Injector Definition, Uses, and Principle 


Injectors Definition, uses and principle:-

Injector, a device for injecting liquid fuel into an Internal Combustion engine. The term is also used to describe a device to inject feed water into a boiler.

The typical sequence of four stroke diesel engine cycle events includes a single intake valve, fuel-injection nozzle, and exhaust valves, as shown here.

The injected fuel is ignited to compress hot air into the cylinder, spark-ignition being a more efficient process than internal-combustion engines.

Diesel engine fuel must be highly atomic in form for proper combustion. This is usually accomplished with a plunger and cylinder arrangement (solid injection), which accurately quantifies the amount of liquid fuel in the combustion chambers through the nuclear nozzles.

Injector Definition, Uses, and Principle

Compressed air (air injection) is sometimes used in place of a rider. These injectors are widely used in such diesel devices as rail engines, trucks, buses, earth movers, ships and stationary power plants, and sometimes aircraft and motor trucks are found in spark-ignition engines.

Boiler feed water injectors employ a high-velocity steam to force water into the jet boiler.

Because it was difficult to believe that boiler steam could bring both itself and the feed water back to the boiler, the introduction of such injectors (1859) by their inventor, Henry Gifford, generated much interest.


They can use exhaust steam at atmospheric pressure to deliver water at 1 Megacassal (150 pounds per square inch). The principle is similar to that employed in ejector. In a mixture with relatively cold feed water, the steam condenses, providing most of its momentum to the water.

The kinetic energy associated with the resulting high velocity is converted into pressure in a convergent-divergence pathway, which causes water to reach the boiler. Now almost entirely replaced by centrifugal boiler feed pumps, such injectors are primarily of historical interest.

Type of Injectors:-

There are many types of injectors some injectors are as follows-

1. Pressure Needle type.

2. Electro-magnet type.

3. Pintal type.

4. Pintex type.

5. Single hole type.

6. multi hole type.

7. Centrifugal type.