Chapter 15 Combustion & Draft

Question 1

The incomplete combustion of carbon results in the formation of carbon ___________.

a) Tetrachloride
b) Monoxide
c) Dioxide
d) Trioxide

Answer 1

b) Monoxide

Question 2

When a unit amount of fuel is burned completely, the heat produced is called the _________ of the fuel.

a) Heat content
b) Heating value
c) Excess air
d) Combustion efficiency

Answer 2

b) Heating value

Question 3

The conditions for complete combustion include:

a) Low furnace temperature
b) Cool heating surfaces
c) Thorough mixing of water and fuel
d) Enough air

Answer 3

d) Enough air

Question 4

The amount of air required to supply just enough oxygen for complete combustion is called _________ air.

a) Excess
b) Theoretical
c) Tertiary
d) Primary

Answer 4

b) Theoretical

Question 5

________ forms the greatest percentage of the combustible elements in a fuel.

a) Sulphur
b) Hydrogen
c) Carbon
d) Wood

Answer 5

c) Carbon

Question 6

An advantage of using natural gas as a fuel is:

a) More storage space is required
b) Has less heating value than oil
c) Less expensive than coal
d) Easily mixed with air

Answer 6

d) Easily mixed with air

Question 7

A draft system that is motorized and mounted on the front of the boiler is ______ draft.

a) Natural
b) Forced
c) Induced
d) Balanced

Answer 7

b) Forced