Freezer technology helps manufacturers of frozen dairy products do more for less.

First things first: Freezers have to keep products at the proper temperature. Above and beyond the basic function, though, there have been notable improvements to the various types of freezing equipment used to produce and store frozen dairy products like ice cream and other frozen dairy-based desserts. Today’s freezers are built to be more automated, accurate, consistent, versatile, low maintenance and efficient, not to mention durable and reliable, whether they are extrusion or hardening systems, small-batch freezers or large spiral freezers. Ultimately, beyond affecting the coldness of the product, such advances can impact quality.

If it sounds like those are hot demands for freezer technology, it is because correct freezing of products is pivotal to the taste and appearance of the product and, for the manufacturer, the potential difference between profit and waste.

Those margins are crucial to many in the frozen dairy products industry, since this country is the world’s most prolific producer of ice cream and other dairy treats. According to the U.S. Dairy Export Council (USDEC), Arlington, Va., the U.S. churns out about 40 percent of the world’s frozen dairy desserts.

Freezers used for frozen desserts are getting an intense 24/7 workout, too. According to USDEC, the nation’s frozen dairy dessert manufacturers have nearly doubled the production of frozen dairy products per plant in recent years.

Ice cream and novelties aren’t the only items produced in today’s dairy plants, either. Cheese manufacturers, too, are going beyond cooling, opting to freeze products like shreds for exports or foodservice use.

To keep pace with greater and more diverse output, manufacturers are investing in freezers that ensure that products are being made in the best, most efficient ways. Those that provide freezing systems for use in dairy plants report that manufacturers are looking to get more out of their equipment while keeping a cap on cost.

“They are looking for energy, health and safety, cost and flexibility,” says Glen Smith, engineer for Realcold Milmech USA Ltd., Kansas City, Mo., which supplies case-chilling or freezing tunnels and plate freezers, mostly used in the dairy industry for cooling or freezing blocks or cases of cheese and butter, hardening ice cream and other boxed or bulk dairy products.

When it comes to such flexibility, recent freezer technology has focused on features that address manufacturers’ need for versatility.

One notable example is the renaissance of low-fat ice cream. After many low-fat ice creams did not perform up to expectations when they were introduced, many ice cream makers went back to the proverbial drawing board to come up with formulations and processes that truly mimic full-fat ice cream, often requiring the use of high-tech freezers that are just as important as the balance of ingredients in an ice cream base.

“You have to applaud manufacturers, because they consciously said that they didn’t want to make a lower-fat product, but a better product that the consumer says tastes as good as the regular ice cream. The manufacturers gave themselves a better margin and gave the consumer a better product,” says Neal White, president of WCB Ice Cream, an ice cream equipment suppler in Northvale, N.J.

One example of a new freezing system developed around such trends is WCB Ice Cream’s CREAM freezer, featuring continuous product recirculation. “Manufacturers have been looking for recipes and manufacturing methods to come up with creamier, smoother products that still have the attributes of lower fat,” White says. “We developed our ice cream freezer to continually work the product more, and the more work you do, it promotes smaller ice crystals.”

CREAM stands for Continues Recirculation with complete Emulsification of overrun Air and Mix. Unlike other systems, CREAM does not use a secondary cooling unit that requires a high horsepower.

The development of next-generation low-fat ice cream likewise has impacted freezer technology at Gram Equipment, a Denmark-based manufacturer with U.S. offices in Tampa, Fla. “We have gone with a dasher that can have an adjustable speed. Some of these low-fat mixes are extremely hard to freeze, but we can adjust it,” says Herb Fish, regional sales manager, noting that a new churning control has been added to the freezer as well.

Beyond the types of products that are being frozen, manufacturers grapple with other issues that come into play in their choice of freezer technology.

Efficiency, for one thing, is top-of-mind. “Energy will not be getting any cheaper, so systems like the SRT that use less energy for will continue to prove their worth,” Smith says of one of Realcold’s freezer models.

Overall efficiency also ties into the labor involved in operating equipment. To that end, freezers are designed to accommodate labor issues, whether it’s from a resource or safety standpoint. “The cost and administration of health and safety for companies is a major concern. Freezer or cooler spaces are not the most pleasant environment to work in and often present an increased risk of injury to staff,” Smith says, adding that Realcold SRT, MRT and plate freezers help eliminate such concerns, since employees are no longer needed to work in those areas.

Among other upgrades, Realcold recently completed an IQF (individual quick freezing) tunnel for freezing mozzarella, using carbon dioxide rather than ammonia as the refrigerant. By doing so, the tunnel can be part of a closed-loop system, Smith says.

Likewise, Gram Equipment introduced a GIF 2000 model last year, with a new compact design and an option for carbon dioxide cooling. One reason for offering carbon dioxide was to make a safer working environment for employees, Fish says.

Another concern among those who freeze dairy products is floor space, especially as manufacturers add more production and packaging lines. How much room a freezer occupies, whether for extrusion, hardening or storage purposes, has a ripple effect. “Everybody within the ice cream industry has a footprint they use to produce certain items in, and if the items require extra equipment, it becomes burdensome to a plant. The production area is valuable real estate,” White says, adding that unit size was a consideration in the development of the CREAM freezer. “We stayed within the same footprint as the existing freezers, and that was a challenge.”

Gram Equipment kept floor space as a priority when engineering and upgrading its line of freezers, which include the new GIF 2000 and a GIS 4000 model. “It’s a smaller footprint than we had before. We moved all electronic components to the top of the freezer and we put the barrel and pumps on bottom,” Fish explains, adding that the freezer can be used with one or two discharge pumps.

The crunch for space has also led to freezers that are built to spec. “Another area of concern is that often freezers are made as ‘standard’ units, capable of certain temperatures or throughputs. but more and more we are seeing customers that may have cost constraints, or existing building restrictions, refrigeration system constraints that this approach doesn’t solve. Our units have always been custom designed to suit applications, often being designed around what space is available,” Smith says, noting that “future proofing” is built into such freezers, allowing for increased capacity or changing product specifications.

Versatility, whether or not it results in a custom machine, is reflected in other types of freezers now on the market. Gram Equipment, for instance, recently added new low-temperature freezer capability. “We can take our freezer turn it into a low-temp freezer. It has flexibility from that standpoint,” Fish says, adding that a different type of inlet pump and dasher were used.

In addition, for those doing smaller product runs or testing new products, Gram Equipment now offers self-contained models. “There are fully automatic little machines,” Fish says. “They are like a full-blown freezer but on a smaller scale.”

CLARIFICATION
The Processing Technology article in the March 2007 issue, “Fit for Service,” reported that Fristam Pumps is developing larger-capacity pumps for release later this year. In fact, Fristam already has such equipment available — its front pull-out seal centrifugal FPR 4001 and liquid-ring FZX 2400 model pumps.