploy its work force more effectively. On top of that, the dense storage has reduced product damage and eliminated the need to store products off site. That alone saves the costs of two to three trucks and the drivers that were previously needed to ferry products back and forth to the satellite locations.
Best of all, using automated equipment for storage and retrieval means fewer people have to work in the sub-zero temperatures. And that should warm the hearts of frites lovers from Waterloo to London to Munich and beyond.
About the Author
David Maloney has been a journalist for more than 35 years and is currently the editorial director for DC Velocity and Supply Chain Quarterly magazines. In this role, he is responsible for the editorial content of both brands of Agile Business Media. Dave joined DC Velocity in April of 2004. Prior to that, he was a senior editor for Modern Materials Handling magazine. Dave also has extensive experience as a broadcast journalist. Before writing for supply chain publications, he was a journalist, television producer and director in Pittsburgh. Dave combines a background of reporting on logistics with his video production experience to bring new opportunities to DC Velocity readers, including web videos highlighting top distribution and logistics facilities, webcasts and other cross-media projects. He continues to live and work in the Pittsburgh area.
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