The diameter of Cornish boiler varies from
0.5 to 1 m
1 to 2 m
1.25 to 2.5 m
2 to 3 m
Correct Answer :
B. 1 to 2 m
Related Questions
Steam in water tube boiler as compared to fire tube boiler
Can be raised rapidly
Is raised at slower rate
Is raised at same rate
Could be raised at fast/slow rate depending on design
The overall efficiency of thermal power plant is
Boiler efficiency, turbine efficiency, generator efficiency
All the three above plus gas cycle efficiency
Carnot cycle efficiency
Regenerative cycle efficiency
A steam turbine, in which a part of the steam after partial expansion, is used for process heating and the remaining steam is further expanded for power generation, is known as
Back pressure turbine
Pass out turbine
Low pressure turbine
Impulse turbine
Fire tube boilers are limited to a maximum design working pressure of
1 kg/cm
6 kg/cm
17 kg/cm²
100 kg/cm²
The water tubes in a Babcock and Wilcox boiler are
Horizontal
Vertical
Inclined
Horizontal and inclined
The turbine blades are
Straight
Circular
Curved
None of these
The critical pressure ratio for initially superheated steam is __________ as compared to initially dry saturated steam.
More
Less
Same
None of these
Which of the following is required for a steam condensing plant?
Condenser
Condensate pump
Air extraction pump
All of these
There is always some steam left in the clearance space from the previous stroke. This steam left in the clearance space is called
Wet steam
Saturated steam
Superheated steam
Cushion steam
The high pressure and low pressure cylinders in a receiver type compound engine are regarded as having cranks
180° to each other
90° to each other
0° to each other
None of these
Which type of boiler can meet rapid changes of load?
Vertical fire tube type
Horizontal fire tube type
Horizontal water tube type
Forced circulation type
The mechanical draught _________ with the amount of smoke.
Increases
Decreases
Does not effect
None of these
The critical pressure ratio for initially dry saturated steam is
0.546
0.577
0.582
0.601
Coke is produced by
Pulverising coal in inert atmosphere
Heating wood in a limited supply of air at temperatures below 300°C
Strongly heating coal continuously for about 48 hours in the absence of air in a closed vessel
Enriching carbon in the coal
Calorific value of coal is of the order of
200-400 kcal/ kg
800-1200 kcal/ kg
2000-4000 kcal/ kg
5000-8000 kcal/ kg
Heating wet steam at constant temperature is heating it at constant
Volume
Pressure
Entropy
Enthalpy
De-Laval turbines are mostly used
Where low speeds are required
For small power purposes and low speeds
For large power purposes
For small power purposes and high speeds
An air preheater is installed
Before the economiser
Before the superheater
Between the economiser and chimney
None of these
Adiabatic process is
Essentially an isentropic process
Non-heat transfer process
Reversible process
Constant temperature process
Parson's turbine is a
Simple impulse turbine
Simple reaction turbine
Impulse-reaction turbine
None of these
Boiler parameters are expressed by
Tonnes/hr. of steam
Pressure of steam in kg/cm²
Temperature of steam in °C
All of the above
A nozzle is said to be a convergent nozzle
When the cross-section of the nozzle increases continuously from entrance to exit
When the cross-section of the nozzle decreases continuously from entrance to exit
When the cross-section of the nozzle first decreases from entrance to throat and then increases from its throat to exit
None of the above
The saturation temperature of steam with increase in pressure increases
Linearly
Rapidly first and then slowly
Slowly first and then rapidly
Inversely
Which is not the correct statement about moisture in coal?
Inherent moisture and surface moisture are different things
In some coals moisture may be present up to 40%
Some moisture in coal helps in better burning which is not possible with completely dry coal
It increases thermal efficiency
The friction in the nozzle __________ exit velocity of steam.
Has no effect on
Decreases
Increases
None of these
The length of shell of a Locomotive boiler is
1 m
2 m
3 m
4 m
Thermal efficiency of well maintained boiler will be of the order
40 %
50 %
75 %
90 %
A device in which some portion of waste heat of flue gases is recovered to heat the air before it passes to the furnace for combustion purpose, is known as
Superheater
Air-preheater
Economiser
Injector
For a Parson's reaction turbine, if α₁ and α₂ are fixed blade angles at inlet and exit respectively and β₁ and β₂ are the moving blade angles at entrance and exit respectively, then
α₁ = α₂ and β₁ = β₂
α₁ = β₁ and α₂= β₂
α₁ < β₁ and α₂ > β₂
α₁ = β₂ and β₁ = α₂
A device used to put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit, is called
Blow off cock
Stop valve
Superheater
None of these