New hybrid oven technology may be creating more efficient and targeted bakes, but it is also streamlining changeovers. More precise controls remove the opportunity for human error.
“Controls technology is the main improvement on hybrid ovens,” Mr. Knott said of Franz Haas’ latest hybrid innovations. “We’ve bettered recipe management and gap control.”
Hybrid ovens, like most commercial tunnel ovens, are recipe-driven through a PLC. Settings such as time, temperature and humidity are programmed into the PLC for each product, so operators simply have to select the appropriate recipe. The oven will take it from there, removing responsibility from operators to set every parameter correctly. Today’s hybrid ovens go a step further from programming the basics, however.
“All control points that would normally be set manually will now be set automatically with servo drives,” said Damian Morabito, president, Topos Mondial.
For example, if damper one needs to be half-closed and damper two needs to be ¾ open, these settings can be programmed into the PLC, and servo drives will set the dampers automatically without operator intervention.
“This allows for quicker product commissioning and ease of start-up moving forward, particularly if a plant has many different products that they run through the same oven,” said Tremaine Hartranft, director of technical services, Reading Bakery Systems (RBS). RBS’ hybrid ovens also feature automatic controls.
J4 hybrid tunnel ovens, represented in the United States by Topos Mondial, also now can control the pressure in the baking chamber as product moves throughout the oven’s zones. Ovens that maintain a negative pressure optimize burner efficiency, but as product moves through the baking chamber and different zones, maintaining that negative pressure can be challenging.
“They’ve developed technology to keep a negative pressure in the baking chamber no matter what’s happening in the oven, whether the heat demand changes or as the product moves throughout,” Mr. Morabito explained. “Through controls, they’re monitoring the chamber pressure and adjusting the circulating fan to optimize the efficiency of the burner and, therefore, the efficiency of heat transfer.”
In managing various types of heat transfer, it’s critical that oven suppliers marry those different technologies properly in the oven as well. Combining infrared, convection and steam can create a flexible oven, but it won’t be effective if not combined properly.
“Original equipment manufacturers must effectively integrate and deliver each technology in measured proportions at the appropriate time and with targeted accuracy across each piece being produced,” said Scott McCally, president, Auto-Bake Serpentine, which offers bakers advanced proportional control of each thermal technology both over and under the products throughout the entire serpentine oven.
With so much control at bakers’ fingertips, testing during the design phase is critical for getting the right mix of heat technologies in a hybrid oven.
“Babbco has long offered customers the ability to develop real-world baking profiles in its state-of-the-art Innovation Center using a variety of industrial-class ovens,” said Jerry Barnes, sales, applications and systems engineering, Babbco. “After spending time in the Innovation Center working with our oven technology experts, bakers can have their questions answered and leave knowing exactly what is best for their application.”
Testing not only helps bakers determine the precise baking profile needed in the oven, but it also streamlines the start-up process by working a lot of the bugs out in the testing center.
Knowing how critical testing is to a successful start-up, Middleby Bakery has invested more than $10 million in product innovation centers around the world. Bakers can develop and test products and processes on industrial equipment at these facilities.
J4 offers bakers the ability to test product on its hybrid ovens and all the individual technologies at its R.&D. center. In this way, bakers can be assured that they’ve chosen the right technology for their operational demands.
“I would advocate the baker test it and prove it out for themselves, see the throughput numbers and feel comfortable with it,” Mr. Morabito said.
This article is an excerpt from the October 2019 issue of Baking & Snack. To read the entire feature on ovens, click here.