Pulse combustion – how it works

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Pulse – Combustion

Text in the illustration

air gas gas intake with flapper valve igniter (spark plug) air intake flapper valve air and gas are drawn into the combustion chamber through the flapper valves A B the air/gas mixture is ignited by the spark plug, creating the first pulse the pulse closes the gas and air flapper valves and pushes the combustion products out through the tail pipe reflected shockwave reflected shockwave air air/gas mixture gas when the reflected shockwave reaches the combustion chamber, it is hot enough to ignite the air/gas mixture without the aid of the spark plug this second pulse closes the flapper valves, sends the combustion products down the tailpipe and starts a repeating, self-sistaining combustion process igniter (spark plug) tailpipe tailpipe shockwave adapted from LENNOX illustration Pulse combustion – how it works as the shockwave leaves the combustion chamber, negative pressure is created that draws open the flapper valves and draws more air/gas mixture into the combustion chamber meanwhile, at the end of the tailpipe, the shockwave is being reflected back to the combustion chamber C D
air
gas
tailpipe
air intake flapper valve
gas intake with flapper valve
igniter (spark plug)
A
air and gas are drawn into the combustion chamber through the flapper valves
shockwave
B
the air/gas mixture is ignited by the spark plug, creating the first pulse
the pulse closes the gas and air flapper valves and pushes the combustion products out through the tail pipe
reflected shockwave
air/gas mixture
C
as the shockwave leaves the combustion chamber, negative pressure is created that draws open the flapper valves and draws more air/gas mixture into the combustion chamber
meanwhile, at the end of the tailpipe, the shockwave is being reflected back to the combustion chamber
D
when the reflected shockwave reaches the combustion chamber, it is hot enough to ignite the air/gas mixture without the aid of the spark plug
this second pulse closes the flapper valves, sends the combustion products down the tailpipe and starts a repeating, self-sistaining combustion process
adapted from LENNOX illustration

Generated explanation

Four sequential diagrams show the operating cycle of a pulse-combustion heating assembly with a combustion chamber, air and gas intake flapper valves, spark-plug igniter, and curved tailpipe. In stage A, air and gas enter the chamber through the flapper valves. In stage B, spark ignition produces a pressure pulse that closes the valves and pushes combustion products through the tailpipe. Stage C shows negative pressure reopening the valves to admit a fresh mixture while a shockwave reflects from the end of the tailpipe. In stage D, the returning hot shockwave ignites the mixture without the spark plug, repeating the combustion cycle.

Components

combustion chamber air intake gas intake air intake flapper valve gas intake flapper valve igniter (spark plug)tailpipe

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