WorksheetsFuel Gas Chapter 3
Total questions: 65
Worksheet time: 43mins
fuels used to produce heat by combustion in various types of appliances exist only as liquids or gases
true
false
the actual composition of wet natural gas depends on the type of well and geographical location where the fuel gas originates
true
false
the three basic requirements for combustion are the existence of fuel, oxygen or air, and a source of ignition
true
false
spontaneous combustion is combustion in which the fuel is only partially burned and is capable of being burned further under proper conditions
true
false
products of combustion are the constituents resulting from the combustion of a fuel with the oxygen of the air, including the inert gases but excluding air
true
false
it is important to know the specific gravity of a particular gas when calculating flows through piping systems and when sizing gas burner orifices
true
false
the second law of thermodynamics, the law of conservation of energy, states that energy cannot be created or destroyed but can be changed from one form to another
true
false
for combustion to take place, two atoms of oxygen for every one atom of carbon, and one atom of oxygen for every two atoms of hydrogen are required
true
false
nitrogen and carbon dioxide are examples of noble gases
true
false
combustion air includes three components: fuel combustion air, excess air, and dilution air
true
false
since complete or perfect combustion is only possible under theoretical conditions, gas appliances must be adjusted so that all fuel gas is completely burned and no harmful products of incomplete combustion are produced
true
false
most gas burners consist of only one burner type
true
false
fuel gas is normally delivered into the appliance combustion chamber under pressure
true
false
non-aerated pilot flames should not have any flame impingement as any flame contact will cause flame chilling and incomplete
true
false
types of pilot burners include the aerated pilot, post-aerated pilot, and non-aerated pilot
true
false
it is acceptable for a pilot flame in a pilot burner to be exposed to falling scale because it does not impair ignition of the main burner
true
false
burner can be manually operated or automatically operated
true
false
one characteristic of a properly functioning atmospheric burner is a nearly orange flame produced at the burner ports
true
false
premixing in an atmospheric burner is a condition that occurs when a mixture of air and gas ignites in the mixing tube of a burner rather than at the burner ports
true
false
one of the most common causes of unstable gas flames is improper primary air supply to an atmospheric burner
true
false
because BLANK gas is compsed of more than 75% methane, it usuallyis represented by the chemical formula for methane, CH4
wet natural
manufactured
dry natural
liquid petroleum (LP)
The BLANK of a gas is the ratio of a substance to that of air at 68 F degree (20 C) and 1 atmosphere of pressure
expansion ratio
specific gravity
viscosity
density
The BLANK of an element include its heat value, limits of flammability, ignition temperature, maximum flame temperature, and flame speed
chemical properties
physical properties
chemical composition
phyical composition
the BLANK for natural gas is 1,200F (649c)
maximum flame temperature
boiling point
ignition temperature
upper flammable limit
The boiling of BLANK, at 1 atmosphere, is -258F (-161c)
propane
butane
manufactured gas
natural gas
The BLANK of natural gas can only be reached at perfect combustion
boiling point
total heating value
maximum flame temperature
ignition temperature
a delayed mixing burner is a burner that utilizes a process in which the fuel and air leave the burner nozzle unmixed and thereafter mix relatively slowly, largely through diffusion, resulting in a(n) BLANK flame
red
orange
blue
yellow
the specific gravity of BLANK gas is 1.52
propane
butane
natural
manufactured
BLANK has a heating value total of 3,200 btu/ft3, which means it combusts at approximately three times the energy as natural gas
propane
butane
biogas
manufactured gas
according to the BLANK law of thermodynamics, the heat energy in a flame will flow to the lower temperature of the air or water contained in a gas appliance, which, in turn, will flow on to lower-temperature areas
fourth
third
second
first
the elements necessary to start and sustain comustion are fuel, BLANK, and heat
hydrogen
nitrogen
carbon
oxygen
a BLANK burner is a fuel gas burner in which the fuel gas and air are not mixed untiul just as they leave the burner port, after which mixing usually is very rapid
zero-governor
delayed mixing
premix
nozzle mixing
BLANK air is the air for combustion externally supplied to the flame at the point of combustion and is not mixed with fuel before it enters the combustion chamber
primary
secondary
excess
dilution
BLANK air is necessary to cool the hot vent gases and to control the draft influence on the appliance combustion chamber
excess
secondary
primary
dilution
the gas pressure range classified as high pressure is from BLANK psi
5 to 80
1 to 45
2 to 50
3 to 75
a(n) BLANK burner is an atmospheric burner that utilizes a chimney or vent stack to pull in secondary air and remove the products of combustion
natural-draft
inspirating
induced-draft
forced-draft
a(n) BLANK burner is a mechanical-draft burner that utilizes a motorized fan at the outlet of the combustion chamber to draw air into the chamber
inshot
inspirating
induced-draft
delayed mixing
BLANK burner normally are used with mechanical-draft or power burners supplied to large commerical furnaces and heaters requiring higher gas pressures
multi-port
small-port
large-port
tile-port
a(n) BLANK burner mixes gas supplied at a high pressure with air at normal atmospheric pressure
aspirating premix
inspirating premix
fan mixing type premix
mechanical premix type
a zero-governor burner is an example of a(n) BLANK burner
aspirating premix
mechanical premix type
fan mixing premix
inspirating premix
BLANK pilot are becoming increasingly popular on all types of gas equipment because of reduced susceptibility to the accumulation of lint and/or dust
aerated
post-aerated
non-aerated
continuous
a safety feature of a(n) BLANK pilot is the ability of the pilot to burn fuel in the combustion chamber if there is a leak at the burner
interrupted
intermittent
continuous
discontinuous
an atmospheric burner is adjusted properly when the height of the inner cone is approximately BLANK % of the maximum visible cone height
10
25
50
70
BLANK sometimes occur when a burner is first ignited, and then disappear as the burner warms up
flashbacks
floating flames
lifting flames
yellow-tipped flames
a BLANK flame is caused by an insufficient draft
luminous
floating
lifting
yellow-tipped
NFPA 54 defines a(n) BLANK as any device that utilizes gas as a fuel or raw material to produce light, heat, power, refrigeration, or air conditioning
(a)
BLANK gas is wet natural gas that comes from oil wells, meaning the gas is associated with oil
(a)
BLANK is the ratio of the density of a substance to the denisty of a reference substance, both at specified physical conditions
(a)
BLANK is the measured rate of expansion of the flame front moving toward the air-gas mixture issuing from a burner port in a combustion reaction
(a)
BLANK is the phenomenon that occurs when a flame front moves back through a burner nozzle and possibly back to the air-fuel mixing point
(a)
BLANK is the science of thermal energy (heat) and how it transforms to and from other forms of energy
(a)
in combustion of fuel gas, the BLANK are fuel gases such as natural gas or propane containing highly flammable molecules of carbon and hydrogen, and oxygen contained in the air surrounding a gas appliance and its gas burner
(a)
the BLANK is the theroretical or mathematically exact volume of air that must be mixed with fuel gas to achieve perfect combustion
(a)
BLANK air is air that passes throught the appliance combustion chamber and flues in addition to the quantity that is theoretically required for complete combustion, to ensure all of the fuel is burned
(a)
BLANK can occur when there is not enough oxygen to burn a fuel gas completely
(a)
if a number of multi-port burners are used together, they are referred to as a(n) BLANK
(a)
in addition to the main gas burners, a gas appliance will have a(n) BLANK gas burner that is used to ignit the main burner
(a)
the most common cause of BLANK in an atmospheric burner are a gas burner set with a high amount of primary air and/or low burner port loading (flow rate)
(a)
a(n) BLANK is an adjustable device for varying the size of the primary air inlet or inlets to control primary air flow
(a)
the cause of BLANK flames is an inadequate amout of primary air being supplied to the burner for complete combustion
(a)
BLANK is the act or process of burning; the process through which heat is released when combining the combustible elements of a fuel source with oxygen when that substance is ignited
(a)
BLANK combustion is the state reached when the mathematically exact volume of air required to completely burn the fuel gas is being used
(a)
BLANK is the general term used to describe a number of gaseous compounds used as fuel to generate heat or light energy
(a)
a(n) BLANK burner is a fuel gas burner in which the fuel gas and air are mixed before they are introduced into the combustion chamber for ignition
(a)
a(n) BLANK flame is a gas flame that lifts off a burner port
(a)
