Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Gas > Combustion > Flashcards

Combustion Flashcards

1
Q

If only 2 units of oxygen are required for complete combustion of 1 unit of methane, why must 10 units of air be supplied for complete combustion of 1 unit of methane

A

There are 2 units of oxygen in 10 units of air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

An inspirated burner is found on a?

A

Natural draft appliance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What force makes stack action possible

A

Buoyancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

A flame with a two part cone is developed by what type of burner

A

Pre mix burner

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the maximum equivalent length of a combustion air duct ducting allowed without increasing the size

A

20 feet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Combustion air sizing is taken from the appliances ———?

A

Input rating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define the term combustion

A

The rapid oxidation of fuel resulting in the production of heat or heat and light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

When gas burns properly, the hydrogen combines with the oxygen of the air to produce—————-, the carbon combines with the oxygen to produce————- and the ————— in the air passes through the flame unchanged.

A

Water vapour

Carbon dioxide

Nitrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define combustion air

A

The air required to completely burn the fuel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Define primary air

A

Air required for the initial stages of the combustion process and is mixed with the fuel prior to combustion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define secondary air

A

Air required for the intermediate and final stages of the combustion process and is mixed with the fuel prior to combustion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define excess air

A

Air supplied for the combustion process in excess of, but not required theoretically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Define combustion products

A

Constituents resulting by uniting the fuel with oxygen, usually thought of as being gas, primary air or secondary air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define range of flammability

A

The percentage of gas present in a gas/ air mixture between the upper and lower limits that will burn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Define incomplete combustion

A

Combustion that does not convert all the carbon and or hydrogen into water vapour and or carbon dioxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Define lift off

A

The gas/air mixture speed exceeds the flame speed resulting in a flame that burns too high above the burner

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Define flashback

A

The gas/air mixture is slower than the flame speed causing the flame to burn inside the burner, possibly at the orifice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What 3 components are required for combustion

A

Fuel
Heat (ignition)
Oxygen (air)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What product creates concern when incomplete combustion occurs

A

Carbon monoxide (Co)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What flame color is most likely to indicate poor combustion

A

Yellow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What flame color usually indicates dust or dirt passing through the flames

A

Orange

22
Q

What colour of flame indicates good combustion

A

Blue

23
Q

What are the two constituents of the products of combustion that can form due to incomplete combustion of fuel

A

Aldehydes and carbon monoxide

24
Q

A compound that consists of only hydrogen and carbon would be a definition of?

A

Hydrocarbon

25
Q

What condition produces upward flow of vent gasses in a natural draft appliance

A

Chimney effect

26
Q

What does the term Venturi principle mean

A

Partial vacuum due to fluid flow through a narrow opening

27
Q

What is the range of flammability of a fuel

A

The amount of fuel/air mixture that will burn

28
Q

Define the heating value of fuel

A

The heat in a volume of fuel that is released by combustion

29
Q

What does lp refer to as fuel

A

Liquified petroleum gasses

30
Q

What controls the amount of air that can enter an atmospheric burner

A

Air shutters

31
Q

What are the products which result from complete combustion of the reactants oxygen and methane

A

Carbon dioxide and water vapour

32
Q

What three conditions are needed for combustion to take place

A

Oxides, fuel , heat

33
Q

What are the three mechanisms by which heat is transferred

A

Radiation, conduction, convection

34
Q

Which type of heat can easily be focused

A

Radiation

35
Q

How does latent heat differ from sensible heat

A

Latent heat does not change the temperature of a substance

36
Q

What is the difference between heat and temperature

A

Heat is energy, temperature is a specific point on a thermostat

37
Q

What is specific heat

A

Energy needed to warm a specific volume of a substance by one degree

38
Q

How does a metallic object become warmer by heating it from one end only

A

Heat energy conducts from molecule to molecule through the metal

39
Q

Which form of latent heat changes propane liquid to propane gas

A

Vaporization

40
Q

What are two different names for a non aerated flame

A

Luminous flame or non linting flame

41
Q

Which type of flame is a Bunsen flame

A

Aerated flame

42
Q

What are the two main burner classes

A

Atmospheric and forced draft

43
Q

Why are ports of induced draft burners larger than ports of natural draft burners

A

To reduce flow restriction through the burner

44
Q

Why does the induced draft appliance use a fan on the outlet of the appliance

A

To overcome the resistance of the heat exchanger to the flow of products of combustion through it

45
Q

Why do some burners have flame deflectors

A

To prevent hot spots in the combustion chamber

46
Q

How is temperature measured

A

Thermometer

47
Q

What temperature in Fahrenheit is represented by a temperature of 273 Celsius

A

273x1.8+32 = 523.4 Fahrenheit

48
Q

Why are gas infrared heaters becoming so popular

A

Heat is not wasted by warm air lost to outdoors when overhead doors are open

49
Q

What approximate percentages of combustion air are primary air and secondary air

A

60% and 40%

50
Q

Why is the production of carbon monoxide from an appliance such a concern

A

It accumulates in the blood and asphyxiates

Gas (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions