Food Engineering

Tech Update: Clean-in-Place continues to evolve

April 11, 2003
As demand for hygienic design increases, CIP systems are redefining the meaning of clean.

Cleaning the membranes in ultrafiltration systems has required manual intervention, but materials that can withstand temperatures up to 90¿C make CIP with hot water possible. Source: Osmonics Inc.
Unlike old soldiers, food processing equipment neither dies nor fades away. The same is true of clean-in-place (CIP) systems and components, many of which continue to serve plant sanitation needs a half-century after being placed into service.

"We routinely get calls for support for CIP systems that we installed in 1963, '64," laughs Robert Beers, manager of food and beverage engineering at Ecolab Inc. Mechanical support is no problem, but older systems predate the advances in controls technology that have swept the equipment world. "Rather than retrofit an old cam timer, it would probably be better to put in a new I/O," says Beers.

CIP monitoring and data acquisition is advancing rapidly, driven in part by regulatory requirements such as HACCP and 21 CFR 11, the electronic signature aspect of the food code. Embedded microprocessors and industrial computers with touch-screen operator interfaces are taking the verification process to new levels of accuracy, just as the earliest CIP systems brought repeatability to sanitation procedures.

Ecolab traces its involvement in CIP to seminal dairy systems in the 1950s. Manually operated valves controlled the rinse/clean/rinse/sanitize cycle in those systems. Control automation has progressed through the PLC era to industrial PCs that can control multiple CIP systems and manage hundreds of custom CIP programs. Systems for the pharmaceuticals industry already meet the needs of electronic signature capture, and security features like operator ID are coming into play. "Having the ability to validate and document processes and identify who had access to the equipment is becoming more critical," says Beers.

"The technology available today has obsoleted equipment made even five or six years ago," agrees Tom Niverth, technical manager at Nu-Meat Technology Inc., which supplied several CIP-capable units to Future Beef Operations, this year's Food Engineering New Plant of the Year (see story on page 34). "Most of the advances are in electronics, but sanitation technology also is advancing." Ultraviolet light and other alternatives to chemical sanitizers are being evaluated for effectiveness with food equipment, for example.



The use of ozonated water from portable generators has been validated as an effective washdown technique for food plants. The next step is to incorporate it in CIP systems. Source: Air Liquide

How clean is clean?

While its roots remain in dairy, CIP and its precepts have spread well beyond to include juices and other pumpable products, pharmaceuticals and solid foods. "There aren't many people around still who classify themselves as clean-in-place experts because the technology is pretty well understood now," notes Doug Hartel, an engineer who designed his first dairy CIP system 42 years ago. Hartel recalls using components from a dishwasher to introduce chemicals to the cleaning solvent and air-operated valves because sanitary valves had not yet been developed. "It's not as much of a mystery anymore," he says.

As knowledge of the concepts and techniques spread, equipment manufacturers began designing CIP features into their equipment, eliminating the need to cobble together a CIP retrofit later on. Today, "equipment pretty much comes pre-packaged with CIP," according to Bob Albert, project manager with Suitt Construction Co., Richmond, Va. "Manufacturers are doing it for their own protection. Even if you don't specify CIP, you get it anyway."

"The cleaning system used to be an afterthought to the design, engineering, instrumentation and controls of a system," adds Hartel. "But clean in place should be integral to the design, and it should be validated along with the rest of the system." Hartel recently formed a consortium called Hartel International to do just that, producing turnkey systems for makers of cosmetics and injectable drugs as well as food processors.

Another notable change is the escalation in hygienic standards. "Degrees of sanitation" have evolved, Hartel observes, as processors refine procedures to meet the rigors of aseptic products over basic dairy.

Riboflavin testing is an example. Equipment for pharmaceutical manufacture was the first to undergo validation procedures that included coating contact surfaces with a riboflavin solution, then rinsing the interior with the CIP devices designed for the process. If any untreated areas that could harbor trace amounts of contamination remain, they are exposed by illuminating the interior with an ultraviolet light. "We have done riboflavin testing for pharmaceutical equipment, and it's on the horizon" of 3A standards for dairy equipment, says Brian Gerke, vice president of A&B Process Systems, which designs and builds process flow systems for the food and beverage industry.

Hartel International also is making use of riboflavin testing, reports vice president Jon Ambrose, and microbial swabs and plate counts are coming into play. "The range of repeatability used to be very large," he says. Today, the expectations are for "very tight cleaning ranges."

The spread of CIP beyond dairy and the global nature of food production is adding fuel to a movement toward international sanitation standards. "As production demands grow and downtime becomes a greater concern, CIP is more in demand, not just in dairy but to a wider group in the food industry," Gerke maintains. That's why 3A and the European Hygienic Equipment Design Group (EHEDG) are trying to reach consensus on a worldwide standard protocol.

"There is a definite effort to standardize on a protocol for equipment," says Ecolab's Beers, but 3A and EHEDG can only address half of the CIP equation. The other half involves the sanitizers that are used, and differences in local and national regulations on what can be used and discharged make global standards extremely unlikely.



CIP functionality is built into the Menozzi brine mixers at Future Beef Operations in anticipation of meat processing’s migration to the technology.

New sanitizing solutions

The health issue being addressed and the degree of sanitation desired impact the sanitizing options available. When environmental and food regulatory considerations are added to the mix, the selection of a sanitizing solution can be more complicated than the product recipe itself.

Strictly speaking, sanitation refers to a reduction of microbial levels to a safe range from a public health standpoint. Food safety and liability concerns encourage processors to go beyond that and to disinfect (destruction of all vegetative cells) and even sterilize (the statistical destruction and removal of all living organisms). Counterbalancing these objectives are practical and economic considerations: continuous rinsing with hot water for half an hour might produce sterility, but it would cost a small fortune and could disrupt production schedules. A few cups of an approved chemical can speed the process and lower costs, provided their use is consistent with the process and the equipment.

An old solution that is finding new uses in CIP is ozone. Ozonated water can replace or at least reduce the amount of chemicals used for cleaning. A recent study by the Toxicology Group LLC, an independent testing division of NSF International, concluded that a 30-second treatment of food contact surfaces with ozonated water produces a 5-log reduction in organic contamination levels. That's the sanitation standard for food product contact as defined by the Association of Official Analytical Chemists.

Unlike chlorine, ozonated water doesn't leave any residue, so a rinse is not necessary if simple sanitation is the goal, points out Joanne Burris, food & beverage market manager for Air Liquide America, sponsor of the Toxicology Group study. "A lot of companies are changing their sanitation procedures to take advantage of ozone to improve sanitation and food safety." A cheese processor reduced CIP sanitation to a two-step process from four, she says, while others are incorporating ozonated water as a final intervention or as an additional step.

But global solutions remain elusive. The European Community has yet to approve ozone for either direct contact with food or as a food-surface sanitizer.

"The most critical aspect of using ozone to disinfect is the ability to carefully control the ozone residual," according to Dale D. Mork of Osmonics Inc. Mork has designed a system that uses an advanced dissolved ozone monitor with PID control logic to "ensure that the ozone level is high enough to effectively kill all organisms, but not so high that certain materials in the process water loop may be degraded."

Though such a system has yet to be deployed, Osmonics' Fred Libatore says ozone injection has great potential as a replacement for chlorine. He envisions ozone being used in conjunction with reduced concentrations of chemical cleaners.

Ozone generators could be incorporated into central CIP units, the traditional delivery mechanism. As plants have scaled up, those systems have grown to epic proportions; A&B's Gerke reports CIP systems with 5,000-gallon recovery vessels are being installed. Along with supersized CIPs come flow meters and other add-ons to monitor system performance and troubleshoot problem areas.



Migration to meat

Portability is the counter trend, and portability is helping to make CIP applicable to a broader range of foods. Not only are portable CIP units less expensive than large, central systems, they allow plant operators to isolate cleaning to specific batch processing equipment.

Future Beef's ground beef room exemplifies that. The equipment is not served by a central CIP system, though the floor plan includes a room that could house such a unit. Instead, the equipment is "CIP-able," says Suitt's Albert: pipes, pumps and tanks are built into most of the equipment, and crews using hand-held foamers and high-pressure hoses can sanitize units, one piece at a time. But the PLCs, chart recorders and other components of a fully automated and verifiable CIP system are absent.

"We made everything with spray nozzles, but we didn't build it as a system with controls," explains Alan Davidson, owner of Food Processing Equipment Co., which designed and built Future Beef's ground beef equipment. "USDA requires visual inspection of meat processing equipment to make sure sanitation dealt with any bits and pieces on contact surfaces. CIP can augment that process."

Very few ground-beef processors require Future Beef's level of production flexibility, points out Albert. Instead of week-long product runs, production might switch from 1 lb. loaves of 90 percent lean to 5 lb. loaves of 75 percent lean beef during the course of a shift. "With the equipment's CIP capability, they can do a rudimentary cleaning before switching grades during lunch or break time," he says.

Screw conveyors and blenders were included in the CIP design, which is a new development, Davidson says. The glass bead finish on the equipment approaches the finish of polished steel in terms of cleanability. "If there was ever a sanitation issue, the equipment is configured to allow a modest midstream correction" to bypass the problem area and continue production elsewhere, he adds.

Although Suitt did not specify CIP functionality, "Equipment is getting larger and more difficult to clean, so we saw a need for this feature," Davidson says. Similarly, the European-built ovens and brine mixers in the plant's further processing department bundled CIP with the rest of the package. "Water and waste processing costs so much in Europe, so they design their equipment with washdown frugality in mind," says Albert. "CIP isn't just ball sprayers, it's a total package of metallurgy, welding technique and shape."

The automated cleaning feature of Future Beef's Germos oven and smokehouse isn't CIP overkill, Nu-Meat's Niverth insists. Daily washdown of the unit's walls, floors and ceilings is recommended, and the frequency might increase depending on the product mix. The intent is not to replace human monitoring of the sanitation process but rather the manual drudgery.

For more information:

Brian Gerke, A&B Process, 888-258-2789
Joanne Burrows, Air Liquide America, 713-624-8709, joanne.burrows@airliquide.com
Terri Bringgold, Ecolab Inc., 651-293-2549
Alan Davidson, Food Processing Equipment Co., 501-751-9392
Jon Ambrose, Hartel International, 901-821-0288, jon.ambrose@hartelinternational.com
Jim Ryan, Nu-Meat Technology, 908-754-3400
Fred Libatore, Osmonics Inc., 760-598-3334, flibatore@osmonics.com
Bob Albert, Suitt Construction Co., 804-794-9300