Sunday, February 3, 2008


A carburetor is a device that vaporized a liquid fuel such as gasoline and mixed it with air in the proper ratio for combustion in an internal-combustion engine, such as the gasoline engine that powers most Automobiles. Under ordinary condition the ratio a gasoline to air should be about 1:15 by weight. A higher ratio of gasoline is called a richer mixer, and a lower ratio is called leaner.

A simple form or carburetor consists of a float chamber, a jet nozzle, and an air chamber that is narrowed at one point. Such as narrowing in a chamber or tube is called a venture. A float valve keeps the gasoline at a constant level in the float chamber. When the engine is running, air is drawn into the air chamber, where it is accelerate by the venture. In accordance with Bernoulli's Law, this high-velocity air creates a low pressure region, and the jet nozzle, which is attached in this region, draws a fine spray of gasoline from the float chamber into the venture. Here it mixes the air, and the mixture is then fed to the engine cylinders, where it is ignited. A choke valve at the entrance to the carburetor is used to reduce the amount of air entering the chamber when the engine is cold, producing a richer mixture.

In practice, carburetors use various means to ensure an optimal mixture of gasoline and air under differing conditions, including idling and rapid acceleration. Instead of having a carburetor, an engine can have a system of fuel injection, which delivers a metered quantity of gasoline directly to each cylinder. Fuel injection has always been used with diesel engines; it has also been gaining in use with gasoline engine.

An automotive fuel system consists of the carburetor or fuel injector, the fuel tank, the fuel pump, and the fuel filter, along with tubing connecting the parts.

No comments: