The enthalpy of vaporization is minimum at
Absolute zero
373oK
Critical temperature
Triple point
Which aspect is not true in the context of latent heat?
No change in temperature during supply of latent heat
Its value increases with increase in temperature and pressure
For water evaporating at atmospheric pressure, its value is about 540 kcal/kg
At critical pressure and temperature conditions, the enthalpy of vaporization has a minimum value
Dryness fraction of a steam is given by
Where ms is the mass of dry steam in a certain mass of wet steam and mw is the mass of water vapour in suspension in the same mass of wet steam
At any point under the dome of temperature entropy plot, the quality of steam is
Less than 50%
Between 0 and 100%
Steam is superheated
Unpredictable
Which is not the advantage of water tube boiler in comparison to fire tube boiler?
High evaporation rate
Less immume to failure in feed water supply
Easy transport and quick erection at site
All parts easily accessible for cleaning, inspection and repairing
Which aspect is not true in the context of superheaters?
Heat of combustion gases is transferred to surface of superheaters by convention, radiation or both
Superheaters mainly follow a counter flow arrangement
Interdeck superheaters are placed between the bank or row of water tubes
Superheaters are essentially coil pipes made from stainless steel
Circulation of water is by natural convention currents in
Lamont boiler
Benson boiler
Velox boiler
Babcock-wilcox boiler
Forced circulation of water takes place in
Locomotive boiler
Lamont boiler
Babcock-wilcox boiler
Stirling boiler
Which of the following high pressure boiler has the unique characteristic of absence of steam separating drum?
Lamont boiler
Benson boiler
Velox boiler
Loeffler boiler
Which of the following is a once through boiler?
Lancashire boiler
Velox boiler
Benson boiler
Babcock-wilcox boiler
Once-through boiler is named as such because
Flue gas passes only in one direction
Steam is sent out only in one direction
Air is sent through the same direction
There is no recirculation of water
Once-through boilers will not have
Drums, headers and pumps
Drums, steam separators and pumps
Drums, headers and steam separators
Drums, headers, steam separators and pumps
Benson boiler is one of the high pressure boilers having
One drum
One water drum and one steam drum
Three drum
No drum
Match list I and list II and select the correct answer using the codes given below the lists:
List I
(Types of boiler)List II
(Classification of boiler)babcock and Wilcox
Lancashire
Lamont
Cochran 1.forced circulation
2.fire tube
3.water tube
4.vertical
(A,1), (B,2), (C,3), (D,4)
(A,3), (B,2), (C,1), (D,4)
(A,2), (B,3), (C,1), (D,3)
(A,2), (B,4), (C,1), (D,3)
A supercritical boiler has a pressure range of
50-100 bar
100-150 bar
150-200 bar
225-250 bar