Valio, Finland's biggest dairy company, has recently enhanced the production of its Lapinlahti whey powder plant of over 10 percent by implementing the proprietary NAPCON Controller solution (Advanced Process Control, APC) developed by the technology and engineering company Neste Jacobs. The results were so convincing that Valio now in a similar way is optimizing a milk powder plant in Seinäjoki, Finland, consisting of both an evaporator and a spray dryer. Since whey and milk powder production is about drying fluids, the process is very energy consuming. NAPCON balances the need of energy within the desired product specifications so that the energy consumption is minimized.
"Valio ships over 60 million kilos of milk and whey powders annually", says Antero Ylitalo, Production Manager of Valio Powder Production." That means we are talking big money when the productivity boosts with more than ten percent without higher energy consumption or costly hardware investments." Another important benefit is that NAPCON can predict the moisture content and in real time adjust the water balance. The optimization adapts even to changes in outdoor humidity. The moisture content is a critical factor especially at the final stages of the production line where a spray dryer removes the last part of the water, while still keeping the valuable properties of the milk or whey.
In a milk powder production line evaporators are used to remove excess water before the concentrate enters the spray dryer. By controlling both of the drying stages simultaneously with NAPCON, even more savings can be gained, and it is possible to ensure that both units continuously are run in an optimal way. This type of system has already been implemented at the Valio Seinäjoki plant.
"Too large water content makes the powder sticky and disturbs the process", Vesa Strand, Production Manager of Seinäjoki plant, explains. "On the other hand, if the powder is too dry it generates dust and uses excess energy. With NAPCON we can allow an increase in the average moisture content in the process and still keep the moisture content of the final powder product very close to its target value under all circumstances."
Easy Integration
The NAPCON solution in Valio's two production plants consists of two tools; NAPCON Indicator that calculates the material and energy balance information and NAPCON Controller that controls the process using Multivariable Model-Predictive Control (MMPC). In addition to the MMPC solution, the deliveries to Valio also include an OPC UA connection (Open Process Control Unified Architecture) between NAPCON and Valio's process control system.
"The results from the first optimization project made us so convinced of Neste Jacobs' expertise and superiority to carry out high-end production optimization projects that it was easy to partner up again", Antero Ylitalo says. "Now we are looking into developing our cooperation even further." Keijo Yli-Opas, Chief Application Engineer at Neste Jacobs points out that NAPCON Controller (Neste Jacobs' proprietary APC solution) can be implemented in traditional whey and milk powder plants anywhere in the world. "Important parts of our offering are also full engineering and implementation services plus client training", he says and adds: "The solutions provided to Valio were of course not identical, but it usually does not take more than a few months to trim the solution for the needs of different kinds of production processes."
One thing that considerably can speed up an optimization project is the possibility to establish a remote data connection between the process and Neste Jacobs engineers. "It makes it possible to work on the project from any distance", Keijo Yli-Opas says. "The connection also provides a solid platform for continued maintenance services."
Facts:
NAPCON Indicator: Indicates immeasurable process operating key values and key process information for APC applications.
NAPCON Controller: Multivariable, model-predictive Advanced Process Controller.
Spray drying:
The principle of a spray dryer is to transform the concentrate into many small droplets, which then are transformed into powder particles when they are exposed to a fast current of hot air.
When the spray dryer can be controlled so that it always uses the right amount of heat, a whey or milk powder plant can significantly increase the production using the same amount of energy as before. At the same time the risk for shutdowns due to bag filter clogging is also significantly reduced.
Typically an evaporator removes the excess water before the powder enters the spray dryer. If the process line consists of both units, Advanced Process Control can provide even more optimization possibilities.
NAPCON is a registered trademark of Neste Jacobs.
