After cleaning and maintenance, eliminating water within freezers remains paramount to a smooth start-up. Ice not only poses a worker safety issue, but it also can expand and crack the freezer’s structure or damage the drive.
Jonathan Lasecki, Ashworth’s chief engineer, suggested using proper food-safe lubricants after regular sanitation.
“You need to be careful with any water because oil and water don’t mix,” he said. “When you mix them together and they start freezing, you can have catastrophic failure very quickly.”
Rushing into production is never a good idea when freezing products.
“Operators need to leave enough time to dry out the freezer and make sure nothing is leaking before they take it to cold temperatures,” said Kenneth King, commercial support manager at Ashworth. “When they bring the temperature down really fast, they can freeze the belt to the support rails and potentially cause damage to the system as well as the belt.”
Once in operation, routinely search for signs of frost or ice buildup in the freezer.
“As moisture builds up in a production freezer, it can degrade the performance of the freezer itself,” said Erik Fihlman, program manager, bakery and prepared foods for Linde L.L.C. “Moisture ingress from the surrounding work environment can be a big contributor to potential downtime, and new freezers are designed to minimize this.”
On spiral freezers, Anthony Salsone, sales engineer, G&F Systems, said properly designed entry and exit vestibules limit or even prevent condensation that can disrupt the process, represent a major food safety concern and restrict the efficiency of the spiral blast freezer.
Meanwhile, IJ White offers its Auto Pressurization System that automatically balances the pressure differential at the infeed and discharge openings on spiral blast freezers. The P.L.C.-controlled system significantly reduces the amount of cold freezing air spilling from the spiral’s low opening and prevents warm, moist air infiltration from entering a higher conveyor opening. As a result, Peter White, president, IJ White Systems, said Ultra Series blast freezers can save energy while increasing the production time between coil defrosts.
However, Mr. Fihlman pointed out that moisture also naturally emits from baked foods during freezing.
“Whether it’s cookie dough or buttered-up Texas toast, the product contains a certain amount of moisture, and when the product freezes, the moisture wants to leave,” he said. “Where’s it going to go? It’s going to go inside that spiral freezer or tunnel chamber, and that moisture builds up.”
To protect performance, Mr. Fihlman recommended bakers rely on a freezer that can provide a modulated flow of cryogen based on heat removal demand — using either liquid nitrogen or liquid carbon dioxide — to quickly create a “crust” that seals in moisture and helps prevent ice from forming on the floor or walls.
In coolers for setting caramel or chocolate or for making chips, cleaning without water reduces the chance for bacteria formation and subsequent contamination. IPCO recently rolled out a food-safe, salt-based system to remove gunky material buildup, mainly, but not only, for bake oven belts.
“Think of it as a shocking device where you’re shooting salt at the belt that pulverizes and cleans it,” said Craig Bartsch, general manager, belts, IPCO North America. “It’s almost like a sand blaster. We put it over the belt, and it’s shooting salt at a high velocity on the belt. It breaks up the material on the belt, and there is a vacuum system that recoups the salt and debris.”
Overall, he added, the whole process may take about 8 hours. When completed, the bakery can place the mobile unit on another cooling belt.
“With this system, bakers sometimes can clean while the lines are in operation if they can find an area of the belt where they can access it while in production,” Mr. Bartsch said.
Advantech Bakery Technology uses ultraviolet light to kill bacteria and viruses hidden in and around the coil areas of its new line of modular-designed cooling tunnels. That’s vital in many bakery and snack plants because the cooler comes after the oven.
“Once you bake it, the product cools down and heads to packaging,” explained Russ Garland, president of Advantech. “Anytime you can eliminate bacteria growth in the airstream components, it’s a good thing.”
Advantech partnered with Atlantic Ultraviolet Corp. to supply the Ster-l-ray germicidal ultraviolet lamps as a broader sanitary design initiative for its coolers, which are designed for enrobed and coated cookies, bars, pretzels, and even gluten-free snacks. Its coolers feature double doors to provide quick access for cleaning and maintenance as well as impingement plates and ductwork that are independent from the hoods.
“This allows you to take those components and clean them in another area of the bakery,” Mr. Garland said.
Often the best sanitary design eliminates or reduces moving parts in freezers, said David Bogle, global R.&D. director, spiral platform, Intralox. It also makes those parts easier to repair.
“For instance, drum motors historically were all located in the freezer under a spiral,” he noted. “Now, those motors are located above the freezer box, which is a much easier environment for a motor and gearbox.”
With coolers and freezers, proper sanitation and timely maintenance ensure maximum uptime and nip unexpected surprises in the bud.