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

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


by

1 Answer

Answer :

(A) Packing may be crushed due to thermal expansion/contraction of the

components of the equipments

by

Related questions

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

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

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

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

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)

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

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

Disc compensators are provided in large diameter fuel gas carrying pipelines to (A) Keep the pipe in proper orientation (B) Make the pipe joint leak-proof (C) Account for contraction/expansion of pipe due to temperature changes of the surroundings (D) Account for the pressure variation side the pipeline

Description : Disc compensators are provided in large diameter fuel gas carrying pipelines to (A) Keep the pipe in proper orientation (B) Make the pipe joint leak-proof (C) Account for contraction/expansion ... due to temperature changes of the surroundings (D) Account for the pressure variation side the pipeline

Last Answer : (C) Account for contraction/expansion of pipe due to temperature changes of the surroundings

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

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)

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)

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

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

Low viscosity absorbent is preferred for reasons of (A) Rapid absorption rates and good heat transfer characteristics (B) Improved flooding characteristics (C) Low pressure drop on pumping (D) All (A), (B) and (C)

Description : Low viscosity absorbent is preferred for reasons of (A) Rapid absorption rates and good heat transfer characteristics (B) Improved flooding characteristics (C) Low pressure drop on pumping (D) All (A), (B) and (C)

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

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 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

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

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

Due to which of the following reasons the cables should not be operated too hot ? (a) The oil may loose its viscosity and it may start drawing off from higher levels (b) Expansion of the oil may cause the sheath to burst (c) Unequal expansion may create voids in the insulation which will lead to ionization (d) The thermal instability may rise due to the rapid increase of dielectric losses with temperature (e) All of the above

Description : Due to which of the following reasons the cables should not be operated too hot ? (a) The oil may loose its viscosity and it may start drawing off from higher levels (b) Expansion of the ... instability may rise due to the rapid increase of dielectric losses with temperature (e) All of the above

Last Answer : (e) All of the above

A stress which develops within an object when it attempts to expand or contract in response to a temperature changes, but cannot, due to being held rigidly in place.  a. elongation  b. thermal stress  c. expansion contraction  d. thermal expansion

Description : A stress which develops within an object when it attempts to expand or contract in response to a temperature changes, but cannot, due to being held rigidly in place.  a. elongation  b. thermal stress  c. expansion contraction  d. thermal expansion

Last Answer : thermal stress

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

Stacked packing compared to dumped packing (A) Provides poorer contact between the fluids (B) Gives lower pressure drop (C) Both (A) and (B) (D) Gives higher pressure drop

Description : Stacked packing compared to dumped packing (A) Provides poorer contact between the fluids (B) Gives lower pressure drop (C) Both (A) and (B) (D) Gives higher pressure drop

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

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

Flooding in a vapor-liquid contacting equipment occurs in a tray, when the pressure drop through a tray is __________ the liquid head available in the downcomer. (A) Less than (B) More than (C) Same as (D) Very much less

Description : Flooding in a vapor-liquid contacting equipment occurs in a tray, when the pressure drop through a tray is __________ the liquid head available in the downcomer. (A) Less than (B) More than (C) Same as (D) Very much less

Last Answer : (B) More than

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

Minimum possible diameter of a packed column is decided mainly bythe(A) Flooding(B) Gas viscosity(C) Liquid density(D) Liquid hold up

Description : Minimum possible diameter of a packed column is decided mainly bythe (A) Flooding (B) Gas viscosity (C) Liquid density (D) Liquid hold up

Last Answer : (A) Flooding

45 The function of conservator in a transformer is A. To protect against internal fault B. To reduce copper as well as core losses C. To cool the transformer oil D. To take care of the expansion and contraction of transformer oil due to variation of temperature of surroundings

Description : 45 The function of conservator in a transformer is A. To protect against internal fault B. To reduce copper as well as core losses C. To cool the transformer oil D. To take care of the expansion and contraction of transformer oil due to variation of temperature of surroundings

Last Answer : D. To take care of the expansion and contraction of transformer oil due to variation of temperature of surroundings

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

Extremely large or small volumes of fluids are generally best routed through the shell side of a shell and tube heat exchanger, because of the (A) Less corrosion problems (B) Flexibility possible in the baffle arrangement (C) Low pressure drop (D) High heat transfer co-efficient

Description : Extremely large or small volumes of fluids are generally best routed through the shell side of a shell and tube heat exchanger, because of the (A) Less corrosion problems (B) Flexibility possible in the baffle arrangement (C) Low pressure drop (D) High heat transfer co-efficient

Last Answer : (B) Flexibility possible in the baffle arrangement

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

Flooding in a column results due to (A) High pressure drop (B) Low pressure drop (C) Low velocity of the liquid (D) High temperature

Description : Flooding in a column results due to (A) High pressure drop (B) Low pressure drop (C) Low velocity of the liquid (D) High temperature

Last Answer : (A) High pressure drop

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

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)

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

For laminar flow of Newtonian fluids through a circular pipe, for a given pressure drop and length & diameter of pipe, the velocity of fluid is proportional to (where, μ = fluid viscosity ) (A) μ (B) 1/μ (C) √μ (D) 1/√μ

Description : For laminar flow of Newtonian fluids through a circular pipe, for a given pressure drop and length & diameter of pipe, the velocity of fluid is proportional to (where, μ = fluid viscosity ) (A) μ (B) 1/μ (C) √μ (D) 1/√μ

Last Answer : (B) 1/μ

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

Even though bubble cap towers are very effective for humidification operation, they are not used commonly in industries, because of the (A) High evaporation losses of water (B) High pressure drop of the gas (C) Difficulty in its fabrication (D) None of these

Description : Even though bubble cap towers are very effective for humidification operation, they are not used commonly in industries, because of the (A) High evaporation losses of water (B) High pressure drop of the gas (C) Difficulty in its fabrication (D) None of these

Last Answer : (B) High pressure drop of the gas

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

Film boiling is usually not desired in commercial equipments, because (A) The heat transfer rate is low in view of the large temperature drop (B) It is difficult to maintain (C) It is not economic (D) None of these

Description : Film boiling is usually not desired in commercial equipments, because (A) The heat transfer rate is low in view of the large temperature drop (B) It is difficult to maintain (C) It is not economic (D) None of these

Last Answer : (A) The heat transfer rate is low in view of the large temperature drop

Perforated plate towers are unique for solvent extraction because, they provide (A) Higher contact area (B) Better contact of the phase (C) Repeated coalescence & redispersion of the drop phase (D) None of these

Description : Perforated plate towers are unique for solvent extraction because, they provide (A) Higher contact area (B) Better contact of the phase (C) Repeated coalescence & redispersion of the drop phase (D) None of these

Last Answer : (C) Repeated coalescence & redispersion of the drop phase

Solvent extraction is the terminology applied to the liquid-liquid extraction, which is preferred for the separation of the components of liquids, when (A) Extracting solvent is cheaply & abundantly available (B) One of the liquid components is heat sensitive (C) Viscosity of liquid components is very high (D) One of the liquid components has very high affinity towards the solvent

Description : Solvent extraction is the terminology applied to the liquid-liquid extraction, which is preferred for the separation of the components of liquids, when (A) Extracting solvent is cheaply & abundantly available ... very high (D) One of the liquid components has very high affinity towards the solvent

Last Answer : (D) One of the liquid components has very high affinity towards the solvent

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)

How does the flow of air occur in natural draught cooling towers? a) Natural pressure head density between cold outside air and humid inside air b) Variation in pressure of both cold outside air and humid inside air c) Due to the given air vents and vacuum ports d) Because of difference in the volume of both the of airs

Description : How does the flow of air occur in natural draught cooling towers? a) Natural pressure head density between cold outside air and humid inside air b) Variation in pressure of both cold outside air and ... given air vents and vacuum ports d) Because of difference in the volume of both the of airs

Last Answer : Natural pressure head density between cold outside air and humid inside air

How does the flow of air occur in natural draught cooling towers? a) Natural pressure head density between cold outside air and humid inside air b) Variation in pressure of both cold outside air and humid inside air c) Due to the given air vents and vacuum ports d) Because of difference in the volume of both the of airs

Description : How does the flow of air occur in natural draught cooling towers? a) Natural pressure head density between cold outside air and humid inside air b) Variation in pressure of both cold outside air and ... given air vents and vacuum ports d) Because of difference in the volume of both the of airs

Last Answer : Natural pressure head density between cold outside air and humid inside air

Which of the following is an undesirable property of a manometricliquid? (A) Non-sticky & non-corrosive nature (B) High vapour pressure (C) Low viscosity & surface tension (D) Low co-efficient of thermal expansion

Description : Which of the following is an undesirable property of a manometricliquid? (A) Non-sticky & non-corrosive nature (B) High vapour pressure (C) Low viscosity & surface tension (D) Low co-efficient of thermal expansion

Last Answer : (B) High vapour pressure

Use of packed towers for distillation is generally limited to the (A) Small sizes (B) Multi-component distillation (C) High pressure operation (D) Vacuum distillation

Description : Use of packed towers for distillation is generally limited to the (A) Small sizes (B) Multi-component distillation (C) High pressure operation (D) Vacuum distillation

Last Answer : (A) Small sizes

Diffusion co-efficient generally depends upon the temperature, pressure & the nature of the components of the system. Its dimension is not the same as that of the (A) Mass transfer co-efficient (B) Thermal diffusivity (C) Kinematic viscosity (D) Volumetric diffusivity

Description : Diffusion co-efficient generally depends upon the temperature, pressure & the nature of the components of the system. Its dimension is not the same as that of the (A) Mass transfer co-efficient (B) Thermal diffusivity (C) Kinematic viscosity (D) Volumetric diffusivity

Last Answer : (A) Mass transfer co-efficient

Pick out the wrong statement: (A) Change in barometric pressure does not affect the relative humidity (B) In case of a packed tower, the operating velocity is about half of the flooding velocity, generally (C) 'Elution' means the desorption of the adsorbed solute by a solvent (D) The equilibrium moisture content of the solid can be reduced by increasing the absolute humidity

Description : Pick out the wrong statement: (A) Change in barometric pressure does not affect the relative humidity (B) In case of a packed tower, the operating velocity is about half of the ... (D) The equilibrium moisture content of the solid can be reduced by increasing the absolute humidity

Last Answer : (D) The equilibrium moisture content of the solid can be reduced by increasing the absolute humidity

Duriron is (A) Acid resistant, brittle and very hard (B) High silicon iron (C) Prone to breakage due to thermal expansion because of its very high co￾efficient of thermal expansion (D) All (A), (B) and (C)

Description : Duriron is (A) Acid resistant, brittle and very hard (B) High silicon iron (C) Prone to breakage due to thermal expansion because of its very high co￾efficient of thermal expansion (D) All (A), (B) and (C)

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

Which one of the following statements is correct ? (a) Dynamic viscosity is the property of a fluid which is not in motion (b) Surface energy is a fluid property giving rise to the phenomenon of capillarity in water (c) Cavitation results from the action of very high pressure (d) Real fluids have lower viscosity than ideal fluids

Description : Which one of the following statements is correct ? (a) Dynamic viscosity is the property of a fluid which is not in motion (b) Surface energy is a fluid property giving rise to the phenomenon ... results from the action of very high pressure (d) Real fluids have lower viscosity than ideal fluids

Last Answer : (d) Real fluids have lower viscosity than ideal fluids