A new cold chain for Collect&Go

“We developed a solution ourselves for the transport of fresh and frozen products with regular trailers, without refrigerated trucks, implementing significant innovation and in a sustainable way.”

Londerzeel's Collect&Go distribution centre (DC) is gradually rolling out a new delivery system. It used to deliver fresh products with a cart that was transferred into the pickup point's refrigerator. Transferring is no longer necessary today. Ordered products are put directly from the DC's refrigerated warehouse into folding crates that are placed in pairs into a newly developed cool box.

Self-developed cooling plates there keep the contents cool. That filled cool box is then transported to one of Collect&Go's 210 collection points in Belgium. When customers pick up their orders there, a store co-worker reads the temperature data for that box.

Indeed, the pickup points are equipped with receivers that automatically display each box's sensor and temperature history. If everything meets the requirements, payment follows by the customer taking his filled folding crate. There are already 5,000 individual cool boxes for fresh products in use at Collect&Go. Moreover, the same concept is now being used for frozen food.

First, the corners of the preformed base plate are welded. Then the bottom is filled with a water-graphite mixture and the lid is welded shut. The added graphite increases the thermal conductivity coefficient of the water by a factor of 3. “Due to that better conductivity, the plate does not cool first on outer edges and corners but maintains the same (ice) temperature everywhere.”

When the truck delivers fresh products to the pick-up point in the morning, it takes the used boxes back to the DC in Londerzeel. The operator puts the hot cassettes on a modular belt. ‘Air knives' ensure that the cassettes are blown dry in the conditioned room before sliding them into the freezing machine. The cooling plates are visually inspected.

The integrated checkweigher checks that all cassettes have the expected weight and are not leaky. “Our automation takes care of the transport to and handling in the freezer," says Sven Doms, who is in charge of the automation of the machinery and thus also the automatic transport of the cold chain. The cooling plates are frozen at -20 °C the day before delivery. Keeping moisture out of the machine was a challenge. “A dew point of -20 °C is ideal. There will be some frost ripening but minimal.”

The cooling plates then enter a 5.7 m high storage buffer that can hold up to 1,500 cooling plates. This all happens in a room 30 m by 7.5 m and 6.7 m high. The ambient temperature there is -7 °C. “The automation is completely done according to our own concept," Doms says. “We shifted to more robust, mechanical sensors that click off as the cooling plates pass through the freezer. With optical measurement, the risk of a miscount was too high.”

That count must be 'correct'. Always. Today, the freezer is still loaded and unloaded manually. Now engineers are working hard to automate that supply and removal. The plates will automatically be placed on a roller conveyor and enter and exit the plate freezer in groups of six. In a second phase, the loading and unloading of cool boxes will also be automated.

“We are proud that we were able to make this happen," says Doms, who points to the multidisciplinary nature of the project and the collaboration with external partners. “Covid added an extra exciting challenge. The uncertainty about the availability of materials, price fluctuations, delivery times etc. Remote engineering of a box is not obvious either. At some point it does require hands-on.”

This article previously appeared in Engineeringnet.