In a white paper on steam generators and heat recovery technology, Clayton Industries discusses how Frito-Lay transformed waste heat to toast corn chips at its southern Georgia facility.
Legend has it that the renowned Greek inventor Archimedes - originator of the compound pulley and the hydraulic screw - used the sun’s heat as a weapon of war in defending the Sicilian city of Syracuse from a Roman invasion fleet. Using the principle of the parabolic reflector, as seen in a modern solar furnace, he is said to have arranged an array of mirrors on a hillside to focus the sun’s rays on the invaders’ ships, thus igniting them.
Fact or fancy, the story indicates that making heat work harder is a preoccupation of long standing.
Today, spurred by accelerating costs, processors of snacks are turning to equally imaginative methods to boost energy efficiency. One of the common methods is the recovery and recycling of heat generated during processing.
Among the numerous facilities operated by Plano, Texas-based Frito-Lay is its 350,000-sq.-ft. production facilities in southern Georgia, where vast quantities of corn chips and snack specialties are produced. Here, gas-fired ovens on three parallel processing lines use heat to toast corn chips. Until recently, however, the heat after baking was simply stack-vented from the plant’s roof.
Realizing that the same heat could be recovered, converted to steam and re-introduced into the plant’s main steam supply stream, its management team thoroughly quantified the energy cost reductions that this would realize and researched available heat recovery technology.
In Georgia, Frito-Lay addressed this challenge by contacting Clayton Industries of City of Industry, Calif., where it designs and manufactures steam generators and heat recovery systems. Clayton recommended three, roof-installed heat recovery boilers each serving its own toasting oven. Putting the boilers on the roof, Clayton noted, was an option less expensive than ground installation.
The toaster ovens are situated in long conveyor systems that deliver corn chips formed and cut. Here, toasting adds the “crunch” that appeals to snack lovers, and heat is subsequently channeled to a vertical channel much like an exhaust hood outlet, and introduced into a heat recovery boiler. The heat creates steam in the boiler core, and that steam is routed to a remotely located separator, which in turn sends it to the processing supply stream. Processing heat is captured and returns as processing heat.
In 2007, Clayton heat recovery boilers were installed at the snack food facility. The economies enjoyed as a consequence have confirmed the accuracy of its executives’ predictions, and the company’s capital investment already has been recouped.
Clayton Industries’ Thermal Products Division manufactures a broad range of direct-fired steam generators and waste heat steam generators used by major industries.
Editor’s Note: For more information, go to www.claytonindustries.com.