In a packed bed absorption column, the channelling will be noted by the (A) Increase in flow rate (B) Sharp drop in pressure drop (C) Sharp rise in pressure drop (D) None of these

In a packed bed absorption column, the channelling will be noted by

the

(A) Increase in flow rate

(B) Sharp drop in pressure drop

(C) Sharp rise in pressure drop

(D) None of these

by

1 Answer

Answer :

(B) Sharp drop in pressure drop

by

Related questions

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

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

For a packed bed reactor; the presence of a long tail in the residence time distribution curve is an indication of: (A) Ideal plug flow (B) Bypass (C) Dead zone (D) Channelling

Description : For a packed bed reactor; the presence of a long tail in the residence time distribution curve is an indication of: (A) Ideal plug flow (B) Bypass (C) Dead zone (D) Channelling

Last Answer : (C) Dead zone

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)

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)

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 possibility of tower wall collapse (B) Packed towers are preferred over plate towers for handling corrosive and foamy liquids (C) Diameter of randomly packed tower is normally more than 1.2 metres (D) Due to uneven supply and improper distribution of liquid, problem of channelling, loading & flooding is generally encountered in packed towers

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

Very tall packed towers are divided into series of beds to (A) Reduce the overall pressure drop (B) Avoid channelling (C) Reduce liquid hold-up (D) Avoid flooding

Description : Very tall packed towers are divided into series of beds to (A) Reduce the overall pressure drop (B) Avoid channelling (C) Reduce liquid hold-up (D) Avoid flooding

Last Answer : (B) Avoid channelling

Plate towers are preferred to packed towers, when large temperature changes are involved, because of the reason that the (A) Packing may be crushed due to thermal expansion/contraction of the components of the equipments (B) Pressure drop in the equipment will be very high (C) Viscosity variation of the fluids may cause channelling/flooding (D) None of these

Description : Plate towers are preferred to packed towers, when large temperature changes are involved, because of the reason that the (A) Packing may be crushed due to thermal expansion/contraction of the ... C) Viscosity variation of the fluids may cause channelling/flooding (D) None of these

Last Answer : (A) Packing may be crushed due to thermal expansion/contraction of the components of the equipments

The main reason for dividing a tall packed tower into series of small towers is to (A) Minimise the overall pressure drop (B) Avoid flooding (C) Reduce liquid hold up (D) Avoid channelling

Description : The main reason for dividing a tall packed tower into series of small towers is to (A) Minimise the overall pressure drop (B) Avoid flooding (C) Reduce liquid hold up (D) Avoid channelling

Last Answer : (D) Avoid channelling

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 (A) > 4 :1 (B) < 8 : 1 (C) > 8:1 (D) < 6:1

Description : 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 (A) > 4 :1 (B) < 8 : 1 (C) > 8:1 (D) < 6:1

Last Answer : (C) > 8:1

In a dry packed bed, the pressure drop will be changed by increasing the flow rate as (A) V1.8 (B) V-0.8 (C) V (D) V-1

Description : In a dry packed bed, the pressure drop will be changed by increasing the flow rate as (A) V1.8 (B) V-0.8 (C) V (D) V-1

Last Answer : (A) V1.8

Pick out the correct statement. (A) For identical gas flow rates, less pressure drop occurs through a plate tower than through a packed tower (B) Plate column can handle greater liquid loads without flooding than packed column, but the liquid hold up is more in the case of plate column (C) For the same duty, plate columns weigh less than packed columns (D) All (A), (B) and (C)

Description : Pick out the correct statement. (A) For identical gas flow rates, less pressure drop occurs through a plate tower than through a packed tower (B) Plate column can handle greater liquid loads without flooding than packed ... duty, plate columns weigh less than packed columns (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

For flow of fluids through packed bed, the superficial velocity is (A) Less than the average velocity through channels (B) More than the average velocity through channels (C) Dependent on the pressure drop across the bed (D) Same as the average velocity through channels

Description : For flow of fluids through packed bed, the superficial velocity is (A) Less than the average velocity through channels (B) More than the average velocity through channels (C) Dependent on the pressure drop across the bed (D) Same as the average velocity through channels

Last Answer : (A) Less than the average velocity through channels

Pressure drop in a packed bed for laminar flow is given by the __________ equation. (A) Kozeny-Carman (B) Blake-Plummer (C) Leva's (D) Fanning friction factor

Description : Pressure drop in a packed bed for laminar flow is given by the __________ equation. (A) Kozeny-Carman (B) Blake-Plummer (C) Leva's (D) Fanning friction factor

Last Answer : (A) Kozeny-Carman

For laminar flow of a fluid through a packed bed of spheres of diameter d, the pressure drop per unit length of bed depends upon the sphere diameter as (A) d (B) d 2 (C) d 4 (D) d

Description : For laminar flow of a fluid through a packed bed of spheres of diameter d, the pressure drop per unit length of bed depends upon the sphere diameter as (A) d (B) d 2 (C) d 4 (D) d

Last Answer : (D) d

Pressure drop in packed bed for turbulent flow is given by the __________ equation. (A) Kozeny-Carman (B) Blake-Plummer (C) Leva's (D) Hagen-Poiseuille’s

Description : Pressure drop in packed bed for turbulent flow is given by the __________ equation. (A) Kozeny-Carman (B) Blake-Plummer (C) Leva's (D) Hagen-Poiseuille’s

Last Answer : (B) Blake-Plummer

Pick out the wrong statement. (A) Critical moisture content is not a property of the material itself (B) A sharp increase in pressure drop gives an indication of the flooding in a distillation column (C) Separation of components is not possible in liquid extraction, if selectivity is unity (D) Dehydration of ethyl alcohol is most economically done by molecular distillation at very high vacuum

Description : Pick out the wrong statement. (A) Critical moisture content is not a property of the material itself (B) A sharp increase in pressure drop gives an indication of the flooding in a ... unity (D) Dehydration of ethyl alcohol is most economically done by molecular distillation at very high vacuum

Last Answer : (D) Dehydration of ethyl alcohol is most economically done by molecular distillation at very high vacuum

Flooding in a distillation column is detected by a sharp (A) Increase in Murphree plate efficiency (B) Decrease in pressure drop (C) Decrease in liquid hold up in the column (D) Increase in pressure drop

Description : Flooding in a distillation column is detected by a sharp (A) Increase in Murphree plate efficiency (B) Decrease in pressure drop (C) Decrease in liquid hold up in the column (D) Increase in pressure drop

Last Answer : (D) Increase in pressure drop

Channelling is most severe (A) In towers packed with stacked packing (B) In towers packed randomly with crushed solids (C) In dumped packing of regular units

Description : Channelling is most severe (A) In towers packed with stacked packing (B) In towers packed randomly with crushed solids (C) In dumped packing of regular units

Last Answer : (A) In towers packed with stacked packing

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

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

Which of the following same diameter columns gives lowest pressure drop per unit height? (A) Bubble-cap column (B) Sieve-plate column (C) Packed column (stacked)

Description : Which of the following same diameter columns gives lowest pressure drop per unit height? (A) Bubble-cap column (B) Sieve-plate column (C) Packed column (stacked)

Last Answer : (C) Packed column (stacked)

Which of these columns incurs the lowest pressure drop? (A) Packed column (with stacked packing) (B) Packed column (with dumped packing) (C) Bubble plate column (D) Pulse column

Description : Which of these columns incurs the lowest pressure drop? (A) Packed column (with stacked packing) (B) Packed column (with dumped packing) (C) Bubble plate column (D) Pulse column

Last Answer : (A) Packed column (with stacked packing)

A gas (density = 1.5 kg/m3 , viscosity = 2 × 10 ‒5 kg/m.s) flowing through a packed bed (particle size = 0.5 cm, porosity = 0.5) at a superficial velocity of 2 m/s causes a pressure drop of 8400 Pa/m. The pressure drop for another gas, with density of 1.5 kg/m3and viscosity of 3 × 10 ‒5kg/m.s flowing at 3 m/s will be (A) 8400 Pa/m (B) 12600 Pa/m (C) 18900 Pa/m (D) 16800 Pa/m

Description : A gas (density = 1.5 kg/m3 , viscosity = 2 10 -5 kg/m.s) flowing through a packed bed (particle size = 0.5 cm, porosity = 0.5) at a superficial velocity of 2 m/s causes a pressure drop of 8400 Pa/m. The ... flowing at 3 m/s will be (A) 8400 Pa/m (B) 12600 Pa/m (C) 18900 Pa/m (D) 16800 Pa/m

Last Answer : (B) 12600 Pa/m

Pressure drop in a fluidised bed reactor is __________ that in a similar packed bed reactor. (A) Less than (B) Greater than (C) Same as (D) None of these

Description : Pressure drop in a fluidised bed reactor is __________ that in a similar packed bed reactor. (A) Less than (B) Greater than (C) Same as (D) None of these

Last Answer : (B) Greater than

__________ column is used in gas absorption process. (A) Wetted wall (B) Sieve/perforated tray (C) Bubble cap (D) Packed

Description : __________ column is used in gas absorption process. (A) Wetted wall (B) Sieve/perforated tray (C) Bubble cap (D) Packed

Last Answer : (D) Packed

Absorption factor method is used to calculate the number of ideal stages, when (A) Operating line lies above the equilibrium line (B) Operating line lies below the equilibrium line (C) Both operating and equilibrium lines are parallel (D) Pressure drop in the column is very high

Description : Absorption factor method is used to calculate the number of ideal stages, when (A) Operating line lies above the equilibrium line (B) Operating line lies below the equilibrium line (C) Both operating and equilibrium lines are parallel (D) Pressure drop in the column is very high

Last Answer : (C) Both operating and equilibrium lines are parallel

. The most widely used crude topping column in refineries is the__________ column.(A) Bubble-cap(B) Packed bed(C) Fluidised bed(D) Perforated plate

Description : . The most widely used crude topping column in refineries is the__________ column. (A) Bubble-cap (B) Packed bed (C) Fluidised bed (D) Perforated plate

Last Answer : (A) Bubble-cap

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)

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)

For gas absorption, low viscosity solvents are preferred, because of their (A) Better flow characteristics (B) Low pumping pressure drop (C) Rapid absorption rates(D) All (A), (B) and (C)

Description : For gas absorption, low viscosity solvents are preferred, because of their (A) Better flow characteristics (B) Low pumping pressure drop (C) Rapid absorption rates (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

For liquid flow through a packed bed, the superficial velocity as compared to average velocity through the channel in the bed is (A) More (B) Less (C) Equal (D) Independent of porosity

Description : For liquid flow through a packed bed, the superficial velocity as compared to average velocity through the channel in the bed is (A) More (B) Less (C) Equal (D) Independent of porosity

Last Answer : (B) Less

Pick out the correct statement. (A) Fanning friction factor is inversely proportional to Reynolds number always (B) The property of a randomly packed bed (with raschig rings) is given by the ratio of the total volume to the volume of voids in the bed (C) Mach number in an incompressible fluid is always unity (D) Mach number is given by the ratio of the speed of the fluid to that of sound in the fluid under conditions of flow

Description : Pick out the correct statement. (A) Fanning friction factor is inversely proportional to Reynolds number always (B) The property of a randomly packed bed (with raschig rings) is given by the ratio of the ... the ratio of the speed of the fluid to that of sound in the fluid under conditions of flow

Last Answer : (D) Mach number is given by the ratio of the speed of the fluid to that of sound in the fluid under conditions of flow

Which of the following equations applies to the fluid flow through a packed bed for very large Reynolds number? (A) Fanning equation (B) Blake-Plummer equation (C) Hagen-Poiseuille equation (D) Kozeny-Carman equation

Description : Which of the following equations applies to the fluid flow through a packed bed for very large Reynolds number? (A) Fanning equation (B) Blake-Plummer equation (C) Hagen-Poiseuille equation (D) Kozeny-Carman equation

Last Answer : (B) Blake-Plummer equation

Which of the following equations is valid for laminar flow of a fluid through packed bed? (A) Fanning equation (B) Kozeny - Karman equation (C) Hagen-Poiseuille equation (D) Blake-Plummer equation

Description : Which of the following equations is valid for laminar flow of a fluid through packed bed? (A) Fanning equation (B) Kozeny - Karman equation (C) Hagen-Poiseuille equation (D) Blake-Plummer equation

Last Answer : (B) Kozeny - Karman equation

Fluid flow in a real packed bed can be approximated as __________ model. (A) Plug flow (B) Dispersion (C) Mixed flow (D) Tank in series

Description : Fluid flow in a real packed bed can be approximated as __________ model. (A) Plug flow (B) Dispersion (C) Mixed flow (D) Tank in series

Last Answer : (B) Dispersion

In case of staged packed bed reactors carrying out exothermic reaction, use (A) High recycle for pure gas (B) Plug flow for dilute liquid requiring no large preheating of feed (C) Cold shot operations for a dilute solution requiring large preheating to bring the stream upto the reaction temperature (D) All (A), (B) and (C)

Description : In case of staged packed bed reactors carrying out exothermic reaction, use (A) High recycle for pure gas (B) Plug flow for dilute liquid requiring no large preheating of feed (C) Cold shot operations for a ... preheating to bring the stream upto the reaction temperature (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Inside the distillation column, the (A) Driving force for the vapour flow is the pressure drop (B) Liquids are not always at their bubble points (C) Pressure increases gradually from bottom to the top of the column (D) None of these

Description : Inside the distillation column, the (A) Driving force for the vapour flow is the pressure drop (B) Liquids are not always at their bubble points (C) Pressure increases gradually from bottom to the top of the column (D) None of these

Last Answer : (A) Driving force for the vapour flow is the pressure drop

In an operating distillation column, the (A) Vapors and liquids are at their dew point and bubble point respectively (B) Driving force for the liquid flow is its specific weight (C) Driving force for the vapor flow is the pressure drop, as the pressure decreases gradually from the bottom to the top of the column (D) Highest temperature is encountered at the top of the column

Description : In an operating distillation column, the (A) Vapors and liquids are at their dew point and bubble point respectively (B) Driving force for the liquid flow is its specific weight (C) Driving force for ... bottom to the top of the column (D) Highest temperature is encountered at the top of the column

Last Answer : (C) Driving force for the vapor flow is the pressure drop, as the pressure decreases gradually from the bottom to the top of the column

A packed tower compared to a plate tower for a particular mass transfer operation (A) Incurs smaller pressure drop (B) Allows installation of cooling coils (C) Is less costly when built in large sizes/diameters (D) Is more suitable, if suspended solids are present in fluid stream

Description : A packed tower compared to a plate tower for a particular mass transfer operation (A) Incurs smaller pressure drop (B) Allows installation of cooling coils (C) Is less costly when built in large sizes/diameters (D) Is more suitable, if suspended solids are present in fluid stream

Last Answer : (A) Incurs smaller pressure drop

Under conditions of flooding in packed tower, the gas pressure drop (A) Decreases rapidly (B) Increases rapidly (C) Remain constant (D) Is maximum

Description : Under conditions of flooding in packed tower, the gas pressure drop (A) Decreases rapidly (B) Increases rapidly (C) Remain constant (D) Is maximum

Last Answer : (D) Is maximum

Use of raschig rings in place of crushed stones as packing in packed beds (other things being same) (A) Increases pressure drop, increases surface area (B) Increases pressure drop, decreases surface area (C) Decreases pressure drop, increases surface area (D) Decreases pressure drop, decreases surface area

Description : Use of raschig rings in place of crushed stones as packing in packed beds (other things being same) (A) Increases pressure drop, increases surface area (B) Increases pressure drop, decreases ... (C) Decreases pressure drop, increases surface area (D) Decreases pressure drop, decreases surface area

Last Answer : (C) Decreases pressure drop, increases surface area

Out of the following gas-liquid contacting devices, for a given set of operating conditions, gas pressure drop is the least in __________ tower. (A) Wetted wall (B) Bubble cap (C) Perforated tray (D) Packed

Description : Out of the following gas-liquid contacting devices, for a given set of operating conditions, gas pressure drop is the least in __________ tower. (A) Wetted wall (B) Bubble cap (C) Perforated tray (D) Packed

Last Answer : (A) Wetted wall

The reason for preferring packed towers over plate towers in distillation practice is that the packed tower operation gives (A) Low pressure drop and high hold up (B) High pressure drop and low hold up (C) Low pressure drop and low hold up (D) High pressure drop and high hold up

Description : The reason for preferring packed towers over plate towers in distillation practice is that the packed tower operation gives (A) Low pressure drop and high hold up (B) High pressure drop and low hold ... C) Low pressure drop and low hold up (D) High pressure drop and high hold up

Last Answer : (C) Low pressure drop and low hold up

Pressure drop through plate tower as compared to that through packed tower, for the same duty will be (A) Less (B) More (C) Equal (D) Either (A) or (B); depends on the packing height

Description : Pressure drop through plate tower as compared to that through packed tower, for the same duty will be (A) Less (B) More (C) Equal (D) Either (A) or (B); depends on the packing height

Last Answer : (B) More

Priming of a centrifugal pump is done to (A) Increase the mass flow rate of fluid (B) Develop effective pressure rise by the pump (C) Avoid chances of separation inside the impeller (D) None of these

Description : Priming of a centrifugal pump is done to (A) Increase the mass flow rate of fluid (B) Develop effective pressure rise by the pump (C) Avoid chances of separation inside the impeller (D) None of these

Last Answer : (C) Avoid chances of separation inside the impeller

. If a single tube pass heat exchanger is converted to two pass, then for the same flow rate, the pressure drop per unit length in tube side will (A) Increase by 1.8 times (B) Decrease by 2 2 (C) Increase by 2 16 (D) Remain unchanged

Description : . If a single tube pass heat exchanger is converted to two pass, then for the same flow rate, the pressure drop per unit length in tube side will (A) Increase by 1.8 times (B) Decrease by 2 2 (C) Increase by 2 16 (D) Remain unchanged

Last Answer : (C) Increase by 2 16

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

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

Two fluids are flowing through two similar pipes of the same diameter. The Reynold's number is same. For the same flow rate if the viscosity of a fluid is reduced to half the value of the first fluid, the pressure drop will (A) Increase (B) Decrease (C) Remain unchanged (D) Data insufficient to predict relative pressure drop

Description : Two fluids are flowing through two similar pipes of the same diameter. The Reynold's number is same. For the same flow rate if the viscosity of a fluid is reduced to half the value of the ... (A) Increase (B) Decrease (C) Remain unchanged (D) Data insufficient to predict relative pressure drop

Last Answer : (B) Decrease

Pick out the correct statement. (A) Ponchan-Savarit method is more accurate than McCabe-Thiele method to determine the number of theoretical stages required for the separation of non￾ideal binary system by distillation (B) A sharp decrease in pressure drop is an indication of flooding in a distillation coloumn (C) Solvent used in extractive distillation should be of high volatility (D) Flash distillation is suitable for separating components which have very close boiling temperature

Description : Pick out the correct statement. (A) Ponchan-Savarit method is more accurate than McCabe-Thiele method to determine the number of theoretical stages required for the separation of ... Flash distillation is suitable for separating components which have very close boiling temperature

Last Answer : (A) Ponchan-Savarit method is more accurate than McCabe-Thiele method to determine the number of theoretical stages required for the separation of non￾ideal binary system by distillation

Which one of the following devices is not used for both the absorption as well as the liquid-liquid extraction processes? (A) Packed towers(B) Plate towers(C) Spray towers(D) Wetted wall columns

Description : Which one of the following devices is not used for both the absorption as well as the liquid-liquid extraction processes? (A) Packed towers (B) Plate towers (C) Spray towers (D) Wetted wall columns

Last Answer : (D) Wetted wall columns

To increase the absorption factor, (where, G = gas flow rate, S = solvent flow rate) (A) Increase both 'G' and 'S' (B) Decrease both 'G' and 'S' (C) Increase 'S' and decrease 'G' (D) Increase 'G' and decrease 'S'

Description : To increase the absorption factor, (where, G = gas flow rate, S = solvent flow rate) (A) Increase both 'G' and 'S' (B) Decrease both 'G' and 'S' (C) Increase 'S' and decrease 'G' (D) Increase 'G' and decrease 'S'

Last Answer : (C) Increase 'S' and decrease 'G

Which of the following liquid-vapor contacting devices provides maximum contact surface area for a particular duty? (A) Sieve plate column (B) Bubble cap column (C) Randomly packed column (D) Wetted wall column

Description : Which of the following liquid-vapor contacting devices provides maximum contact surface area for a particular duty? (A) Sieve plate column (B) Bubble cap column (C) Randomly packed column (D) Wetted wall column

Last Answer : (D) Wetted wall column