Editor’s Note: This article on the history and impact of advances in clean-in-place (CIP) technology is the fifth in a series for Food Quality. In “FoodTech: Tools That Changed the Industry,” we look at various technologies and tools, such as CIP, that have played a key role in and had an indelible impact on the food industry.
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Explore This IssueOctober/November 2010
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Pete Fernholz remembers the days when his dad, who worked at a milk plant for 40 years, had to help take apart a milk processing system and clean it with tubular brushes. It was a costly and time-consuming step in the process of trying to assure sanitized milk. Nowadays, closed-loop systems use clean-in-place (CIP) technology, which allows pipes and other production components to be cleaned automatically with less human intervention, reducing cleaning time, costs, and possible contamination events.
“Milk is the most sensitive food product,” said Fernholz, vice president of research and development, food and beverage global CIP at Ecolab Food and Beverage, which builds programmable logic controllers (PLCs) for CIP systems, designs CIP systems, and develops new chemical cleaners. “Anyone running a fluid food plant has a challenge with sanitation,” he said. “Automation of CIP systems was a big event [in the industry].”
“CIP has become part of the main industry because, with this efficiency in cleaning, you don’t have to dismantle the instrument,” said Digvir Jayas, PhD, distinguished professor in the University of Manitoba’s Department of Biosystems Engineering. Since CIP systems were first integrated into production lines in the 1950s, said Dr. Jayas, they have evolved to have microprocessor controls, flow controls, and better detergents.
Because of the CIP system’s simplicity, there haven’t been a lot of major leaps forward technologically; instead, incremental improvements have introduced automation and better cleaners and tried to further simplify the CIP process. Typically, an improvement in equipment technology went hand in hand with better chemistry. For example, microprocessor controls allowed a distributed configuration for the CIP systems. That meant that, in order to save energy and detergent costs, one area of the plant with a particular fluid food product could get a lower concentration of chemical cleaner at a different velocity than another area with a different product, Dr. Jayas said.
Only recently have companies been able to improve chemistry to the point where lower water temperatures could be used for washes to save energy, a major cost in CIP. Aeolus Technologies Ltd., in the United Kingdom, has gone a step further, developing CIP systems that use air instead of water and chemical cleaners, thereby saving on water, detergents, and energy.
From Hand Wash to Hands Off
CIP systems typically clean tanks, pipelines, processing equipment, and process lines by circulating water and chemical solutions, making unnecessary the dismantling and manual cleaning of those elements with brushes. Higher temperatures and stronger detergents can be used in CIP systems than in manual cleaning.
Dr. Jayas said CIP systems are classified as single-use, reuse, or multi-use systems, depending on whether the cleaning solution is used just one time, many times, or for a few cycles of cleaning. Single use is best suited for cleaning heavy soil loads. Reuse allows for reclamation and reuse of cleaning solution and final rinse water and is generally good for light soil loads. Multi-use systems fall between single use and reuse, with the final rinse water and solution used for a few cleaning cycles. Environmental impact issues and costs of chemistry drove the move to systems that could reuse detergents in the 1960s and 1970s, said Bruce Blanchard, national sales manager at GEA Process Engineering Inc., a CIP system designer and installer.
Manual cleaning systems were replaced in some fluid processing plants by closed-loop CIP systems in the late 1950s, and automation took hold in the 1960s, offering more cost and time savings. CIP systems evolved to include sensors that could detect pH, turbidity, and conductivity to help save on cleaning product costs and improve efficiency. Also in the 1960s, centralized systems in the United States began to be replaced with distributed systems that allowed certain parts of processing to use more or less detergent, for example, and to be isolated if there was a contamination event. European processors still tend to use centralized CIP systems because of limited factory space.
The next big change in the CIP market came in the 1980s, when PLCs replaced the pin-drum systems that turned and activated the cleaning system. With PLCs, operators merely needed to activate a program on the controller to get the CIP system going.
At the same time, improvements in chemical sanitizers helped to cut high energy costs from heating water and extend product shelf lives. In the mid-1980s, for example, oxonia-peracid, a chemical biocide, hit the market. Fernholz said it could extend fluid milk shelf life to as long as 21 days, compared to seven days in the 1950s. Peracid is now widely used. The caustic powders used in the 1960s were replaced by liquid alkaline, then chlorinated alkalines, then additives to caustic (detergents blended on site). More recently, single-stage acids were added to the process, according to Holger Theyssen, senior director of research and development in food and beverage for Diversey Inc., in Mannheim, Germany. The detergents that are now in development share an emphasis on green cleaning, which is a growth area, Dr. Jayas added.
Companies are also currently working on ways to mine data to help pinpoint parts of the system that could be optimized, areas of potential failure, and ways to save on water, energy, and cleaning product costs.
Cutting Steps to Cut Costs
Large fluid food processors are very sensitive to their “green” image, said Steve Wnuk, MBA, senior director of global food and beverage marketing at Diversey. “We’re seeing continued high interest in sustainability solutions, with rapid CIP solutions paying off for business,” he said.
We’re seeing continued high interest in sustainability solutions, with rapid CIP solutions paying off for business.
—Steve Wnuk, MBA, Diversey
Diversey is developing a rapid CIP platform that reduces the number of steps in the process down to three from the typical five to seven. A typical CIP process first pre-rinses, then adds detergent, rinses, sanitizes, and final rinses. Diversey’s product, which the company expects will hit the market in the second quarter of next year, will pre-rinse, add a detergent-sanitizer, then final rinse without heat. Fewer steps will mean energy and time saved.
“There’s a savings in chemistry by using cold or ambient water,” Theyssen said. “We have chemistry that works in cold water.” The chemistry uses an acid detergent-sanitizer combination product that eliminates the need for a separate sanitizer step. The product can be used for a mix of light and heavy soil burdens. Theyssen added that the product reduces cleaning time and water and energy use while improving operating efficiency, resulting in a 51% cost reduction. “It is lower carbon, so it is green,” he said.
Diversey also has several programs that allow it to evaluate efficiency and efficacy at processing plants. For example, the AquaCheck program evaluates chemical use and is aimed at improving sanitation and decreasing expenses. SecureCheck assesses cleaning and sanitation procedures for cleaning efficacy and identifies risk points in a facility. And EnergyCheck is a new pilot system designed to check energy use.
Wnuk said one benefit of such programs is that results are put into a database so tests from future customers can be compared to a baseline. “We have performed more than 400 water interventions with AquaCheck, so we have a proprietary database,” he said. “We can gather [a customer’s] information and compare it against our database.”
Ecolab’s Fernholz also sees the potential for mining the rich data collected during the CIP process. He predicts advancements in software for developing supervisory control and data acquisition systems, which collect step records of information off of PLCs used in the CIP system. “A lot of data has piled up. It’s impossible to look for errors and exceptions in 125 washes occurring over 24 hours. Reports are in primitive form now,” Fernholz said. “A future development will be diagnostic tools that could help predict a failure.”
Ecolab is applying chemistry to reduce water temperatures and, in turn, energy consumption. The company’s Advantis acid detergent can clean at a lower temperature, Fernholz says, reducing a typical 150ºF cleaning to 110ºF. Dropping the temperature 40 degrees could help to save 10% to 15% on overall fuel costs, he said.
Water and energy are the expensive parts of CIP systems, with some 30% to 40% of a facility’s steam energy alone associated with CIP, Fernholz said. “We’ll have a continued focus on chemistries that operate at lower temperatures and decrease water consumption,” he said.
“The challenge to cold cleaning is chemistry. Most cleaners are less active in lower temperatures, so it’s necessary to reformulate the chemistry,” explained GEA’s Blanchard.
Aeolus took perhaps the most straightforward path toward reducing water, temperature, and the need for new chemistry: The company cut them out almost entirely, opting instead to use turbulent air for clearing and cleaning pipes.
The company’s Whirlwind pipe cleaning technology works in a four-phase clearing, cleaning, and drying process. In phase one, the first clearing is performed, as is initial product recovery. A laminar air stream is blown through the product that remains in the processing pipe work, recovering up to 90% of it. Because some product remains on the inner surface of the pipe work, phase two uses a whirlwind generated within the airstream to clear the remaining product.
After this phase of the process, less than 5% of product typically remains on inner pipe surfaces. During phase three, a small amount of water or cleaning agent is introduced into the airflow, with cleaning accomplished by the turbulent air and water mix acting on the inner surfaces of the pipe work. This process results in an inner surface that is 100% clean, according to information provided by the company.
Phase four consists of drying the pipeline using heated air. Warming the whirlwind airflow removes any traces of water droplets on the inner surface of the pipe work. The surfaces are dried so production can be restarted quickly.
CIP systems evolved to include sensors that could detect pH, turbidity, and conductivity to help save on cleaning costs and improve efficiency.
Peter Chavasse, business development manager at Aeolus, said the technology has been on the market for a number of years but was not publicized much before his company bought the business. In addition, there is a time curve for customers to adopt new technology, he said.
“This approach takes CIP to a different level,” said Chavasse. “We can save water, reduce waste and effluent, and reduce energy use.” Companies in Europe making pasta sauces, wines and spirits, and cosmetics currently use the Whirlwind System.
He said some companies just use the first two phases, while others may use the system twice a day for two weeks and then use a traditional CIP system to do a wet cleaning. The Whirlwind can be retrofitted onto existing CIP installations, or it can totally replace wet CIP cleaning, he said. The company is currently studying the scalability of the technology, hoping to install it in larger plants in the United States.