Pick out the wrong statement pertaining to the cooling towers. (A) In case of induced draft cooling tower, the fan is placed at the top of the tower (B) Effectiveness of forced draft cooling tower is reduced by the recirculation of the humid and hot discharged air (C) A natural draft cooling tower is recommended to be used, when the air humidity is low and air temperature is also low (D) Effectiveness of a mechanical draft cooling tower is reduced with increase in air wet-bulb temperature

Pick out the wrong statement pertaining to the cooling towers.

(A) In case of induced draft cooling tower, the fan is placed at the top of the

tower

(B) Effectiveness of forced draft cooling tower is reduced by the

recirculation of the humid and hot discharged air

(C) A natural draft cooling tower is recommended to be used, when the air

humidity is low and air temperature is also low

(D) Effectiveness of a mechanical draft cooling tower is reduced with

increase in air wet-bulb temperature


by

1 Answer

Answer :

(D) Effectiveness of a mechanical draft cooling tower is reduced with

increase in air wet-bulb temperature

by

Related questions

Pick out the wrong statement. (A) Different solids have different equilibrium moisture curves (B) Total condenser or reboiler is considered equivalent to one theoretical plate in McCabe-Thiele method of theoretical plate calculation for distillation column (C) Heat removal load on cooler remains constant, even with increase of the reflux ratio in a distillation column (D) Even a forced draft cooling tower cannot cool water below the wet bulb temperature

Description : Pick out the wrong statement. (A) Different solids have different equilibrium moisture curves (B) Total condenser or reboiler is considered equivalent to one theoretical plate in McCabe-Thiele method of ... (D) Even a forced draft cooling tower cannot cool water below the wet bulb temperature

Last Answer : (C) Heat removal load on cooler remains constant, even with increase of the reflux ratio in a distillation column

When the temperature and humidity of air is low, we usually use __________ draft cooling tower. (A) Natural (B) Forced (C) Induced (D) None of these

Description : When the temperature and humidity of air is low, we usually use __________ draft cooling tower. (A) Natural (B) Forced (C) Induced (D) None of these

Last Answer : (A) Natural

In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the (A) Range is 15°F (B) Approach is 10°F (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the (A) Range is 15°F (B) Approach is 10°F (C) Both (A) & (B) (D) Neither (A) nor (B)

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

In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the (A) Range is 15°F (B) Approach is 10°F (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the (A) Range is 15°F (B) Approach is 10°F (C) Both (A) & (B) (D) Neither (A) nor (B)

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

Pick out the wrong statement. (A) With decrease in feed temperature, the number of plates required for binary distillation decreases for a given ‘L/V’ ratio (B) The extraction per unit of total height for a short packed column is more effective than for a tall column, in case of liquid-liquid extraction(C) Natural draft cooling towers are made of ferroconcrete and its cross￾section is wider at the bottom(D) Vander wall adsorption is also called chemisorption

Description : Pick out the wrong statement. (A) With decrease in feed temperature, the number of plates required for binary distillation decreases for a given L/V' ratio (B) The extraction per unit ... and its cross￾section is wider at the bottom (D) Vander wall adsorption is also called chemisorption

Last Answer : (D) Vander wall adsorption is also called chemisorption

Differentiate induced draft and forced draft cooling towers based on (i) Location of fan (ii) Corrosion of blades (iii) Efficiency (iv) Fan size

Description : Differentiate induced draft and forced draft cooling towers based on (i) Location of fan (ii) Corrosion of blades (iii) Efficiency (iv) Fan size

Last Answer : Differentiate induced draft and forced draft cooling towers based on (i) Location of fan (ii) Corrosion of blades (iii) Efficiency (iv) Fan size

Pick out the wrong statement (A) A horizontal line on the humidity chart indicates the temperature changes at constant molal humidity (B) When water is cooled from 80 to 70°C by exposure to the air with a wet bulb temperature of 60°C, then both the approach & the range would be 10°C (C) For unsaturated air-water vapor mixture at atmospheric conditions, the wet bulb temperature & adiabatic cooling lines are the same (D) Relative saturation of unsaturated mixture of water vapor & air cannot be increased by either reducing the mixture temperature or by increasing the total pressure

Description : Pick out the wrong statement (A) A horizontal line on the humidity chart indicates the temperature changes at constant molal humidity (B) When water is cooled from 80 to 70°C by exposure ... & air cannot be increased by either reducing the mixture temperature or by increasing the total pressure

Last Answer : (D) Relative saturation of unsaturated mixture of water vapor & air cannot be increased by either reducing the mixture temperature or by increasing the total pressure

The most efficient cooling tower out of the following is (A) Induced draft (B) Forced draft (C) Natural draft (D) Atmospheric

Description : The most efficient cooling tower out of the following is (A) Induced draft (B) Forced draft (C) Natural draft (D) Atmospheric

Last Answer : (A) Induced draft

Use of natural draft cooling tower is practised, when the air has low (A) Humidity (B) Temperature (C) Both 'a' & 'b' (D) Neither 'a' nor 'b'

Description : Use of natural draft cooling tower is practised, when the air has low (A) Humidity (B) Temperature (C) Both 'a' & 'b' (D) Neither 'a' nor 'b'

Last Answer : (C) Both 'a' & 'b

Define Forced Draft And Induced Draft Cooling Towers?

Description : Define Forced Draft And Induced Draft Cooling Towers?

Last Answer : If the fan is located at the bottom of the tower and air is blown by the fan up through the descending water it is called as forced draft cooling towers. If the fan is located at the top of the ... on the tower's side and drawn up and discharge through the fan casing, it is called as induced draft.

During sensible heating of humid air (A) Relative humidity increases (B) Dew point remains constant (C) Dry bulb & wet bulb temperature increases (D) Both 'b' & 'c'

Description : During sensible heating of humid air (A) Relative humidity increases (B) Dew point remains constant (C) Dry bulb & wet bulb temperature increases (D) Both 'b' & 'c'

Last Answer : (D) Both 'b' & 'c'

The term "cooling range" in a cooling tower refers to the difference in the temperature of (A) Cold water leaving the tower and the wet bulb temperature of the surrounding air(B) Hot water entering the tower and the wet bulb temperature of thesurrounding air(C) Hot water entering the tower and the cooled water leaving the tower(D) None of these

Description : The term "cooling range" in a cooling tower refers to the difference in the temperature of (A) Cold water leaving the tower and the wet bulb temperature of the surrounding air (B) Hot water entering the ... air (C) Hot water entering the tower and the cooled water leaving the tower (D) None of these

Last Answer : (C) Hot water entering the tower and the cooled water leaving the tower

The term "approach" in a cooling tower refers to the difference in the temperature of the (A) Cold water leaving the tower and the wet bulb temperature of the surrounding air (B) Hot water entering the tower and the wet bulb temperature of the surrounding air (C) Hot water entering and the cooled water leaving the cooling tower (D) None of these

Description : The term "approach" in a cooling tower refers to the difference in the temperature of the (A) Cold water leaving the tower and the wet bulb temperature of the surrounding air (B ... (C) Hot water entering and the cooled water leaving the cooling tower (D) None of these

Last Answer : (A) Cold water leaving the tower and the wet bulb temperature of the surrounding air

What Are The Advantages Of Induced Draft Cooling Tower Over Forced Draft Cooling Tower?

Description : What Are The Advantages Of Induced Draft Cooling Tower Over Forced Draft Cooling Tower?

Last Answer : 1. The outlet water comes in contact with the driest air and warmest water comes in contact with most humid air. 2. The re-circulation is seldom a problem. 3. The first cost is low due to the reduction in pump power consumption.

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

In a furnace employing forced draught as compared to induced draught, (A) Air is sucked in, so air leaks are more and hence the furnace efficiency is reduced (B) The fan operates hot and hence blades are liable to corrosion and erosion (C) Positive pressure exists in the furnace (D) None of these

Description : In a furnace employing forced draught as compared to induced draught, (A) Air is sucked in, so air leaks are more and hence the furnace efficiency is reduced (B) The fan operates hot and hence blades are liable to corrosion and erosion (C) Positive pressure exists in the furnace (D) None of these

Last Answer : (C) Positive pressure exists in the furnace

Flue gas from the heating chamber of byproduct coke ovens is removed by (A) Forced draft fan (B) Induced draft fan (C) Steam ejector (D) Natural draft

Description : Flue gas from the heating chamber of byproduct coke ovens is removed by (A) Forced draft fan (B) Induced draft fan (C) Steam ejector (D) Natural draft

Last Answer : (D) Natural draft

The equipment frequently used for adiabatic humidification-cooling operation with recirculating liquid is (A) Natural draft cooling tower (B) Induced draft cooling tower (C) Spray chamber (D) None of these

Description : The equipment frequently used for adiabatic humidification-cooling operation with recirculating liquid is (A) Natural draft cooling tower (B) Induced draft cooling tower (C) Spray chamber (D) None of these

Last Answer : (C) Spray chamber

During dehumidification of unsaturated air wet bulb temperature & partial pressure of vapor are not constant. However, during evaporative cooling process with recirculated water supply, the __________ remains constant. (A) Wet bulb temperature (B) Partial pressure of water vapor (C) Relative humidity (D) None of these

Description : During dehumidification of unsaturated air wet bulb temperature & partial pressure of vapor are not constant. However, during evaporative cooling process with recirculated water supply, the __________ remains ... pressure of water vapor (C) Relative humidity (D) None of these

Last Answer : (A) Wet bulb temperature

Moist air is cooled along the line of constant __________ , when it is passed over a cold & dry cooling coil, such that no condensation occurs? (A) Enthalpy (B) Relative humidity (C) Wet bulb temperature (D) Dew point temperature

Description : Moist air is cooled along the line of constant __________ , when it is passed over a cold & dry cooling coil, such that no condensation occurs? (A) Enthalpy (B) Relative humidity (C) Wet bulb temperature (D) Dew point temperature

Last Answer : (D) Dew point temperature

__________ remains constant during the adiabatic cooling of moist air. (A) Wet bulb temperature (B) Dry bulb temperature (C) Relative humidity (D) Specific humidity

Description : __________ remains constant during the adiabatic cooling of moist air. (A) Wet bulb temperature (B) Dry bulb temperature (C) Relative humidity (D) Specific humidity

Last Answer : Option A

Can a cooling tower cool water below the wet bulb temperature of inlet air? (A) Yes (B) No (C) Yes; but height of cooling tower will be prohibitively high (D) Yes; but the air flow rate should be excessively high

Description : Can a cooling tower cool water below the wet bulb temperature of inlet air? (A) Yes (B) No (C) Yes; but height of cooling tower will be prohibitively high (D) Yes; but the air flow rate should be excessively high

Last Answer : (B) No

The temperature of water cooled in cooling tower is always __________ temperature of entering air. (A) More than the wet bulb (B) Less than the wet bulb (C) Equal to the wet bulb (D) Equal to the dry bulb

Description : The temperature of water cooled in cooling tower is always __________ temperature of entering air. (A) More than the wet bulb (B) Less than the wet bulb (C) Equal to the wet bulb (D) Equal to the dry bulb

Last Answer : (A) More than the wet bulb

The minimum temperature to which the water can be cooled in a cooling tower is the __________ temperature of air. (A) Ambient (B) Dry bulb (C) Dew point (D) Wet bulb

Description : The minimum temperature to which the water can be cooled in a cooling tower is the __________ temperature of air. (A) Ambient (B) Dry bulb (C) Dew point (D) Wet bulb

Last Answer : C) Dew point

Minimum temperature upto which water can be theoretically cooled down in the cooling tower by evaporative cooling is equal to the __________ temperature of air. (A) Wet bulb (B) Dry bulb (C) Saturation (D) Dew point

Description : Minimum temperature upto which water can be theoretically cooled down in the cooling tower by evaporative cooling is equal to the __________ temperature of air. (A) Wet bulb (B) Dry bulb (C) Saturation (D) Dew point

Last Answer : Option A

In the natural draft cooling tower_________ is not required a) Fan b) tower c) Nozzle d) none of the above

Description : In the natural draft cooling tower_________ is not required a) Fan b) tower c) Nozzle d) none of the above

Last Answer : Fan

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

Design of hyperbolic cooling tower standard for all cooling tower a) Mechanical draft b) Natural draft c) Both a & b d) Neither a & b

Description : Design of hyperbolic cooling tower standard for all cooling tower a) Mechanical draft b) Natural draft c) Both a & b d) Neither a & b

Last Answer : b) Natural draft

Pick out the wrong statement. (A) In case of heat transfer by purely forced convection, GR /Re 2 ≤ 1 (B) The equivalent diameter of heat transfer for a duct of square cross￾section (having each side as 'x') is equal to 4x (C) Distillation process is not the same as evaporation (D) The effectiveness of nucleate boiling depends basically on the ease with which the bubbles are formed and detached from the heating surface

Description : Pick out the wrong statement. (A) In case of heat transfer by purely forced convection, GR /Re 2 ≤ 1 (B) The equivalent diameter of heat transfer for a duct of ... nucleate boiling depends basically on the ease with which the bubbles are formed and detached from the heating surface

Last Answer : (B) The equivalent diameter of heat transfer for a duct of square cross￾section (having each side as 'x') is equal to 4x

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 cooling effect in a cooling tower cannot be increased by (A) Increasing the air velocity over the wet surfaces (B) Reducing the humidity of entering air (C) Lowering the barometric pressure (D) None of these

Description : The cooling effect in a cooling tower cannot be increased by (A) Increasing the air velocity over the wet surfaces (B) Reducing the humidity of entering air (C) Lowering the barometric pressure (D) None of these

Last Answer : (D) None of these

The cooling effect in a cooling tower can be speeded up by (A) Increasing the air velocity and area of exposed wet surface (B) Reducing the barometric pressure (C) Reducing the humidity of the air (D) All (A), (B) and (C)

Description : The cooling effect in a cooling tower can be speeded up by (A) Increasing the air velocity and area of exposed wet surface (B) Reducing the barometric pressure (C) Reducing the humidity of the air (D) All (A), (B) and (C)

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

Forced recirculation of furnace gases is practised (A) To increase heat transfer by convection (B) To ensure uniform temperature (C) In furnaces, operating below 750°C (D) All (A), (B) and (C)

Description : Forced recirculation of furnace gases is practised (A) To increase heat transfer by convection (B) To ensure uniform temperature (C) In furnaces, operating below 750°C (D) All (A), (B) and (C)

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

. Most cooling towers are capacity rated at a "standard" wet bulb temperature of ___of • 72°F • 52°F • 78°F • 75°F

Description : . Most cooling towers are capacity rated at a "standard" wet bulb temperature of ___of • 72°F • 52°F • 78°F • 75°F

Last Answer : 78°F

Hyperbolic cooling towers are also referred as a. Natural draft towers b. Cross flow towers c. Hyperboloid towers d. None of the above

Description : Hyperbolic cooling towers are also referred as a. Natural draft towers b. Cross flow towers c. Hyperboloid towers d. None of the above

Last Answer : Hyperboloid towers

In which system is Cooling of hot water is done on tray as step by? a) Mechanical draught cooling system b) Hyperbolic cooling tower c) Atmospheric cooling tower d) Wet cooling tower

Description : In which system is Cooling of hot water is done on tray as step by? a) Mechanical draught cooling system b) Hyperbolic cooling tower c) Atmospheric cooling tower d) Wet cooling tower

Last Answer : Atmospheric cooling tower

In which system is Cooling of hot water is done on tray as step by? a. Mechanical draught cooling system b. Hyperbolic cooling tower c. Atmospheric cooling tower d. Wet cooling tower

Description : In which system is Cooling of hot water is done on tray as step by? a. Mechanical draught cooling system b. Hyperbolic cooling tower c. Atmospheric cooling tower d. Wet cooling tower

Last Answer : Atmospheric cooling tower

. In which system is Cooling of hot water is done on tray as step by? a) Mechanical draught cooling system b) Hyperbolic cooling tower c) Atmospheric cooling tower d) Wet cooling tower

Description : . In which system is Cooling of hot water is done on tray as step by? a) Mechanical draught cooling system b) Hyperbolic cooling tower c) Atmospheric cooling tower d) Wet cooling tower

Last Answer : Atmospheric cooling tower

Which of the following remains constant during evaporative cooling process with recirculated water supply? (A) Relative humidity (B) Partial pressure of vapour (C) Wet bulb temperature (D) None of these

Description : Which of the following remains constant during evaporative cooling process with recirculated water supply? (A) Relative humidity (B) Partial pressure of vapour (C) Wet bulb temperature (D) None of these

Last Answer : (C) Wet bulb temperature

Which of the following decreases during evaporative cooling process with recirculated water supply? (A) Wet bulb temperature (B) Relative humidity (C) Partial pressure of vapour (D) None of these

Description : Which of the following decreases during evaporative cooling process with recirculated water supply? (A) Wet bulb temperature (B) Relative humidity (C) Partial pressure of vapour (D) None of these

Last Answer : (D) None of these

Which of the following increases during evaporative cooling process with recirculated water supply? (A) Wet bulb temperature (B) Relative humidity (C) Partial pressure of vapour (D) Both (B) and (C)

Description : Which of the following increases during evaporative cooling process with recirculated water supply? (A) Wet bulb temperature (B) Relative humidity (C) Partial pressure of vapour (D) Both (B) and (C)

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

During sensible cooling process (A) Relative humidity decreases (B) Relative humidity increases (C) Wet bulb temperature decreases (D) Both (B) and (C)

Description : During sensible cooling process (A) Relative humidity decreases (B) Relative humidity increases (C) Wet bulb temperature decreases (D) Both (B) and (C)

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

How Mechanical Draft Cooling Towers Are Classified?

Description : How Mechanical Draft Cooling Towers Are Classified?

Last Answer : Mechanical draft cooling tower is classified into three types: 1. Forced draft tower. 2. Induced draft counterflow tower. 3. Induced draft cross flow tower.

In natural draft cooling tower the air flow is obtained by___________ a) Difference in air pressure b) difference in air temperature c) Difference in air speed d) none of the above

Description : In natural draft cooling tower the air flow is obtained by___________ a) Difference in air pressure b) difference in air temperature c) Difference in air speed d) none of the above

Last Answer : Difference in air pressure

Which among the following are the components of natural draft cooling tower a) Supply basin b) reinforced concrete c) Hot water distribution d) none of the above

Description : Which among the following are the components of natural draft cooling tower a) Supply basin b) reinforced concrete c) Hot water distribution d) none of the above

Last Answer : reinforced concrete

Factors affecting cooling of water in a cooling tower are: a. Temperature of air b. Humidity of air c. Temperature of hot air d. All of the above

Description : Factors affecting cooling of water in a cooling tower are: a. Temperature of air b. Humidity of air c. Temperature of hot air d. All of the above

Last Answer : Ans:- d. All of the above

Noise produced by cooling fans (employed in air cooled heat exchangers or cooling tower) is mainly caused due to the turbulence created by blade passage through air. It can be reduced by use of a slower fan (A) With greater number of blades (B) Of increased diameter (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Noise produced by cooling fans (employed in air cooled heat exchangers or cooling tower) is mainly caused due to the turbulence created by blade passage through air. It can be reduced by use of a slower fan (A) With greater ... (B) Of increased diameter (C) Both (A) & (B) (D) Neither (A) nor (B)

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