Multiple effect evaporators ar used to (A) Increase the steam economy & decrease the capacity (B) Increase the steam economy & the capacity (C) Decrease the steam economy & the capacity (D) Decrease the steam economy & increase the capacity

Multiple effect evaporators ar used to

(A) Increase the steam economy & decrease the capacity

(B) Increase the steam economy & the capacity

(C) Decrease the steam economy & the capacity

(D) Decrease the steam economy & increase the capacity

by

1 Answer

Answer :

(B) Increase the steam economy & the capacity

by

Related questions

A multiple effect evaporator as compared to a single effect evaporator of the same capacity has (A) Lower heat transfer area (B) Lower steam economy (C) Higher steam economy (D) Higher solute concentration in the product

Description : A multiple effect evaporator as compared to a single effect evaporator of the same capacity has (A) Lower heat transfer area (B) Lower steam economy (C) Higher steam economy (D) Higher solute concentration in the product

Last Answer : (C) Higher steam economy

Pick out the wrong statement. (A) The value of hydrostatic head increases with increase in vacuum in the effect in a multiple effect evaporator system (B) Entering velocity of the liquid in the tubes of natural circulation evaporators is in the range of 0.3 to 0.9 metre/second (C) Duhring's plot is used for calculating the concentration of solution (D) In a multiple effect evaporation system, the number of effects is limited by the total boiling point rise

Description : Pick out the wrong statement. (A) The value of hydrostatic head increases with increase in vacuum in the effect in a multiple effect evaporator system (B) Entering velocity of the liquid in ... a multiple effect evaporation system, the number of effects is limited by the total boiling point rise

Last Answer : (C) Duhring's plot is used for calculating the concentration of solution

Pick out the wrong statement: (A) The capacity of an evaporator is reduced by the boiling point elevation (B) Corrosive liquid is normally passed through the tubes in a shell and tube heat exchanger (C) Steam jet ejector is used for vapor compression in a thermal recompression evaporator (D) Heat sensitive materials should be concentrated in high pressure evaporators

Description : Pick out the wrong statement: (A) The capacity of an evaporator is reduced by the boiling point elevation (B) Corrosive liquid is normally passed through the tubes in a ... recompression evaporator (D) Heat sensitive materials should be concentrated in high pressure evaporators

Last Answer : (D) Heat sensitive materials should be concentrated in high pressure evaporators

In a multiple effect evaporator, the effect of boiling point elevation is to (A) Reduce the capacity (B) Reduce the economy (C) Increase the economy (D) None of these

Description : In a multiple effect evaporator, the effect of boiling point elevation is to (A) Reduce the capacity (B) Reduce the economy (C) Increase the economy (D) None of these

Last Answer : (A) Reduce the capacity

The advantage of backward feed multiple effect evaporators over forward feed units is that (A) Heat sensitive material can be handled (B) There is no additional cost of pumping (C) Most concentrated liquid is at highest temperature (D) Equal heat transfer co-efficients exist in various effects

Description : The advantage of backward feed multiple effect evaporators over forward feed units is that (A) Heat sensitive material can be handled (B) There is no additional cost of pumping ... liquid is at highest temperature (D) Equal heat transfer co-efficients exist in various effects

Last Answer : (C) Most concentrated liquid is at highest temperature

Black liquor generated during paper manufacture is concentrated in a (A) Single effect evaporator (B) Single effect evaporator followed by a crystalliser (C) Multiple effect evaporator (D) Multiple effect evaporators followed by a crystalliser

Description : Black liquor generated during paper manufacture is concentrated in a (A) Single effect evaporator (B) Single effect evaporator followed by a crystalliser (C) Multiple effect evaporator (D) Multiple effect evaporators followed by a crystalliser

Last Answer : (C) Multiple effect evaporator

Multiple effect evaporators are commonly used in the manufacture of P. Paper Q. Superphosphate R. Sugar S. Fats (A) P and Q (B) P and R (C) P and S (D) R and S

Description : Multiple effect evaporators are commonly used in the manufacture of P. Paper Q. Superphosphate R. Sugar S. Fats (A) P and Q (B) P and R (C) P and S (D) R and S

Last Answer : (C) P and S

Reason for operating an evaporator in multiple effects is to secure (A) Increased steam economy (B) Decreased steam consumption (C) Both (A) and (B) (D) Increased capacity

Description : Reason for operating an evaporator in multiple effects is to secure (A) Increased steam economy (B) Decreased steam consumption (C) Both (A) and (B) (D) Increased capacity

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

The capacity of double-effect evaporator is less than half of the capacity of two single effects, each of which is operating over same terminal temperature difference, when the (A) Solution has an elevation of boiling point (B) Evaporators operate under vacuum (C) Evaporators operate at atmospheric pressure (D) None of these

Description : The capacity of double-effect evaporator is less than half of the capacity of two single effects, each of which is operating over same terminal temperature difference, when the (A) Solution has ... B) Evaporators operate under vacuum (C) Evaporators operate at atmospheric pressure (D) None of these

Last Answer : (A) Solution has an elevation of boiling point

A backward feed multiple effect evaporator is better than forward feed for concentrating cold feed, because it provides (A) Higher economy (B) Lower capacity (C) Both (A) & (B) (D) Lower economy

Description : A backward feed multiple effect evaporator is better than forward feed for concentrating cold feed, because it provides (A) Higher economy (B) Lower capacity (C) Both (A) & (B) (D) Lower economy

Last Answer : (A) Higher economy

Multiple effect evaporation accounts for (A) Steam economy (B) Lower operating costs(C) Investment economy(D) None of these

Description : Multiple effect evaporation accounts for (A) Steam economy (B) Lower operating costs (C) Investment economy (D) None of these

Last Answer : (A) Steam economy

Pick out the wrong statement. (A) Economy of a multiple effect evaporator is not influenced by the boiling point elevation (B) Two identical cubes of iron and copper will have the same heat content under the same conditions of temperature (C) Double pipe heat exchangers are mostly used in the field of refrigeration (D) Finned tube heat exchangers are suitable for heating air by steam

Description : Pick out the wrong statement. (A) Economy of a multiple effect evaporator is not influenced by the boiling point elevation (B) Two identical cubes of iron and copper will have the same heat ... in the field of refrigeration (D) Finned tube heat exchangers are suitable for heating air by steam

Last Answer : (B) Two identical cubes of iron and copper will have the same heat content under the same conditions of temperature

Evaporation by thermo compression results in the (A) Saving of steam (B) Realisation of multiple effect economy in a single effect (C) Both (A) and (B) (D) None of these

Description : Evaporation by thermo compression results in the (A) Saving of steam (B) Realisation of multiple effect economy in a single effect (C) Both (A) and (B) (D) None of these

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

In a single evaporator system, the steam economy __________ by creating vacuum in the evaporator. (A) Increases (B) Decreases (C) Remain constant (D) May increase or decrease, depends on the vacuum

Description : In a single evaporator system, the steam economy __________ by creating vacuum in the evaporator. (A) Increases (B) Decreases (C) Remain constant (D) May increase or decrease, depends on the vacuum

Last Answer : (A) Increases

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

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

It is not preferable to use superheated steam in evaporators, because of its very (A) High temperature (B) High pressure (C) Low film co-efficient (D) None of these

Description : It is not preferable to use superheated steam in evaporators, because of its very (A) High temperature (B) High pressure (C) Low film co-efficient (D) None of these

Last Answer : (C) Low film co-efficient

Steam consumption in kg/hr in case of an evaporator is given by (where, C & E are capacity the economy of the evaporator respectively).(A) C/E (B) E/C (C) CE (D) 1/CE

Description : Steam consumption in kg/hr in case of an evaporator is given by (where, C & E are capacity the economy of the evaporator respectively). (A) C/E (B) E/C (C) CE (D) 1/CE

Last Answer : (A) C/E

. In evaporators, lowering the feed temperature (A) Increases the heating area required (B) Reduces the economy (C) Both (A) and (B) (D) Decreases the heating area required

Description : . In evaporators, lowering the feed temperature (A) Increases the heating area required (B) Reduces the economy (C) Both (A) and (B) (D) Decreases the heating area required

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

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 gases in solvent increases at a fixed temperature (C) Decrease in Murphree plate efficiency is an indication of entrainment in distillation column (D) The capacity of a distillation column is maximum at total reflux

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

Economy of an evaporator is influenced by the (A) Steam pressure (B) Feed temperature (C) Number of effect (D) Both (B) & (C)

Description : Economy of an evaporator is influenced by the (A) Steam pressure (B) Feed temperature (C) Number of effect (D) Both (B) & (C)

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

The effect of friction on the flow of steam through a nozzle is to decrease the __________ of steam. (A) Wetness (B) Mass flow rate (C) Both 'a' & 'b' (D) Neither 'a' nor 'b'

Description : The effect of friction on the flow of steam through a nozzle is to decrease the __________ of steam. (A) Wetness (B) Mass flow rate (C) Both 'a' & 'b' (D) Neither 'a' nor 'b'

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

The number of kg vaporised per kg of steam fed to the evaporator is defined as (A) Capacity (B) Rate of evaporation (C) Economy (D) Rate of vaporisation

Description : The number of kg vaporised per kg of steam fed to the evaporator is defined as (A) Capacity (B) Rate of evaporation (C) Economy (D) Rate of vaporisation

Last Answer : (C) Economy

Kg of liquid evaporated per hour in an evaporator is defined as its (A) Capacity (B) Economy (C) Steam load (D) None of these

Description : Kg of liquid evaporated per hour in an evaporator is defined as its (A) Capacity (B) Economy (C) Steam load (D) None of these

Last Answer : (A) Capacity

Pick out the wrong statement. (A) Bubble size increases with the dynamic viscosity of the liquid in case of nucleate pool boiling (B) Thermal conductivity of a dry material is more than that of the damp material (C) Ratio of its capacity to economy equals the steam consumption in kg/hr in an evaporator (D) Vaporisation of organic substances in evaporator mostly causes foam formation

Description : Pick out the wrong statement. (A) Bubble size increases with the dynamic viscosity of the liquid in case of nucleate pool boiling (B) Thermal conductivity of a dry material is more than ... in kg/hr in an evaporator (D) Vaporisation of organic substances in evaporator mostly causes foam formation

Last Answer : (B) Thermal conductivity of a dry material is more than that of the damp material

Viscous & heat sensitive liquids are concentrated in __________ evaporators. (A) Open pan (B) Long tube (C) Agitated film (D) None of these

Description : Viscous & heat sensitive liquids are concentrated in __________ evaporators. (A) Open pan (B) Long tube (C) Agitated film (D) None of these

Last Answer : (C) Agitated film

LMTD for evaporators & condensers for a given terminal parameters & set of conditions for counter-flow is equal to that for parallel flow. In such heat exchangers, with one of the fluids condensing or evaporating, the surface area required is the least in the __________ flow. (A) Parallel (B) Mixed (C) Counter flow (D) Same in either 'a', b' or 'c'

Description : LMTD for evaporators & condensers for a given terminal parameters & set of conditions for counter-flow is equal to that for parallel flow. In such heat exchangers, with one of the fluids condensing or evaporating, the surface ... Parallel (B) Mixed (C) Counter flow (D) Same in either 'a', b' or 'c'

Last Answer : (D) Same in either 'a', b' or 'c'

Forced circulation evaporators are normally used for concentrating liquids having (A) Scaling characteristics (B) High viscosity (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Forced circulation evaporators are normally used for concentrating liquids having (A) Scaling characteristics (B) High viscosity (C) Both (A) & (B) (D) Neither (A) nor (B)

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

Pick out the wrong statement. (A) 'Solvates' are chemical compounds formed by solute with their solvents. When water is the solvent, then it is called a 'hydrate' (B) In heat exchanger calculations (Δt) weighted is used in place of Δt, when it involves more than one sequence of heating or cooling i.e., desuperheating & condensation or condensation & sub-cooling (C) Heat transfer co-efficient during nucleate boiling is not influenced by the agitation imparted (D) In case of short tube vertical evaporators, area of central downtake is about 50 to 100% of the total tube cross-sectional area

Description : Pick out the wrong statement. (A) 'Solvates' are chemical compounds formed by solute with their solvents. When water is the solvent, then it is called a 'hydrate' (B) In heat exchanger ... vertical evaporators, area of central downtake is about 50 to 100% of the total tube cross-sectional area

Last Answer : (C) Heat transfer co-efficient during nucleate boiling is not influenced by the agitation imparted

case of condensers & evaporators operating under given terminal conditions, LMTD (logarithmic mean temperature difference) for counter flow as compared to that for parallel flow is (A) More (B) Less (C) Equal (D) Much more

Description : case of condensers & evaporators operating under given terminal conditions, LMTD (logarithmic mean temperature difference) for counter flow as compared to that for parallel flow is (A) More (B) Less (C) Equal (D) Much more

Last Answer : Option C

What is the steam economy in case of a single effect evaporator system? (A) 1 (B) > 1 (C) < 1 (D) 0.1

Description : What is the steam economy in case of a single effect evaporator system? (A) 1 (B) > 1 (C) < 1 (D) 0.1

Last Answer : (C) < 1

Steam economy in case of a triple effect evaporator will be (A) 1(B) < 1 (C) > 1 (D) Between 0 and 1

Description : Steam economy in case of a triple effect evaporator will be (A) 1 (B) < 1 (C) > 1 (D) Between 0 and 1

Last Answer : (C) > 1

. A dilute aqueous solution is to be concentrated in an evaporator system. High pressure steam is available. Multiple effect evaporator system is employed, because (A) Total heat transfer area of all the effects is -less than that in a single effect evaporator system (B) Total amount of vapor produced per Kg of feed steam in a multiple effect system is much higher than in a single effect (C) Boiling point elevation in a single effect system is much higher than that in any effect in a multi-effect system (D) Heat transfer co-efficient in a single effect is much lower than that in any effect in a multi-effect system

Description : . A dilute aqueous solution is to be concentrated in an evaporator system. High pressure steam is available. Multiple effect evaporator system is employed, because (A) Total heat transfer area of ... in a single effect is much lower than that in any effect in a multi-effect system

Last Answer : (B) Total amount of vapor produced per Kg of feed steam in a multiple effect system is much higher than in a single effect

Vacuum is generally maintained in the vapour space of an evaporator mainly to (A) Get economical temperature difference by using moderate pressure steam (B) Facilitate forward feeding in multiple effect evaporation (C) Concentrate heat sensitive materials (D) Achieve very high concentration of the final product

Description : Vacuum is generally maintained in the vapour space of an evaporator mainly to (A) Get economical temperature difference by using moderate pressure steam (B) Facilitate forward ... (C) Concentrate heat sensitive materials (D) Achieve very high concentration of the final product

Last Answer : (A) Get economical temperature difference by using moderate pressure steam

Small scale evaporation is done in a (A) Heat exchanger (B) Condenser(C) Multiple effect evaporator(D) Steam jacketed kettle

Description : Small scale evaporation is done in a (A) Heat exchanger (B) Condenser (C) Multiple effect evaporator (D) Steam jacketed kettle

Last Answer : (D) Steam jacketed kettle

In a co-current double pipe heat exchanger used for condensing saturated steam over the inner tube, if the entrance and exit conditions of the coolant are interchanged, then the rate of condensation will (A) Increase (B) Decrease (C) Remain unchanged (D) Either increase or decrease; depends on the coolant flow rate

Description : In a co-current double pipe heat exchanger used for condensing saturated steam over the inner tube, if the entrance and exit conditions of the coolant are interchanged, then the rate of condensation ... Decrease (C) Remain unchanged (D) Either increase or decrease; depends on the coolant flow rate

Last Answer : (C) Remain unchanged

Latent heat of dry steam at atmospheric pressure is 539 Kcal/kg; which __________ with increase in the pressure of steam. (A) Decreases (B) Increases (C) Remain same (D) May increase or decrease

Description : Latent heat of dry steam at atmospheric pressure is 539 Kcal/kg; which __________ with increase in the pressure of steam. (A) Decreases (B) Increases (C) Remain same (D) May increase or decrease

Last Answer : (A) Decreases

A steam carrying pipeline is insulated with two layers of insulating materials with the inferior insulation material forming the inner part. If the two insulating layers are interchanged, the heat conducted will (A) Increase (B) Decrease (C) Remain unaffected (D) May increase or decrease; depends on the thickness of each layer

Description : A steam carrying pipeline is insulated with two layers of insulating materials with the inferior insulation material forming the inner part. If the two insulating layers are interchanged, the heat conducted ... ) Remain unaffected (D) May increase or decrease; depends on the thickness of each layer

Last Answer : Option C

Economy of a multiple effect evaporator is not influenced much by the (A) Boiling point elevations (B) Temperature of the feed (C) Rate of heat transfer (D) Ratio of the weight of the thin liquor to thick liquor

Description : Economy of a multiple effect evaporator is not influenced much by the (A) Boiling point elevations (B) Temperature of the feed (C) Rate of heat transfer (D) Ratio of the weight of the thin liquor to thick liquor

Last Answer : (A) Boiling point elevations

Economy of a multiple effect evaporator depends upon the (A) Heat balance consideration (B) Rate of heat transfer (C) Both (A) and (B) (D) Neither (A) nor (B

Description : Economy of a multiple effect evaporator depends upon the (A) Heat balance consideration (B) Rate of heat transfer (C) Both (A) and (B) (D) Neither (A) nor (B

Last Answer : (A) Heat balance consideration

For a cold dilute feed to produce thick viscous liquor, backward feeding as compared to forward feeding results in (A) Increased economy (B) Decreased economy (C) Lower capacity (D) No effect on economy

Description : For a cold dilute feed to produce thick viscous liquor, backward feeding as compared to forward feeding results in (A) Increased economy (B) Decreased economy (C) Lower capacity (D) No effect on economy

Last Answer : (A) Increased economy

A multiple effect evaporator has a capacity to process 4000 kg of solid caustic soda per day, when it is concentrating from 10% to 25% solids. The water evaporated in kg per day is (A) 6000 (B) 24000 (C) 60000 (D) 48000

Description : A multiple effect evaporator has a capacity to process 4000 kg of solid caustic soda per day, when it is concentrating from 10% to 25% solids. The water evaporated in kg per day is (A) 6000 (B) 24000 (C) 60000 (D) 48000

Last Answer : (B) 24000

Optimum number of effects in a multiple effect evaporator is decided by the (A) Cost benefit analysis (B) Floor area availability (C) Terminal parameters (D) Evaporation capacity required

Description : Optimum number of effects in a multiple effect evaporator is decided by the (A) Cost benefit analysis (B) Floor area availability (C) Terminal parameters (D) Evaporation capacity required

Last Answer : (A) Cost benefit analysis

Optimum number of effects in a multiple effect evaporator is decided by the (A) Cost benefit analysis (B) Floor area availability (C) Terminal parameters (D) Evaporation capacity required

Description : Optimum number of effects in a multiple effect evaporator is decided by the (A) Cost benefit analysis (B) Floor area availability (C) Terminal parameters (D) Evaporation capacity required

Last Answer : (A) Cost benefit analysis

Evaporators used in caustic soda recovery and production plant are made of (A) Monel metal(B) Gun metal(C) Wood metal(D) Babbitt metal

Description : Evaporators used in caustic soda recovery and production plant are made of (A) Monel metal (B) Gun metal (C) Wood metal (D) Babbitt metal

Last Answer : (A) Monel metal

Brass tubes are used in the manufacture of tubes of evaporators used in sugar and salt industries, mainly because of its (A) High co-efficient of thermal expansion (B) Low thermal conductivity (C) High corrosion resistance (D) All (A), (B) and (C)

Description : Brass tubes are used in the manufacture of tubes of evaporators used in sugar and salt industries, mainly because of its (A) High co-efficient of thermal expansion (B) Low thermal conductivity (C) High corrosion resistance (D) All (A), (B) and (C)

Last Answer : (C) High corrosion resistance

The type of liquor circulation system to be ' employed in evaporators (viz. natural or forced circulation) is determined mainly by the __________ of the liquid. (A) Viscosity (B) Density (C) Thermal conductivity (D) Corrosive nature

Description : The type of liquor circulation system to be ' employed in evaporators (viz. natural or forced circulation) is determined mainly by the __________ of the liquid. (A) Viscosity (B) Density (C) Thermal conductivity (D) Corrosive nature

Last Answer : (A) Viscosity

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

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

Open pan evaporators are preferred to be used, when the solution to be concentrated is (A) Scaling (B) Highly viscous (C) Corrosive (D) Salty

Description : Open pan evaporators are preferred to be used, when the solution to be concentrated is (A) Scaling (B) Highly viscous (C) Corrosive (D) Salty

Last Answer : (B) Highly viscous

Forced circulation evaporators are useful for the concentration of viscous, salting and scale forming liquors. Which of the following is a forced circulation evaporator? (A) Long vertical evaporator (B) Horizontal tube evaporator (C) Agitated film evaporator (D) Calandria vertical tube evaporator

Description : Forced circulation evaporators are useful for the concentration of viscous, salting and scale forming liquors. Which of the following is a forced circulation evaporator? (A) Long vertical evaporator (B) Horizontal tube evaporator (C) Agitated film evaporator (D) Calandria vertical tube evaporator

Last Answer : (C) Agitated film evaporator

Absorption accompanied by heat evolution results in (A) Increased capacity of the absorber (B) Increase in equilibrium solubility (C) Decrease in equilibrium solubility (D) None of these

Description : Absorption accompanied by heat evolution results in (A) Increased capacity of the absorber (B) Increase in equilibrium solubility (C) Decrease in equilibrium solubility (D) None of these

Last Answer : (C) Decrease in equilibrium solubility