Burner material upgrades resulted in extended operating life and improved performance.

The average American's love affair with snack foods is well documented. Baked or fried, tortilla chips and other treats are consumed seemingly as quickly as they can be produced. For example, in the United States' snack food market, tortilla chips are second in sales only to potato chips. And, according to Snack World magazine, the total 1997 U.S. retail sales of tortilla chips topped $3.4 billion, representing more than 1.3 billion pounds of chips.

To build a tortilla chip oven with a production output high enough to satisfy these demands, Casa Herrera Inc. needed tough components. After exploring its options, Casa Herrera determined that an all-alloy gas infrared burner from Red-Ray Manufacturing Co., Cliffside Park, NJ, met the challenge.

Infrared burners have been used for more than 60 years in process heating, drying and curing applications due to their concentrated, high energy output. This single characteristic allows processors to increase production by replacing or supplementing other forms of process heating equipment with infrared. When operating continuously at high temperatures, industrial environments place stringent performance demands on burners. Rugged, durable designs such as a gas-fired impingement type infrared burner provide reliable service in a range of operating conditions.

Constant evaluation leads to continuous improvement, though, and Red-Ray found it could increase the durability of its most durable infrared burners -- its Model F-type infrared impingement burner -- by upgrading the materials of construction. This improved design was just what Casa Herrera needed for its high output ovens.

Casa Herrera ovens using Red-Ray infrared burners can provide production rates of more than 3,000 lb/hr.

More Chips, Please!

Founded in 1950, Casa Herrera Inc., Pomona, CA, has pioneered many diverse machinery designs used worldwide to process corn tortillas, flour tortillas and tortilla chips. Tortilla products continue to gain popularity throughout the world.

"The consumer demand for tortilla chips has grown steadily and rapidly since our company's founding," said Ron Meade, CEO of Casa Herrera. "We continue to meet the challenge of increasing capacity and improving the entire process. Our ovens needed to operate faster and with higher energy output to satisfy our customer's growing demands."

Due to the speed and energy efficiency of infrared technology, most tortilla chip ovens utilize infrared burners to bake corn tortilla chips.

"We have used infrared impingement burners in our ovens for more than 18 years due to their energy efficiency and rugged construction," Meade said. "What has changed is the design -- over the years, we've added more burners to increase production rates from 600 lb per hour in our original ovens to more than 3,000 lb per hour in our latest designs," Meade said. Ambient operating temperatures also have increased, making it tougher on all internal oven parts, including the burners.

The metal components on Red-Ray's F-SS-A burners are constructed of a high temeprature alloy rather than cast iron to provide increased high temperature dimensional stability and better erosion resistance over time.

Viva Infrared

Casa Herrera is not the only oven manufacturer looking for durable burners: The desire for longer burner life is common in all industries. "Some Red-Ray burners have been used continuously for more than 30 years in the field," said Tim O'Neal, product and applications manager at Red-Ray.

Of course, how the burner is operated and maintained influences product durability, reliability and overall performance. For example, burners that have been regularly maintained and operated at correct firing conditions in a clean environment are much more likely to outlast burners that are neglected or operated in an extremely dirty environment. Increasing burner life expectancy is a function of good preventative maintenance, clean filtered premix air-fuel, correct firing rates, appropriate air-fuel proportioning and mild ambient conditions. Physical damage and/or chemical corrosion also can reduce burner life, but Red-Ray's infrared impingement burner is designed with this in mind.

"Constructed out of cast iron metal parts, the heavy cast burner section base and side plates of the Model F-type burner hold the refractory in place and help protect it from physical damage," O'Neal noted.

Rugged construction ensures product durability. For the Model F-SS-A infrared impingement burner used by Casa Herrera, Red-Ray replaced the cast-iron components with parts made from a high temperature alloy and stainless steel. The metallurgical upgrades provide increased high temperature dimensional stability and erosion resistance over time. Field testing at several customers' plants confirmed the improvements.

"One building products' customer with a demanding curing and paint drying operation installed 100 new F-SS-A burners sections," O'Neal said. After more than two years in continuous service curing coated parts, the redesigned alloy burners continue to perform reliably, despite being continuously subjected to ambient temperatures from 600 to 1,000oF (316 to 538oC).

To satisfy Casa Herrera and other customers with stringent requirements, Red-Ray will continue to push the performance envelope.

"The all-alloy burner components, used in combination with stainless steel manifolds, deliver high temperature corrosion resistance while preventing warpage and bowing," said Tom Bannos, president of Red-Ray Manufacturing Co. "We're proud of the high level of performance and reliability the F-SS-A provides. But, as new applications for process heating evolve, we will continue to improve upon our burner technology to satisfy our customers needs."

Ron Meade is happy to hear that, and Casa Herrera's customers are sure to be pleased as well.

"We're now supplying ovens with the F-SS-A burners, with great results. Our customers report that the new burners already have demonstrated a 50% increase in burner life before requiring preventive maintenance. Our test results further confirmed that the F-SS-A burner is the most efficient infrared burner for our application."

So, Casa Herrera's customers can continue to produce the volume of chips needed. Hopefully, the salsa makers can keep up.

For more information from Casa Herrera, call (909) 392-3930 or visit www.casaherrera.com. For more information from Red-Ray Manufacturing Co., Branchburg, N.J., call (908) 722-0040 or visit www.red-ray.com.