For the same system, if the same liquid used in an absorber is decreased, the tower height will

Related MCQs

• H2S is being absorbed in a gas absorber unit. The height of the transfer unit based on the overall mass transfer coefficient on the gas side is 0.4 m. The equilibrium data is given by, y = 1.5 x. The bulk concentration of H2S has to be reduced from 0.05 to 0.001 mole fraction in the gas side. The height of the tower (in metres) corresponding to an operating line given by, y = 5x + 0.001 is
• Acetone is to be removed from air in an isothermal dilute absorber using pure water as solvent. The incoming air contains 5 mole% of acetone (yin = 0.05). The design equation to be used for obtaining the number of trays (N) of the absorber is, N+2 = 6 log (yin/yout).For 98% recovery of acetone, the number of trays required is/are:
• At the same gas flow rate, the pressure drop in a packed tower being irrigated with liquid __________ that in dry packed tower.
• A natural draft cooling tower is filled with wooden grids, which covers about __________ percent of the tower height.
• In a packed tower, the value of HETP equals HTUOG, when the equilibrium and the operating lines are (where, HETP = height equivalent to a theoretical plate HTUOG = overall gas phase height of a transfer unit).
• Pressure drop through plate tower as compared to that through packed tower, for the same duty will be
• For the gas absorption, the height of a transfer unit, based on the gas phase is given by (G: superficial molar gas velocity, L: superficial molar liquid velocity, FG: mass transfer co-efficient, moles/m2, a: interfacial area per unit volume of tower)
• The minimum liquid rate to be used in an absorber corresponds to an operating line
• Tower diameter may be decreased by
• In a moderately sized packed absorption tower, channelling (which is most severe with stacked packings) can be minimised by taking the ratio of tower diameter to packing diameter