How dryer airflow automation can increase energy efficiency

In the production of extruded feed, hot air drying accounts for almost 50 % of the total energy consumption. Naturally, our customers in the industry have incentive to improve fossil fuel efficiency to convert gas savings directly to bottom line earnings and a reduction of carbon footprint.

However, opportunities to reduce gas consumption in the dryers are often overlooked due to anxiety of compromising process- and product integrity. Many modern pet food facilities have dampers, valves, etc. that are locked in fixed positions, arising from an initial equipment run-in phase. If gas savings are to be realized across all products and production lines, active- and online adjustments of process airflow is needed. This is to react towards shifting production conditions and -volume flow as well as product size, composition and recipe.

GRAINTEC’s new dryer airflow automation makes use of information retrieved from sensors placed in air ducts, to judiciously adjust air flow control measures to appropriate positions. This allows dryers to react on relevant processing conditions. “Recent studies have demonstrated that by implementing dryer airflow automation in extruded pet food production, annual gas savings of 3 – 10 % can be realized, depending on processing conditions”, says Anders Haubjerg, Sr. Process Engineer in the Business and Technology Development at Graintec A/S. And he continues; “That is often around a year in payback time, so we do encourage our customers to contact us to hear more – this is a real opportunity to pick the low hanging fruits”.