Ovens: Alternative Ovens
August 01, 2009
by Shane Whitaker
To adapt to ever-changing market demands, bakeries desire systems that are able to produce a wide variety of baked products. Healthier and artisanstyle breads and rolls continue to be popular among consumers, but there are so many different styles of these products that bakeries must adjust their processes to make what is most sought after by consumers.
“It used to be that bakers would have a 5- to 7-year plan as to what their equipment would produce and what they would plan to make,” said Michael Eggebrecht, baker and equipment consultant for WP Bakery Group, which is a subsidiary of Kemper Bakery Systems, Shelton, CT. “Now it seems they are lucky if they have a 2-year plan.”
Whereas tunnel ovens can offer many advantages to high-speed bread and bun bakeries making the same products day-in and day-out, many other bakeries have different needs and are making a variety of products. And these bakeries may desire something that is more responsive to changing processes than a traditional tunnel oven. And there are many different oven styles that can be adapted into industrial bakeries, including multi-deck, rack, spiral and serpentine ovens.
Bakeries with modular systems such as the Matador deck or the multi-deck Megador tunnel ovens have the flexibility to quickly adjust to changes in the market place, according to Mr. Eggebreht. WP Bakery Group offers the Matador oven with up to 10 decks and a robust steaming system. The oven uses a patented cyclothermic gas heating system to guarantee the oven can meet the special temperature curves needed by bakers’ products at all times.
Particular products require a special temperature curve during the baking cycle, and the Matador is able to have falling and rising temperatures within the oven to meet these needs, he added. The new Navigo control system manages the temperatures in the oven and makes the baking process more flexible and controllable, according to Mr. Eggebrecht. The new control system can also reduce energy consumption by up to 10%. To increase efficiency to 100%, he said WP Bakery Group connects its ovens with fully automatic loading systems such as the Ober, which can keep three 10-deck Matador ovens full, assisting with the company’s efforts to offer industrial production with handcrafted quality, according to Mr. Eggebrecht. The Ober loader can also be used with the company’s latest offering, the Pellador, a wood-fired oven. The Pellador, which has the same size and dimensions as the Matador, uses wood pellets in a canister behind the oven to heat the porous baking stones in the deck oven. The Pellador bakes on a traditional falling-temperature curve, making it most suitable for imparting its wood-fired look and taste into 1-kg craft bread loaves.
Another goal of the WP Bakery Group is to reduce energy costs, and all of its ovens are specially insulated to reduce energy consumption and minimize the affect of escaping heat on ambient bakery temperature. Its ovens also can include heat recovery systems giving the baker the ability to use exhaust gases to heat water for processing or sanitation. While these systems have not yet been sold in the US, they are being installed by European bakers, and Mr. Eggebrecht noted that Europe generally leads the US on these new technologies by a couple of years.
Also designed for artisan-style breads are industrial ovens from MIWE America, Hillsborough, NJ. The European-manufactured ovens, including its industrial Thermo-rollomat, are known for their thermal oil heating systems. Because a central heating unit can heat multiple ovens, thermal oil ovens are more energy efficient than other systems, noted Harry Jacoby, president of MIWE America.
Thermal oil ovens offer a 15 to 30% savings compared to hot gas circulating ovens, according to MIWE. Its advantages to products include better volume and crust on baked foods because of the smooth heat deliv- ered by the thermal oil. The products also lose less moisture, and bakers do not need to worry about foods burning because of lower temperature in the heating plates at the same baking temperatures.
The Thermo-rollomat can be designed with up to seven separate decks, each acting as a selfcontained baking chamber that gives it great flexibility to produce a variety of products at one time. The design also allows for a large baking area in a small footprint.
SERPENTINE AND SPIRALS.
Smaller footprints are also true for the serpentine ovens from Auto-Bake Pty. Ltd., which is represented exclusively in North America by Dunbar Systems, Inc., Lemont, IL. The Serpentine oven uses vertical space and takes up a fraction of the space required by traditional ovens. The Serpentine oven has trays being transported along multiple horizontal levels of the oven in an S-shape, resulting in an oven having a footprint of just one-tenth of an equivalent-output tunnel oven, and its ultra-low surface-area-tovolume ratio results in an inherent energy efficiency according to Amanda Hicks, director of marketing for the Hornsby, Australiabased company.
The company’s recent innovations have been very customer driven. “For example, the development of the ‘free pan’ transport interface was in response to a recognized need for a Serpentine oven that could be adopted by both smaller and intermediate bakers,” Ms. Hicks said. “With this technology, Auto Bake customizes the solution depending on the product requirements and existing equipment. This includes desired throughput and tray sizes such as the ability to use the customer’s existing rack oven trays.”
Auto-Bake has extended its range of convection and convection-radiant hybrid ovens with the introduction of its 2-pan-wide variant, allowing industrial bakers new levels of flexibility, according to Ms. Hicks. “The wider convection oven is ideal for high-volume baking applications,” she said. “The uniform heat distribution pattern featured in the narrower convection ovens is maintained in the two-tray wide variant. Products are baked from all angles, top, bottom and sides, which is ideal where products are closely packed throughout the baking process.”
Auto-Bake Serpentine ovens also offer flexibility, with product changes achieved by simply changing trays as well as infeed and depanning tooling, she said. The ovens are available in a range of heating system options, including thermal oil or electric radiant heat as well as gas-fuelled convection, and precision-controlled thermal zone and baking control yields unrivalled quality of product, according to Ms. Hicks. “The fully automated system offers userfriendly touch-screen management and control of all baking processes and parameters,” she said.
While Heat and Control’s spiral oven systems have been used for years in the meat and poultry industry, the company has actively presented the ovens to the bakeries only within the past few years, according to Doug Kozenski, sales manager, Heat and Control, Hayward, CA. “Spiral ovens provide the advantage of large linear belt lengths in a compact area,” he said. “Many baking ovens require hundreds of feet of cook length, and a spiral oven provides that in a linear length of 30 ft or less. Generally spirals do not require the use of trays, so the cost of the trays and all the re- quired handling, cleaning and storage of trays is eliminated. Spiral ovens offer a large cook volume or long cook time in a compact space with highly controlled airflow and temperature settings.”
The uniform application of heat is one of the spiral system’s most sought after qualities. “This ensures that all product is cooked evenly with even color development,” Mr. Kozenski said.
Designed to bake a variety of products, the oven is available in either single- or twin-drum designs and features the latest heating technologies including high-efficiency gas burners or thermal fluid coil systems. “The baking environment can be dry heat, steam or a combination of the two,” he noted. “This again provides for the maximum flexibility to meet varying product and production needs.”
A single centerline-mounted circulation fan for each drum draws air up the interior of the drum and then distributes the air evenly throughout a 360° pattern. “The air then moves across the heat source and across the individual conveyor tiers,” Mr. Kozenski observed. “The velocity and volume of the air in relation to the design of the drum ensure equal and uniform heat across all tiers from all angles.”
Also known for its unique airflow is Revent, which uses an upward airflow in its rack ovens. Kristie Peckham, national sales manager, Revent, Piscataway, NJ, said the company is known in the wholesale industry for its quality of bake generated by the upward airflow that “gives an even bake from top to bottom and from the inside of the rack to the outside of the rack.”
Revent and other suppliers offer a variety of roll-in rack ovens for the wholesale industry, and for operations that are producing everything from breads and rolls to cookies and muffins to cakes and pies, rack ovens will provide the flexibility to produce this wide assortment of products.
Besides flexibility, Ms. Peckham said bakeries are looking for two things when it comes to their ovens. “They want to save on energy costs and maintenance costs.” Revent’s design and engineering help make it the highest-rated energy-effi cient oven available, she added. Gemini Baking Equipment Co., Philadelphia, PA, recently installed six Gemini V62 industrial rack ovens at a variety bakery. The bakery had a limited amount of space available yet needed to triple its baking capacity, according to Mark Rosenberg, founder of Gemini. The client needed to produce 3,000 loaves of pan bread per hour using these ovens, and the installation included an automated rack loading and unloading system, allowing the bakery to operate with approximately six fewer people per shift.
Gemini offers semi-automated rack loading and unloading systems that can be added to any bakery using manual rack-style retarders and proofers. “This semi-automated system requires the client to manually move the rack through the proofer and/or retarder but eliminates any manual loading or unloading of oversized boards and or pans onto or off of mobile racks,” Mr. Rosenberg explained.
The V62 rack ovens accommodate two double racks with 40 to 80 pans of capacity dependent on product and shelf spacing. The ovens also feature a high-volume steam system to assure proper steaming throughout the production day. “Because these rack ovens produce their own steam, the added costs to purchase and operate a separate boiler are eliminated,” Mr. Rosenberg noted. “This installation also required the chance to bake different style products at the same time. Which is why they selected a rack oven system instead of a fully automated tunnel oven.”
An electronic control panel on the V62 stores up to 99 recipes, controlling temperature, steaming and moisture evacuation, and the ovens feature a patented IBS rotation system that alternates direction for a very even bake, according to Mr. Rosenberg. The oven also features a unique noncorrosive cascading steam system and stainless steel interior and exterior.
Belshaw Adamatic Bakery Group offers USAdesigned BARO rack ovens with 5-in. insulation to assist with energy efficiency. These ovens have all the features North American bakery operators need, according Mike Baxter, product information and marketing, Belshaw Adamatic, Auburn, WA, such as tough build, steam control, programming and a full set of automation features.
So when looking outside of the traditional tunnel or tray ovens used by bakeries, there is a wide selection of ovens that can be employed for finishing baked foods. These ovens offer many features and heating styles, giving them the flexibility to help bakers adapt to the always changing marketplace.