Degrees of Separation

Dairy Field, Sep 2004 by Petrak, Lynn

The latest separator equipment is built for efficiency, durability and, increasingly, capacity.

It's one of the oldest and most essential points in dairy production. The separation process, in which different liquids and solids are separated from each other in a large tank or centrifuge, is the virtual starting point for milk, cheese, ice cream, dairy powders and other dairy products and has been, since separators were first introduced in the 1890s.

If not done correctly, the final product will not be formulated properly, and if done too slowly or inefficiently, a plant's profitability can suffer due to lost volume, energy costs or operating time.

With separation at the beginning phase of the production process playing such a key role, suppliers are updating separators with state-of-the-art features and technology. There may not be many new models of separators rolling out every year and although there are only a handful of separator manufacturers in the United States, changes are being made to meet processors' demands for reliability, speed, efficiency, durability and volume. "It's the most integral and expensive piece of equipment in the plant. It's the Swiss watch, if you will," says Mark Etcheverry, sales manager for Statco Engineering and Fabricators, Huntington Beach, Calif., which sells and reconditions separators for dairy customers around the country.

Because so many industries rely on this pivotal equipment, leading separator suppliers continually refine their technology and equipment features. In addition to dairy processing plants, separators can be found in other food and beverage facilities, from juice plants to breweries, as well as various industrial environments, ranging from oil drilling to pharmaceutical manufacturing to wastewater treatment.

As in those other industries, dairy processors are seeking equipment that will enable them to do tilings better and quicker, as capacity demands increase and as product lines broaden. "For some of the larger dairies, the capacities are going up, and there has also been the consolidation of dairies," says Jeff Biel, product manager, separation and filtration, for Tetra Pak, a Vernon Hills, Ill-based packaging and production equipment supplier that distributors a line of separators, including Alfa Laval machinery. "They want to do more and do it efficiently."

That was exactly what operators at California Dairies Inc., Artesia, Calif., were seeking when they decided to replace separators for powdered butter applications in three facilities during a plant remodeling project a few years ago. "We were looking for better skimming efficiencies and better energy efficiency. Machines today are more efficient when it comes to separating milk and cream," recalls Harry DeLint, vice president of engineering, noting that the company chose Tetra Pak's HMRPX 718 models, which have resulted in energy savings and more operator-friendly use. "All the fat we can get out of there and turn into butter, the better we are." The new separators were placed between raw milk receiving and milk evaporation systems, with one high-capacity plant running four separators at once.

Tied into efficiency, of course, is the all-important concept of profitability. "Basically, and again with the pressure the dairy industry is facing, they need to look at their bottom line. If they put a piece of equipment in a plant, it has to save them money or increase their bottom line and we are doing that with better efficiencies," says Biel.

An efficient separator system has an inherent financial benefit, adds Etcheverry. "It's important, because with separators, you are separating the fat or part of it to sell products you have labeled to a certain fat content. Also, with the extra butterfat, you can sell that for profit," he says.

A Solid Explanation

Separators have been used in the production of milk for more than a century, dating back to the first models developed by the brand that is now known as Alfa Laval. As milk varieties expanded, the need for more sophisticated separators also has grown, with processors separating and reintroducing milk fat for different fat-based product types.

During the separation process, a separator's motor-driven centrifuge rapidly spins raw milk in order to remove heavier milk solids from the rest of the fluid and to separate the cream from the skim milk. For fluid milk, milk fat can be gradually added back in at various levels to make whole milk, 2%, 1% and other such varieties.

Separators are also used in cheese production for whey, a byproduct of the cheesemaking process. Cheese fines can be removed from whey through a centrifugal clarifier, with additional fat removed in a whey separator. Plants that manufacture dairy-based powders also utilize separators, to take out milk proteins during the drying process. Lactose, whey protein, casein and butter oil can all be recovered through the use of separation technology. On the quality and food-safety side, separators have been used for clarification purposes to help remove bacteria.