Question

1. Air at 95°F and 1 atm containing 0.0225 lbm H2O per lbm dry air is send to a condenser at the rate of 500 ft3 humid air per minute.

(a) What is the mass flow rate of dry air in this feed stream (lbm/min)?

(b) The air leaves the cooler saturated with water at 55°F and 1 atm. If the mass

flow rate of dry air was 50 lbm/min, find the rate at which water is condensed from the stream (lbm H2O/min). Assume everything in the initial problem statement is correct except for the volumetric feed rate.

2.

Saturated steam at T1(°C) and 7.0 bar is combined with superheated steam at T2(°C)and 10.0 bar in a ratio (1.96 kg of steam at 10/bar)/(1.0 kg of steam at 7 bar). The product stream is at 250 °C and 7.0 bar. The process operates at steady-state

(a). What is the temperature, T1, T2?

(b). What key assumption was required to determine the temperature in part B? If

that assumption failed, would the temperature you determined in part B be too high or too low?

Answer 1

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Here lo.3518 3 md moles O.S75 H20 H6./aq mde d IS-&6 mole a So O.5AS1 86 maley Gotal make 16.42 NOLD maleyHo Tatl mole maleacion d O. S 16.u3 O.03S

mdes d dn Total moles air mde ecin S.86 .43 O.96S Hac dencity d humid aix- 0.040 04651bmf3 > caleutab feed mass Cu)- male ration x detal deed vetu ate X ott3)min 36.91 Lbm/min . mo sS 1.

in uxrle mass Hee, mlu hetion ai y mec fhos Wmodeoton d Where maliation 0,965 No Substifid the alue O-025 X Sobmin 0.9G3 o.03626 X5 818.1