Mixing Innovations Keep Beverages Flowing

“74 percent of consumers surveyed in the spring of 2011 expected to spend more in that coming year on non-alcoholic beverages than they had in 2010. ”

- 2011 study by market research firm AlixPartners

The beverage industry is bigger, more trend-driven and more diverse than ever. The American Beverage Association says just its slice of the industry (carbonated soft drinks, energy drinks, ready-to-drink teas and bottled water) amounts to a $119 billion, annual economy.

It is also growing. A 2011 study by market research firm AlixPartners indicated that 74 percent of consumers surveyed in the spring of that year expected to spend more in that coming year on non-alcoholic beverages than they had in 2010. Several market studies point to impressive growth in sub-segments including energy drinks, ready-to-drink teas and sports drinks, all of which more than eclipse the erosion of carbonated soft drinks sales.

This complex beverage industry means that beverage plant managers and engineers have more variables to work with and a higher level of expectations to meet. While it may be pretty basic on the surface, mixing and blending beverages and then packaging them for sale is not nearly as simple as it once was.

Remember when there was only formula for orange juice? "Now, do you want no-pulp, light pulp or heavy pulp?" asks Wallace Wittkoff, hygienic market director for Pump Solutions Group, which includes pump brands such as Wilden, Mouvex and Almatec (www.psgdover.com).

"Beverage processors need to thermally handle the juice differently than the pulp. If you break the pulp sac, all the pulp falls to the bottom. So they separate the pulp and then add it back in at the end to whatever proportion they desire. A centrifugal pump could pump the beverage just fine, but could break those pulp sacs. But a diaphragm pump gently handles mixing the pulp back in," he says.

Wittkoff also notes that the Wilden Hygienic series is designed with internal geometries that prevent pulp from getting lodged in seal areas or back sides of rotors so pulp is completely removed during clean-in-place. Otherwise, pulp can remain even after cleaning.

Some of the most important changes have taken place in the blending room, where new technologies allow for faster, more accurate and more thorough blending of the ever-increasing ingredients and fortification that goes into today's products.

It doesn't end there, of course, as filling and packaging equipment has also changed dramatically. And throughout a beverage plant, there are ongoing efforts to reduce energy use and push the envelope on the levels of hygiene, functionality and ease of maintenance.

A better mix
Mixing and blending for beverages is typically achieved in a large-format vat blending system. But as beverage formulations have become more varied and complex, and have come to include more high-value fortification and functional ingredients, the approach to blending has changed too, says Rick Earley, beverage and dairy market manager at Admix Inc. (www.admix.com) Manchester, N.H.

"With all the beverage folks, what they want to do is to wet, disperse and blend all of these critical ingredients into a liquid," he says. "We are able to save them energy and reduce batch times through things like in-line and powder induction blending that takes place before the mix reaches the batch tank.

"Most beverage plants have gone to high-shear mixers in their batch tanks, but with in-line and powder induction there is less heating and mixing needed once the product reaches those tanks," he adds.

Additionally, ingredients can be mixed at floor level, eliminating the need to elevate those materials to the top of a tall batch tank, says Daniel Osiedacz, blending/mixing product manager at Fristam Pumps (www.fristam.com) Middleton, Wis.

"You would rather not have personnel positioned at the top of the tank. And if you are blending directly in the tank, you have to have some way of getting the ingredients up there," Osiedacz says. "Also, when you dump a big bag of powder into a vat filled with liquid a portion of it doesn't get mixed in right away."

A common negative outcome of batch blending is that some of that undissolved, un-hydrated powder bonds together. Those clumps can be reduced, but it is nearly impossible to eliminate the smallest clumps or agglomerations, commonly referred to as "fish eyes."

"Those usually have to be removed by some sort of filtration, and that's a waste of raw material," Osiedacz notes. As beverage manufacturers add botanicals to energy drinks and vitamins to dietary supplements, the ability to lessen or eliminate raw material loss becomes more attractive.

Premixing can reduce costs in another way, says Chris Ryan, technical author at Silverson Machines (www.silverson.com) East Longmeadow, Mass. "We can help manufacturers cut their running costs by preparing premixes and formulations without the need for heating the base liquid," he says. "This applies to ingredients like pectin and gum arabic as well. We know of two major producers who have come to our site for trials and have been amazed at the results achieved with water at ambient temperature. The savings in this instance would allow payback for the mixer in no time."

Premix procedures
Powder induction mixers and inline blenders use pumps upstream of the vat mixer to meter and blend liquid and dry ingredients while recirculating the slurry.

Inline blenders work in three stages. During stage 1, high-speed rotation of the rotor blades within the mixing workhead exerts suction, drawing liquid and solid materials into the rotor/stator assembly. Next, during stage 2, centrifugal force drives the materials towards the periphery of the workhead, where they are subjected to a milling clearance between the ends of the rotor blades and the inner wall of the stator. This is followed by stage 3, where intense hydraulic shear forces the materials at high velocity through the perforations in the stator, then through the machine outlet and along the pipework. At the same time, fresh materials are continually drawn into the workhead, maintaining the mixing and pumping cycle.