Taking Heat From the Baking Industry


Industrial automation and process applications requiring a chiller or heat exchanger can come in all types of shapes and sizes, and cooling capacity demands can range from a few hundred Btu/hr. for bench top lab equipment to many million Btu/hr. for laser applications.

Chiller sizing for large-scale end users such as beverage, chemical or plastics manufacturing usually will demand central systems to achieve the massive cooling capacity requirements compared with small- to medium-range point of use automation applications. These unique differences become more challenging for original equipment manufacturers (OEMs) as machine designers must anticipate a wide range of end-user operating environments and operator skill levels when specifying chillers or heat exchangers in contrast to end-user facilities where cooling capacity requirements are location specific and operator skill levels are known.

Burford Corporation, a baking equipment OEM, had to undergo this learning path so they reached out to SMC Corporation of America, an automation components manufacturer, for help in improving machine performance in their spray applicators used to enhance the browning process of hamburger buns prior to the baking.

Burford Corporation’s spray applicators are used to enhance the browning process of hamburger buns before baking.

 
Practical Solutions Through Innovation

Burford Corporation, Maysville, Oklahoma, a division of Middleby since 2017, was founded in 1961 and has been a trusted brand in industrial baking of hamburger, hot dog and hoagie buns for decades. It is the inventor of the Twist Tie machine that seals the bags of bread loaves; they have since expanded their product offerings to seed topping applicators, pan oilers, pan shakers, splitting and dough imprinting equipment, as well as spraying and glazing equipment.

Burford® was awarded a 2020 American Society of Baking (ASB) Innovation Award on Operational Excellence for its Smart Pattern Splitter that uses low-pressure water which replaced cutting knives to split the top of bakery products in a wide variety of patterns controlled by a servo motor before the baking process. This innovation not only enhanced operator safety, it also dramatically increased the versatility of the designs on the bakery products at the touch of a screen in a matter of seconds.

With this commitment to product innovation and customer satisfaction, Burford’s Director of Operations, Brian Risch, reached out to Grant Blood at SMC to consult on opportunities Burford identified to enhance the performance of their spray applicators.

Burford worked with SMC to enhance the performance of its spray applicator.

 

Spray Applicators for Industrial Baking

As any home baker will know, before bread dough is baked, the top side will usually be brushed with an egg wash, a thin coat of milk, honey or butter in order to create an appetizing brown coloring and crunchy crust. In industrial baking settings, automation is adopted as a sensible alternative to manual processes for attaining higher throughput when food safety, operator safety, quality and taste are not compromised.

Burford’s spray applicator is an integral building block to the baking automation process by accurately spraying a coating or glaze on the top of each hamburger bun, positioned inside of large baking trays as they travel along on a high-speed conveyor before entering an industrial oven.

The glazes are usually an end-user proprietary blend or a third party supplied pre-mix, and not manufactured by Burford; placing the machine designers in the dark and causing them to speculate on the glaze ingredients passing through the applicators. A recurring comment from end-user bakeries was how the applicator’s spray nozzles became gummed up resulting in costly downtime for cleaning or replacing.

Diagnosing how to extend the cleaning cycles of the spray nozzles and reduce downtime, Risch learned the glazes were always some variety of ingredients blended together into an emulsion. He and his team concluded that over time the emulsions were separating into two parts, a top oily/fatty layer and a bottom layer of liquid.

Emulsions can be partially stabilized by adding an emulsifier, an agent that contains both oil-like and water-like properties to help temporarily bind the emulsion together. However, as time elapses the two layers will naturally begin to separate. In the case of the spray applicators, the only controllable factor remaining for delaying the separation phase of the glaze was temperature stability. Viscosity or the measure of a fluid’s resistance to flow is a factor of temperature, and as a fluid’s temperature rises, its viscosity decreases and flows faster. Conversely, as the same fluid’s temperature is lowered, its viscosity increases and flows slower. 

The solution Risch and his team determined would be to lower the temperature of the emulsion inside the applicator’s storage tank, hold that temperature, and delay the oily/fatty substance and liquid solution from separating while extending the glaze’s useable shelf life. The next challenge was to assess in what kinds of conditions the spray applicators would be operating at the countless end-user baking facilities globally. What would the ambient temperature be? What kind of emulsion would be sprayed etc.? As an OEM machine builder, Burford engineers would have to correctly gauge the “sweet spot” for all variables of its customers as well as the upper and lower limits of that range. Now, Burford needed a process to control glaze temperature.

 

Chillers for Enhancing Spray Applicator Performance

To gain insight about chillers, and how to specify and size them for the spray applicators, Risch reached out to SMC and learned about the company’s no-obligation Chiller Sample Evaluation Program. After initially sizing a chiller, a customer can use the program to try out the selected unit for the application and evaluate the chiller’s cooling capacity performance for up to 45 days. The customer can then upsize, downsize or validate the sample chiller was the most appropriately sized unit. After cooling capacity is confirmed, the next steps to chiller selection are to factor in whether the operating environment has access to facility water, available power supply, ambient temperature, available floor space, and other space constraints.

Since adding a chiller to Burford baking equipment was new territory for Risch’s team, Blood worked with the engineers to brainstorm the typical industrial baking environment and list their access to resources.

  • Access to facility water? Not guaranteed, so an air-cooled chiller would be best.
  • Power supply? Not an issue since SMC chillers are designed to be compatible globally, therefore standard models are 100 VAC (50/60Hz), 115 VAC (60 Hz) or 200 to 230 VAC (50/60 Hz) covering most industrialized economies.
  • Ambient temperature inside industrial bakeries? A moving target. Therefore, SMC would recommend the spray applicator and chiller be positioned as far upstream from the ovens as the baking process would allow.
  • Available floor space and other space constraints? Unknowable, therefore, the smaller in dimensions the better.

Next, Risch and his team debated what temperature to target for the chiller’s setpoint for improving the emulsion’s thermal stability. They did not take this discussion lightly knowing at lower temperatures the glaze would have longer shelf life but with tradeoffs of ranging from becoming thicker and gooier to potentially negatively affecting how it sprayed on the dough. They decided to set the upper limit at room temperature 67°F (19.5°C), as this was the glaze manufacturers recommended and the lower limit at just above freezing. Testing would reveal at what temperature range was the “Goldilocks Zone.”

 

Chiller Sample Evaluation Program 

Based on the application at Burford, SMC’s Chiller and Dryer Group selected an air cooled, mid-range 3.0 kW (10,000 btu) with thermal stability ± 0.18°F (± 0.1°C) from the company’s HRS Series of chillers for evaluation. The test chiller arrived at Burford’s Research and Development Department a few days later. Risch was initially concerned. 

“I can’t use this, it isn’t made from stainless steel and the enclosure protection won’t hold up in a flour dusty baking environment,” Risch said. However, Blood reassured Risch the guts of the test unit, including the refrigeration compressor, condenser, evaporator, recirculating pump and temperature sensor, were all identical to a soon-to-be-released environmentally resistant model that would address all of those concerns. He made a case for testing the proof of concept in a lab setting to evaluate chiller sizing, cooling capacity and to observe how the relationship of lowering the temperature of a typical glaze would affect its fluidity and how it would spray in Burford’s equipment. 

After hearing more about the chiller, Risch decided to test the HRS. Based on his longtime relationship with Blood, he knew he could count on SMC to deliver the stainless steel model in time for the International Baking Industry Exposition (IBIE). Blood also promised Burford President, Clay Miller, the environmentally resistant HRS-R version would arrive in time for IBIE.

SMC’s HRS-R chiller helps Burford’s spray applicator maintain the proper temperature of any given glaze applied to hamburger buns. 

 

New Spray Applicator a Success

The test HRS chiller integrated well with the spray applicator’s cooling system, which features a water-jacketed dual-layer tank. The tank is comprised of an inner 20-gallon tank storing the glaze and an outer jacket housing the cooling media (ethylene glycol R410A) to dissipate the heat and stabilize the temperature of the glaze in the inner tank.

The continuous stream of data from testing assured Risch and his team their thermal stability idea was the practical and innovative solution they were looking for. 

“Through our R&D phase and our plant testing, we determined that controlling the temperature of the glaze was critical to achieve the required spray pattern and extend the runtime of the glaze sprayer equipment,” Risch said. 

The HRS not only performed well but it also met the need to consume very little floor space, which is highly valued in bakeries of any size. The HRS has a smaller footprint since it is only 15 inches wide by 20 inches long, yet it delivers equal cooling capacity to larger competitive chillers. The robust HRS-R is also engineered with a stainless steel cover and electrical box rated IP54 for dust and water splash protection. Additionally, all electrical cable entries are rated IP67.

Features of the SMC HRS-R chiller include a stainless steel cover and electrical box rated IP54 for dust and water splash protection, as well as IP67-rated electrical cable entries.

Burford’s launch of the new spray applicator at industry event proved to be a success based on  orders for units equipped with the HRS-R chiller option. Many at the company’s booth at IBIE appreciated the chiller’s simple control panel featuring separate current temperature and set temperature displays combined with upward and downward arrows for temperature adjustment.  

“The chiller sample program is really the reason we ended up using SMC,” Risch said. “Their development of the increased environmental protection version and willingness to provide a unit for testing was a real advantage.”

 

About the Authors

Zane C. Baker, SMC America’s National Product Sales Manager, has been working in a sales capacity at SMC for 27 years in Marketing, Life Sciences, Product Sales Specialist and currently managing a team dedicated to chillers and dryers at a national level, Email: zbaker@smcusa.com

Shinji "Tak" Takahashi has been working in SMC Marketing for 15 years, focusing on product development and product promotion.

About SMC Corporation of America

SMC Corporation of America is headquartered in Noblesville, Indiana, and is a subsidiary of SMC Corporation in Japan. SMC Corporation is the world’s largest pneumatics company dedicated to factory automation with technical development centers in Japan, the United States, Europe and China. There are 26 sales offices in the United States and five sales offices in Canada supported by domestic engineering, manufacturing and inventory located in Noblesville. To learn more, visit www.smcusa.com.

All photos courtesy of SMC Corporation of America.

To read similar Food Industry articles visit https://coolingbestpractices.com/industries/food. For similar Chiller Technology articles visit https://coolingbestpractices.com/technology/chillers.
 

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