The function of injector used in small steam plants is to
Create vacuum in furnace
Create vacuum at turbine exhaust
Pump feed water
Dose chemicals in feed water
Correct Answer :
C. Pump feed water
Related Questions
Which of the following is required for a steam condensing plant?
Condenser
Condensate pump
Air extraction pump
All of these
In forced recirculation type boiler,
Heating takes place at bottom and the water supplied at bottom gets converted into the mixture of steam bubbles and hot water which rise to drum
Water is supplied in drum and through down comers located in atmospheric condition it passes to the water wall and rises to drum in the form of mixture of water and steam
Feed pump is employed to supplement natural circulation in water wall type furnace
Water is converted into steam in one pass without any recirculation
In a reaction turbine, when steam flows through the moving blades,
Pressure increases while velocity decreases
Pressure decreases while velocity increases
Pressure and velocity both decreases
Pressure and velocity both increases
Which of the following statement is wrong?
Locomotive boiler is a water tube boiler
Water tube boilers are internally fired
Lamont boiler is a low pressure water tube boiler
All of the above
For the same length of stroke and speed of crankshaft, the piston speed for a double acting steam engine is _________ the piston speed of single acting steam engine.
Equal to
Twice
Three times
Four times
A turbine is said to have an axial discharge when the steam leaves the blade tip at _________ to the direction of the blade motion.
60°
90°
180°
270°
The diameter of internal flue tubes in a Lancashire boiler compared to its shell is
One-half
One-third
Two-fourth
Two-fifth
The fire tubes in a Cochran boiler usually have _________ diameter.
6.25 mm
62.5 mm
72.5 mm
92.5 mm
The critical pressure ratio is given by (where p₁ = Initial pressure of steam, and p₂ = Pressure of steam at throat or critical pressure)
p₁. p₂
p₁/p₂
p₂/p₁
p₁ + p₂
In a 50% reaction turbine stage, tangential component of absolute velocity at rotor inlet is 537 m/s and the blade velocity is 454 m/s. The power output in kW of steam will be
260 kW
282 kW
296 kW
302 kW
Throttle governing of steam engines is a method of controlling the engine output by varying
Volume of intake steam
Pressure of intake steam
Temperature of intake steam
All of these
The coal requirement per kW hour generation in the thermal power plant is of the order of
0.1 to 0.2 kg
0.2 to 0.4 kg
0.6 to 0.8 kg
1.0 to 1.5 kg
The value of the reheat factor varies from
1.02 to 1.06
1.08 to 1.10
1.2 to 1.6
1.6 to 2
In locomotives, the draught is produced by
Chimney
Induced draft fan
Both combined (A) and (B)
Steam jet draught
Which is not correct statement about pulverised fuel firing?
High burning rate is possible
Heat release can be easily controlled
Fuel burns economically
It is the best technique for burning high ash content fuel having low fusion ash
In a throttling process
Steam temperature remains constant
Steam pressure remains constant
Steam enthalpy remains constant
Steam entropy remains constant
The efficiency of a pressure-velocity compounded impulse turbine is __________ as compared to pressure compounded impulse turbine.
Same
Less
More
None of these
The mechanical draught _________ with the amount of smoke.
Increases
Decreases
Does not effect
None of these
The state of vapour under saturation condition is described by
Pressure alone
Temperature alone
Pressure and temperature
Pressure and dryness fraction
The ratio of the useful heat drop to the isentropic heat drop is called
Condenser efficiency
Nozzle efficiency
Boiler efficiency
Vacuum efficiency
Which of the following statement is correct?
A horizontal steam engine requires less floor area than a vertical steam engine
The steam pressure in the cylinder is not allowed to fall below the atmospheric pressure
The compound steam engines are generally non-condensing steam engines
All of the above
The size of a boiler drum in pulverised fuel fired boiler, as its size and capacity, (steam pressure and flow ratings) increase
Increases
Decreases
Remains unchanged
Increases/decreases depending on steam temperature requirements
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
The numbers of fire tubes in a Cochran boiler are
75
115
165
225
A device used to heat feed water by utilising the heat in me exhaust flue gases before leaving through the chimney, is known as
Economiser
Fusible plug
Superheater
Stop valve
The isentropic enthalpy drop in moving blade is two-third of the isentropic enthalpy drop in fixed blades of a turbine. The degree of reaction will be
0.4
0.56
0.67
1.67
Proximate analysis of fuel is determination of percentage of
Carbon, hydrogen, nitrogen, sulphur, moisture
Fixed carbon, ash, volatile matter, moisture
Higher calorific value
Lower calorific value
In water wall furnace, the heat is transferred to the water walls by
Convection
Radiation
Conduction
Radiation and conduction
The number of flue tubes in Lancashire boiler is
Zero
One
Two
Four
For combustion of a fuel, following is essential
Correct fuel air ratio
Proper ignition temperature
O₂ to support combustion
All the three above