Integral Role for Clean-in-Place Technology

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.

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.

A number of companies custom design and install clean-in-place systems such as the one shown here.

“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.

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Figure 1. Aeolus Technologies Ltd. has developed clean-in-place systems that use air instead of water and chemical cleaners.

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.