Explore topic-wise InterviewSolutions in .

This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.

1.

What is the main disadvantage of the nuclear weigher?(a) They are not mobile(b) Accuracy depends on speed of material(c) They are big in size, requires large amount of space(d) Consumes large amount of electricityThe question was asked in an internship interview.This is a very interesting question from Coal Weighing Methods in chapter Steam Power Plant of Energy Engineering

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The correct answer is (c) They are big in size, requires LARGE amount of space

Easy explanation: Main disadvantage of the nuclear weighing machine is that its accuracy depends on a CONSISTENT speed of MATERIAL movement and the CONDITION of the detectors since this should be kept clean at all times as otherwise absorption value of gamma-rays will be affected.

2.

What is the purpose of bucket elevators in coal handling?(a) Used to move coal horizontally(b) Used to lift coal vertically(c) Used to separate the crushed coal and pulverized coal(d) Used to pour the coal vertically at right angles into furnaceThe question was asked in quiz.The origin of the question is Stages of Coal Handling topic in division Steam Power Plant of Energy Engineering

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The correct answer is (B) Used to lift coal vertically

Easy explanation: Centrifugal and continuous types of bucket elevators are used for lifting coal to moderate height (about 30m). It consists of BUCKETS fixed to a chain moving over two sprockets. The buckets carry coal from bottom and discharge at the top at a speed ranging between 15 m/min to 36 m/min.

3.

How the oxidation of coal is eliminated?(a) By exposing it to the sunlight(b) By turning the entire coal heap upside down periodically(c) By circulating air uniformly(d) By burning coal at very high temperaturesThe question was asked during a job interview.My question is from Fuel Handling System, Storage of Coal in portion Steam Power Plant of Energy Engineering

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Correct ANSWER is (c) By circulating AIR uniformly

To explain: The heat of oxidation is REMOVED by circulating air uniformly through layers. Air thus circulated carries AWAY the EXCESS heat, maintaining coal below its combustion temperature of 343K. Oxidation can also be avoided by sealing the coal heap asphalt, fine coal dust or bituminous powder.

4.

How does atomization of fuel occur in an atomizing burner of oil burner?(a) High pressure movement of fuels(b) By spraying the fuel at high pressure(c) By impinging two streams of fuel(d) By spark ignition methodThe question was asked in an interview for job.My question is from Fuel Burning Equipments in section Steam Power Plant of Energy Engineering

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The correct answer is (c) By impinging TWO streams of fuel

The explanation is: In the atomizing burner, oil is DELIVERED under pressure through a central TUBE. Steam or air is supplied along the annular space between the oil pipe and the concentric outer tube. NEAR the tip of the BURNERS the two streams impinge resulting in atomization of fuel.

5.

How is pulverization done in bowl mill?(a) By bowl and steel balls(b) By bowl and roller(c) By bowl and impact hammer(d) By bowl and batanThis question was addressed to me in final exam.My question is based upon Pulverised Mills in portion Steam Power Plant of Energy Engineering

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Right choice is (B) By bowl and roller

The explanation is: The bowl mill consists of rollers and power DRIVEN bowl in which PULVERIZATION takes PLACE as the coal passes in between the sides of the bowl and the rollers. The automatic control charges the supply of coal to the bowl.

6.

What decides the efficiency of pulverized fuel firing system?(a) Turbulence of air(b) Size of coal powder(c) Primary air(d) FeederThe question was asked in an internship interview.My doubt stems from Pulverised Fuel Burning topic in division Steam Power Plant of Energy Engineering

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Right choice is (b) Size of coal powder

Explanation: The size coal powder decides the EFFICIENCY of the pulverized fuel firing system. The fineness of the coal should be such as 70%. Of it would PASS through a 200 MESH sieve and 90% through 50 mesh sieve.

7.

Usage of highly preheated secondary air in pulverized fuel firing helps in ______(a) Heats fuel at pace(b) Takes less time to finish the process(c) Rapid flame propagation(d) Reduces the troubles and problems caused in the systemThe question was asked in exam.Question is taken from Pulverised Fuel Burning in division Steam Power Plant of Energy Engineering

Answer» CORRECT answer is (C) Rapid flame propagation

Best explanation: Using highly preheated secondary AIR helps in raid flame propagation. This also increases the ability of system to use HIGH combustion air temperature. The furnace MAKES it possible to complete combustion with minimum travel of flame travel since it is pre-heated.
8.

Which device is used for feeding the fuel automatically to boiler or furnace in power plants?(a) Relay(b) Mechanical stoker(c) Master controller(d) Feed pumpThe question was posed to me during an interview.My question comes from Fuel Burning in section Steam Power Plant of Energy Engineering

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The correct option is (b) Mechanical stoker

Easy EXPLANATION: Mechanical stoker is the DEVICE which automatically FEEDS a solid fuel (such as coal) into combustion chamber of a boiler or furnace, and PROVIDES air for the proper combustion; may INCLUDE a means for automatically removing solid products of combustion.

9.

Which type of furnace cannot be used in the modern era plants?(a) Hand fired furnace(b) Electric arc furnace(c) Solar furnace(d) Central warm air furnaceI got this question in a national level competition.My query is from Fuel Burning in division Steam Power Plant of Energy Engineering

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Correct choice is (a) Hand fired furnace

Explanation: A hand fired furnace is simple in design, but it cannot be used in modern power PLANTS because of its LOWER COMBUSTION efficiency. It does not respond QUICKLY to fluctuating loads and control of DRAUGHT is very difficult.

10.

How much pounds of CO2 is emitted per million BTU (British thermal unit- common thermal unit) when coal is burnt?(a) 139(b) 117(c) 157(d) 205This question was addressed to me during an interview.I'm obligated to ask this question of Fuel Burning in section Steam Power Plant of Energy Engineering

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Right option is (d) 205

Easy explanation: 205 MILLION BTU is the POUNDS of CO2 that is emitted when coal is burnt. The amount of CO2 produced when a fuel is BURNED is a function of carbon content of fuel. The heat content, or the amount of energy produced when a fuel is burned, is mainly DETERMINED by the carbon(C) and hydrogen (H) content of the fuel.

11.

What type of reaction is burning?(a) Endothermic reaction(b) Exothermic reaction(c) Synthesis reaction(d) Decomposition reactionI got this question during an online exam.I need to ask this question from Fuel Burning in section Steam Power Plant of Energy Engineering

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The correct answer is (b) EXOTHERMIC reaction

The explanation is: Burning is an exothermic reaction. A fuel is a STORE of chemical energy that we CONVERT into useful energy to our purposes. For example, we can use the energy stored in NATURAL gas to cook our food. To release this energy, we usually burn the fuel. Burning is a chemical reaction in which the fuel reacts with oxygen gas in air and gives out energy in terms of heat. We call this TYPE of reaction as exothermic reaction.

12.

What does ESP stand for in dust collection?(a) Endothermic sensor plate(b) Extrasensory perception(c) Electrostatic precipitators(d) Electronic stability programI have been asked this question by my school teacher while I was bunking the class.I want to ask this question from Coal Weighing Methods in division Steam Power Plant of Energy Engineering

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Right answer is (c) Electrostatic precipitators

Easy explanation: With stringent air quality restriction by the governments, majority of POWER PLANTS in the WORLD use electrostatic precipitators (ESP’s) for dust removal. An ESP can handle large volumes of flue gases accompanied low pressure DROP and high COLLECTION efficiency (99.5%). It facilitates easy removal of dust particles.

13.

Why are heavy impurities provided in the process of ball and race mill?(a) To resist upward thrust caused by secondary air stream(b) To resist downward thrust caused by primary air stream(c) To resist upward thrust caused by primary air stream(d) To resist downward thrust caused by secondary air streamI had been asked this question during an online interview.I want to ask this question from Pulverised Mills topic in portion Steam Power Plant of Energy Engineering

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Right option is (c) To resist upward thrust CAUSED by PRIMARY air stream

Explanation: The mill is provided with a means of separating heavy impurities from the coal and thus reducing wear and possible damage to the grinding element. These heavy particles resist the upward thrust caused by the primary air stream and COLLECT in a COMPARTMENT in the base of mill, and then they are REMOVED periodically.

14.

What type of feeder is used to supply the coal in ball and race mill?(a) Ring main feeder(b) Parallel feeder(c) Radial feeder(d) Rotating table feederI have been asked this question during an interview.This interesting question is from Pulverised Mills topic in division Steam Power Plant of Energy Engineering

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The correct option is (d) Rotating table feeder

To explain: The coal is supplied through the rotating table feeder at the upper right to fall on the inner side of the races. The moving balls and races trap coal between them to CRUSH it to powder. SPRING HOLDS down the upper STATIONARY race and adjusts the force needed for crushing.

15.

What is the advantage of breaking coal into smaller pieces in pulverized fuel handling?(a) Easy coal feeding(b) No clogging coal since they are in powder form(c) Exposes more surface of the coal(d) Increase in combustion rateI have been asked this question during an interview.Question is from Pulverised Fuel Burning in section Steam Power Plant of Energy Engineering

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16.

How much capacity of heat is possible to produce by the travelling grate stoker?(a) 80 * 10^6 kJ/m^2.hr(b) 40 * 10^6 kJ/m^2.hr(c) 25 * 10^6 kJ/m^2.hr(d) 65 * 10^6 kJ/m^2.hrI had been asked this question in final exam.My question is based upon Type of Stokers topic in portion Steam Power Plant of Energy Engineering

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Right option is (a) 80 * 10^6 kJ/m^2.hr

Best explanation: The spreader STOKER has wide applications with respect to the fuels used as well as to the BOILER sizes. A wide VARIETY and poor quality coal can be burnt efficiently with this TYPE of stoker. This type of stoker can be used for boiler capacities of 80 tons to 150 tons of steam per hour. The heat release rate of 80 * 10^6 kJ/m^2 hr is possible with travelling grate.

17.

Proper regulation of Pulverized fuel results in _________(a) better fuel economy(b) high output work(c) efficient regulation of heat(d) proper combustionI had been asked this question by my college director while I was bunking the class.I need to ask this question from Pulverised Fuel Burning topic in chapter Steam Power Plant of Energy Engineering

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Correct option is (a) BETTER fuel economy

The explanation: The rate of pulverized coal feed can be REGULATED PROPERLY resulting in fuel economy. Since coal is in the powdered FORM, coal of any grade can be used. Wide grade of low grade fuel can be burnt easily. Practically the coal used does not form any slagging or clinkers.

18.

Where is the place at which the volatile matter and fine particles burnt in the spreader stoker?(a) Over the grate(b) In steam gauge(c) In the suspension(d) In the coal bedI had been asked this question in semester exam.My question comes from Type of Stokers topic in division Steam Power Plant of Energy Engineering

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The correct option is (C) In the suspension

The best I can explain: The air supplied by the FORCED draught fan enters the furnace through the OPENINGS provided in the grate. A PORTION of this air is used to burn the fuel on the grate and remaining air is utilized to burn the volatile matter and fine particles in suspension.

19.

Why does burnt gases with content of N2, CO2, H2, O2 and H2O re-enter the boiler in overfeed system?(a) To dismiss the ash content in the gases formed(b) Due to incomplete burning(c) For complete removal of moisture(d) To complete the burn the coalThe question was asked in final exam.Query is from Principle of Stoker topic in chapter Steam Power Plant of Energy Engineering

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Right answer is (B) Due to INCOMPLETE burning

The explanation is: The burnt gases re-enter the boiler containing N2, CO2, O2, H2O and CO if the burning is incomplete. During incandescence, the fuel is continuously loses its carbon by oxidation until only the ash remains.

20.

Why is secondary air supplied in overfeed system?(a) To burn the unburnt gases(b) To maintain constant heat intensity(c) To completely remove water vapors formed due to primary air supply(d) To create distillation process for the raw coal suppliedThe question was asked during an interview.Origin of the question is Principle of Stoker in division Steam Power Plant of Energy Engineering

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Correct ANSWER is (a) To BURN the unburnt gases

To elaborate: Additional SECONDARY air is supplied at the top of the bed to burn the remaining combustible gases (volatile matter+CO+H2). The secondary air is supplied at very high speed to create turbulence for COMPLETE combustion of unburnt gases.

21.

How is volatile matter of raw coal is lost in the overfeed system?(a) Condensation(b) Distillation(c) Combustion(d) EvaporationI got this question in an online quiz.I'm obligated to ask this question of Principle of Stoker topic in section Steam Power Plant of Energy Engineering

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The correct choice is (b) Distillation

Easiest EXPLANATION: Raw coal that is continuously supplied on the surface of the BED loses it volatile matter by distillation in this zone. The REQUIRED for the distillation of coal is given by incandescent coke below the fresh fuel, hot gases diffusing through the surface of the bed and hot gases and flame in the FURNACE above.

22.

What is used in case, to throw coal into furnace that is set off far from the supply?(a) Speed convey belt(b) Bucket chain(c) Paddle(d) Steam jetThe question was posed to me in an international level competition.Origin of the question is Fuel Burning topic in chapter Steam Power Plant of Energy Engineering

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The CORRECT option is (d) Steam jet

To explain: Steam jet from the boiler or a mechanical catapult may also be used to throw COAL into far reach of the FURNACE. The mechanical means used in the system depend on the design, COMBINATIONS of screw feed, the conveyor belt, the BUCKET chain, the paddle and the ram.

23.

What is the most important factor that is essential for economical working of a power plant?(a) Abundant fuel input(b) Rotational speed of turbines(c) Efficient transfer of heat energy to water(d) Proper maintenance Ash and other waste handling systemsI had been asked this question in a national level competition.This intriguing question comes from Fuel Burning in chapter Steam Power Plant of Energy Engineering

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Correct option is (c) EFFICIENT transfer of heat energy to water

Easiest explanation: The economical working of power plant depends upon factors such as efficient transfer of heat energy to water for GENERATION of STEAM and efficient COMBUSTION of fuel in combustion chamber. Many improvements have been made in design of the furnace to increase the rate of combustion.

24.

What is in plant coal handling system?(a) Maintenance of coal during emergencies(b) Maintenance of coal inside the boiler(c) Maintenance of coal inside the power production area(d) Maintenance of coal while transporting/moving itThe question was posed to me during an interview.I need to ask this question from Fuel Handling System, Storage of Coal in chapter Steam Power Plant of Energy Engineering

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The correct answer is (c) Maintenance of coal inside the power production area

To EXPLAIN: For easy, smooth and rapid operation mechanical HANDLING system is embraced for inplant handling of coal. Inplant handling begins RIGHT from the coal delivery POINT unto the furnace FIRING system.

25.

What types of rays does the nuclear weigher used to measure the weight?(a) Infrared rays(b) Ultraviolet rays(c) Gamma rays(d) X-ray wavesThe question was asked during a job interview.I'm obligated to ask this question of Coal Weighing Methods topic in division Steam Power Plant of Energy Engineering

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Right answer is (c) Gamma RAYS

For explanation: Nuclear weighing system operates on gamma ray, Works on gamma rays absorption PRINCIPLE. A radio-active SOURCE located in the source HEAD EMITS gamma rays which pass through the material on the conveyor to the detector.

26.

Which coal burner is used to burn crushed coal instead of pulverized coal?(a) Cyclone burner(b) Tangential burner(c) Turbulent burner(d) Stream-line burnerI got this question in final exam.The doubt is from Fuel Burning Equipments topic in portion Steam Power Plant of Energy Engineering

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Right answer is (a) Cyclone burner

Explanation: Cyclone burners are used to burn CRUSHED coal instead of pulverized coal. This is to ELIMINATE fly ash handling problems. It consists of a cyclone furnace. Crushed coal of about 8 mm size is FED from the FEEDER to the centre of the cyclone along with primary AIR.

27.

In which coal burners are fuel and air streams ejected in horizontal direction?(a) Tangential burner(b) Cyclone burner(c) Stream-line burner(d) Turbulent burnerI got this question in my homework.The doubt is from Fuel Burning Equipments topic in division Steam Power Plant of Energy Engineering

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The correct choice is (a) Tangential burner

For explanation: In tangential burners, fuel and air STREAMS are EJECTED in horizontal direction tangent to an imaginary CIRCLE at the CENTRE of the furnace. The burners are placed at the corners of the furnace to ensure INTENSE turbulence and thorough mixing of fuel and air.

28.

The output of the mill can be controlled by the _________ located in the exhaust fan inlet duct.(a) Dampers(b) Blowers(c) Air duct(d) Ventilator’sThe question was asked during an interview.I would like to ask this question from Pulverised Mills in division Steam Power Plant of Energy Engineering

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The correct choice is (a) Dampers

For EXPLANATION: The output of the mill can be controlled by the dampers located in the exhaust FAN INLET duct. These dampers vary the FLOW of air through the mill, thus controlling the rate of fuel removed from the mill. The dampers are operated by the boilers automatic combustion control.

29.

Which system was used before direct firing system in pulverized fuel firing?(a) Unit system(b) Burner and pulverizer system(c) Bin system(d) PulverizerI had been asked this question in an interview for internship.Question is from Pulverised Fuel Handling topic in chapter Steam Power Plant of Energy Engineering

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Right option is (c) Bin system

For explanation I would say: Bin system was widely used before pulverizing equipment BECAME reliable ENOUGH for continuous STEADY operation. This system EMPLOYS a LIMITED number of large capacity pulverizes at a central point to prepare coal for all the burners.

30.

Which type of draught system is used in the pulverized fuel firing system?(a) Forced draught(b) Balanced draught(c) Induced draught(d) Natural draughtI had been asked this question in an interview for job.Question is taken from Pulverised Fuel Handling in chapter Steam Power Plant of Energy Engineering

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The correct answer is (c) Induced draught

To elaborate: Induced draught system is USED in pulverized fuel firing system. The PRIMARY air from the Induced draught fan carries pulverized COAL from the mill to the burner through short delivery PIPE. In the separator, the big coal particles are separated from the fine dust these again FALL down into the mill.

31.

How is the fuel selected in the pulverized fuel system?(a) Depending on its size(b) Depending on its grade(c) Depending on volatile matter content(d) Depending the chemical compositionThis question was posed to me during an interview for a job.My query is from Pulverised Fuel Handling topic in portion Steam Power Plant of Energy Engineering

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Right option is (c) Depending on volatile matter content

Best explanation: In PULVERIZED FUEL firing SYSTEM, coal with 20% volatile matter is considered as the best fuel for the PLANT, as high volatile coals are harder to grind when compared to low volatile coals. In stoker firing, the characteristics of the coal plays very important role in selection of coal.

32.

Which type of oil burners are used for domestic purposes?(a) Atomizing burner(b) Vaporizing burner(c) Steam jet atomization burner(d) Mechanical atomization burnerI have been asked this question in an online interview.My doubt is from Fuel Burning Equipments topic in chapter Steam Power Plant of Energy Engineering

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Right option is (B) Vaporizing burner

Best explanation: The vaporizing burners are used for domestic PURPOSE especially in portable AIR HEATERS, cooking stoves etc. petromax stove which burns KEROSENE is a classical example of a vaporizing burner. Here an upward moving high velocity fuel jet is allowed to strike against hot moving plate. The vapor burns with a short intense flame.

33.

In which type of machine is the coal reduced to fine powders?(a) Blender(b) Crushers(c) Grinder(d) RollersI have been asked this question in my homework.Origin of the question is Pulverised Fuel Burning topic in portion Steam Power Plant of Energy Engineering

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The correct option is (c) Grinder

For explanation I WOULD say: Coal is reduced to fine powder in grinding mill. Coal is pulverized to INCREASE its SURFACE EXPOSURE. The pulverization of coal means of exposing a large surface area of the coal to action of oxygen and CONSEQUENTLY accelerates combustion.

34.

Which coal burner has the circular discharge orifices?(a) Tangential burner(b) Stream-line burner(c) Turbulent burner(d) Cyclone burnerThis question was posed to me in an interview.The origin of the question is Fuel Burning Equipments topic in portion Steam Power Plant of Energy Engineering

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The correct answer is (c) Turbulent burner

Easiest EXPLANATION: Turbulent is MADE up of CIRCULAR discharge orifices or with straight narrow outlets. It is placed in the wall of water cooled FURNACES. The fuel and air mixture pass through the burner such that they mix properly at FURNACE entrance.

35.

Which coal burner is called Long-flame burner?(a) Tangential burner(b) Turbulent burner(c) Stream line burner(d) Cyclone burnerI had been asked this question during an interview for a job.My enquiry is from Fuel Burning Equipments in portion Steam Power Plant of Energy Engineering

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The correct option is (c) Stream line burner

Explanation: Stream line burner is called as Long-flame burner, ALSO known as U-flame burner. It is designed to fire downwards in the furnace without any turbulence. Thin FLAT streams of air and FUEL mixture is DISCHARGED in the furnace which travels CONSIDERABLY long distance producing long flame.

36.

What is the purpose of rotary scoop shaped rejecter arms in impact mill?(a) To send back the coal back into grinder for second run(b) To throw the large particles back into the grinder(c) To eliminate ash from the pulverizer(d) To eliminate rocks and solid particles that has mixed up with the coalThe question was posed to me in final exam.This intriguing question comes from Pulverised Mills in division Steam Power Plant of Energy Engineering

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Right answer is (b) To throw the LARGE particles back into the grinder

For explanation: The FINELY pulverized coal in the final stage of GRINDING is carried with the air to the burner through the rotating scoop rejecter arms which throw the large particles back into the grinding section. The final stage grinding consists of pegs carried on a rotating disk and TRAVELLING between stationary pegs.

37.

Which mechanism is used for the uniform distribution of the coal in multi retort stoker?(a) Reciprocating ram(b) Nozzle(c) Screw conveyor(d) Steam jet blowersThe question was posed to me in an interview.This is a very interesting question from Type of Stokers topic in section Steam Power Plant of Energy Engineering

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Correct choice is (a) RECIPROCATING ram

Explanation: the multi retort stoker consists of a series of ALTERNATE RETORTS and TUYERE boxes for supply of air. Each retort is fitted with a reciprocating ram for feeding and pusher plates for the uniform distribution of coal. The coal falling from the hopper is pushed forward during the INWARD stroke ram.

38.

Why is direct firing system considered better than bin system in pulverizer fuel firing?(a) It has long operating procedure(b) The auxiliaries used in system consume large amount of power(c) The initial cost of system is very high(d) The transportation of coal is much more complexThis question was posed to me during an interview.The query is from Pulverised Fuel Handling topic in division Steam Power Plant of Energy Engineering

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Correct answer is (a) It has long operating procedure

The explanation: The BIN system INVOLVES many stages of drying, storing and transportation and HENCE the process takes extra AMOUNT of time & chances of fire hazards are more. Never the less, it is still in use at many older plants.

39.

Where is the coal feeding mechanism located in spreader type stoker?(a) Above the grate(b) Right side of the grate(c) Left side of the grate(d) Below the grateI had been asked this question during a job interview.This interesting question is from Type of Stokers in section Steam Power Plant of Energy Engineering

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The CORRECT option is (a) Above the grate

The best explanation: The coal feeding and distribution mechanism is located in the FRONT above the grate of a spreader stoker. A PORTION of coal is supplied containing fine particles fine particles of coal BURNS in SUSPENSION and remaining falls to the grate.

40.

Which is the zone where the water vapors carried in air reacts with carbon in over-feed system?(a) Green coal bed zone(b) Incandescent zone(c) Combustion zone(d) At the ash pitI have been asked this question during a job interview.Origin of the question is Principle of Stoker topic in section Steam Power Plant of Energy Engineering

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The correct option is (B) Incandescent zone

For explanation I would say: The water vapor carried with air reacts with Carbon in incandescent zone and FORMS CO, CO2, and H2. Part of CO2 formed reacts with air C passing through incandescent zone and converts into CO. The gases leaving the incandescent region of FUEL bed consist of N2, CO2, CO, H2 and H2O.

41.

Where exactly are mechanical stokers used?(a) In transportation of fuels(b) In small capacity plants(c) In large capacity plants(d) For domestic usageThe question was posed to me during a job interview.My enquiry is from Fuel Burning in section Steam Power Plant of Energy Engineering

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Correct answer is (c) In large capacity plants

To explain: MECHANICAL stokers are usually used in large and medium capacity plants. Mechanical stokers are used to fire almost all kinds of coal. This produces less SMOKE than hand firing. A stoker CONSISTS of a power feeding MACHINE and a grate.

42.

What is the function of sizer in coal handling?(a) To separate the coal depending on size(b) To check the amount of fuel that is supplied(c) To pick the coal of required size(d) To divert the coal flow into different burnersThe question was posed to me during an online exam.Question is from Stages of Coal Handling in portion Steam Power Plant of Energy Engineering

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The correct choice is (c) To PICK the COAL of required size

To EXPLAIN: The function of the sizer is to pick the coal of REQUIRES size, which is coming from the crusher. The un-sized coal is fed back to the crusher. The function of crusher is to crush the coal to uniform size.

43.

On which factor is the coal fed to the pulverizing mill in pulverized fuel firing system?(a) Steam generating rate(b) Capacity of intake of coal(c) On the rate of speed of the feeder(d) Depending on the temperature that is governed inside the combustion chamberI got this question during an interview for a job.My question is from Pulverised Fuel Handling in chapter Steam Power Plant of Energy Engineering

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Correct answer is (a) Steam generating rate

Best explanation: The feeder supplies coal too the pulverizing MILL after drying coal in hot AIR. It is supplied at a VARIABLE rate governed by the combustion requirements of furnace and steam generating rate. In the pulverizing mill the coal is CRUSHED to the REQUIRED size (fine powder).

44.

In what manner is the coal is fed to all the burners in pulverized fuel system?(a) Through a common feeder(b) Parallel feeding(c) From separate feeder(d) Series mesh feedingI got this question in homework.My question comes from Pulverised Fuel Handling in chapter Steam Power Plant of Energy Engineering

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Right answer is (C) From separate feeder

To explain: The pulverized coal is FED to the VARIOUS burners through separate FEEDERS. The bin may contain coal required for 12 to 24 hours of supply. The quantities of fuel and air can be regulated accurately and separately. This leads GREATER degree of flexibility.

45.

What are provided for the supply of air in single retort stoker?(a) Nozzles(b) Air ducts(c) Tuyere’s(d) Air blowersThe question was asked in quiz.This is a very interesting question from Type of Stokers topic in portion Steam Power Plant of Energy Engineering

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Correct answer is (c) Tuyere’s

The best I can EXPLAIN: The air is SUPPLIED through the tuyeres PROVIDED along the upper edge of the grate. The ASH and clinkers are collected on the ash plate provided with dumping arrangement. The coal feeding capacity of a single retort STOKER varies from 100 to 2000 kg per hour.

46.

What is the function of magnetic separator in coal handling?(a) To remove impurities(b) To separate bituminous coal(c) To remove iron particles(d) To separate metal contentsThis question was posed to me during an internship interview.Origin of the question is Stages of Coal Handling topic in division Steam Power Plant of Energy Engineering

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Right OPTION is (c) To remove iron particles

Easiest explanation: The function of the magnetic separator is to remove iron particles which otherwise MAY choke the burners besides DAMAGING other equipment’s. The iron particles are trapped by the magnetic PULLEY while the belt carrying coal passes over it. It is collected in a chute.

47.

Why is it necessary to use noncandescent materials in place of coal storage area?(a) To avoid it from catching fire(b) To act as a fire resistor during the cause of fire(c) To avoid it from acting as a supporter of fire(d) To provide a cool environmentI have been asked this question in an interview for internship.This intriguing question originated from Fuel Handling System, Storage of Coal topic in portion Steam Power Plant of Energy Engineering

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48.

What happens due to the pressure in the pulverizer?(a) Pulverized fuel is blown into boiler room(b) Increases the rate of combustion(c) Makes the process is vigorous(d) The large particles in the pulverized fuels are removed outI have been asked this question in exam.This interesting question is from Pulverised Mills topic in division Steam Power Plant of Energy Engineering

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Correct ANSWER is (a) Pulverized fuel is blown into BOILER room

For explanation: As the casing of the PULVERIZER is under pressure, the leakage of fine coal through the mill casing CAUSES the pulverized fuel to be blown out into the boiler room. The fan used with this mill handles only air THEREFORE the blades erosion by coal particle is eliminated.

49.

Why pre-heater air and the tempered air are introduced in the pulverizer of ball mill?(a) To carry the ash out(b) To increase the combustion rate(c) To carry pulverized coal(d) To dry the coal by removing the moistureI got this question by my college director while I was bunking the class.My question is from Pulverised Mills topic in chapter Steam Power Plant of Energy Engineering

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Correct choice is (c) To carry pulverized coal

The best explanation: A mixture of TEMPERING air and HOT air from pre-heater is introduced in the pulverizer. These streams of air carry the pulverized coal and pass through the classifier. The over-sized PARTICLES are thrown out of the air STREAM in the classifier and fine MATERIAL is passed to the burner through exhaust fan.

50.

What is used to remove moisture air after cyclone separation in the pulverized fuel system?(a) Sponge pad(b) Dry filters(c) Fabric bag(d) Hot airI have been asked this question during an internship interview.I need to ask this question from Pulverised Fuel Handling in division Steam Power Plant of Energy Engineering

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