Diameter of raschig rings used in packed tower in industry is normally around __________ inches. (A) 2 (B) 8 (C) 12 (D) 18

Diameter of raschig rings used in packed tower in industry is normally

around __________ inches.

(A) 2

(B) 8

(C) 12

(D) 18

by

1 Answer

Answer :

(A) 2


by

Related questions

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

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

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 most common packing used in industrial operations is __________ rings. (A) Raschig (B) Lessing (C) Cross-partition (D) Single spiral

Description : The most common packing used in industrial operations is __________ rings. (A) Raschig (B) Lessing (C) Cross-partition (D) Single spiral

Last Answer : (C) Cross-partition

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

For raschig rings, the sphericity is (A) 0.5 (B) 1 (C) < 1

Description : For raschig rings, the sphericity is (A) 0.5 (B) 1 (C) < 1

Last Answer : (C) < 1

Sphericity is the ratio of the surface area of a spherical particle having the same volume as the particle to the surface area of the particle. Which of the following has the maximum value of sphericity? (A) Sphere(B) Cube(C) Cylinder (L/D = 1)(D) Raschig rings

Description : Sphericity is the ratio of the surface area of a spherical particle having the same volume as the particle to the surface area of the particle. Which of the following has the maximum value of sphericity? (A) Sphere (B) Cube (C) Cylinder (L/D = 1) (D) Raschig rings

Last Answer : (A) Sphere

Which of the following ceramic packing materials is the costliest of all? (A) Berl saddles (B) Raschig rings (C) Pall rings (D) Intalox saddles

Description : Which of the following ceramic packing materials is the costliest of all? (A) Berl saddles (B) Raschig rings (C) Pall rings (D) Intalox saddles

Last Answer : Berl saddles

Diameter to height ratio for a raschig ring is (A) 1 (B) 0.5 (C) 2 (D) 8

Description : Diameter to height ratio for a raschig ring is (A) 1 (B) 0.5 (C) 2 (D) 8

Last Answer : (A) 1

Sphericity of raschig ring (whose length and diameter are equal) is (A) > 1 (B) < 1 (C) 1 (D) 2

Description : Sphericity of raschig ring (whose length and diameter are equal) is (A) > 1 (B) < 1 (C) 1 (D) 2

Last Answer : (C) 1

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)

Hydrogenation of oil is carried out in a/an __________ in Vanaspati manufacturing plant. (A) Agitated vessel (B) Sieve tray column (C) Bubble cap column (D) Packed tower

Description : Hydrogenation of oil is carried out in a/an __________ in Vanaspati manufacturing plant. (A) Agitated vessel (B) Sieve tray column (C) Bubble cap column (D) Packed tower

Last Answer : (A) Agitated vessel

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

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

Sodium bicarbonate is produced during soda ash manufacture using a __________ tower. (A) Plate (B) Baffle (C) Packed (D) None of these

Description : Sodium bicarbonate is produced during soda ash manufacture using a __________ tower. (A) Plate (B) Baffle (C) Packed (D) None of these

Last Answer : (B) Baffle

Operating velocity in a packed tower is usually __________ the flooding velocity. (A) Half (B) Twice (C) Equal to (D) More than

Description : Operating velocity in a packed tower is usually __________ the flooding velocity. (A) Half (B) Twice (C) Equal to (D) More than

Last Answer : (A) Half

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

Packed column distillation is limited to the column __________ metres. (A) Height < 6 (B) Diameter < 0.6 (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Packed column distillation is limited to the column __________ metres. (A) Height < 6 (B) Diameter < 0.6 (C) Both (A) & (B) (D) Neither (A) nor (B)

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

SO3 is absorbed using H2SO4 in a (A) Cast iron packed tower (B) Stainless steel plate tower (C) Packed steel tower lined with acid proof bricks (D) None of these

Description : SO3 is absorbed using H2SO4 in a (A) Cast iron packed tower (B) Stainless steel plate tower (C) Packed steel tower lined with acid proof bricks (D) None of these

Last Answer : (C) Packed steel tower lined with acid proof bricks

Which of the following is the most suitable for extraction in a system having very low density difference? (A) Mixer-settler extractor (B) Centrifugal extractor (C) Pulsed extractor (D) Packed extraction tower

Description : Which of the following is the most suitable for extraction in a system having very low density difference? (A) Mixer-settler extractor (B) Centrifugal extractor (C) Pulsed extractor (D) Packed extraction tower

Last Answer : (B) Centrifugal extractor

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)

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

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

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)

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

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)

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

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

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

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

The distribution of heights of American women aged 18 to 24 is approximately normally distributed with a mean of 65.5 inches and standard deviation of 2.5 inches. Calculate the z-score for a woman six feet tall. a. 2.60 b. 4.11 c. 1.04 d. 1.33

Description : The distribution of heights of American women aged 18 to 24 is approximately normally distributed with a mean of 65.5 inches and standard deviation of 2.5 inches. Calculate the z-score for a woman six feet tall. a. 2.60 b. 4.11 c. 1.04 d. 1.33

Last Answer : a. 2.60

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

Tray spacing in a distillation column of dia 10-12 ft. used in petroleum refinery may be around __________ inches. (A) 5 (B) 30 (C) 60 (D) 100

Description : Tray spacing in a distillation column of dia 10-12 ft. used in petroleum refinery may be around __________ inches. (A) 5 (B) 30 (C) 60 (D) 100

Last Answer : (B) 30

Dynamite is a tool that can be used to cut down trees. To cut a tree 18 inches in diameter requires five sticks of dynamite: one on the north, south, east and west sides of the tree, and the fifth stick on the side to which the tree should fall. During construction of a dam, a tree 18 inches in diameter was completely covered by water. Since the treetop was fouling the boat's propellers, it had to be cut down. A diver went down and put a stick of dynamite on the four sides of the tree. Since the current is flowing south at 2 knots per hour, on which side of the tree would you instruct the diver to put the fifth stick of dynamite if you wanted the tree to fall north? -Riddles

Description : Dynamite is a tool that can be used to cut down trees. To cut a tree 18 inches in diameter requires five sticks of dynamite: one on the north, south, east and west sides of the tree, and the ... you instruct the diver to put the fifth stick of dynamite if you wanted the tree to fall north? -Riddles

Last Answer : It doesn't matter where the fifth stick is placed, since the tree won't fall in any direction. Being wood, it will float and rise to the surface.

If the path of liquid across the plate is very long as in case of large diameter tower, Murphree efficiency can be __________ percent(A) 100(B) > 100(C) < 100(D) None of these

Description : If the path of liquid across the plate is very long as in case of large diameter tower, Murphree efficiency can be __________ percent (A) 100 (B) > 100 (C) < 100 (D) None of these

Last Answer : (B) > 100

Nominal Pipe Size (NPS) of a pipe less than 12 inches in diameter indicates its(A) Inner diameter(B) Outer diameter(C) Thickness(D) Neither inner nor outer diameter

Description : Nominal Pipe Size (NPS) of a pipe less than 12 inches in diameter indicates its (A) Inner diameter (B) Outer diameter (C) Thickness (D) Neither inner nor outer diameter

Last Answer : (D) Neither inner nor outer diameter

Raschig ring made of porcelain cannot be used for treating concentrated (A) Hydrochloric acid (B) Nitric acid (C) Alkalis (D) Sulphuric acid

Description : Raschig ring made of porcelain cannot be used for treating concentrated (A) Hydrochloric acid (B) Nitric acid (C) Alkalis (D) Sulphuric acid

Last Answer : (C) Alkalis

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

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)

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

Ash content in the coke produced from a coking coal having 20% ash may be around __________ percent. (A) 6 (B) 12 (C) 18 (D) 24

Description : Ash content in the coke produced from a coking coal having 20% ash may be around __________ percent. (A) 6 (B) 12 (C) 18 (D) 24

Last Answer : (D) 24

the diameter of a frisbee is 12 inches. what's the area of the frisbee? -General Knowledge

Description : the diameter of a frisbee is 12 inches. what's the area of the frisbee? -General Knowledge

Last Answer : Area of a circle = pi x radius squared. Radius of a Frisbee of diameter 12 in. = 12/2 = 6 ins. Area of Frisbee = 3.14 x (6 x 6) = 3.14 x 36 = 113.04 sq in.

Can the efficiency of a plate in the distillation tower be greater than 100%? (A) Yes (B) Normally not; but is possible if infinite number of plates are put(C) Never(D) Yes; if the reflux ratio is maximum

Description : Can the efficiency of a plate in the distillation tower be greater than 100%? (A) Yes (B) Normally not; but is possible if infinite number of plates are put (C) Never (D) Yes; if the reflux ratio is maximum

Last Answer : (C) Never

What is the minimum overlap required when splicing bracing? a. 300mm (12 inches) b. 400mm (16 inches) c. 600mm (24 inches) d. 450mm (18 inches)

Description : What is the minimum overlap required when splicing bracing? a. 300mm (12 inches) b. 400mm (16 inches) c. 600mm (24 inches) d. 450mm (18 inches)

Last Answer : a. 300mm (12 inches)

Shatter index of metallurgical coke on 2 inches and 0.5 inch screen should be respectively around __________ percent. (A) 80 and 97 (B) 95 and 100 (C) 40 and 70 (D) 25 and 97

Description : Shatter index of metallurgical coke on 2 inches and 0.5 inch screen should be respectively around __________ percent. (A) 80 and 97 (B) 95 and 100 (C) 40 and 70 (D) 25 and 97

Last Answer : (A) 80 and 97

Pressure maintained in the high pressure primary tower of a three stage crude oil distillation system is about __________ kg/cm2 . (A) 1.5 (B) 3 (C) 6 (D) 12

Description : Pressure maintained in the high pressure primary tower of a three stage crude oil distillation system is about __________ kg/cm2 . (A) 1.5 (B) 3 (C) 6 (D) 12

Last Answer : (B) 3

Coking time in narrow by-product coke ovens is around __________ hours. (A) 18 (B) 48 (C) 8 (D) 80

Description : Coking time in narrow by-product coke ovens is around __________ hours. (A) 18 (B) 48 (C) 8 (D) 80

Last Answer : (A) 18

Percentage of alcohol in **** may be around __________ percent. (A) 2-8 (B) 18-23 (C) 27-32 (D) 1-4

Description : Percentage of alcohol in beer may be around __________ percent. (A) 2-8 (B) 18-23 (C) 27-32 (D) 1-4

Last Answer : (A) 2-8

How many cubic inches 3 inch diameter pipe 8 ft long?

Description : How many cubic inches 3 inch diameter pipe 8 ft long?

Last Answer : how many cubic inches in a 3 inch diameter pipe 8 ft long

How many square inches in a 8 inch diameter circle?

Description : How many square inches in a 8 inch diameter circle?

Last Answer : Area = pi*42 = 50.265 square inches to 3 decimal places