HEUFT tunnel ovens: all-rounders

Thermal oil oven specialist HEUFT offers the VULKAN oven in this category. Thermal oil is an excellent heat conductor, transporting 2,600 times more energy than air. Hot thermal oil runs inside the VULKAN’s radiators, which are positioned inside baking chambers. “The result is that, with our thermal oil technology, we need 45% less power to heat our ovens in comparison with traditional oven systems heated with hot air. On average, we can save 25% to 40% on energy consumption,” explains Simon Tabruyn, Export Manager, HEUFT.

Any heating method works just as well for thermal oil; either gas, fuel, or electricity will have the same results on the baking quality. Taking the ongoing energy crisis into account, HEUFT built a hybrid heat exchanger, to allow bakeries to switch between electricity and gas or fuel as an energy source. Other possible alternatives include liquid gas, biogas, wood pellets and hydrogen. “This means you can choose at any moment the type of energy you want to use: electricity during the day, when solar panels are producing electricity, and gas during the night, for example,” Tabruyn illustrates.

The VULKAN can bake up to 12 tons of bread per hour, with a baking surface that can span 540 sqm. And it will require a small footprint to not only bake high volumes, but also diverse products. Tabruyn explains, “An advantage of our system is that we can easily work with different temperature zones. For example, we can build an oven with five or more decks for tray-baked products or tin breads and two additional decks with a stone belt, for artisan products. This makes it two-ovens-in-one which can be set to bake products coming from two different production lines. And all this on the same footprint!” Future expansions in production volumes/variety are also considered in the design of the VULKAN oven; it can incorporate built-in additional decks, which can be easily enabled when needed. In this way, it is not necessary to stop the line to add decks.

To best control temperature, top and bottom heating always work independently and different temperature zones can be chosen over the oven’s length. There are no temperature fluctuations: “A constant temperature is maintained thanks to the three-way valves that are continuously regulating the amount of hot oil going into the oven to preserve the requested temperature,” the specialist from HEUFT explains.

Optimized and mindful process
The VULKAN tunnel oven is insulated with 700 mm of Rockwool, to preserve heat so that none radiates through. In addition, it is also equipped with a heat recovery system that uses flue gases for the burner and baking vapors from the oven to heat water up to 95°C. The hot water is then stored in tanks and can be used for various purposes, from feeding the crate washing machine, to heating the offices, or for cleaning. “Our Heat recovery management system controls the different heat recovery units and integrates it into the building requirements, custom-made. It is even possible to use it for air conditioning solutions,” HEUFT’s specialist details.

The Energy Management System (EMM) is this oven’s smart energy-saving tool. It can measure precisely how much energy the oven needs during production. Using this data, the automated control system automatically shuts down one heat exchanger completely to be more efficient and to maximize energy savings.

Moreover, all HEUFT ovens can be equipped with steam and turbulence systems, which help with process efficiency and product quality. To optimize efficiency, steam can also be generated with thermal oil heating, for example. Depending on the product, some convection (turbulence) can be added in certain oven zones. “This can be helpful if you’re looking for good volume and a crispy crust,” Tabruyn explains.

Sustainability is also considered. Thermal oil technology contributes initially to considerable energy savings; if the oil is heated with an electric heat exchanger, there are no carbon emissions at all.