Tech Update: Clean-in-place systems benefit from automation
February 1, 2007
A little more than a year ago, Food Engineering looked at the state of CIP and process control integration. Regulations were and still are a key driver for processors to implement CIP, and most regulatory bodies allow electronic documentation of CIP data. These regulations include FDA’s Pasteurized Milk Ordinance, 3-A Sanitary Standards Organization’s 3-A rules, FDA’s HACCP and 21 CFR Part 11, and the newly-emerging ISO 22000 standard. According to Gabe Miller, Sanimatic product development manager, most processors are now using 3-A standards, BISCC (Baking Industry Sanitation Standard Committee) and AMI (American Meat Institute) sanitary design principles when specifying new equipment.
With some applications, however, processors still prefer manual cleaning instead of automated CIP. Kevin Roe, A&B Process Systems process engineer, had such an application with a butter melt system. The customer needed a continuous supply of liquid butter at a minimum rate of 1,500 lbs. per hour. Though CIP options were available, manual cleaning of the receiving tank was preferred. The tank accepts 40-lb. blocks of butter. Roe designed the tank as a 3-A sanitary unit with hinged end covers for easy access to all interior surfaces.
Where possible, it makes sense to think of CIP as part of the process. India’s Bangalore Milk Union, Ltd. set into operation its totally automated, mega-sized dairy. Prior to automating, it couldn’t keep up with demand. The dairy realized that it had to automate both the process and CIP to be competitive. With sights set at a capacity of 160,000 to 265,000 gallons per day, it now commands a 60% market share with annual revenues of $46.4 million. Key to keeping the milk flowing is an integrated CIP system.
The dairy checks milk quality using several parameters as it arrives at the main gate. From the point of arrival, each operation is automated with controls for fat separation, temperature and flow control, pasteurization and system CIP. The Rockwell PLC-5/80C-based platform with RSView32 software gathers and distributes data for production, maintenance, breakdown, quality and CIP, along with utility and pressurized water supply system measurements. With the combined process control and CIP systems, the dairy realizes $444,000 savings annually in water, electricity, manpower and heating oil.
Save on water, chemicalsOne of the first questions customers ask of Rick Nelson, Ecolab manager, engineering project sales, is how much water is a CIP system going to use? They also want to know what’s going down the drain-both the makeup of the chemicals and the concentration. Customers like to conserve wherever they can. So if there is product left in the line that can be flushed out into a holding tank and used for animal feed before CIP begins, this is a desirable step. Many states have a department responsible for checking chemical containment at plants and the effluents as well. One trend Nelson sees is the disappearing chart recorder and the increased usage of electronic documentation of CIP process parameters. When a regulator needs to see proof of what went down the drain, it’s much easier to pull it out of the database than shuffle through a roomful of paper charts and documents.
According to Steve Cook, food process engineer at Central States Industrial, food manufacturers are becoming more aware of waste and taking steps to reduce it. For example, pigging systems are an effective way to push products from lines during changeovers or before CIP. Manual pigging systems can be used, and in some applications, pneumatically-driven pigs automatically clean out the lines before CIP. Other areas being addressed include:
- Optimizing heating with different heat exchange technologies such as steam injection or plate heat exchangers,
- Improving safety,
- Optimizing chemical usage by using chemical pumps (instead of manual addition), conductivity probes for measuring concentration and simple PLC controls.
Exotic sensorsTransition sensors determine when one phase of an automatic CIP cycle ends and the next should begin. Initially, pH or conductivity sensors were used to detect the acid or alkali concentration of washes and rinses. Optical-based sensors can, according to Cook, be used to detect when pre-rinsing has become ineffective and the wash cycle should be started. This reduces rinse water and time. An optically-based transition sensor sends a beam of light into a passing liquid and then measures the backscatter produced by suspended solids, providing an output of the concentration of solids or fat molecules.
Relatively short lifetimes of open-probe electrodes has been a problem with early conductivity sensors, according to J. K. Quackenbush, Invensys senior application specialist, conductivity/resistivity. Today’s electrodeless conductivity sensors are non-invasive, provide a 3-A approved design and typically have a 3-A-approved and FDA-compliant PEEK™ bore material, making them especially suitable for CIP caustics and acids. Processors will find with sensors like Foxboro’s 871FT sanitary device that loops can be calibrated without having to remove the sensor from the process line.
According to Gerry Broski, market manager for Thermo Fisher Scientific, through the use of advanced sensors, such as the company’s CrystalVision CO2 concentration sensors, CIP can be monitored and controlled to a greater degree providing documented results, higher throughput and energy and material savings. Broski also speaks of more exotic sensors. “One of our advanced research projects is a collaborative effort with the University of Minnesota to develop detection systems for mycotoxins.”
Another method of determining the transition point of wash and rinse cycles (or interface detection) is to use an inline turbidity meter or colorimeter installed at strategic points in the process. This device, according to Steve Croucher, optek product specialist, allows immediate detection of product-to-product and product-to-water interfaces. These interface detectors reduce product waste and water consumption. In addition, the photometric sensors allow users to send effluents with lower levels of biochemical oxygen demand (BOD) to municipal and plant wastewater treatment systems.
“To many [food] companies, process control is new,” Croucher adds. “Installing instrumentation inline for real-time monitoring reduces maintenance costs, product loss and improves overall process efficiency. Years ago, process efficiency wasn’t a priority, but as companies become more competitive and market changes occur, process control has become imperative to any company’s success over its competitors.” Some of the CIP techniques that producers have developed are so proprietary that they are kept as confidential as the food recipes themselves.
The performance of today’s sensors and transmitters allows CIP skid builders to achieve major improvements in conservation. According to Tetra Pak’s Automation Manager, Axel Andersson, “We use high quality transmitters to secure the signal information, and the PLC program will not complete CIP recipes unless time, conductivity and temperature settings have been met.” To minimize water usage, Tetra Pak offers CIP system options with turbidity sensors, which indicate the interface between white water and only water. Should customers require conformance to ISA88 batching systems, Andersson says it’s easy to accommodate them as its CIP system is already based on an ISA88 architecture.
To batch or not to batch?While integrating existing batches with CIP processes looks appealing, some producers are still reticent to apply ISA88 to CIP. According to Tony Suda, business development manager at ESE Inc., many of ESE’s customers cannot afford to meet all of the criteria set forth in the ISA88 standards. ESE, a food automation, analytical and optimization company located in Wisconsin, uses ISA88 to help customers define phases of their recipes. “Many of the steps in a CIP system can be considered phases and by tying them together, a CIP sequence can be developed,” Suda explains.
But, there’s another reason some customers don’t want to apply ISA88 to CIP. “Many of our customers feel they have a relatively good handle on what is needed to wash the equipment quickly and efficiently,” Suda explains. “They do not need to ‘customize’ the cleaning because they have done it for years and it has become standard versus the uncertainty of making the product [conforming to ISA88 standards].”
That ISA88 more or less forces electronic record keeping may be a life-saver to some producers. Imagine the following situation related by James Stanley, Emerson Process business development specialist. “What happens when the guy signs off on CIP but forgot to do it?” The new shift comes in, and the manager thinks the system has been cleaned because someone from the shift before said it was, or it was noted on a clipboard. Then the current shift manager finds that bacteria levels are high, and wonders why. Electronic record keeping as part of ISA88 would leave no doubts that the job wasn’t done.
Why not build CIP automated record keeping into equipment? According to Gavin Clements, LINK business manager at FMC FoodTech, the inclusion of automated CIP software modules in equipment like large refrigeration systems can prevent the problems just described. In this equipment, a software module provides totally automated CIP, supplying a record of the cleaning process (chemicals, water, concentration, process parameters, etc.) and a log of the results. Software looks at the temperature and duration of the steam, and algorithms decide how long it will take to kill the bugs. It uses a growth modeling program. “What we’re trying to do is take out some of the guesswork in cleaning,” says Clements.
Some equipment may be more ready for CIP than producers think. According to Paul Moylan, Rockwell global food and beverage industry leader, if the CIP machine is controlled leveraging the OMAC (www.omac.org) specification, by definition it complies with ISA88.01, which makes it relatively simple to include CIP control in an ISA88.01 recipe procedure. Including the deviation parameters and reporting on deviations would be necessary. It may also be required to continuously monitor, trend and historize CIP parameters so that there is a complete record of all CIP activities that could affect efficacy.
Whether or not a food processor uses ISA88 to integrate a process system with CIP will still require some careful planning. According to Blake DeFrance, Cognex product marketing specialist for In-Sight Vision Sensors, CIP can be integrated much more easily as an automated step given the availability of CIP packages that can be purchased holistically with the entire process at a facility in mind. Such process systems can be purchased as a package that is flexible enough to meet the unique demands of each facility, but is built to meet applicable standards and specifications. In this way, efficacy can be proven because individual components of the system that monitor steps in the CIP process (such as flowmeters) can communicate seamlessly with data logging devices built into the system. The alternative is to try to cobble together a jumbled network of components which may not have been designed to connect to the over-seeing data-logging architecture.
For processors with the luxury of starting a new line from scratch, there are major benefits to an integrated CIP system. According to Dean Ford, director of automation solutions, food and beverage, at MAVERICK Technologies, an international beverage manufacturer needed to add fruit juice processing capabilities to an existing carbonated beverage facility. It required a control system and manufacturing execution system (MES) to monitor and supervise the fully automated batch process that also included an automated CIP system. The batch tracking system supports 15 different storage vessels that feed ingredients into one of three mix tanks. Each tank has four load cells and several flowmeters. While there were more than 75 different juice recipes defined and validated, there were more than 150 CIP recipes defined and validated. The batch MES is the master repository for all the recipes and is consistent with ISA’s ISA88 batch standard.
Canbra Foods Ltd. of Alberta, Canada, uses ISA88-compliant batch software for both process control and CIP. Canbra produces cooking and salad oils, margarine, and proteins. According to Rick Kurio, control systems coordinator at Canbra’s Lethbridge facility, “We chose RSBizWare Batch to write the recipes for the milk preparation process and to control the CIP process for each tank.” He says that the software follows the ISA88 model, providing a cut-and-paste approach to develop and configure recipes. “We are using eight milk recipes and 10 CIP recipes.” The software has helped Canbra minimize production bottlenecks, increase efficiency and provide a safer work environment. Since automating the process, Kurio says that Canbra has seen a $45,000 per year savings.
Matt Ruth, director of the food and beverage group at Advanced Automation, says his company has been installing automated CIP systems in parallel with process control systems for ten years for customers who need to increase production time and asset utilization. If producers have the equipment in place and a batching system up and running, it may pay to extend the batch system to include the CIP system for the benefit of electronic record keeping. But a 50-year old plant may not be amenable to retrofits-equipment or software. Therefore, processors may want some opinions from their system integrator before making big dollar commitments.
For more information:
Gabe Miller, Sanimatic,
Kevin Roe, A&B Process Systems, 888-258-2789
Rick Nelson, Ecolab, email@example.com,
Steve Cook, Central States Industrial, firstname.lastname@example.org,
J. K. Quackenbush, Invensys,
Gerry Broski, Thermo Fisher Scientific, email@example.com, 763-783-2600
Steve Croucher, optek, firstname.lastname@example.org,
Axel Andersson, Tetra Pak, email@example.com,
Tony Suda, ESE Inc., firstname.lastname@example.org, 800-236-4778
James Stanley, Emerson Process, email@example.com, 512-832-3386
Gavin Clements, FMC FoodTech, firstname.lastname@example.org,
Paul Moylan, Rockwell,
John Lewis, Cognex,
Dean Ford, Maverick Technologies, email@example.com,
Matt Ruth, Advanced Automation, firstname.lastname@example.org, 610-458-8700 ext. 274