There are Four different methods by which Fuel may be Ignited in Internal Combustion (IC) Engines.In my earlier post,you have come to know about Comparison of Coil & Magneto Ignition Systems.That Systems are under Spark Ignition System,as like this another Three Systems are as,
01)Hot Tube Ignition.
02)Hot Combustion Chamber Ignition.
We will see two Systems in this part and another two,in the next part-B
01)Hot Tube Ignition Method:-
This is the old method which was used in old days,now this method has become obsolete.But to gain some knowledge,here I disclose some description.This method used in Gas and Light Oil Engines,a porcelain or metal tube closed one end is heated red hot from an external source,to Temperature well above the Ignition Temperature of the Fuel so that when the latter is injected into the tube it immediately ignites.
The tube is heated at middle,through a Timing Valve,the hot tube communicates alternatively with the Cylinder when Ignition takes place and with the Atmosphere during expansion.In some Gas Engines this Timing Valve has been dispensed with and the ignition tube is in free communication with the Cylinder throughout,the instant of firing being determined by Compression of some of the Explosive Mixture into to the tube.As the Engine starts the heat of the tube from the previous explosion is sufficient to ignite the Fuel in the next cycle.
This method is mostly used on Engine working on "Otto Cycle" and consists in ignite the Fuel by producing a high tension Electric Spark.The Engines which are using this type of Ignition method are called "Spark Ignition Engines".In which one Spark must be produced at each cylinder at the correct moment.
Remaining two methods are covered in next post.