A cross-sectional view of a 1-m-long gas preheater is shown in the sketch. The device provides 14 g/min preheated gas at 150°C to a chemical reactor. The heater rods dissipate 700 watts each. To prevent chemical breakdown of the gas, it is important that the wall of the gas flow channel not exceed 300°C. The aluminum body containing the gas flow channel and the heater elements distributes heat transferred from the heater elements to the gas but cannot exceed 325°C. Assuming a heat transfer coefficient of 500 W/m² K between the gas and the surfaces of the rectangular flow channel, determine whether the aluminum body operates within the required maximum temperature. Estimate the heat transfer coefficients for the exterior surfaces from Table 1.3 and compare your results with an assumption that the surfaces are insulated.

Data from in Table 1.3

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1.5 Heating element 0.25 farfa 0.625 Aluminum body 0.125. Flow channel 0.25 (5 places) 1.5 Heating element 1m]