Ovens fitting in a tight spot
July 1, 2015
by Charlotte Atchley
Unless starting from scratch — building a new bakery from the ground up — floor space in a plant is going to be a limited resource. When putting in a new line or piece of equipment in an existing facility, square footage often must be navigated and delegated fairly.
The oven, arguably one of the most important pieces of a bakery production line, deserves a top spot in floor space delegation. In some bakeries, this can be easier said than done, but there are definitely strategies and equipment options to help bakers maximize space without sacrificing capacity. Automation, plant layout and even the type of oven can all lend a hand.
Maximizing space on the floor requires some bakers to get creative in their plant layouts. The automation around the oven can be just as vital to saving space as the oven itself. Automated loading and unloading can be particularly critical and must be designed correctly in instances of tight space constraints, explained Damian Morabito, president, Topos Mondial, Pottstown, PA. The wonders of space-saving technology do not stop there, either. “Bakers can further save on space by designing an automated final proofer system or an automated product cooling conveyor system to be built above the oven,” he noted.
That area above the oven or even just the space above the baker’s head is another go-to strategy suppliers recommend to bakers looking for a place to install their equipment.
“Vertical space can be used for many production options such as intermediate proofing of a dough piece prior to moulding or final forming, building a proof box over an existing tunnel oven, cooling of bread in a high spiral or race-track conveyor system,” said Ashley Morris, director of sales, North America, Kaak Group, represented in the US by Naegele, Inc., Alsip, IL. “I would recommend all bakers look up prior to thinking that they lack space to expand production.”
This use of vertical space even applies to the oven itself, which can be mounted on platforms above the rest of the bakery floor. All it takes is a bit of
ingenuity. According to Kevin Knott, technical sales manager, Franz Haas Machinery of America, Inc., Richmond, VA, when a baker doesn’t have the necessary room on the production floor for a tunnel oven but plenty of height, placing the system on a platform is not out of the question. “It’s something we’ve done a number of times,” he said. “An oven is not that heavy of a machine. It’s basically sheet metal, and it’s full of space. It’s not really a heavy machine, and it’s not a dynamic load.”
Conveying systems can conveniently carry product up to the platform for baking and back down again once the baked goods move through the oven.
The only other concern Franz Haas Machinery encountered, Mr. Knott noted, was the operators’ access to the controls. In the end, the PLC actually sits on the equipment up on the platform but is connected to an human machine interface (HMI) below so that operators don’t have to climb stairs every time to monitor or change the operation.
Playing around with the oven’s length-vs.-width configuration can also free up some territory on the bakery’s main level. “A longer oven gives more throughput, but that dictates floor space,” said Brett Cutler, technical services supervisor, Baker Perkins Inc., Grand Rapids, MI. To maintain throughput but shorten its length, the oven has to go wider. By increasing its width, bakers can either boost their throughput by maintaining the length or shorten the span of the oven and set free that floor space.
This solution is not without its limitations. “The wider the oven is, the more difficult it is to get a full width sample, and that makes it more difficult on your employees,” Mr. Cutler said. It’s also critical to ensure that the heat application remains consistent across the width.
Shortening the tunnel
Tinkering with the layout of a plant combined with space-saving automation can help bakers find a little extra room in their existing space, but the biggest factor in how much space an oven takes up is the footprint of the oven itself. While space can be a factor in oven choice, it shouldn’t be the first thing a baker considers.
Space-saving aside, the oven must still be able to fully bake and develop the product and impart to it the desirable characteristics associated with that bakery item. “You have to bake it and get the correct characteristics within that product in terms of its moisture content, coloring, texture, bite and shelf life,” said Geoff Hawley, sales director, Baker Perkins.
For example, Mr. Cutler explained that recirculating-heat ovens can save on space and provide bakers with a higher air flow. However, if the baked good can’t absorb that heat as quickly as it is produced, its outside may be baked and crisp, but the inside will be underdeveloped. “Thinner products, such as pita chips or crackers, are more accepting of that than thick products,” he said. Finding the right oven that will deliver the right bake characteristics within the limited space is a juggling act of needs.
Tunnel ovens are one of the most space-consuming ovens, but they do provide long runs, which some bakeries find necessary. There are ways to reduce oven length, hybrid technology being one. “Instead of using all direct gas-fired highly radiant ribbon burners for crackers, you can add a section of impingement air or high velocity air at the very end to get more effective drying of your product,” Mr. Cutler said. This can not only shorten the length of the tunnel oven but also improve the product quality by offering the baker more control over color and moisture.
Hybrid ovens that use different types of heat to make a more efficient bake can solve not only product quality and production efficiency concerns, but also space issues. Reading Bakery Systems’ Prism oven series offers hybrid configurations that use direct gas-fired burners in the first zones of the ovens to quickly develop product and establish flavor profiles. Later zones use convection for efficient moisture removal and color. “Generally, these can reduce the overall oven length from the traditional direct gas-fired where the entire oven is composed of the same technology,” said Vince Pasquini, pretzel and snack technical sales engineer, Reading Bakery Systems, Robesonia, PA.
The company’s Spectrum series also uses an oven-over-dryer arrangement to reduce the length of the system when making pretzels and low-moisture snacks. The oven bakes the snacks in a single layer at an elevated temperature to a lower moisture condition. The product is then returned under the baking chamber through the dryer at a lower temperature until the final desired moisture content is achieved. Multi-pass dryers can also shorten the footprint of the oven by finishing the product in the dryer.
By using a post-oven dryer to process cookies and similar items, bakers can shorten their oven and improve product quality. The Macrowave Post-Bake Dryer from Radio Frequency, Millis, MA, can replace the last two-thirds of an oven while improving color, moisture levels and shelf life. The dryer can also enable an oven to produce 30% more product per hour, which increases efficiency.
New oven designs can also speed up bake times, which will in turn increase throughput or, if bakers want, can shorten the oven to maintain throughput. “New oven designs can reduce bake times as much as 35%. This allows bakers to increase their production rates with existing oven floor space,” explained Charles Foran, chairman, Babbco, Inc., Raynham, MA. “Alternately, smaller ovens may be used to maintain current production rates, while freeing up floor space for other purposes.”
Bakers can also take advantage of vertical space in their oven decision, by going with a multi-deck oven. Through automated loading and unloading systems, these ovens can stretch their baking space into the heights of the bakery, freeing up square footage on the floor.
“The multi-deck oven is a great solution if you wish to increase your baking capacity without taking more of the valuable bakery floor space,” Mr. Morris said.
Not only does a multi-deck oven greatly reduce its footprint, but also each level operates independently. Kaak Group’s multi-deck oven options include different baking surfaces: stone, steel hinge plate or wire mesh. “You can even feed multiple production lines into different decks of the same oven, so one oven footprint can handle two or more production lines,” Mr. Morris observed.
A stacked tunnel oven is also an option, where two tunnel ovens can be installed on top of each other, occupying the same footprint as one. This allows bakers extra capacity for one product or to run two products at the same time. “They are both completely separate ovens with separate zoning and burners,” Mr. Morabito said. This design feature of Topos Mondial’s J4 stacked tunnel oven offers bakers a high level of control.
The WP Megador Multi-Layer Tunnel Oven from WP Bakery Group USA, Shelton, CT, can also offer tight control over baking profiles, which increases baking capacities and flexibility while existing within space limitations. The oven is made up of modules with upper and lower heating circuits. “In this way, the upper and lower heating can be controlled separately,” said Patricia Kennedy, president. The system is available in both cyclothermic and thermal oil heating systems, which offers bakers flexibility for both continuous or batch baking.
Thermal oil, according to Mr. Bloom, provides bakers with enhanced control over the heat in their multi-deck tunnel ovens. “Thermal oil ovens with multiple decks can have different circuits of oil, and each one has different temperature control,” he said. “The heat on every deck would be the same, or you can create different zones. The fact is the temperature is so reliably controllable that you can build a multi-deck oven and ensure the results will be the same on every deck.”
Mecatherm, Barembach, France, offers four different space-saving ovens into the company’s portfolio: the FTC, FMP2, FTS and FTM. All feature multiple decks on which products can continuously move, freeing up floor space. They are also all modular. “They consist of several juxtaposed cooking cells, which are all independent ovens with their own temperature and hygrometry settings,” said Alexandre Ziminski, production unit manager, ovens, Mecatherm.
Their compact design saves energy, and their capabilities reduce labor with only two operators needed to run the oven.
Multi-deck ovens require some thought behind loading and unloading systems. This process can be automated, but these ovens can only be loaded one deck at a time. Cinch Bakery Equipment, Clifton, NJ, offers its Thermodeck oven, which offers traditional deck oven baking results. The Thermocar oven combines rack and deck oven technology but doesn’t need a loader. Operators can transport product on racks from proofing through cooling.
“Bakers can take a rack that has proofed product and slide it inside the Thermocar,” said Cindy Chananie, president, Cinch. “The oven bakes like a deck oven, but the functionality acts like a rack oven.” This oven is suited more for a small- or intermediate-size bakery, not for high production runs.
Auto-Bake’s use of tiered oven design can stack a 300-ft-long tunnel oven into a space of 30 ft on the floor, according to Jim Diver, director of sales, Dunbar Systems, Inc., Lemont, IL, which represents Auto-Bake in North America. The Serpentine oven’s compact design frees up floor space for mixing and packaging. The company can also mount atmospheric or refrigerated coolers above the oven, depending on space needs. This opens up room for more production lines to be added.
The oven can vary its four heat zones, and with a simple change of pans, the oven can bake a combination of products such as cookies, cakes, snack cakes, muffins, croissants, scones, buns or bread. The tiered oven also reduces bake times, which results in high production rates and shorter oven designs. “This design allows heat to rise within the oven, and you gain that residual heat where you might have lost it in a conventional or tunnel oven,” Mr. Diver said. “By doing that, the baker saves some energy and allows the product to bake quicker.”’
Beyond the tunnel
The tray oven is another option, which can take up only half the floor space of a tunnel oven. The Vesta Tray Oven from AMF Bakery Systems, Richmond, VA, boasts saving bakers about 33% floor space over a tunnel oven and consuming less energy at the same time. However, these ovens can require a lot of maintenance. “They are highly mechanical and require frequent lubrication and occasional chain replacements,” explained Phil Domenicucci, baking systems specialist for AMF. To overcome this, the company uses a high-quality oven chain with additional lubrication ports and a newly designed trunnion shaft that eliminates the wobble experienced with conventional trunnion shafts.
Baker Thermal Solutions’ tray ovens grant baker control flexibility with partitioned zone control. “This is essential for highly specialized products,” said Scott McCally, product manager, thermal group, for Stewart Systems and Baker Thermal Solutions, subsidiaries of the Middleby Corp., Elgin, IL. The oven’s standard 8:1 bake range makes it well suited for a wide variety of product offerings.
A conveyorized oven saves on floor space by spiraling product up and down through the baking chamber. This type of oven, however, is a large open space which offers some zone control. “We can shift heat output between zones as well as distinguish top and bottom heat such that we achieve good external and internal product characteristics,” Mr. McCally said of Stewart Systems’ standardized conveyorized ovens. These ovens are best suited for high speed and high volume rather than artistic breads and sweet products with low throughput.
The company’s new Texas Titan line of conveyorized proofer and oven equipment provides enough throughput capacity that a bakery can replace two production lines with this one hybrid line. It delivers product consistency with its robust convection system. The Titan oven has an air recirculation rate of one oven volume per minute. “This baking scheme virtually eliminates cold corners,” Mr. McCally said. “Cold corners can lead to condensation on the surface of the product that in turn creates undesirable white splotches.”
AMF’s BakeTech Continuous Oven also saves on floor space while providing an even bake, particularly with buns, because the oven bakes one pan wide. The trade-off is these ovens also require regular lubrication and sometimes frequent temperature control adjustments. AMF offers chain tracks with Emisshield, a nano-emissive coating that reduces the amount of lubrication by as much as 50%. To control temperature, the BakeTech oven monitors the amount of moisture in the exhaust and adjusts the internal temperature accordingly.
As far as hearth ovens go, the WP Matador stone hearth oven from WP Bakery Group can be built in towers. “The largest hearth deck oven we build not in tower formation is 279 sq ft,” Ms. Kennedy said. “But we can build up in the tower formation and get 465 sq ft in the same footprint.” The oven can also provide four baking temperatures in one tower, allowing the bakery to produce several different types of products with varying bake times in the same oven system.
With the right oven and the right space-saving strategy, suppliers and bakers can work together to find the solution to a bakery’s floor space issues.