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In-line monitoring makes CIP-system more efficient

Published: 12-11-2015, | Member: NIZO

Using in-line sensors to continuously monitor a Cleaning in Place (CIP) system, could save time and provide crucial information about the cleaning process. NIZO food research and Schneider Electric are currently developing and testing such a system at FrieslandCampina.

Thorough cleaning of processing equipment is key to increasing food safety. Therefore, CIP is standard practice for most food manufacturers. In the dairy industry, equipment is cleaned once to three times a day using alkali and acid detergents and/or disinfectants. In other industries such as beverage production, cleaning is necessary too, though less frequently.

Upon installation of the system, its results are usually recorded and validated, but once in operation the process is usually assumed to run like clockwork. Manufacturers normally only consider optimization of CIP when facing quality or capacity problems. Only then is there suddenly a need for data on the cleaning process or for a time-saving, accelerated process.

But there are other reasons for optimizing the CIP process besides capacity and time. The benefits include the reduction of energy, water and chemicals.

“We’ve found that cleaning processes in the food industry tend to be based on overkill,” said Maykel Verschueren, Processing and Safety Division Manager at NIZO food research. “Processes are designed to clean longer than strictly necessary, just to be sure no soil is left. Optimization and continuous monitoring of the cleaning process could save time and costs without compromising food safety. We know from experience that cleaning times can be shortened by ten to thirty per cent.”

Usually, the CIP system’s effectiveness is monitored by establishing a number of parameters such as time, temperature and chemical concentration. Most manufacturers record this information and analyze it manually, which is not only labor intensive but also has several drawbacks. Such a snapshot of the current situation is necessarily imprecise, as the cleaning process is not always exactly the same, for example due to malfunctioning, unplanned waiting times, or the presence of more or less soil than average.

In addition, this type of ‘offline monitoring’ is equipment-specific and does not provide an overview of the cleaning results in other process lines. Manufacturing plants often consist of dozens of different lines and pieces of equipment that are cleaned independently.

Now, NIZO food research and Schneider Electric — a research institute and an ICT company — are currently developing a fully computerized system for continuous CIP system monitoring, and testing it in a pilot project at a FrieslandCampina dairy processing plant. The system uses in-line sensors specifically designed to identify frequently-occurring soil in dairy processing equipment.

New parameter
The new in-line system monitors five parameters that are crucial to the cleaning process: time, temperature, chemical concentration, flow and turbidity. “The latter parameter is new in automatic CIP monitoring,” explained Verschueren. “Turbidity is a key parameter. As soon as the cleaning solution runs clear, you know the equipment is clean. Monitoring this parameter provides crucial feedback that can prevent needlessly long cleaning and save time.”

“In-line monitoring of CIP-systems also has other advantages, ” Verschueren added. “It creates a continuous stream of data about the cleaning process. This enables immediate intervention if something goes wrong. The data are also consistently logged, forming an audit trail that can be used to analyze the process. This is important for tracking and tracing and quality control.”

Pay back period
Verschueren expects the final results of the pilot project at FrieslandCampina later this year. “We developed this in-line CIP monitoring system with the dairy industry in mind. We expect to be able to achieve up to thirty per cent shorter cleaning times. With such savings, the pay back period for the system will be short. We think other industries, like the beverage industry, could benefit from the system too. Technological advances are made every day; I expect the sensors needed for non-dairy fluids to be available soon,” he said.

The food industry has long expressed an interest in optimizing CIP systems. NIZO food research and Schneider Electric took up the challenge, working towards solutions in a project they termed OptiCIP. Over the past few years, NIZO developed a method with an in-line turbidity sensor that provides data on the turbidity of the cleaning solution. Turbidity is a key indicator of the amount of soil present and the speed at which it is being removed. This enables operators to manage and optimize the cleaning process. At the same time, Schneider Electric independently developed a software tool for automatically monitoring CIP processes. NIZO and Schneider combined their knowledge in this new OptiCIP application.

NIZO food research