Home
About Us
Contact Us
Privacy Policy
Search
Home
→
Mass Transfer
→
Operating velocity in a packed tower is usually __________________ the flooding velocity ?
Related MCQs
For stripping of a gas in a counter current stripper, the operating line __________?
In gas-liquid contact operation, the number of ideal stages, N = (xa – xb)/(xb – x*b). This is true when the stripping factor ‘S’ is __________?
The Reynolds number of the liquid was increased 100 fold for a laminar falling film used for gas-liquid contacting. Assuming penetrating theory is applicable, the fold increase in the mass transfer co-efficient (Kc) for the same system is__________?
Large scale usage of flash distillation is practised in __________?
The boiling points of pure components of a binary system __________ with increase in total pressure of the system ?
During sensible cooling process __________?
The velocity, concentration and temperature boundary, for the boundary layer development on a flat plate during connective mass transfer will be same, if__________?
Pick out the wrong statement ?
In triangular co-ordinates, the ternary composition point falls __________ of the triangle?
Co-current absorbers are usually used when the gas to be dissolved in the liquid is __________?
When acetone is added in a two layer mixture of methyl isobutyl ketone and water at 30°C, the acetone distributes between the two layers and the composition of the layer follows two solubility curves. For this system ?
Molecular sieves are regenerated by heating to __________ °C?
Pick out the wrong statement. Generally for physical adsorption, a gas of__________?
Which of the following processes is followed by unsaturated air (with dry bulb temperature 12°C and relative humidity 47%) passing through water spray washer (temperature of water being constant at 40°C ?
Which of the following is not fixed by the process requirements, in the design of absorbers ?
Reboiler is considered as one theoretical plate, because__________?
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 ?
Large scale drying of wheat is done in a __________ dryer?
With increase in temperature, the leaching rate increases due to__________?
In distillation where q is defined as the moles of liquid flow in the stripping section per mole of feed introduced, for saturated liquid feed__________?
Though, theoretically the adsorption & desorption isotherms is expected to coincide but sometimes at least a part of the isotherms does not coincide and this phenomenon is known as adsorption hysteresis. In such cases, the desorption equilibrium pressure is __________ that obtained for adsorption?
In an absorption column, the flooding velocity for random packing is __________ that for stacked/regular packing?
In case of cooling towers, the ratio of the rates of heat and mass transfer is indicated by the __________ number ?
Unsaturated air (with dry and wet bulb temperatures being 35 and 25°C respectively) is passed through water spray chamber maintained at 35°C. The air will be__________?
Mass transfer co-efficient is defined as__________?
Large quantity of silica gel is normally dried in a __________ dryer?
The value of „L/mG’ ratio for economical absorption operation ranges from __________?
In a single stage extraction process, 10 kg of pure solvent S (containing no solute A) is mixed with 30 kg of feed F containing A at a mass fraction xf = 0.2. The mixture splits into an extract phase E and a raffinate phase R containing A at xB = 0.5 and xR = 0.05 respectively. The total mass of the extract phase is (in Kg) ?
Dried finished product sampled from various parts of a __________ dryer exhibits nonuniformity in the moisture content?
In steam distillation, the __________?
A slurry is to be dried to produce flaky solid. Which dryer would you recommend ?
Which of the following parameters remains constant during chemical dehumidification ?
Coffee is prepared from coffee beans by leaching with__________?
The equation, NA = (DAB . Pt /RTZ) (y1 – y2) is for __________?
Penetration theory states that the mass transfer co-coefficient is equal to (where, De is diffusivity and ‘t’ is time) ?
The relative volatility of a binary mixture at the Azeotropic composition is __________?
For absorbing a sparingly soluble gas in a liquid, the__________?
Moisture content of a substance when at equilibrium with a given partial pressure of the vapour is called the __________ moisture?
For the flow of gases through a capillary, with increase in temperature, the permeability __________ as per Knudsen law?
With increase in the liquid flow rate at a fixed gas velocity in a randomly packed counter current gas-liquid absorption column, the gas pressure drop__________?
A natural draft cooling tower is filled with wooden grids, which covers about __________ percent of the tower height?
The Knudsen diffusivity is proportional to (where, T = absolute temperature) __________?
Which of the following processes is not an example of adsorption applied to gaseous separations ?
The cooling effect in a cooling tower can be speeded up by __________?
To remove all the moisture from a wet solid it requires exposure to __________ air?
Pore size of the molecular sieve 5A is __________ mm ?
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) ?
Perforated plate towers are unique for solvent extraction because, they provide__________?
The equation, NA = (DAB . Pt /RTZ . PBM) (PA1 – PA2) is for__________?
For the same system, if the same liquid used in an absorber is decreased, the tower height will__________?
The commonly used solvent in supercritical extraction is__________?
Operating velocity in a packed tower is usually __________________ the flooding velocity ?
A. Half
B. Twice
C. Equal to
D. More than
Correct Answer:
Half
✔
Last Updated:
February 15, 2019