22.5-4. minimum liquid flow in a packed tower. the gas stream from a chemical reactor contains 25 mol % ammonia and the rest are inert gases. the total flow is 181.4 kg mol/h to an absorption tower at 303 k and 1.013 × 105 pa pressure, where water containing 0.005 mol frac ammonia is the scrubbing liquid. the outlet gas concentration is to be 2.0 mol % ammonia. what is the minimum flow l min ⁡ ′ using 1.5 times the minimum, plot the equilibrium and operating lines. ans. l min ⁡ ′ = 262.6kg mol/h

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

Aquick transition of the operating speed of a shaft from its critical speed will whirl amplitude. (a) increase (b) limit (c) not affect (d) zero

Asimple rankine cycle uses water as the working fluid. the water enters the turbine at 10 mpa and 480c while the condenser operates at 6 kpa. if the turbine has an isentropic efficiency of 80 percent while the pump has an isentropic efficiency of 70 percent determine the thermal efficiency