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

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

1 Answer

Answer :

(B) Dispersion
by

Related questions

For a fluidised bed reactor, the most suitable/relevant model is a __________ model. (A) Tank in series (B) Bubbling bed (C) Plug flow (D) None of these

Description : For a fluidised bed reactor, the most suitable/relevant model is a __________ model. (A) Tank in series (B) Bubbling bed (C) Plug flow (D) None of these

Last Answer : (B) Bubbling bed

The single parameter model proposed for describing non-ideal flow is the __________ model. (A) Tank in series (B) Dispersion (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The single parameter model proposed for describing non-ideal flow is the __________ model. (A) Tank in series (B) Dispersion (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

Pick out the wrong statement. (A) For a first order consecutive reaction, a tubular flow reactor as compared to a stirred tank reactor provides higher overall selectivity(B) For an ideal mixed reactor at steady state, the exit stream has the samecomposition as fluid within the reactor and the space time is equivalent toholding time for constant density system(C) Plug flow reactor (PFR) is always smaller than mixed reactor for allpositive reaction orders for a particular duty(D) Reaction rate does not decrease appreciably as the reaction proceeds incase of an autocatalytic reaction

Description : Pick out the wrong statement. (A) For a first order consecutive reaction, a tubular flow reactor as compared to a stirred tank reactor provides higher overall selectivity(B) For an ideal ... D) Reaction rate does not decrease appreciably as the reaction proceeds in case of an autocatalytic reaction

Last Answer : (A) For a first order consecutive reaction, a tubular flow reactor as compared to a stirred tank reactor provides higher overall selectivity

Pick out the wrong statement. (A) The vessel dispersion number (D/UL) for plug flow and mixed flow approaches zero and infinity respectively (B) Space time in a flow reactor is a measure of its capacity and is equal to the residence time when the density of reaction mixture is constant (C) Mixed reactor is always smaller than the plug flow reactor for all positive reaction orders for a particular duty (D) In an ideal tubular flow reactor, mixing takes place in radial direction and there is no mixing in longitudinal direction

Description : Pick out the wrong statement. (A) The vessel dispersion number (D/UL) for plug flow and mixed flow approaches zero and infinity respectively (B) Space time in a flow reactor is a ... ideal tubular flow reactor, mixing takes place in radial direction and there is no mixing in longitudinal direction

Last Answer : (C) Mixed reactor is always smaller than the plug flow reactor for all positive reaction orders for a particular duty

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

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)

The ratio of Murphree plate efficiency to point efficiency is always > 1 in a __________ flow model. (A) Plug (B) Perfectly mixed (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The ratio of Murphree plate efficiency to point efficiency is always > 1 in a __________ flow model. (A) Plug (B) Perfectly mixed (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (A) Plug

The ratio of Murphree plate efficiency to point efficiency is 1 in a __________ flow model. (A) Plug (B) Perfectly mixed (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The ratio of Murphree plate efficiency to point efficiency is 1 in a __________ flow model. (A) Plug (B) Perfectly mixed (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (B) Perfectly mixed

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

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 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

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

__________ columns are used for liquid dispersion in a continuous gas phase. (A) Packed (B) Pulse (C) Bubble cap (D) Sieve plate

Description : __________ columns are used for liquid dispersion in a continuous gas phase. (A) Packed (B) Pulse (C) Bubble cap (D) Sieve plate

Last Answer : (A) Packed

What is the dispersion number for a plug flow reactor? (A) 0 (B) ∞ (C) 1 (D) -1

Description : What is the dispersion number for a plug flow reactor? (A) 0 (B) ∞ (C) 1 (D) -1

Last Answer : (A) 0

The vessel dispersion number (D/μL) for plug flow is (A) 0 (B) 500 (C) 750 (D) ∞

Description : The vessel dispersion number (D/μL) for plug flow is (A) 0 (B) 500 (C) 750 (D) ∞

Last Answer : (A) 0

Kinetics of a catalytic reaction can be best studied on a/an __________ reactor. (A) Mixed (B) Integral (plug flow) (C) Differential (flow) (D) Either (A), (B) and (C)

Description : Kinetics of a catalytic reaction can be best studied on a/an __________ reactor. (A) Mixed (B) Integral (plug flow) (C) Differential (flow) (D) Either (A), (B) and (C)

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

The size of plug flow reactor (PFR) for all positive reaction orders and for any given duty, is __________ that of mixed reactor. (A) Greater than (B) Equal to (C) Smaller than (D) Unpredictable from the data

Description : The size of plug flow reactor (PFR) for all positive reaction orders and for any given duty, is __________ that of mixed reactor. (A) Greater than (B) Equal to (C) Smaller than (D) Unpredictable from the data

Last Answer : (C) Smaller than

Kinetics of a solid catalysed reaction can best be studied in a __________ reactor. (A) Batch (B) Plug-flow (C) Mixed (D) None of these

Description : Kinetics of a solid catalysed reaction can best be studied in a __________ reactor. (A) Batch (B) Plug-flow (C) Mixed (D) None of these

Last Answer : (C) Mixed

A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system (in SI units) is given below : Δ P/L = 375 × 10 3 VOM + 10.94 × 10 6 V2 OM (SI units) If water is to be used as the fluidising medium, the minimum fluidisation velocity, VOM is (A) 12 mm/s (B) 16 mm/s (C) 24 mm/s (D) 28 mm/s

Description : A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle ... fluidisation velocity, VOM is (A) 12 mm/s (B) 16 mm/s (C) 24 mm/s (D) 28 mm/s

Last Answer : (B) 16 mm/s

A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system (in SI units) is given below: Δ P/L = 375 × 10 3 VOM + 10.94 × 10 6 V2 OM (SI units) If water is to be used as the fluidising medium, in actual operation, the above bed has a height = 1 m. What is the porosity of the fluidised bed? (A) 0.2 (B) 0.5 (C) 0.7 (D) 0.8

Description : A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system ... What is the porosity of the fluidised bed? (A) 0.2 (B) 0.5 (C) 0.7 (D) 0.8

Last Answer : (C) 0.7

In a/an __________ vessel, the fluid enters and leaves following plug flow. (A) Open (B) Closed (C) Open-closed (D) Close-opened

Description : In a/an __________ vessel, the fluid enters and leaves following plug flow. (A) Open (B) Closed (C) Open-closed (D) Close-opened

Last Answer : (B) Closed

Hydrogenation of oil takes place in a/an __________ reactor. (A) Autothermal (B) Trickle bed (C) Plug flow (D) None of these

Description : Hydrogenation of oil takes place in a/an __________ reactor. (A) Autothermal (B) Trickle bed (C) Plug flow (D) None of these

Last Answer : (B) Trickle bed

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

Description : 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

Last Answer : (B) Sharp drop in pressure drop

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

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

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

Which of the following equipments is not used for liquid dispersion? (A) Wetted wall towers (B) Packed towers (C) Venturi scrubbers (D) Agitated vessels

Description : Which of the following equipments is not used for liquid dispersion? (A) Wetted wall towers (B) Packed towers (C) Venturi scrubbers (D) Agitated vessels

Last Answer : (D) Agitated vessels

Which of the following equipments is used for liquid dispersion? (A) Packed column (B) Venturi scrubber (C) Bubble cap plate column (D) Wetted wall column

Description : Which of the following equipments is used for liquid dispersion? (A) Packed column (B) Venturi scrubber (C) Bubble cap plate column (D) Wetted wall column

Last Answer : Option B

N' plug flow reactors in series with a total volume 'V' gives the same conversion as a single plug flow reactor of volume 'V' for __________ order reactions. (A) First (B) Second (C) Third (D) Any

Description : N' plug flow reactors in series with a total volume 'V' gives the same conversion as a single plug flow reactor of volume 'V' for __________ order reactions. (A) First (B) Second (C) Third (D) Any

Last Answer : (D) Any

For nearly isothermal operation involving large reaction time in a liquid-phase reaction, the most suitable reactor is a __________ reactor. (A) Stirred tank (B) Tubular flow (C) Batch (D) Fixed bed

Description : For nearly isothermal operation involving large reaction time in a liquid-phase reaction, the most suitable reactor is a __________ reactor. (A) Stirred tank (B) Tubular flow (C) Batch (D) Fixed bed

Last Answer : (A) Stirred tank

A backmix reactor (A) Is same as plug-flow reactor (B) Is same as ideal stirred tank reactor (C) Employs mixing in axial direction only (D) Is most suitable for gas phase reaction

Description : A backmix reactor (A) Is same as plug-flow reactor (B) Is same as ideal stirred tank reactor (C) Employs mixing in axial direction only (D) Is most suitable for gas phase reaction

Last Answer : (B) Is same as ideal stirred tank reactor

A back mix reactor is (A) Suitable for gas phase reactions (B) Ideal at very low conversion (C) Same as plug flow reactor (PFR) (D) Same as ideal stirred tank reactor

Description : A back mix reactor is (A) Suitable for gas phase reactions (B) Ideal at very low conversion (C) Same as plug flow reactor (PFR) (D) Same as ideal stirred tank reactor

Last Answer : (D) Same as ideal stirred tank reactor

Statistics question: a binomial model can be approximated with what other model?

Description : Statistics question: a binomial model can be approximated with what other model?

Last Answer : Normal distribution?

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

Pick out the wrong statement. (A) The integral method of analysing kinetic data is used when the data is scattered (B) The differential method of analysing kinetic data requires more accurate or larger amounts of data (C) When the reaction rate is independent of temperature, the reaction is said to be of zero order (D) The ratio of volumes of plug flow reactor to that of mixed reactor is always less than one for identical feed composition, flow rate, conversion and for all positive reaction orders

Description : Pick out the wrong statement. (A) The integral method of analysing kinetic data is used when the data is scattered (B) The differential method of analysing kinetic data requires more accurate ... less than one for identical feed composition, flow rate, conversion and for all positive reaction orders

Last Answer : (C) When the reaction rate is independent of temperature, the reaction is said to be of zero order

With increase in the order of reaction (for all positive reaction orders), the ratio of the volume of mixed reactor to the volume of plug flow reactor (for identical feed composition, flow rate and conversion). (A) Increases (B) Decreases (C) Remain same (D) Increases linearly

Description : With increase in the order of reaction (for all positive reaction orders), the ratio of the volume of mixed reactor to the volume of plug flow reactor (for identical feed composition, flow rate and conversion). (A) Increases (B) Decreases (C) Remain same (D) Increases linearly

Last Answer : (A) Increases

For all positive reaction orders for a particular duty, (A) Mixed reactor is always larger than the plug-flow reactor (B) Ratio of the volume of the mixed reactor to that of the plug-flow reactor decreases with order (C) Reactor size is independent of the type of flow (D) Density variation during reaction affects design

Description : For all positive reaction orders for a particular duty, (A) Mixed reactor is always larger than the plug-flow reactor (B) Ratio of the volume of the mixed reactor to that of the plug-flow ... (C) Reactor size is independent of the type of flow (D) Density variation during reaction affects design

Last Answer : (A) Mixed reactor is always larger than the plug-flow reactor

Pick out the wrong statement: (A) Chemical reactions with high activation energy are very temperature sensitive (B) A flat velocity profile exists in a plug flow reactor (C) The residence time for all the elements of fluid in case of a P.F.R. need not be same (D) Half life of a reaction increases with increased initial concentration for reaction orders more than one

Description : Pick out the wrong statement: (A) Chemical reactions with high activation energy are very temperature sensitive (B) A flat velocity profile exists in a plug flow reactor (C) The residence ... D) Half life of a reaction increases with increased initial concentration for reaction orders more than one

Last Answer : (C) The residence time for all the elements of fluid in case of a P.F.R. need not be same

Which of the following is the most suitable for isothermal operation? (A) Batch reactor (B) Back-mix reactor (C) Plug-flow reactor (D) Fixed bed reactor

Description : Which of the following is the most suitable for isothermal operation? (A) Batch reactor (B) Back-mix reactor (C) Plug-flow reactor (D) Fixed bed reactor

Last Answer : (B) Back-mix reactor

Which of the following will give maximum gas conversion? (A) Fixed bed reactor (B) Fluidised bed reactor (C) Semi-fluidised bed reactor (D) Plug-flow catalytic reactor

Description : Which of the following will give maximum gas conversion? (A) Fixed bed reactor (B) Fluidised bed reactor (C) Semi-fluidised bed reactor (D) Plug-flow catalytic reactor

Last Answer : (C) Semi-fluidised bed reactor

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 equipments is not used in liquid-liquid extraction? (A) Pachuka tank (B) Agitated vessels (C) Centrifugal extractors (D) Packed towers

Description : Which of the following equipments is not used in liquid-liquid extraction? (A) Pachuka tank (B) Agitated vessels (C) Centrifugal extractors (D) Packed towers

Last Answer : (A) Pachuka tank

Exothermic reactions are best carried out in (A) A CSTR (B) CSTR in series (C) A plug flow reactor followed by CSTR (D) CSTR followed by a plug flow reactor

Description : Exothermic reactions are best carried out in (A) A CSTR (B) CSTR in series (C) A plug flow reactor followed by CSTR (D) CSTR followed by a plug flow reactor

Last Answer : (D) CSTR followed by a plug flow reactor

Backmixing is most predominant in (A) A well stirred batch reactor (B) A plug-flow reactor (C) A single CSTR (D) CSTR's connected in series

Description : Backmixing is most predominant in (A) A well stirred batch reactor (B) A plug-flow reactor (C) A single CSTR (D) CSTR's connected in series

Last Answer : (C) A single CSTR

The most unsuitable reactor for carrying out reactions in which high reactant concentration favours high yields is (A) Backmix reactor (B) Plug flow reactor (C) Series of CSTR (D) PFR in series

Description : The most unsuitable reactor for carrying out reactions in which high reactant concentration favours high yields is (A) Backmix reactor (B) Plug flow reactor (C) Series of CSTR (D) PFR in series

Last Answer : A) Backmix reactor

For series reaction, the relative yield (A) Is always greater for plug-flow reactor than for the single CSTR of the same volume (B) Statement in (A) is wrong (C) Decreases with increasing conversion (D) Both (A) and (C) hold good

Description : For series reaction, the relative yield (A) Is always greater for plug-flow reactor than for the single CSTR of the same volume (B) Statement in (A) is wrong (C) Decreases with increasing conversion (D) Both (A) and (C) hold good

Last Answer : (D) Both (A) and (C) hold good

For identical flow rate and feed composition, X plug flow reactors (PER) in series with a total volume V gives the same conversion as single (A) CSTR of volume V (B) PFR of volume V (C) CSTR of volume V/X (D) PFR of volume V/X

Description : For identical flow rate and feed composition, X plug flow reactors (PER) in series with a total volume V gives the same conversion as single (A) CSTR of volume V (B) PFR of volume V (C) CSTR of volume V/X (D) PFR of volume V/X

Last Answer : (B) PFR of volume V

Autocatalytic reactions are best carried out in a (A) CSTR (B) CSTR in series (C) Plug flow reactor (D) Recycle reactor

Description : Autocatalytic reactions are best carried out in a (A) CSTR (B) CSTR in series (C) Plug flow reactor (D) Recycle reactor

Last Answer : (D) Recycle reactor