Lesson 1/Learning Event 2
FIGURE 7. EXAMPLE OF ATOMIZATION.
A liquid can be made to vaporize more rapidly by breaking it up into small drops. This can be done with an
ordinary spray gun. Breaking up a liquid into small droplets is called "atomizing" the liquid. When a liquid
is atomized and air surrounds all the small drops, more of the liquid is able to come in contact with air at
one time and the liquid will vaporize faster.
Gasoline that is not vaporized does not burn. Only the vapors burn. All the fuel in an engine's cylinder
should be burned before the end of its power stroke. Fuel that is still in liquid form is wasted. The fuel
that is left in the combustion chamber will be discharged through the engine's exhaust system. Some of it
may go past the piston into the crankcase and mix with the oil. This can cause damage to the engine
bearings because the gasoline will dilute the oil.
Gasoline fuels are blended mixtures that are refined from crude oil. Part of the mixture vaporizes at low
temperatures for cold engine starts. Other parts of the mixture vaporize better as the engine warms up.
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