G1-G3 Flashcards
7 performance characteristics of a burner
Complete combustion Rapid carryover of flames Quiet operation Immediate ignition Stable flame Uniform heating Wide turndown
6 main components of an atmospheric burner
Burner ports Burner head Venturi Orifice Mixing tube Primary air shutter
Why is a luminous flame yellow
Carbon in the flame biting off
Where are luminous flame burners used
Range top pilots
Fireplace lighters
Sandpan burners
Explain the operation of a atmospheric burner
Premix of some combustion air before ignition produces a blue or Bunsen flame smaller and more stable
Bernoulli’s theorem
High velocity low pressure
Limits of flam nat gas
4-14%
2 methods of measuring flame speeds
Bunsen burner m1 in oa tube
Flame speed of natural gas for each measurement method
Bunsen 12 inches / sec
Tube 25 in / sec
Which is faster burning hydrogen or acetylene
Hydrogen
When referring to the graph in fig 6 what is the burning velocity of acetylene
8.75
Name the three zones of a Bunsen flame
Outer mantle outer cone inner cone
I’m which zone of the Bunsen flame is the gas completely burned
Outer mantle
The maximum flame speed of natural gas occurs at what mixture of gas and air
10% gas and air
What is port loading
Amount of gas/air mixture passing thru a port
For most applications what is port loading for natural gas
25000 30000
2 most common results of unstable flames
Flashback and liftoff
How does flashback occur
When flow velocity from the ports are greater than the burning speed
What conditions may cause a waving flame
Drafts cracked heat exchangers
What conditions cause flame rollout
Overfiring
Vent blockage
Decreased sec air supply
On a non aerated pilot burner what would cause a lazy yellow flame
Orifice is too large
On a non aerated pilot burner, what would cause a lazy yellow flame
Orifice is too large
On a non aerated pilot burner what causes a lifting blowing flame
High gas pressure
On an aerated pilot burner what conditions cause a small blue flame
Low gas pressure
Clogged filter
Clogged orifice
On a aerated pilot burner what conditions cause a hard sharp flame
Orifice too small use of manufactured gas (coke gas)
3 main functions of a pilot burner
To ignite main burner flame
To provide a mount for thermocouple
To heat thermocouple or power pile
Two main types of pilot burner
Aerated
Non aerated
Two types of single port burners
Inshot
Upshot
Advantages of a multi port burner
Provide good heat transfer
Spread flames for secondary air to reach them
Provide stable blue flames
Name some common types of multi port burners
Drilled port
Drilled pipe
Slotted port
Ribbon port
What are some of the advantages of cast iron drilled port burners w small raised bosses for each port
Greater port length reducing flashback
More opportunity for secondary air to surround the flame jet
What is the range of port sizes for drilled port burners
No larger than 29
No smaller than 42
What are the critical factors in a drilled pipe burner design
Port size Tots port area Ratio of port area to cross section Total length Distance from mixer to first port
What are the disadvantages of the slotted port burner
Slots must be narrow, subject to plugging
Length of slot causes warping in hot places
Which type of burner uses a ceramic burner for radiating surface
Infrared radiant burner
Which type of burner is arranged so that the streams of the gas air mixture intersect each other to slow velocity and maintain a stable flame through a wide turndown
Barber burner
Where in relation to the combustion chamber would the combustion air blower be located in a forced draft burner system
Upstream of the combustion chamber
What is the name for a class of burners that do not require assistance from a fan to supply combustion air or to vent the flue products according to the natural gas and propane installation code
Natural draft burner
Which type of burner is equipped with a blower that produces just enough pressure to overcome the resistance of the burner and the appliance
Forced draft burner
Which type of burner has the Dan located at the flue outlet of the appliance
Induced draft burner
Which type of burner is equipped with a fan or blower that produces sufficient pressure to overcome the resistance of the burner only
Fan assist burner
Which type of burner mixes the required amount of air and gas before ignition
Pre mix burner
What device does an aspirating burner use to regulate the gas supply
Zero governor
Which type of burner mixes the required air and gas with a mechanical device
Blower mix burner
Which component of dual fuel burner directs the air fuel mixture to the appropriate part of the combustion chamber
Then blast tube
