Unformatted text preview: square brass plates [r
532.5 lbm/ft3 and Cp
(lbm · °F)] that are initially at a uniform temperature of 75°F
are heated by passing them through an oven at 1300°F at a rate
of 450 per minute. If the plates remain in the oven until their
average temperature rises to 1000°F, determine the rate of heat
transfer to the plates in the furnace and the rate of entropy generation associated with this heat transfer process.
7–l24 Long cylindrical steel rods [r
7833 kg/m3 and
Cp 0.465 kJ/(kg · °C)] of 10-cm diameter are heat treated by
drawing them at a velocity of 3 m/min through a 7-m-long
oven maintained at 900°C. If the rods enter the oven at 30°C
and leave at 700°C, determine (a) the rate of heat transfer to
the rods in the oven and (b) the rate of entropy generation associated with this heat transfer process. Oven 900°C
3 m/min 6m
steel, 30°C FIGURE P7–124
7–125 The inner and outer surfaces of a 5-m
wall of thickness 30 cm are maintained at temp...
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This document was uploaded on 11/28/2012.
- Spring '09