Duplex feed pumps are used in small steam boilers. These operate on the principle of
Centrifugal pump
Axial flow pump
Gear pump
Reciprocating pump
Correct Answer :
D. Reciprocating pump
Related Questions
The critical pressure ratio for initially dry saturated steam is
0.546
0.577
0.582
0.601
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
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
The diameter of flue tube in a Cornish boiler is _________ that of the shell.
One-fourth
One-third
Two-fifth
Three-fifth
The efficiency of steam turbines may be improved by
Reheating of steam
Regenerative feed heating
Binary vapour plant
Any one of these
The high steam and low water safety valve is used to blow off steam when the
Steam pressure exceeds the working pressure
Water level in the boiler becomes too low
Both (A) and (B)
None of the above
In a Woolf type compound engine, the high pressure and low pressure cylinders
Have common piston rod
Are set at 90°
Have separate piston rod
Are set in V-arrangement
The fire tubes in a Scotch marine boiler are
Horizontal
Vertical
Inclined
None of these
The natural draught is produced by
Steam jet
Centrifugal fan
Chimney
Both (A) and (B)
When the nozzle operates with the maximum mass flow, the nozzle is said to be
Choked
Under-damping
Over-damping
None of these
Natural water circulation, by convection in water tube boilers, with increase in pressure of boiler
Increases
Decreases
Remain unaffected
First increases and then decreases
The fire tubes in a Locomotive boiler has _________ diameter.
4.75 mm
5.47 mm
7.45 mm
47.5 mm
Orsat meter is used for
Gravimetric analysis of the flue gases
Volumetric analysis of the flue gases
Mass flow of the flue gases
Measuring smoke density of flue gases
The working pressure range for a LaMont boiler is
0.5 to 10 MN/m²
1 to 15 MN/m²
2.5 to 15 MN/m²
3.5 to 20 MN/m²
For water, at pressures below atmospheric;
Melting point rises slightly and boiling point drops markedly
Melting point rises markedly and boiling point drops markedly
Melting point drops slightly and boiling point drops markedly
Melting point drops slightly and boiling point drops slightly
The velocity of flue gases (V) through the chimney under a static draught of (H') metres is given by
V = 2g H'
V = 2g/H'
V = H'/2g
V = 2gH'
In a reaction turbine, when steam flows through the fixed blades,
Pressure increases while velocity decreases
Pressure decreases while velocity increases
Pressure and velocity both decreases
Pressure and velocity both increases
The ratio of the useful heat drop to the isentropic heat drop is called
Condenser efficiency
Nozzle efficiency
Boiler efficiency
Vacuum efficiency
In case of non-condensing steam engines, the pressure of steam in the cylinder during exhaust stroke is _________ the condenser pressure.
Equal to
Lower than
Higher than
None of these
The friction present between the steam and the nozzle surfaces reduces the heat drop by
10 to 15 %
15 to 25 %
25 to 40 %
40 to 60 %
The pressure of feed water has to be raised before its entry into the boiler. The pressure is raised by a device known as
Feed pump
Injector
Feed check valve
Pressure gauge
Secondary air is the air used to
Provide air around burners for obtaining optimum combustion
Transport and dry the coal
Convert CO (formed in lower zone of furnace) into CO₂ at higher zone
Air delivered by induced draft fan
Heating of dry steam above saturation temperature is known as
Enthalpy
Superheating
Super saturation
Latent heat
In case of condensing steam engines, the pressure of steam in the cylinder during exhaust stroke is _________ the atmospheric pressure.
Equal to
Lower than
Higher than
None of these
Reheating of steam under ideal conditions takes place at constant
Entropy
Enthalpy
Pressure
Temperature
In a steam engine, superheated steam from the boiler is fed into the steam chest at a pressure of
10 atmospheres
20 atmospheres
30 atmospheres
40 atmospheres
Pick up wrong statement about desired properties of a good fuel
High calorific value
Produce minimum smoke and gases
Ease in storing
High ignition point
The economiser is used in boilers to
Increase thermal efficiency of boiler
Economise on fuel
Extract heat from the exhaust flue gases
Increase flue gas temperature
The feed check valve is used in order to
Regulate flow of boiler water
Check level of water in boiler drum
Recirculate unwanted feed water
Allow high pressure feed water to flow to drum and not allow reverse flow to take place
The basic purpose of drum in boiler is to
Serve as storage of steam
Serve as storage of feed water for water wall
Remove salts from water
Separate steam from water