An air heater consists of a cylindrical former 0.50m long and 1.9 cm diameter, closely wound with thin resistance wire. The heater is installed across a rectangular duct 0.50m wide by 0.1m high, into which air at 15°C is blown at a velocity of 7.0m/s. The wire surface temperature is maintained at 540°C and its emissivity is 0.85. The duct walls, at 15.0°C, may be assumed black to incident radiant heat. Convection transfer is correlated by: Nu = 0.26 Re0.6 Pr0.3 Estimate the kilowatt input to the heater. Answer: 1.62 kW steps on how tp reach this

An air heater consists of a cylindrical former 0.50m long and 1.9 cm diameter, closely wound with thin resistance wire. The heater is installed across a rectangular duct 0.50m wide by 0.1m high, into which air at 15°C is blown at a velocity of 7.0m/s. The wire surface temperature is maintained at 540°C and its emissivity is 0.85. The duct walls, at 15.0°C, may be assumed black to incident radiant heat. Convection transfer is correlated by: Nu = 0.26 Re0.6 Pr0.3 Estimate the kilowatt input to the heater. Answer: 1.62 kW steps on how tp reach this

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter11: Heat Transfer By Radiation

Section: Chapter Questions

Problem 11.52P

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