How to expand your freezer's capacity
Sept. 1, 2015
by Dan Malovany
Be prepared. Following this motto can save a lot of money and even more aggravation if bakers make a calculated bet on the future when installing a freezer. All too often, frozen baked goods manufacturers underestimate their companies’ potential for growth. As a result, when the unexpected good news happens, they find themselves scrambling to meet customers’ demands. Or they’re sacrificing speed-to-market because expanding freezer capacity generally requires a time-consuming, capital-intensive project.
It’s not exactly an act of kindness — nor a sign of chutzpah — to invest for success, especially in a system such as a freezer that can quickly become a pain in the bottleneck. Rather, it’s just common sense. As Andrew Knowles, sales support manager for JBT FoodTech advised, “First and most importantly, new plants need to have enough foresight to design for expansion. Special considerations need to be made for future cooling capacity, additional footprint for future lines and more.”
The solution to bolstering capacity involves examining — and anticipating — where the bakery’s limitations are, according to Ashley Morris, sales manager, The Kaak Group, which is represented in North America by Naegele Inc. Bakery Systems, Alsip, IL. In some cases, equipment manufacturers such as The Kaak Group offer turnkey concepts that integrate proofing, baking and freezing. “Some of the key criteria are to make all options available to the customer during the design process,” Mr. Morris said. “This can be in the form of alternative line layouts, visiting existing bakeries producing similar products or incorporating machinery in the production line that can be expanded in the future.”
Boosting a freezer’s volume doesn’t always require structural changes to the facility, noted Anthony Salsone, sales engineer, G&F Systems, Roosevelt, NY. G&F Systems partners with Air Management Technologies (AMT), an environmental engineering firm based in Lewisburg, PA, when it comes to installing freezers.
“Because future growth is often unknown and unpredictable, all G&F Systems spiral blast freezers are designed and manufactured with variable frequency drives, allowing for a greater range of dwell times and product throughput,” he said. “However, if this built-in range is not enough, expanding an existing system is possible but will be difficult and may not be cost-effective or practical.”
If the actual space within the spiral freezer allows, adding a wider belt will enable a frozen pie producer, for instance, to significantly increase throughput by placing four 8-in. desserts across the belt instead of three at a time. “They may need a 30-in. belt for now, but if they know they are going to expand in the future, they need to initially buy a bigger system to accommodate for that growth,” said Jonathan Lasecki, chief engineer, Ashworth Bros., Inc., Winchester, VA. “Or they may design the spiral freezer to have two different conveyor belts in the same unit so they can run two products through one freezer.”
Selecting proper technology
Some systems are simpler to expand than others. “Linear systems, such as impingement technology, tend to be the easiest to expand from a mechanical perspective, assuming the facility has additional length,” observed Dylan Comer, freezer applications engineer, JBT FoodTech. “However, there is nothing that can be done if you want to expand capacity without expanding footprint, outside of supplying a colder temperature.”
Structurally supported — or large spiral technology — freezers are the most difficult systems for adding future capacity, said Brandon Somerfield, JBT’s product line manager. That’s because each of the spiral’s tiers needs to be supported by a rail structure, which means any future vertical expansion requires much more than just installing additional belting. Besides being labor-intensive, “adding height to the system can often pose safety concerns to the contractors performing the expansion work,” he observed.
Cryogenic freezers provide bakers and pizza producers with flexibility. “Since belt speed and temperature can both be controlled, systems can be designed to accommodate future capacity needs,” said Mark DiMaggio, head of food & beverage, Linde LLC, Murray Hill, NJ. “Processing temperature might be adjusted from 0°F to -200°F, for example, or the belt speed can be increased or decreased to accommodate varying production rates and product line changes. Leading technology suppliers can help bakeries make those adjustments.”
Modular designs of cryogenic freezers can create much-needed capacity by simply adding a section that increases the time the product spends freezing. Additionally, Mr. DiMaggio said, combining a cryogenic-assist or cryo-mechanical tunnel system with an existing spiral — or other type of freezer — can raise a line’s total volume.
Boosting a freezer’s uptime
Yet another way to bump up throughput involves slashing the time it takes to defrost a freezer. “Sequential defrosting is a great way on continuous 24/7 production,” Mr. Morris suggested. “When purchasing a freezing system, the customer should make the manufacturer aware what production time is available for the defrosting process. The manufacturer should then design a system that, if required, will automatically start defrosting a set of evaporators while keeping the others running. This gives the customer 24/7 production without the worry of shutting down for defrosting.”
In some freezers, condensation results in major food safety concerns, but these issues can be resolved. “Entry and exit vestibules can limit and prevent condensation and will vary, depending on the application,” Mr. Salsone said. Bakers should also consider the spiral blast freezer temperature, plant environment, system capacity and energy costs, just to name a few. “If sanitation can be addressed satisfactorily, the operation can be continuous with no downtime required,” he added.
Surface flour also can give birth to food safety issues, noted John Bauer, freezer applications engineer with JBT. “Flour can get sucked into the belt mesh, restricting collapse or accumulate on the floor and become difficult to clean,” he said. If the flour dust accumulates on the freezer’s coils, it may also significantly reduce heat-transfer capabilities.
However, sequential defrosting and clean-in-place (CIP) systems that keep the operation up and running between sanitation cycles may affect the belt’s performance, which is one of the biggest components in spiral freezers, according Bryan Hobbs, Ashworth’s sales and service manager of North America.
CIP systems continuously clean equipment parts that sanitation personnel can’t access easily — making freezers more reliable and less likely to have an unexpected breakdown. But is there a downside to increasing uptime? Probably not. That said, greater diligence is required when running longer periods between maintenance.
“You have to prepare for more thorough inspections when you do maintenance because those opportunities come less frequently,” Mr. Hobbs said. “Certainly, it’s better for the baker to produce for longer periods at a time. All of the benefits of that are fantastic, but they should anticipate the need to do more thorough inspections rather than a couple hours of maintenance every day.”
Belt design should also be considered with continuous sanitation systems, noted Kenneth King, Ashworth’s commercial support manager. Durability and sanitary design is something the company incorporates into its belt lines. “We’re trying to facilitate how CIP units flush debris out of the belt by minimizing cracks and crevices in key areas of the belt assembly where pathogens and other contaminants can actually form,” he said.
Although many types of plastic belts are used in most spiral freezers, other systems may require a polyethylene (PE) variety, observed Sebastian Miles, industry segment manager, food, Habasit America, Suwanee, GA. “In an extremely low-temperature room (about -95°F) with non-spiral belts, you will probably see a lot more PE belts,” he said. “PE gets stronger as the temperature drops, but it also turns more brittle.”
Begging a question or two
Bakers should also calculate energy costs before purchasing a spiral blast freezer. Central systems by companies such as AMT can supply multiple freezer or refrigeration systems and provide the flexibility to reduce overall peak tonnage. Additionally, the systems can provide waste heat recovery that can be used elsewhere in a bakery.
Available floor space may also be a deciding factor in what type of freezer a baker selects. “State-of-the-art cryogenic freezers provide considerably higher production rates per unit of floor space than older cryogenic and mechanical freezers,” Mr. DiMaggio said.
Bakers also should query how a spiral blast freezer will interact with other parts of the facility. “What are the hidden food safety, environmental and structural considerations for the bakery?” Mr. Salsone asked.
They should also determine the current — and future — range of products. “Do they want this line to be dedicated to one particular product, or do they want the flexibility to run rolls, raw croissants, proofed croissants and bread, for example?” Mr. Somerfield wondered. “Each product type affects spiral feature selections, so knowing what type of design flexibilities the line requires upfront will allow any OEM to deliver an ideal piece of equipment.”
Before purchasing a system, bakers should conduct thorough tests on potential products. “Each bakery product is unique and has specific freezing characteristics,” Mr. Somerfield suggested. “It’s important to know process details such as what happens when a product gets too cold, how long it takes to achieve the desired end texture and temperature, or if the product can handle the collapsed portion of a spiral belt without deformation.” Various companies such as JBT have technical centers that can simulate most full-scale processes.
Overall cost of ownership
When selecting belts — or any freezer component — long-term maintenance should be considered because repairing them — especially during production — is difficult in the harsh environments of most freezers. Bakers should conduct extensive risk analysis to determine the cost of a freezer over time. “Sometimes people can be blinded by a price tag,” Mr. Hobbs said. “They need to consider the total cost of ownership.”
Or, as Mr. Salsone urged, “Ask bakers to ask: ‘Is the equipment engineered for optimal food safety, sanitation, reliability, efficiency and the bakery’s long-term objectives, or is it the lowest initial cost item that can be ‘made’ to work?’ ”
Capital expense is often a small portion of the overall investment in a new machine. “Understanding the total cost of ownership not only allows you to justify the expense, but also helps set maintenance budgets moving forward,” Mr. Somerfield explained. Bakers should consider how many people are required to maintain the equipment, what typical parts will wear down quickly, how often they need to be replaced and the utility requirements.
By conducting due diligence, bakers can do themselves a favor and pay it forward, in more ways than one.