Raising the standard of energy-saving ovens
19 Jun 2019
Nearly everyone enjoys sidling up to a warm kitchen oven on a cold day, but for industrial bakeries, waste heat and wasted energy are no laughing matter. GEA Imaforni ovens help producers minimize their energy requirements, reduce their environmental footprint as well as total cost of ownership (TCO).
There are several trends in the bakery industry that GEA engineers must take into consideration when developing solutions for this sector: a rising middle class worldwide which demands even higher quality products and greater variety and novelty; manufacturer requirements for wider baking lines to increase production and flexibility as well as the need for user-friendly automation controls, quicker changeovers and simple cleaning processes. But one requirement that’s always top of the list is helping manufacturers meet their environmental obligations while at the same time reducing energy costs.
Baking, by its very nature of course requires the application of heat – and in precisely controlled way – and therefore energy. GEA has dedicated decades to developing baking solutions that reduce demand and energy waste.
Turning up the heat on quality
A benchmark in the baking industry, GEA Imaforni ovens are highly valued for their accurate temperature control and ensuring the perfect baking of each product across the entire width of the oven. There are three primary methods of applying gas heat in industrial baking and from which each system takes its name:
- Direct gas fired (DGF) oven: uses radiated heat produced from burning natural gas or LPG; ideal for products that require a lot of heating power
- Indirect radiating or cyclotherm oven: transfers heat to products via gentle and indirect radiation
- Indirect convection oven: air is heated up by passing it through a dedicated heat exchanger; the dough never comes into contact with the products of combustion making it very suitable for delicate products
GEA also offers hybrid tunnel ovens which are divided into sections, utilizing at least two different types of heating for each application. For crackers, for example, DGF is used for the main length of the baking chamber with the remainder heated via convection. In contrast, a combination of cyclothermic and indirect convection is preferable for rotary-molded and wire-cut cookies and hard sweet biscuits. The advantages of using a hybrid oven for certain applications include not only greater flexibility but also better product quality (e.g. color uniformity, moisture content and improved crispness and texture). And in nearly all cases, higher output is achieved.
A GEA Imaforni hybrid oven hard at work at an Asian biscuit plant.
Pushing down energy usage
Regardless of the heating method selected, GEA Imaforni ovens are designed to minimize energy usage. This is achieved, for example, by pre-heating the combustion air necessary for the burners. This is generally most effective when used at the front end of the oven and process when the dough pieces require the highest level of heat input and where set temperatures are higher.
Another heat conserving solution involves passing the hot air from the stacks through a heat exchanger to generate hot water for the bakery which can be used for cleaning purposes, therefore saving energy that would otherwise be consumed by a boiler. Fuel usage can also be optimized by preventing heat escaping from the oven by using advanced forms of insulation, an area where GEA Imaforni sets the bar.
A GEA heat exchanger system provides recovered energy from the oven for further use throughout the plant.
GEA Imaforni also offers another way for reducing energy loss, fitted as standard today on all of its ovens: a pressure sensor and extraction damper feedback system that automatically maintains the ideal moisture extraction level for the product being baked, while minimizing the heat energy lost via the stack. This prevents a common practice whereby operators leave the extraction dampers open wider than is actually required, which wastes energy. The sensor system guarantees that the product is baked under ideal conditions without wasting energy and without the need for operator intervention.
Reap the savings
Although the level of savings manufacturers can achieve depends on the insulation, the temperature profile and general oven settings for achieving optimum baking for specific products, it has been clearly demonstrated that modern energy-saving GEA Imaforni ovens deliver savings in terms of energy consumption of between 10% and 30%. This ensures a healthy ROI, reduces the plant’s dependence on fossil fuels and lowers emissions which carries with it both an environmental as well as a financial benefit.
- David Molinari, Head of Sales Support and Offer Management – GEA Bakery.
Better engineering, better service, better results
Today, there are hundreds of GEA bakery plants operating worldwide. This has been made possible through best-in-class technology and by closely partnering with customers to achieve shared goals: high quality products, product variety, excellent production efficiency, and in an environmentally-responsible way. With a GEA Service contract, producers ensure their own continued success, receiving support throughout the entire life cycle of their installed bakery components and systems: from project engineering, installation and commissioning to maintenance, including improving the performance of the plant and equipment. Combined with the latest in automation and control solutions, such as remote assistance, machine status can be monitored by GEA automation engineers in real-time, ensuring precise and efficient support.
