Related Questions

In a steam engine, superheated steam from the boiler is fed into the steam chest at a pressure of
A 10 atmospheres
B 20 atmospheres
C 30 atmospheres
D 40 atmospheres
One mole feed of a binary mixture of a given composition is flash vaporised at a fixed P and T. If Raoult's law is obeyed, then changing the feed composition would effect
A The product composition but not the fraction vaporised
B The product composition as well as the fraction vaporised
C The fraction vaporised but not the product composition
D Neither the product composition nor the fraction vaporised
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 multieffect system
D Heat transfer co-efficient in a single effect is much lower than that in any effect in a multieffect system
In a single evaporator system, the steam economy __________ by creating vacuum in the evaporator.
A Increases
B Decreases
C Remains constant
D May increase or decrease, depends on the vacuum
An aqueous solution of methanol is to be distilled in a tray column. High pressure steam is available as a source of heat. For a given reflux ratio and overhead composition, two options are being explored; (i) a reboiler is used and (ii) no reboiler is used but steam is fed directly to the bottom of the column. As compared to option (i), in option (ii)
A Less number of trays are required
B Composition of the residue remains unchanged
C More number of trays are required but the residue composition remains unchanged
D More number of trays are required and the residue composition is more dilute in methanol
Steam economy is defined as the amount of evaporation per unit amount of steam used, while the capacity is the total evaporation obtained per hour. Use of multiple effect in evaporation
A Increases capacity
B Increases economy
C Does not affect the capacity
D Both B & C
A uniformly loaded D.C. distributor is fed at both ends with equal voltages. As compared to a similar distributor fed at one end only, the drop at the middle point is
A One-fourth
B One-third
C One-half
D Twice
The ratio of the work-done on the blades per kg of steam to the total energy supplied per stage per kg of steam is called
A Blading efficiency
B Nozzle efficiency
C Stage efficiency
D Mechanical efficiency
For the same heat transfer area and the terminal conditions, the ratio of the capacities of a single effect evaporator to a triple effect evaporator is
A 3
B 0.33
C 1
D 1.33
The refrigeration effect in a dry evaporator compared to flooded evaporator in a similar plant is
A Same
B More
C Less
D More or less depending on ambient conditions

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