No Holding Back
by Lynn Petrak
Contributing Editor

New tank and tube design centers on mantra of efficiency, versatility, capacity and cleanability.
Tanks and tubes are crucial components in a dairy plant, as part of the infrastructure needed to turn raw milk into finished product of one form or another. If a processing facility can be compared to a city, tanks and tubes could be considered the housing and transit systems.
Befitting their role in the daily workings of a dairy plant, tanks and tubes are maintained much like homes and vehicles, with continual upkeep, preventative maintenance and the occasional necessary replacement. Although engineering improvements in tanks and tubes are typically subtle, they are evident in some of the latest designs to come from equipment makers. Such refinements affect virtually all types of tanks and tubes, for vessels used to hold both smaller and large-scale quantities of fluid or powdered products and for the agitation of liquid and powders and for tubes used to move liquid or air from one point to another.
As one might expect, the top-tier issues affecting dairy processors — and, for that matter, any manufacturer that uses tanks and tubes in food and beverage production — are driving forces in raising the bar in tank and tube technology. Chief among those issues these days is efficiency, encompassing both throughput and energy use.
Having equipment that works to the fullest possible potential, after all, gets to the nitty-gritty of expenses. “A lot of interest of dairy manufacturers in their demand for tanks and tubes is efficiency — ‘What does it cost to run this thing?’ ‘What energy is driving it?’” says Jim LeClair, product director for the Americas, Invensys APV, Lake Mills, Wis., which offers process engineering and automation solutions to dairy processors, including equipment like its new Flex-Mix™ Liquiverter featuring a stainless steel tank in a single-shell design.
Tied into efficiency is versatility, in that processors want to be able to maximize space and equipment to accommodate their growing production capability. For example, because dairies are making more and different types of dairy products, they are looking for flexible solutions from machinery providers.
“Quality with efficiency continues to be the name of the game for a producer to survive in today’s highly competitive dairy and beverage market,” says Marcelo Ferrer, account manager, processing systems for Tetra Pak Inc., Vernon Hills, Ill., which supplies a range of food and beverage processing and packaging equipment to the industry, including tanks and vessels. “A result of what we are seeing is an increased need to customize our systems to cover a wide range of products — from plain white milk to smoothies to protein shakes — which normally involves considering the utilization of specialized agitation systems as well as consideration to the type of stainless steel to be used.”
Competition and consolidation within the dairy industry also has led to interest in machines that can hold and handle more product. “Whole processing systems are becoming larger and larger to put more volume through their plant,” reports Joe Schlither, national sales manager, WCB Flow Products, a Delavan, Wis.-based SPX Processing Equipment operation, which uses fittings from Rath Tubing, Janesville, Wis. “Typically, in sizes of tubing and fittings, you are seeing larger capacities and larger diameters.”
Brian Uhlenkamp, vice president of engineering and research and development for St. Cloud, Minn.-based tank system supplier DCI Inc., agrees that “bigger is better” is a more common refrain when it comes to tanks. “We’ve had customer requests for larger tanks with agitation – they are asking for bigger and bigger,” he says, adding that dairies are also looking to put such systems on existing footprints when possible, thus accelerating designs for taller or higher tanks.
Ferrer also notes that capacity is pushing a new envelope. “Another trend due to the need to increase plant efficiencies is that these aseptic tank systems are being delivered in sizes larger than ever,” he says. “That’s because producers are having to maximize their processing and packaging running times to keep up with the increased production complexity.”
Meanwhile, because the old “time is money” adage rings ever true today, dairies that buy or upgrade tanks and tubes also are turning to equipment makers to improve turnaround times. “We’ve put in a warehouse facility on the West Coast to offset some of the delivery issues, because there is demand for getting the product to customers when they want it,” Schlither says.
Not to be overlooked in modern tank and tube design is, of course, durability and reliability. “Quality goes without question — you need to be a validated supplier for these people, after you’ve met certain standards,” Schlither says.
Tank and Tube Showplace
Ensuring quality is often linked to construction. In that vein, the composition of tanks and tubes is being affected by many concurrent industry-wide demands.
LeClair, for one, indicates that changing beverage formulations are affecting the life span of tanks. “New sports drinks create huge strains and corrosion. And new dairy drinks trying to compete with those energy drinks create issues in old dairy-style storage tanks. So you need a higher grade of stainless or different design,” he explains, adding that many Invensys APV tanks are built with Type 316 stainless with Type 304 product cladding, with some dairies opting for higher grades of nickel.
DCI, for its part, has begun using a new type of corrosion-resistant material on its tanks, according to Uhlenkamp. “The material only came on the market two-and-a-half years ago. It’s like stainless, but with a surface finish,” he says. “It mainly prevents cracking, but also with current market trends and stainless-steel prices, it is less expensive than Type 316.” DCI uses such material on many types of vessels, from milk silos to crystallizers, Uhlenkamp notes.
Indeed, higher costs for stainless have led to the use of other material in some systems featuring tanks and tubing. “I’ve seen more recyclable plastics for non-crucial components,” Schlither reports.
Silicone is also being used as an alternative in certain dairy processing facilities as well. The U.K.-based equipment manufacturer CPS Limited, for example, offers high-strength silicone tubing designed especially for dairy applications.
Meantime, those that offer tanks for aseptic storage or processing put a premium on materials to ensure the right conditions for such production. At Tetra Pak, Ferrer says, the company’s most popular tank for the dairy industry is its Tetra Alsafe™ aseptic tank, a complete system comprised of a specially designed aseptic vessel for efficient and quick steam sterilization and cooling with a skid that contains all valves, instrumentation, sterile air package and a control panel with operator interface. The Tetra Alsafe is widely used in the dairy industry as an aseptic buffer tank prior to an aseptic or extended-shelf-life (ESL) filler. Tetra Pak also offers the high acid version of Tetra Alsafe which is designed for aseptic or “ultra clean” applications.
In keeping with the larger capacity trend, vessel manufacturers are coming out with new high-volume components to handle more products. Paul Mueller Co., Springfield, Mo., is one example. “We have 100,000-gallon shop-fabricated tanks, which is the biggest shop tank anyone has ever built,” says national sales manager Paul Hume, adding that the custom system was made for a major California cheesemaking facility.
The push for cleanability is also a catalyst for tank and tube upgrades, and also ultimately touches back to efficiency. “In a tank, the quicker they can clean it the better,” LeClair says. “We’re seeing more requests for true CIP (clean in place) tank systems compared to the old spray walls to cut down on the cleaning time. And because of the price of stainless, tubing is becoming a commodity and dairies are saying, ‘I need to make sure I am idealizing this.’”
At Tetra Pak, cleanability and efficiency are linked as well, exemplified in one add-on available with the Alsafe aseptic tank. “We offer an intermediate steam barrier option that allows a tank to be cleaned in place while another tank on the same processor feed line is still in production,”  says Ferrer, who cites other options aimed at quick and easy sanitation and built-in versatility. “All of these are basically designed to increase a plant’s efficiency and productivity as they allow for increased production uptime.”
Lynn Petrak is a freelance journalist based in the Chicago area.
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