Milking Engineering Science for Dairy

Professor Harry Van den Akker, Bernal Chair in Fluid Mechanics

Ireland produces in the region of 5,400 billion litres of milk annually and about 10% of the global exports of infant milk formula.

Professor Harry Van den Akker, Bernal Chair in Fluid Mechanics, and his team at UL are developing ways to make the multi-billion-euro dairy products industry more efficient.

“Dairy plants didn’t change for decades. To some degree, and I don’t mean this negatively, it was more an art or a profession than a science. The processes, the equipment, the conditions for operating, there were not many changes in them over the years so there is room for improvement,” Professor Van den Akker stated.

“Although many dairy processing plants are run by competent chemists and food scientists, I do think the dairy industry needs more chemical engineers so that the processes can be improved. The way to do that, is by getting a better understanding of these processes. To achieve that, there needs to be more engineering science put into these plants,” he explained.

Ireland is the 10th largest dairy export nation in the world, exporting 85% of all dairy outputs at a value of more than €3.2 billion last year.

Professor Van den Akker, who joined the University of Limerick from Delft, the Netherlands in 2013, is particularly interested in modelling the mixing of fluids and the process of (spray) drying and how these  impact on the quality of our dairy products . But there is more.

“Milk, most of it is water. This is about the rest. In many cases, the water is removed very fast. Then what you have is a slurry, a very concentrated suspension of dairy and dairy ingredients in water. You have to transport it from one vessel to another and sometimes that is an issue. It is certainly an issue if the water has been removed and it has become a powder. Powder has to be transported from one vessel to another and these transport lines very often get clogged. Either they use a hammer to loosen the powder that is sticking to the wall or they have to open it and clean it and that is interrupting the process. It is pretty unpredictable when and why these blockages occur so you need a better understanding of that,” he explained.

UL hosts the national Dairy Processing Technology Centre (DPTC), an industry–academic collaborative research centre aimed at driving long-term growth opportunities for the dairy sector.

According to Professor Van den Akker, studying and modelling the processes involved in dairy processing, and using this information to improve them, will pay industry-wide dividends.

“My interest is in improving processes by increasing the understanding of the flow aspects you need for these processes. My interest is not in the fluid mechanics per se but in where a better understanding of fluid mechanics helps in the manufacture of products. It is engineering really. Applied fluid mechanics make plants more efficient and results in safer and more economic processes and better products,” he said.

The issues Professor Van den Akker and his team in the Bernal Institute and the DPTC are examining are not unique to the Irish dairy industry.

“These issues are everywhere. If they were not, you would just copy what was happening in other countries and transfer it to Ireland but that is not the case. The idea behind the centre is that the dairy industry is modernised to put it in a competitive position and my contribution is mainly by introducing modelling to the world of dairy. A model is an attempt to describe real life so that you can see inside these transport lines, inside these process vessels, inside a spray dryer, to look into this equipment to see what is happening there,  to understand the flow and transport processes between input and output, and to eventually improve the processes,” he outlined.

Professor Van den Akker’s work in creating a better understanding of these processes, and the significance within that of fluid mechanics, will also have relevance in other industries including the pharmaceutical manufacturing where product quality is paramount.

This article is available in the current issue of UL LInks