080103 Properties of Gas and Principles of Combustion Flashcards
What are the two factors that influence the state in which matter exists?
Temperature and Pressure
What is standard atmospheric pressure?
14.7 psia
When pressure increases what happens to boiling temperature?
It increases
What is standard temperature?
60°F
What are the calorific values of methane and propane?
Methane = 1000 BTU/cubic foot Propane = 2500 BTU/cubic foot
What are the specific heat values of water, steam and ice?
Water = 1 Steam = 0.5 Ice = 0.5
How much does 1 imperial gallon of water weigh?
10lbs
Efficiency equation?
Output / Input = Efficiency
The hottest part of a gas flame is…
The tip of the inner cone
Range of flammability air/gas mixture is approximately…
20% oxygen, 80% nitrogen
What is it called when an air/gas mixture moves forward more slowly than the the speed the flame moves back?
Flashback
What is it called when the air/gas mixture moves forward faster than the flame speed moves backwards?
Lift off
What % of oxygen does 1 cubic foot of air contain?
20%
What does a reduced (lazy) yellow flame indicate?
Not enough primary air to the burner
How many cubic feet of primary air are required to light 1 cubic foot of natural gas?
10
How many cubic feet of primary air are required to light 1 cubic foot of propane?
24
Define Charles Law
Increase in temperature = increase in volume
Define Boyls Law
Increase in pressure = decrease in volume
How does heat travel?
Hot to cold
Define temperature
Molecular movement
Define heat
Energy that transfers from one body to another
At what temperature is water most dense?
4°C
A 70°F change is equal to what temperature change in Celsius?
70° / 1.8 = 38.88°C
A 100°C change is equal to what temperature change in Fahrenheit?
100° x 1.8 =180°F
Fahrenheit to Celsius conversion formula
°C = (°F - 32°F) / 1.8
Celsius to Fahrenheit conversion formula?
°F = (1.8 x °C) + 32
Define specific heat capacity
The quantity of heat required to change the temperature of one unit of mass by one degree
Define latent heat
Heat that causes a change of state not temperature
Define sensible heat
Heat that causes a change in temperature only, but not in state
Equation for calculating sensible heat?
Sensible heat = specific heat capacity x mass x temperature change
What are the latent heat values for ice-water and water-steam?
Ice-Water = 144 BTUs/lb 335 KJ/kg
Water-Steam = 970 BTUs/lb 2257 KJ/kg
Latent heat calculations formula?
Latent heat = mass x latent heat value
How many BTU are in 1 cubic foot of natural gas?
1000
What are the liquefaction ratios of propane?
270 cubic feet/cubic foot (liquid)
43.6 Cubic Foot/Gallon (Vapour)
What’s are the specific gravity (or relative density) of CH4 and C3H8?
CH4 = 0.6 C3H8 = 1.5
Calculate the amount of energy required to change 315L of water @ 12°C into steam @ 110°C
833,679 KJ
The boiling point of liquid propane at STP is:
-44°F(-42°C)
How many BTU are contained in 5 imperial gallons of propane?
547800
The range of flammability for CH4 and C3H8 is?
CH4 = 5-15%
C3H8 = 2.3-9.5%
How much would 10 imperial gallons of propane liquid weigh?
51 lbs
When C3H8 changes state from liquid to gas it will expand how many times?
270
