Valio is the biggest milk production company in Finland, receiving 85 percent of the milk produced in the country. It produces whey powder in Lapinlahti, while its Seinäjoki plant produces milk powder. “Valio ships over 60 million kilos of milk and whey powders annually,” says Antero Ylitalo, production manager of Valio powder production.
He explains the process can be energy intensive since whey and milk powder production involves drying fluids. Therefore, the company is always looking for new ways to increase production, without using more energy. Valio attained NAPCON, a proprietary advanced process automation (APC) solution from Neste Jacobs, for its Lapinlahti plant.
“We are talking big money when the productivity is boosted more than 10 percent without higher energy consumption or costly hardware investments.”
The NAPCON solution consists of two tools—an indicator that calculates material and energy balance information and a controller that uses a multivariable, model-predictive control (MMPC) to optimize the production process. The data is delivered via an Open Process Control Unified Architecture (OPC UA) connection between NAPCON and Valio. Because the solution balances the need for energy with the desired product specifications, production at the Lapinlahti plant increased significantly.
“We are talking big money when the productivity is boosted more than 10 percent without higher energy consumption or costly hardware investments,” Ylitalo says. The result was so good, the company decided to also use the solution in its Seinäjoki milk powder plant, which has both an evaporator and a spray dryer. “The results from the first optimization project convinced us.”
The NAPCON solution can predict moisture content and, in real time, adjust the balance, even adapting to changes in environmental humidity. Moisture content is a critical factor, especially at the final stages of the production line, where a spray dryer removes the last of the water while keeping the valuable properties of the milk or whey.
In a milk powder production line, an evaporator is typically used to remove excess water before the concentrate enters the spray dryer. If the line consists of both these units, the APC can provide optimization possibilities.
A spray dryer converts concentrate into many small droplets, which are then transformed into powder particles when they are exposed to a fast current of hot air. When the spray dryer can be controlled so it always uses the right amount of heat, a whey or milk powder plant can significantly increase production using the same amount of energy as before. This kind of control also reduces the risk of shutdowns due to bag filter clogging.
By controlling both the drying stages in an optimal way simultaneously with the NAPCON solution, Valio can save on operating costs
“Too large a water content makes the powder sticky and disturbs the process,” explains Vesa Strand, production manager of the Seinäjoki plant. “On the other hand, if the powder is too dry, it generates dust and uses excess energy.” The NAPCON solution is used to keep the final powder product’s moisture content very close to its target value at all times.
Moreover, a remote data connection between the process and Neste Jacobs engineers can be set up to provide a solid platform for continued maintenance services. The connection makes it possible to work on the project from any distance.