Energy Engineering Multiple Choice Questions on “Stages of Coal Handling”.
1. In which mode of transport are rotary car dumpers used?
A. Road transport
B. Rail transport
C. Transport by sea or river
D. Inside the plant handling
View Answer
Answer: B
clarification: Depending on the mode of transport viz. by sea or road or rail, coal unloading done. Rotary car dumpers are used when the transport is done by rail also coal towers and coal accelerators are used. Coal towers, unloading bridges and self unloading boats are used if the outplant handling of the coal is by sea or river.
2. 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 burners
Answer: C
clarification: 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.
3. 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 contents
Answer: C
clarification: 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.
4. 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 furnace
Answer: B
clarification: 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.
5. What is the function of Gab bucket conveyor in coal handling?
A. To lift the coal vertically
B. To crush the coal
C. To move coal from one place to another
D. To separate crushed coal and powdered coal
Answer: C
clarification: Grab bucket conveyor can grab as well as convey coal from one place to another. It is used with a crane or tower and it has different capacities. It is very essential when all other means of transporting coal is not viable. It has high initial cost but low operating cost.
6. Out of all conveyors which type of conveyor has a greater capacity to convey large amount of coal?
A. Belt conveyor
B. Chain conveyor
C. Screw conveyor
D. Scraper conveyor
Answer: A
clarification: Belt conveyor is used for transporting large quantities of coal over long distances. It consists of an endless belt made of rubber, balata or canvass running over pulleys or end drums. It is economical means of coal transportation at rapid rate.
7. What is the distance at which belt conveyors can convey?
A. 100m
B. 200m
C. 50m
D. 500m
Answer: D
clarification: Belt conveyors can handle upto 50 to 100t/h of load can be carried over a distance of about 500m. These conveyors can be used with inclination upto 20° to the horizontal moving at an average speed of 60 to 90 m/min. However it cannot be used for carrying coal at greater heights.
8. To what is helicoids screw in screw conveyor is attached?
A. To the shaft
B. To the inner case
C. To the bearings
D. To the outer casing
Answer: A
clarification: Screw conveyor is used to transmit coal. It consists of an endless helicoids screw of diameter 150 mm to 500 mm wound around a rotating shaft. One end of the shaft is connected to the drive whereas the other end is supported by a bearing.
9. In what speed range does screw conveyor run at?
A. 60 – 80 rpm
B. 20 – 100 rpm
C. 60 – 120 rpm
D. 90 to 180 rpm
Answer: C
clarification: The screw along with the shaft in screw conveyor rotates at about 60 rpm to 120 rpm and carries coal from one end to another. Screw conveyors are designed to suit different load capacities. These can only be used in very short ranges and tend to get hot if used for longer amount of time.
10. Which type of conveyor has shorter life span?
A. Flight conveyor
B. Belt conveyor
C. Screw conveyor
D. Grab bucket conveyor
View Answer
Answer: A
clarification: Flight conveyor is used for filling large number of storage bins situated under the conveyor. It consists of a steel scrapers attached to chain mechanism. Steel scrapers scrap the coal through a trough and discharge it at the bottom.