Description : Which of the following quantities need not be fixed before starting the design of a co-current absorber? (A) Heat gain or loss (B) Flow rate of entering liquid (C) Flow rate of gas (D) None of these
Last Answer : (B) Flow rate of entering liquid
Description : Pick out the wrong statement (A) Co-current absorbers are usually used, when the gas to be dissolved in the liquid is a pure substance (B) In case of gas absorption, HETP is ... reaction (D) In actual practice, absorption is an endothermic process, while stripping is an exothermic process
Last Answer : (D) In actual practice, absorption is an endothermic process, while stripping is an exothermic process
Description : In SO3 absorber (Contact Process), packing material used is of (A) Cast iron (B) Chemical stoneware (C) Karbate (D) Mild steel
Last Answer : (B) Chemical stoneware
Description : 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). (A) Straight (B) Parallel (C) Both (A) & (B) (D) Neither (A) nor (B
Last Answer : (C) Both (A) & (B)
Description : The minimum liquid rate to be used in an absorber corresponds to an operating line (A) Of slope = 1 (B) Of slope = 0.1 (C) Tangential to the equilibrium curve (D) None of these
Last Answer : (C) Tangential to the equilibrium curve
Description : If G = insoluble gas in gas stream and L = non-volatile solvent in liquid stream, then the slope of the operating line for the absorber is (A) L/G (B) G/L (C) Always < 1 (D) None of these
Last Answer : (A) L/G
Description : Pick out the wrong statement. (A) In a batch reactor, which is exclusively used for liquid phase reactions; temperature pressure and composition may vary with time (B) In a semi-batch reactor, ... system (D) In a continuous flow reactor, both the reactants and the products flow out continuously
Last Answer : (C) In a continuous flow reactor, uniform concentration cannot be maintained throughout the vessel even in a well agitated system
Description : In a packed absorption tower, if the equilibrium and operating lines are both straight lines, then the ratio, HETP/HTUOG __________ the absorption factor. (A) Increases with increase in (B) Is one at unity value of (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) and (B)
Description : HETP is numerically equal to HTU, only when the operating line (A) Lies below the equilibrium line (B) Lies above the equilibrium line (C) And equilibrium lines are parallel (D) Is far from the equilibrium line
Last Answer : (C) And equilibrium lines are parallel
Description : For the same system, if the same liquid used in an absorber is decreased, the tower height will (A) Increase (B) Decrease (C) Remain unaffected (D) Decrease or increase; depends on the type of liquid
Last Answer : (A) Increase
Description : A single pass air heater is connected to a two pass unit. For the air flow rate and other conditions remaining the same, the film heat transfer coefficient for air will vary in the ratio of (A) 2 (B) 2 0.8 (C) 2 0.2 (D) 2 0.5
Last Answer : (B) 2 0.8
Description : In area meter (e.g., Rotameter), with increase in the fluid flow rate, the (A) Pressure drop increases linearly (B) Pressure drop is almost constant (C) Area through which fluid flows does not vary (D) None of these
Last Answer : (B) Pressure drop is almost constant
Description : Clausius-Clapeyron Equation gives accurate result, when the (A) Vapour pressure is relatively low and the temperature does not vary over wide limits (B) Vapour obeys the ideal gas law and the latent heat of ... is negligible compared with that in the vapour state (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Pick out the wrong statement: (A) Absorption factor is constant, when the equilibrium and operating lines are straight (B) In case of a stripper, the equilibrium curve is always below ... (D) In the absorption of low solubility gases, the liquid film is the controlling resistance
Last Answer : (B) In case of a stripper, the equilibrium curve is always below the operating line
Description : When both the fluids flow concurrently in an absorber, the slope of the operating line is (A) -ve (B) +ve (C) 1 (D) -1
Last Answer : (A) -ve
Description : A flood can vary in: (a) size (b) speed of water flow (c) duration (d) all of the above.
Last Answer : (d) all of the above.
Description : A flood can vary in: a) Size b) Speed of water flow c) Duration d) All of the above.
Last Answer : d) All of the above.
Description : An ideal tower packing should not (A) Have low weight per unit volume (B) Have large surface area per unit volume (C) Have large free cross-section (D) Hold up large amount of liquid in the packing
Last Answer : (D) Hold up large amount of liquid in the packing
Description : Channelling in a packed tower results from the (A) High pressure drop (B) Maldistribution of liquid (C) Non-uniformity of packing (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
Description : Pick out the wrong statement. (A) Packed towers are preferred for vacuum operation, because the pressure drop through the packing is less and they (packings) also lessen the ... of liquid, problem of channelling, loading & flooding is generally encountered in packed towers
Last Answer : (C) Diameter of randomly packed tower is normally more than 1.2 metres
Description : Which of the following is an undesirable property in a tower packing? (A) Large surface per unit volume (B) Large free cross-section (C) Low weight per unit volume (D) Large weight of liquid retained
Last Answer : (D) Large weight of liquid retained
Description : Most important factor to be considered in the selection of packings for absorbers is the __________ of packing. (A) Size (B) Durability (C) Porosity (D) Cost
Last Answer : (C) Porosity
Description : The size of the tetrahedral void in the closest packing of atoms is __________ that of the octahedral void. (A) Equal to (B) Greater than (C) Less than (D) Either (A), (B) or (C); depends on the size of atom
Last Answer : (C) Less than
Description : Pick out the wrong statement. (A) The operating line always lies above the equilibrium solubility curve in case of a single component absorber (B) The operating line always lies below the equilibrium ... (D) The solubility of a particular gas in ideal solution in any solvent is always the same
Last Answer : (C) The operating pressure in solvent extraction system should be below vapor pressures of all components
Description : 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 ... by, y = 5x + 0.001 is (A) 2.0 (B) 1.56 (C) 1.0
Last Answer : (A) 2.0
Description : . In contact process, SO3 is absorbed in 97% H2SO4 and not in water, because (A) SO3 gas is sparingly soluble in water (B) Water forms an acid mist, which is difficult to absorb (C) The purity of acid is affected (D) Scale formation in the absorber is to be avoided
Last Answer : (B) Water forms an acid mist, which is difficult to absorb
Description : 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 ... and without total reflux (D) The top and bottom compositions correspond to the maximum enrichment available
Last Answer : (D) The top and bottom compositions correspond to the maximum enrichment available
Description : . The absorption factor is defined as (where, L = liquid flow rate, G = gas flow rate and, m = slope of the equilibrium line). (A) L/mG (B) G/mL (C) mL/G (D) LG/m
Last Answer : (A) L/mG
Description : Pick out the wrong statement. (A) When the concentration difference for the mass transfer becomes zero at the bottom of the gas absorption tower, then the upper end of the operating line touches the ... fixed gas flow rate, the slope of the operating line decreases, in case of gas absorption process
Last Answer : (C) The operating line lies above the equilibrium curve in case of a gas desorber
Description : At the same gas flow rate, the pressure drop in a packed tower being irrigated with liquid __________ that in dry packed tower. (A) Is greater than (B) Is lower than (C) Is same as (D) Cannot be predicted as data are insufficient
Last Answer : (A) Is greater than
Description : Which of the following is not fixed by the process requirements, in the design of absorbers? (A) Flow rate of the entering gas (B) Composition of the entering liquid (C) Terminal concentrations of gas stream (D) None of these
Last Answer : (D) None of these
Description : 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) Decreases (B) Remains unchanged (C) Increases (D) Decreases exponentially
Last Answer : (C) Increases
Description : A trickle bed reactor is the one, which (A) Has altogether three streams either entering or leaving (B) Processes three reactants at different flow rates (C) Processes three reactants with same flow rate (D) Employs all the three phases (i.e. solid, liquid and gas)
Last Answer : (D) Employs all the three phases (i.e. solid, liquid and gas)
Description : The losses in open channel flow generally vary as the (A) Inverse of the roughness (B) First power of the roughness (C) Square of the velocity (D) Inverse square of hydraulic radius
Last Answer : (B) First power of the roughness
Description : For steady ideal fluid flow, the Bernoulli's equation states that the (A) Velocity is constant along a stream line (B) Energy is constant throughout the fluid (C) Energy is constant along a stream line, but may vary across stream lines (D) None of these
Last Answer : (C) Energy is constant along a stream line, but may vary across stream lines
Description : What size lots are sold for packing tape dispensers?
Last Answer : Packing tape dispensers are sold in lots of 12, 24 and 36 rolls. The wider the tape, the smaller the lot size. One would be advised to determine the number of boxes one will be taping before purchasing the tape dispensers.
Description : Explain the constructional features of Gas filled shock Absorber with sketch.
Last Answer : Features: 1. Control tire motion better than non gas shock absorber 2. Vibration is reduced 3. Reduced aeration. 4. Improved handling.
Description : Rate of low temperature oxidation of coal due to bad storage conditions (A) Decreases with increase in surface area (B) Does not vary with increase in surface area (C) Is more for low volatile ... to high volatile coal (D) Is accelerated by storage in large heaps with small surface to volume ratio
Last Answer : (D) Is accelerated by storage in large heaps with small surface to volume ratio
Description : What type of pump may be appropriate for a liquid near saturation, a low flow rate, and very limited NPSHa (net positive suction head available)?
Last Answer : This application is nearly perfect for a turbine regenerative type of pump. Factors that immediately identify your application and pump type are the small flowrate, low NPSHa, and high temperature. The ... in pressure. You can visit the site below to learn more about these types of pumps.
Description : According to Bernoulli's equation for steady ideal fluid flow (A) Principle of conservation of mass holds (B) Velocity and pressure are inversely proportional (C) Total energy is constant throughout (D) The energy is constant along a streamline but may vary across streamlines
Last Answer : Answer: Option D
Description : In an absorption column, the flooding velocity for random packing is __________ that for stacked/regular packing. (A) Greater than (B) Smaller than (C) Equal to (D) Either (A), or (B); depends on the type of packing
Last Answer : (B) Smaller than
Description : For a specific centrifugal air blower operating at constant speed & capacity, the power requirement and pressure vary (A) Directly as square of gas density (B) Directly as gas density (C) Directly as square root of gas density (D) Inversely as gas density
Last Answer : (B) Directly as gas density
Description : Heavy water (D2O) in a nuclear reactor serves as a (A) Coolant (B) Moderator (C) Both (A) & (B) (D) Neutron absorber
Description : Moderating material used in a thermal-reactor should be a (A) Good absorber of neutrons (B) Solid substance (C) Poor absorber of neutrons (D) None of these
Last Answer : (C) Poor absorber of neutrons
Description : An ideal coolant for a nuclear reactor should (A) Be a good absorber of neutrons (B) Be capable of attaining high temperature, only when it is pressurised (C) Have high density, but low heat transfer co-efficient (D) Be free from radiation damage and non-corrosive
Last Answer : (D) Be free from radiation damage and non-corrosive
Description : Lead is (A) Not resistant to corrosion (B) Used as a cathodic material (C) Not used as pigment (in its compound forms) for paints (D) Used as a shock absorber (in mattress form) between the foundation and steel framework of skyscraper buildings
Last Answer : (D) Used as a shock absorber (in mattress form) between the foundation and steel framework of skyscraper buildings
Description : Hydrochloric acid absorber in made of (A) Cast iron (B) Mild steel (C) Karbate (D) Stainless steel
Last Answer : (C) Karbate
Description : ‘L/mG’ is the expression for (A) Absorption factor (B) Brinkman number (C) Slope of operating line in absorber (D) Slope of operating line in stripper
Last Answer : (A) Absorption factor
Description : The operating line for an absorber is curved, when plotted in terms of (A) Mole fractions (B) Mole ratios (C) Partial pressure (D) Mass fractions
Last Answer : (C) Partial pressure
Description : Desirable value of absorption factor in an absorber is (A) 1 (B) < 1 (C) > 1 (D) 0.5
Last Answer : (C) > 1