Wireless personal communication has become so ubiquitous that people often say they have a hard time remembering life without it. The same thing might soon be said about information transfer in the control of food processing.
It is not there just yet, but communication between instruments and control systems is stepping into a digital, wireless scenario in which flow rate, temperature, pressure and more specific product parameters are monitored digitally in real time, and with more two-way communication.
"Today this is still evolving very rapidly," says Ola Wesstrom, senior manager for food and beverage at Endress + Hauser USA (www.us.endress.com), Greenwood, Ind. "The predominant way to transmit has been a purely analog 4-20 mA signal, but now we are seeing more digital.
"The food industry has been slow to adapt to digital communication, but now it is doing that," he continues. "Once you know how to use it, it is easier, and more bi-directional. Now if there is a problem with the instrument itself, you can see that on your data screen. You wouldn’t have known that in the past."
"An abundance of information is now available digitally, over just two wires," says John Martin, food and beverage industry manager at Emerson Micro Motion (www2.emersonprocess.com), Austin, Texas. "Prior to digital protocols, each parameter, including pressure, flow, density, valve position, required a devoted set of wires.
"Using digital protocols allows all the information, including instrument diagnostics, from multi-variable instruments to be sent to the host on a single pair of wires. This has reduced wiring/conduit costs significantly. On a retrofit of most instruments, an existing set of wires can be used on the new, state-of-the-art replacement instrument."
Of course, what a food processor does with that information is also important, and this is where new control technology comes in, says Kris Dornan, process technical consultant at Rockwell Automation (www.rockwell.com), Milwaukee. He says traditional process instrumentation networks have often fallen short in leveraging improved data from digitally wired instrumentation.
"A new trend, however, may usher in a new era for food processing lines," Dornan says. "Process instrumentation equipped with EtherNet/IP — the adaptation of standard Ethernet on the Common Industrial Protocol — can easily and seamlessly share data across the entire infrastructure. From human-machine interfaces to office computers to remote locations, users access information anytime, anywhere, via existing Ethernet networks. With EtherNet/IP-enabled instruments, food manufacturers can capture the real-time, actionable information they need to achieve operational efficiencies and increase productivity."
The systems of today have evolved significantly from those used 20 years ago, providing much more functionality, Dorman adds.
"They are part of a solution that allows for regulatory control, a full model of predictive control where tuning constants can be continuously changed as needed, as well as disaster recovery, batch control and real-time monitoring of fault tolerances."
While costs for upgrading can be substantial, the ROI can be significant. Additionally, scalability within control systems allows companies to provide the right solution at the right cost. "There is a much lower cost of entry for distributed control systems today, especially with the fully scalable PlantPAx process automation system," Dornan says.
One global food processor recently needed to track materials, manpower, methods and machinery. Implementing such a system from Rockwell resulted in a 10 percent lower fixed cost, a reduced material variance of $650,000 per year, and a 15 percent reduction in raw material inventory levels, as well as other benefits.
Sanitary design has also become crucial for instrumentation in any kind of food plant production floor, says Endress + Hauser’s Wesstrom. But the company also offers instruments that can be utilized elsewhere, including in wastewater treatment.
In the end, food manufacturers are looking for control and instrumentation systems that help them be more effective.
"Food and beverage companies operate like companies in any industry and are driven to produce high-quality products on a repeatable basis in the most cost-efficient manner possible," says Emerson’s Martin. "They are willing to look at new technologies that can help them achieve these goals and they will invest in new equipment that can provide high accuracy and highly repeatable measurements. Their final product quality relies on this and their brand can be damaged if their products don’t meet the customers’ expectations."
Additionally, FDA regulations are pushing food companies toward strengthening protections against food contamination. The companies who sell control technology say food plant operators now have new tools that allow full backward tracking and forward tracing capabilities and proper tracking of any ingredient that is used in a food manufacturing line.