Exemple d’automatisation dans un entrepôt stockant des frites surgelées aux États-Unis (en anglais)
In an article1 published on the Modern Materials Handling website, Bob Trebilcock describes how a gigantic frozen storage warehouse works.
Located in Richland, Washington, this warehouse of over 35,000 m² is run by 120 employees working on a three shift system. This enables the warehouse to operate 24 hours per day, five and a half days per week.
Each day, more than 100 trucks loaded with French fries are automatically unloaded thanks to long trailers (around 16 metres) outfitted with chain conveyors. Products coming from three specific manufacturing sites equipped with chain conveyors and pneumatics for automatic unloading are delivered at four docks that have similarly been outfitted with chain conveyors that match the chains of the truck. Thanks to this system, a trailer can be automatically unloaded in about 2 minutes. Products coming from other sites are received at conventional docks and pallets are unloaded by a lift truck. These products are then integrated into the automatic system.
As for storage, products are stored on pallets which can be identified by bar code, ensuring that automation operates properly. The pallets are then inducted onto a pallet conveyor that feeds an overhead monorail system consisting of 36 carts that travel around a nearly 700 metre loop. The carts automatically recover the pallets, which are directed to the freezers. They first enter a transition zone to minimise the temperature lost. There, the pallet is loaded onto a cart on an automated storage and retrieval system (AS/RS) crane. The crane lifts the pallet and the cart moves onto a rail until its storage location. The carts can be recharged in 6 seconds and can travel almost 100 metres before the next charge. They can operate at low temperatures (around -29°C). This AS/RS handles 250 pallets per hour in and out of the system. The facility can store 120,000 pallets, or nearly 900,000 tonnes of products.
At the end of the chain, when products can be packed and shipped, the pallets are transported from the freezer to Stock Keeping Unit (SKU) pallets built for truckload shipment. The facility ships approximately 150 truckloads and 12 rail cars per day.
According to CEO John J. Galiher, automation was inevitable given the business equation his company must work with. On one side of the equation are the demands of customers, and the hope of reducing costs, and on the other side the cost of the facility which continues to rise (i.e. prices of the land and workforce). Automation was a solution to reduce cost since it reduces costs in terms of space, and it also requires fewer employees.
For further information, please follow the link below.
1 Source: TREBILCOCK Bob. Preferred Freezer’s new take on automation. In: Modern Material Handling [online]. 2018-01-22. Available following this link.
2 AS/RS: automated storage and retrieval system