Fuel is atomized

free hit counters

The more surface area of gasoline exposed to the air, the faster a given amount will burn. To produce the rapid burning required in an engine, gasoline must be broken up into tiny droplets and mixed with air. This is called ATOMIZING. Once the entire surface of each droplet of the air-fuel mixture is exposed to the surrounding air, a huge burning area becomes available. Given a spark, the entire amount of gasoline will flash into a flame almost immediately. In effect, atomization causes a sudden, explosion release of heat energy.

EXPLOSION MUST BE CONTAINED

To perform useful, work the explosive force caused by the burning gas must be contained and controlled. To illustrate this point, imagine that a metal lid is suspended on a string and held several inches from the ground. If a mixture of gasoline and air (atomized) were sprayed under it and ignited, the lid would be raised a short distance by the force of the explosion. The reason the lid hardly moved is because the explosion was not confined and directed toward the lid. Instead, the explosion exerted force in all directions, and much of the force was lost. If the gasoline and air mixture is sprayed inside a metal container with a lid, the full force of the explosion will be directed against the lid when the mixture is ignited. This will blow the lid high into the air.

Gasoline Must Burn Quickly

Gasoline placed in a container and ignited will produce a hot flame, yet it will not burn fast enough to produce the rapid release of heat necessary to run and engine. Even though a considerable quantity of fuel may be involved, a large flame will not necessarily result. As we all know, the surface area of a wick in a lighter is quite small. Vapor from the surface of the liquid, combined with oxygen, is what burns readily. If the surface of the liquid is small, relatively little vapor will be given off to provide combusion. Since the liquid must change to vapor before it is burned, it would take considerable time to use up the fuel at this rate. By placing the same amount of fuel in a shallow, wide container, more surface area will contact air and the fuel will burn rapidly. Remember, A small flame is produced, due to small area of exposed fuel. Follow this blog: Next - Fuel atomized.


Search Engine Optimization and SEO Tools

Small Engine Construction and Principles of Operation - Part I

After reading this, you will be able to:

* Explain simple engine operation.
* Know the qualities of gasoline that make you're mower an efficient small engine.
* Know why gasoline is atomized in the small engine.
* Know the basic components of your small engine and know the function of each part.

GASOLINE ENGINES

A gosoline-fueled ingine is a mechanism desinged to transform the chemical energy of burning fuel into mechanical energy. In operation, it controls and applies this energy to mow lawns, cut trees, propel tractors, and perform many other laborsaving jobs. A gasoline engine is an internal combustion engine. Gasoline is combined with air and burned inside the engine. In its simplest form, an engine consists of a ported cyliner, piston, connecting rod, and crankshaft.
The piston is a close fit inside the cylinder, yet it is free to slide on the lubricated walls. One end of the connecting rod is attached to the poston; the other end is fastened to an offset crankpin, or jouranl, of the crankshaft. As the piston moves up and down, the connecting rod forces the journal to follow a circular path, rotating the crankshaft.

SIMPLE ENGINE IN OPERATION

When the engine is cranked, gasoline is atomized (reduced to minute particles) and mixed with air. This mixture is forced through an intake port and into the cylinder, where it is compressed by the piston on the upstroke and ignited by an electrical spark. Combuston forces the piston down to rotate crankshaft. Burning rapidly, the heated gases trapped within the cylinder (combustion chamber) expand and apply pressure to the walls of the cylinder and to the top of the piston. This pressure drives the piston downward on the power stroke, causing the crankshaft to turn. As the piston and connecting rod push the crankshaft journal to the bottom of the stroke, the pressure of the burned gases is released through an exhaust port. Meanwhile, a fresh air-fuel charge enters the cylinder and the momentum of the power stroke turns the crankshaft journal through bottom dead center (BCD) and into the upstroke on another power cycle. Tommorow: Gasoline - The Hydrocaarbon Fuel in Small Engines.