Sophisticated controls enable bakers to execute that heating profile throughout all circumstances a bakery can experience in a day. Bakers can use burner output and air movement to create the desired baking environment and make an oven more nimble throughout production cycles.
As the output of heat, burners have a major impact on efficiency. If they aren’t firing properly — or at all — the bake won’t be ideal. Today’s burners, however, are more efficient than ever before. They can deliver additional BTUs without increasing the size or number of burners in the oven as well as provide better heat balance. New materials and burner design also have led to improved heat transfer.
“The ability to better control the operation of the oven and maintain temperature within one or two degrees of a set point throughout each zone is now the norm,” said John Cavallo, global ribbon burner product manager, Selas Heat Technology Co.
The latest software is giving operators a wealth of data about the burner and heat profiles previously unheard of.
“Today we have the ability to use software in ways not possible even a few years ago,” said Dom Medina, president, Flynn Burner Corp. “The ability to gather data regarding the oven operation and representing it in real time for the operators is valuable as it shows them how the oven is behaving, allowing for better performance and efficiency.”
With superior software bakers have the ability to run the oven in either temperature or energy mode for many products.
“Energy mode in particular enhances the stability and reliability of the bake, maximizing the oven’s performance and product quality,” Mr. Medina said.
Control of the burner temperature is paramount to ensure an even, consistent and efficient baking process. If the burners are not responsive to the product’s temperature needs, hunting can occur. The burners will be firing on and off, searching for the appropriate temperature.
“They’re constantly under- and over-shooting temperature, and that’s very inefficient,” said Damian Morabito, president, Topos Mondial.
Mecatherm’s M-TA oven is very reactive, thanks to modulating burners, which can automatically and precisely adjust to the product load.
“The right amount of heat is supplied to bake the products, and in this way, the right quantity of energy is consumed,” said Marie Laisne, oven product manager, Mecatherm.
Low-burner output is helpful when the oven is already up to the desired temperature. Keeping the burners at full flame will make the oven too hot; they need to be brought down to simply maintain a consistent temperature. J4 cylcothermic ovens feature a burner system with a wide turn-down ratio, so the burner can go from a full flame output to a very low idle output, increasing the range of heat the oven can experience.
“Inefficient burners can’t really idle; they’ll go to a low flame and then off, and then the oven will jump back up,” Mr. Morabito explained. “The heat profile will then be more erratic. You want to deliver even heat, and having a burner that can modulate closely to a low flame is important to that.”
In Auto-Bake Serpentine ovens, burner plasma analyzers ensure a proper air-to-gas ratio, which can result in up to 40% of fuel savings. The ovens also feature a higher burner management system turn-down ratio to enable very low heat during idling or a low product load.
Tagliavini ovens, represented in the United States by Erika Record Baking Equipment, use an energy management system on its Modulart EMT Deck Ovens to determine recovery time for the set temperature and steam generation.
“By selecting the percentage power used to recover heat, the baker can be more precise with the baking profile for a particular product,” said Cindy Chananie, sales consultant at Erika Record. “This is particularly relevant when a baker wants to recover heat quickly for a short bake with products like pizza, which may need 100% of the power. On the other hand, if the baked product is a 3-lb loaf of bread, 100% of the power is too aggressive.”
Burner control and idling is also helpful to keep the oven going during gaps in product flow. For those instances, Franz Haas’ ovens employ gap control to automatically minimize the heat being used when there is no product available.
Gemini Bakery Equipment/KB Systems also offers gap control. Its ovens can sense gaps in product flow and regulate blowers and burners to minimize any heat or energy loss.
Burners may be the heart of providing consistent heat, but controlling air movement in the oven is also a critical factor in convection ovens. Gemini/KB Systems has an inverter-controlled recirculation and turbulence fans that can be menu-driven from the control system. The ovens feature a true turbulence system that enables the operator to reverse airflow from either top-to-bottom or bottom-to-top.
“Due to the efficient nature of convective heat, these zones run at lower temperatures for less energy usage,” said Ken Johnson, president, Gemini/KB Systems. “These turbulence zones are especially important to ensure uniform bottom and side bake for pan products.”
WP Bakery Group’s Matador stone deck ovens feature Xyklotherm technology to control air flow. The hottest air is circulated to the areas that need it most, and cooler air is circulated to the oven.
“This technology provides maximum energy efficiency and even heating in the baking,” said Patricia Kennedy, president, WP Bakery Group.
This article is an excerpt from the April 2019 issue of Baking & Snack. To read the entire feature on ovens, click here.