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

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

1 Answer

Answer :

(A) Capacity
by

Related questions

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

The amount of water evaporated in kg per kg of fuel burnt in a boiler is called the __________ of a boiler. (A) Evaporative capacity (B) Evaporation efficiency (C) Thermal efficiency (D) Steam load

Description : The amount of water evaporated in kg per kg of fuel burnt in a boiler is called the __________ of a boiler. (A) Evaporative capacity (B) Evaporation efficiency (C) Thermal efficiency (D) Steam load

Last Answer : (A) Evaporative capacity

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

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

The actual temperature drop across the heating surface of an evaporator depends on the (A) Liquid depth over the heating surface (B) Solution being evaporated (C) Pressure difference between the steam chest and the vapor space above the boiling liquid (D) All (A), (B) and (C)

Description : The actual temperature drop across the heating surface of an evaporator depends on the (A) Liquid depth over the heating surface (B) Solution being evaporated (C) Pressure difference between the steam chest and the vapor space above the boiling liquid (D) All (A), (B) and (C)

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

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

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

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)

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

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

. 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

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)

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

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

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

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

Evaporation of 1kg of water from a solution in a single effect evaporator requires about __________ kg of steam. (A) 0.4 - 0.6 (B) 1-1.3 (C) 1.8-2 (D) 2 - 2.4

Description : Evaporation of 1kg of water from a solution in a single effect evaporator requires about __________ kg of steam. (A) 0.4 - 0.6 (B) 1-1.3 (C) 1.8-2 (D) 2 - 2.4

Last Answer : (B) 1-1.3

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

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 actual temperature drop across the heating surface in an evaporator depends on the (A) Feed (B) Depth of liquid over heating surface (C) Pressure difference between steam chest and vapour space (D) All (A), (B) and (C)

Description : The actual temperature drop across the heating surface in an evaporator depends on the (A) Feed (B) Depth of liquid over heating surface (C) Pressure difference between steam chest and vapour space (D) All (A), (B) and (C)

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

Define capacity and economy of evaporator.

Description : Define capacity and economy of evaporator.

Last Answer : The capacity of an evaporator is defined as the number of kilogram of water evaporated per hour. The economy of an evaporator is defined as the number of kilogram of water evaporated per kilogram of steam fed to the evaporator.

In a boiler enthalpy of water supplied was 2000 kJ/kg. Enthalpy being added by fuel combustion is 3200 kJ/kg. Using first law of thermodynamics, find amount of heat supplied if steam generation rate is 10 tons per hour.

Description : In a boiler enthalpy of water supplied was 2000 kJ/kg. Enthalpy being added by fuel combustion is 3200 kJ/kg. Using first law of thermodynamics, find amount of heat supplied if steam generation rate is 10 tons per hour.

Last Answer : Heat supplied Q = m (h2-h1) …….(Steady flow energy equation for boiler) ; h2=3200 KJ/kg h1=2000 KJ/kg m = 10 Tons /hour = (10 x 1000)/3600 kg/sec = 2.77 Kg/sec Q = 2.77(3200-2000) = 3324 KJ/sec heat supplied for 10 Tons/hr steam generation

1 kg of wood contains 15% moisture and 5% hydrogen by weight. How much water is evaporated during complete combustion of 1kg of wood? a) 0.6 kg b) 200 g c) 0.15 kg d) none of the above

Description : 1 kg of wood contains 15% moisture and 5% hydrogen by weight. How much water is evaporated during complete combustion of 1kg of wood? a) 0.6 kg b) 200 g c) 0.15 kg d) none of the above

Last Answer : b)200 g

The distillation carried out in such a way that the liquid with the lowest boiling point is first evaporated and recondensed, then the liquid with the next higher boiling point is then evaporated and recondensed, and so on until all the available liquid fuels are separately recovered in the sequence of their boiling points. Such a process is called  A. cracking  B. carbonisation  C. fractional distillation  D. full distillation

Description : The distillation carried out in such a way that the liquid with the lowest boiling point is first evaporated and recondensed, then the liquid with the next higher boiling point is then evaporated and ... is called  A. cracking  B. carbonisation  C. fractional distillation  D. full distillation

Last Answer : Answer: C

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

Description : 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

Last Answer : (B) Increase the steam economy & the capacity

Steam is routed through the tube in case of a __________ evaporator. (A) Basket type (B) Horizontal tube (C) Short tube vertical (D) Long tube vertica

Description : Steam is routed through the tube in case of a __________ evaporator. (A) Basket type (B) Horizontal tube (C) Short tube vertical (D) Long tube vertica

Last Answer : (B) Horizontal tube

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

Steam side heat transfer co-efficient in an evaporator is in the range of __________ kcal/hr.m2°C. (A) 10-50 (B) 100-500 (C) 1000-1500 (D) 5000-15000

Description : Steam side heat transfer co-efficient in an evaporator is in the range of __________ kcal/hr.m2°C. (A) 10-50 (B) 100-500 (C) 1000-1500 (D) 5000-15000

Last Answer : (D) 5000-15000

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

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

In a single effect evaporator, the economy is (A) 1 (B) < 1 (C) > 1 (D) None of these

Description : In a single effect evaporator, the economy is (A) 1 (B) < 1 (C) > 1 (D) None of these

Last Answer : (B) < 1

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

Which of the following situations can be approximated to a steady state heat transfer system? (A) A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmospheric air at 35°C (B) 10 kg of dry saturated steam at 8 kgf/cm2 flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C (C) Boiling brine kept in open vessel when the bottom surface temperature of the vessel is maintained constant at 180°C (D) A sub-cooled refrigerant liquid at 8°C flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C

Description : Which of the following situations can be approximated to a steady state heat transfer system? (A) A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmospheric air at ... flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C

Last Answer : (B) 10 kg of dry saturated steam at 8 kgf/cm2 flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C

Steam undergoes isentropic expansion in a turbine from 5000 kPa and 400°C (entropy = 6.65 kJ/kg K) to 150 kPa) (entropy of saturated liquid = 1.4336 kJ/kg. K, entropy of saturated vapour = 7.2234 kJ/kg. K) The exit condition of steam is (A) Superheated vapour (B) Partially condensed vapour with quality of 0.9 (C) Saturated vapour (D) Partially condensed vapour with quality of 0.1

Description : Steam undergoes isentropic expansion in a turbine from 5000 kPa and 400°C (entropy = 6.65 kJ/kg K) to 150 kPa) (entropy of saturated liquid = 1.4336 kJ/kg. K, entropy of saturated vapour = 7.2234 ... vapour with quality of 0.9 (C) Saturated vapour (D) Partially condensed vapour with quality of 0.1

Last Answer : (A) Superheated vapour

. An evaporator while concentrating an aqueous solution from 10 to 40% solids evaporates 30000 kg of water. The amount of solids handled by the system in kg is (A) 4000 (B) 9000 (C) 4600 (D) 3000

Description : . An evaporator while concentrating an aqueous solution from 10 to 40% solids evaporates 30000 kg of water. The amount of solids handled by the system in kg is (A) 4000 (B) 9000 (C) 4600 (D) 3000

Last Answer : (A) 4000

Fresh orange juice contains 12% (by weight) solids and the rest water 90% of the fresh juice is sent to an evaporator to remove water and subsequently mixed with the remaining 10% of fresh juice. The resultant product contains 40% solids. The kg of water removed from 1 kg fresh juice is (A) 0.4 (B) 0.5 (C) 0.6 (D) 0.7

Description : Fresh orange juice contains 12% (by weight) solids and the rest water 90% of the fresh juice is sent to an evaporator to remove water and subsequently mixed with the remaining 10% of fresh juice. The resultant product contains 40% solids. ... from 1 kg fresh juice is (A) 0.4 (B) 0.5 (C) 0.6 (D) 0.7

Last Answer : (D) 0.7

It is desired to concentrate a 20% salt solution (20 kg of salt in 100 kg of solution) to a 30% salt solution in an evaporator. Consider a feed of 300 kg/min at 30°C. The boiling point of the solution is 110°C, the latent heat of vaporisation is 2100 kJ/kg and the specific heat of the solution is 4 kJ/kg.K. The rate at which the heat has to be supplied in (kJ/min) to the evaporator is (A) 3.06 × 10 5 (B) 6.12 × 10 5 (C) 7.24 × 10 5 (D) 9.08 × 10

Description : It is desired to concentrate a 20% salt solution (20 kg of salt in 100 kg of solution) to a 30% salt solution in an evaporator. Consider a feed of 300 kg/min at 30°C. The boiling point of the solution is 110°C, the latent heat of ... 3.06 10 5 (B) 6.12 10 5 (C) 7.24 10 5 (D) 9.08 10

Last Answer : (A) 3.06 × 10

Industrial steam generators operate at a steam capacity of? (rra) 1300 kg/s (rrb) 1000 kg/s (rrc) 500 kg/s ( d) 125 kg/s

Description : Industrial steam generators operate at a steam capacity of? (rra) 1300 kg/s (rrb) 1000 kg/s (rrc) 500 kg/s ( d) 125 kg/s

Last Answer : ( d) 125 kg/s

In case of a vertical tube evaporator, with increase in the liquor level, the (A) Capacity of the evaporator is decreased (B) Capacity of the evaporator is increased (C) True temperature drop increases (D) Both (B) and (C)

Description : In case of a vertical tube evaporator, with increase in the liquor level, the (A) Capacity of the evaporator is decreased (B) Capacity of the evaporator is increased (C) True temperature drop increases (D) Both (B) and (C)

Last Answer : (A) Capacity of the evaporator is decreased

Increasing the liquor level in the evaporator results in the (A) Decreased capacity (B) Increase in liquor film co-efficient (C) Decreased effect of hydrostatic head (D) Increased true temperature drop

Description : Increasing the liquor level in the evaporator results in the (A) Decreased capacity (B) Increase in liquor film co-efficient (C) Decreased effect of hydrostatic head (D) Increased true temperature drop

Last Answer : (A) Decreased capacity

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

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

What type of steam is generated by evaporator tube of Lamont boiler ? a. Saturated steam b. Unsaturated steam c. Superheated steam d. Flash steam

Description : What type of steam is generated by evaporator tube of Lamont boiler ? a. Saturated steam b. Unsaturated steam c. Superheated steam d. Flash steam

Last Answer : a. Saturated steam

Through what is feed water from hot-well is passed through, before entering steam and water drum in Lamont boiler? a. Evaporator tubes b. Economizer c. Distributor header d. Circulating pump

Description : Through what is feed water from hot-well is passed through, before entering steam and water drum in Lamont boiler? a. Evaporator tubes b. Economizer c. Distributor header d. Circulating pump

Last Answer : b. Economizer

Molarity is defined as the number of gm moles of solute per __________ of solvent. (A) Litre (B) kg (C) gm (D) c.c

Description : Molarity is defined as the number of gm moles of solute per __________ of solvent. (A) Litre (B) kg (C) gm (D) c.c

Last Answer : (A) Litre

Molality is defined as the number of gm moles of solute per __________ of solvent. (A) Litre (B) gm (C) Kg (D) m

Description : Molality is defined as the number of gm moles of solute per __________ of solvent. (A) Litre (B) gm (C) Kg (D) m

Last Answer : (C) Kg

A vessel with a volume of cubic meter contains liquid water and water vapor ion equilibrium at 600 kPa. The liquid water has mass of1kg. Using the steam table, calculate the mass of the water vapor.  A. 0.99kg  B. 1.57 kg  C. 2.54 kg  D. 3.16 kg Formula: from the steam table at 600kPa vƒ = 0.001101 m^3 / kg vg = 0.3157 m^3 / kg Vtot = mƒ vƒ + mg vg mg = (tot-mƒ vƒ) / vg

Description : A vessel with a volume of cubic meter contains liquid water and water vapor ion equilibrium at 600 kPa. The liquid water has mass of1kg. Using the steam table, calculate the mass of the water vapor.  A. 0.99kg  B. 1.57 kg  C ... / kg vg = 0.3157 m^3 / kg Vtot = mƒ vƒ + mg vg mg = (tot-mƒ vƒ) / vg

Last Answer : 3.16 kg

A 10m^3 vessel initially contains 5 m^3 of liquid water and 5 m^3 of saturated water vapor at 100 kPa. Calculate the internal energy of the system using the steam table.  A. 5 x10^5 kJ  B. 8x10^5 kJ  C. 1 x10^6 kJ  D. 2 x10^6 kJ Formula: fromthe steamtable vƒ = 0.001043 m^3 / kg vg = 1.6940 m^3 / kg u ƒ= 417.3 kJ/kg ug= 2506kJ/kg formula: Mvap = V vap/vg M liq = Vliq/ vƒ u =uƒM liq + ug M vap

Description : A 10m^3 vessel initially contains 5 m^3 of liquid water and 5 m^3 of saturated water vapor at 100 kPa. Calculate the internal energy of the system using the steam table.  A. 5 x10^5 kJ  B. 8x10^5 kJ  C. 1 ... 3 kJ/kg ug= 2506kJ/kg formula: Mvap = V vap/vg M liq = Vliq/ vƒ u =uƒM liq + ug M vap

Last Answer : 2 x10^6 kJ

During conversion of ammonium carbamate into urea, presence of large excess of water (A) Increases the yield of urea (B) Adversely affects the yield of urea (C) Reduces the evaporator load by diluting the urea solution (D) Does not affect the yield of urea

Description : During conversion of ammonium carbamate into urea, presence of large excess of water (A) Increases the yield of urea (B) Adversely affects the yield of urea (C) Reduces the evaporator load by diluting the urea solution (D) Does not affect the yield of urea

Last Answer : (B) Adversely affects the yield of urea