Make up water is supplied during cooling tower operation to
compensate for water losses due to
(A) Evaporation
(B) Blowdown
(C) Entrainment
(D) All (A), (B) & (C)

1 Answer

Answer :

(D) All (A), (B) & (C)

Related questions

Description : Make up water is required in a cooling tower to replace the water lost by (A) Evaporation (B) Drift (C) Blowdown and leakage (D) All (A), (B) and (C)

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

Description : Blowdown in a cooling tower (A) Means discarding a small fraction of circulating water to prevent and limit the concentration of salt and impurities (B) Increases the scale forming tendencies of water (C) Is undesirable (D) All (A), (B) & (C)

Last Answer : (A) Means discarding a small fraction of circulating water to prevent and limit the concentration of salt and impurities

Description : In case of evaporators, liquid entrainment results primarily due to (A) High vacuum in the evaporator (B) High evaporation rate (C) Foaming of the solution (D) High heat transfer rate

Last Answer : (C) Foaming of the solution

Description : Drift in a cooling tower is (A) The water entrained by the circulating air (B) Dependent on the water lost by evaporation (C) Desirable (D) All (A), (B) & (C)

Last Answer : (A) The water entrained by the circulating air

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

Description : Which cooling Towers use a process similar to the one found in small evaporation active cooling units a) hyperbolic b) Tower c) condensate loop d) none of these

Last Answer : a) hyperbolic

Description : Multistage operation (as in the case of catalytic oxidation of SO2 ) is not carried out for NH3 synthesis, because of (A) Comparatively higher pressure drop (B) High cost of the high pressure ... for the reactor (C) Higher pumping cost (D) Chances of entrainment and disturbance of catalyst bed

Last Answer : (B) High cost of the high pressure vessel used for the reactor

Description : Plate efficiency in a distillation column is reduced due to the __________ of liquid. (A) Entrainment (B) Foaming (C) Weeping & dumping (D) All (A), (B) & (C)

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

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

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

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)

Description : The armature cores of the D.C. motors are constructed with laminations to ___________. A. eliminate hysteresis B. minimize brush sparking C. reduce eddy current losses D. compensate for armature reaction

Last Answer : Answer: C

Description : The armature cores of the D.C. motors are constructed with laminations to ___________. A. eliminate hysteresis B. minimize brush sparking C. reduce eddy current losses D. compensate for armature reaction

Last Answer : Answer: C

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

Description : Interception losses are due to (i) Evaporation (ii) Transpiration (iii) Stream flow The correct answer is (A) Only (i) (B) (i) and (ii) (C) (ii) and (iii) (D) (i), (ii) and (iii)

Last Answer : Answer: Option A

Description : During short circuit test iron losses are negligible because A. The current on secondary side is negligible B. The voltage on secondary side does not vary C. The voltage applied on primary side is low D. Full-load current is not supplied to the transformer

Last Answer : C) the voltage applied on primary side is low

Description : During short circuit test iron losses are negligible because A. The current on secondary side is negligible B. The voltage on secondary side does not vary C. The voltage applied on primary side is low D. Full-load current is not supplied to the transformer

Last Answer : C) the voltage applied on primary side is low

Description : Plate efficiency (A) Is a function of the mass transfer between liquid and vapour (B) Increases due to foaming (C) Increases due to liquid entrainment (D) Increases due to weeping and dumping of liquid

Last Answer : (A) Is a function of the mass transfer between liquid and vapour

Description : In a cooling tower, water becomes cool by (A) Loosing sensible heat (B) Heat transfer to surroundings (C) Vaporisation due to heat loss to air (D) Loosing latent heat

Last Answer : (A) Loosing sensible heat

Description : Heat load in a cooling tower (A) Means the amount of heat thrown away (KCal/hr.) by the cooling tower (B) Is equal to the number of kg, of water circulated times the cooling range (C) Both (A) & (B) (D) Neither (A) nor (B)

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

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)

Description : The surface of water in a pond remains cool even on a hot day because 1. water evaporates at the surface and evaporation causes cooling 2. the heat absorbed at the surface is transmitted downwards 3. Water in contact with the bottom ... /are correct? (a) 1 only (b) 3 only (c) 1 and 3 (d) 1, 2 and 3

Last Answer : Ans:(a)

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

Description : What is BlowDown Valve?

Last Answer : Answer: Refers to a plug type disc globe valve used for removing sludge and sedimentary matter from the bottom of boiler drums, vessels, driplegs etc.

Description : 349- Pods, heads or ears & freeseeds, lost during the cutting & conveying operation are called as..... (a) Cylinder loss (b) Walker losses ( rack loss) (c) Shoe losses (d) Gathering loss

Last Answer : (d) Gathering loss

Description : IS there a rule of thumb to estimate the footprint of a cooling tower during design phase?

Last Answer : Over the years, this one has seemed to stand the test of time: Every million Btu/h of tower capacity will require approximately 1000 ft2 of cooling tower basin area.

Description : Evaporation losses depend upon (A) Area of the water surface and depth of the water (B) Nature of precipitation and type of vegetation (C) Humidity and wind velocity (D) All the above

Last Answer : Answer: Option D

Description : The use of pressurized radiator cap is to a) Reduce evaporation loss b) Increase engine operating temperature c) Increase boiling point of water d) Reduce heat losses

Last Answer : ans c

Description : Only small amount of evaporation of water produces large cooling effects because of its (A) Large latent heat (B) Low viscosity (C) Small latent heat (D) None of these

Last Answer : (A) Large latent heat

Description : The outlet temperature of cooling water in a heat exchanger is generally not allowed to exceed above 50°C in industrial practice mainly to avoid (A) Its evaporation loss (B) Excessive corrosion (C) Uneconomic LMTD (D) Decrease in heat exchanger efficiency

Last Answer : (B) Excessive corrosion

Description : . Potable water means the water used for (A) Fire-fighting (B) Cooling (C) Drinking (D) Evaporation to produce steam

Last Answer : (C) Drinking

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

Description : Soil mulch is useful in: (A) Minimize evaporation losses (B) Improving aeration (C) Improving drainage (D) Removing weeds

Last Answer : (A) Minimize evaporation losses

Description : Swenson-Walker crystalliser is a __________ unit. (A) Continuous (B) Batch (C) Semi-batch (D) Cooling (adiabatic)-cum-evaporation

Last Answer : (A) Continuous

Description : What loop of a cooling system is often supplied by sea water?

Last Answer : The primary loop.

Description : To get high tray efficiency (A) Interfacial surface between liquid and gas phase should be large (B) Time of contact between the two phases should be less (C) Gas velocity should be very low (D) Liquid entrainment should be severe

Last Answer : (A) Interfacial surface between liquid and gas phase should be large

Description : Pick out the wrong statement. (A) In solvent extraction, the distribution co-efficient should be as large as possible for solvent economy (B) With increase in pressure, the solubility of ... in distillation column (D) The capacity of a distillation column is maximum at total reflux

Last Answer : (D) The capacity of a distillation column is maximum at total reflux

Description : The separation of liquid droplets from the vapor is done by a/an __________, in the evaporators. (A) Steam ejector (B) Entrainment separator (C) Compressor (D) Vacuum pump

Last Answer : (B) Entrainment separator

Description : In Lurgi coal gasifier, (A) Coking coals cannot be used (B) Low carbon conversion efficiency is achieved (C) Entrainment of solids is higher (D) Larger quantity of coal can be processed

Last Answer : (D) Larger quantity of coal can be processed

Description : Umf is the minimum fluidisation velocity for a bed of particles. An increase in the superficial gas velocity from 2 Umf to 2.5 Umf results in (all velocities are smaller than the entrainment velocity of the particles ... (A) Drag on particles (B) Drag on column walls (C) Bed height (D) Bed voidage

Last Answer : (C) Bed height

Description : In continuous fluidisation (A) Solids are completely entrained (B) The pressure drop is less than that for batch fluidisation (C) There is no entrainment of solids (D) Velocity of the fluid is very small

Last Answer : (A) Solids are completely entrained

Description : In the Lurgi coal gasifier (A) Coking coals cannot be used (B) Low carbon conversion efficiency is achieved (C) Entrainment of solids is higher (D) Large quantity of coal can be processed

Last Answer : (D) Large quantity of coal can be processed

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)

Description : When specifying a cooling tower, should I look up historic wet bulb temperatures for my area or should I take measurements?

Last Answer : If this is a new installation, look up historical wet bulb temperatures for area and be sure to report them to the cooling tower manufacturer as ambient wet bulb temperatures . The ... the tower entrance. The entering wet bulb temperature always higher than the ambient wet bulb temperature.

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

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

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

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

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