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POWDER COATING, November 2018 15 Figure 3 Standard pipe casting For our example, we'll examine the bene ts of using electric IR inside a convection oven. e tests employ a standard 300 kilowatt (kW) electric convection oven (see Figure 1) that was retrofitted with approximately 127kW (ten 12.735kW heaters) of electric IR (see Figure 2). e part used for the test was a 350-pound pipe casting (shown in Figure 3). Two tests were performed to examine the amount of energy and time it took the casting to reach a temperature of 350°F in 300kW of convection only (test #1) and a combined 300kW of IR-convection (test #2). ermocouples were placed at di erent points on the casting to make sure it had been heated throughout. In each test, the oven was set to 400°F, and a total of 300kW was used. During the IR-con- vection testing, the IR heat source was left at 100 percent (no modulation or control) while the convection oven cycled to maintain oven temperature at 400°F. Test #1: Convection only. Figure 4 shows the tempera- ture pro le of the part through the use of 300kW of con- vection only. e part reached a temperature of 350°F within 61.7 minutes by using 177 kilowatt hours (kWh), shown in Figure 5. Test #2: IR-convection combination. Conversely, Figure 6 shows the temperature pro le of the part through the use of 300kW of a combination of IR (127kW) and convection (173kW). In this test, the part reached temperature in 38.6 minutes while using 131.5kWh (shown in Figures 7 and 8). In summary, the combination IR-convection oven had both a shorter heat-up time as well as a reduction in energy usage. It allowed the part to reach temperature approximately 37 percent faster than with convection only. As a result, the en- ergy required to heat the part was reduced by approximately 26 percent. Second application: Multiple-size parts at one time At times, industrial customers may need to batch multi- ple-size parts (di erent thickness and weight) within the same POWDER COATING DON'T FORGET! The Quick Web Resource is available now at pcoating.com Link to our featured vendors to nd videos, white papers, case histories, and much more. IT'S EXPERTISE AT A CLICK!