21451. During bottling of cold drinks (e.g. Pepsi), the main resistance to mass transfer for the absorption of carbon dioxide in water lies in the
21452. The overall mass transfer co-efficient for the absorption of SO2 in air with dilute NaOH solution can be increased substantially by
21453. Flooding results in
21454. For the air water system under ambient conditions, the adiabatic saturation temperature and the wet bulb temperature are nearly equal, because
21455. In an operating distillation column, the
21456. Which provide information to electronic control module?
21457. The diffusivity (D) in a binary gas mixture is related to the temperature (T) as
21458. For which of the following unit operations, Lewis number is of significance ?
21459. Tray spacing in a distillation column of dia 10-12 ft. used in petroleum refinery may be around __________ inches.
21460. If a1 and a2 are the relative volatilities when the pressure in the distillation column is 1 and 2 atm respectively. Pick out the correct statement.
21461. The dimension of diffusivity is same as that of the
21462. The temperature to which a vapour gas mixture must be cooled (at varying humidity) to become saturated is called the __________ temperature.
21463. Entrainer used in azeotropic distillation should
21464. In case of steam distillation, the steam leaving the liquid is not completely saturated with distillate vapour, because
21465. Periodic maintenance or preventive maintenance helps to
21466. Leaching of coffee from coffee beans is done by
21467. For contacting a highly soluble gas with a liquid
21468. During drying operation, it is easier to remove the __________ moisture.
21469. With increase in solvent rate, the number of transfer units, NtoG, for a fixed degree of absorption from a fixed amount of gas
21470. Ion exchange process is similar to
21471. A distillation column with N plates is being operated under normal conditions. At some point of time, the operation is shifted to total reflux condition (i.e., no product and residue are being withdrawn and feed to the column is stopped). At the new steady state,
21472. Dryer widely used in a textile industry is __________ dryer.
21473. Hand brakes are applied on
21474. Air at a particular humidity is heated in a furnace. The new dew point
21475. In a packed tower, the value of HETP equals HTUOG, when the equilibrium and the operating lines are (where, HETP = height equivalant to a theoretical plate HTUOG = overall gas phase height of a transfer unit)
21476. The vapour pressure exerted by the moisture contained in a wet solid depends upon the
21477. Who among the following was the Chief Minister of King Marthanda Varma?
21478. Smoke is an example of
21479. Which of the following adsorbant is used in the refinning of sugar ?
21480. Stacked packing compared to dumped packing
21481. In McCabe-Thiele method of theoretical plate calculation for a distillation column, the operating lines of stripping and rectifying sections coincide with the diagonal at __________ reflux.
21482. Which of the following parameters remains constant during chemical dehumidifica-tion?
21483. Drying of a solid involves __________ transfer.
21484. Mechanism of moisture removal in case of freeze drying of food stuff is by
21485. The dew point of an unsaturated gas-vapor mixture does not depend upon the __________ of the mixture.
21486. Which is not concerned directly with mass transfer ?
21487. Removal of __________ exemplifies an adsorption unit operation.
21488. Can the efficiency of a plate in the distillation tower be greater than 100% ?
21489. With increase in the mass velocity of the gas, the rate of drying during the constant rate period __________ , if the conduction and radiation through the solid are negligible.
21490. For gas absorption, low viscosity solvents are preferred, because of their
21491. To remove all the moisture from a wet solid it requires exposure to __________ air.
21492. The operating cost of a distillation column at minimum reflux ratio is
21493. The reflux to a distillation column is 100 moles/hr, when the overhead product rate is 50 moles/hr. The reflux ratio is
21494. Molecular diffusivity of a liquid
21495. The wet and 'dry bulb temperature for a vapour-gas mixture are 25°C and 30°C respectively. If the mixture is heated to 45°C at constant pressure, the wet bulb temperature will be __________ °C.
21496. Henry's law states that the
21497. Ammonia present in the coke oven gas is removed by washing with
21498. With increase in temperature, the leaching rate increases due to
21499. Which of the following processes is not an example of adsorption applied to gaseous separations ?
21500. The critical moisture content in case of drying indicates the __________ rate period.