METHODS OF FUEL INJECTION USED in C.I ENGINES ( DIESEL ENGINES)

There are two methods of fuel injection used in C.I Engines :

a) Air Injection System

b) Air-less or solid Injection

A) AIR INJECTION SYSTEM :

In this method, initially air is compressed to a very high pressure by means of compressor. The fuel was metered and pumped to the nozzle. which was also connected to a source of high pressure air. When the nozzle was opened, the air would sweep the fuel into the engine and deliver a well atomized spray. This method is not used now - a -days because of complicated and expensive system.

B) AIRLESS OR SOLID SYSTEM :

This method has greatly replaced the air injection method. The fuel under pressure is directly injected into the combustion chamber in atomized state. It requires a pump to deliver the fuel at high pressure ( as high as 300bar abs). It may be further classified into the following two commonly used systems.

i) Common Rail System

ii) Individual Pump System

i) COMMON RAIL SYSTEM :

Multi-cylinder high pressure pump is used to supply the fuel at a high pressure to a common rail on header. A metered quantity of fuel is supplied to each cylinder from the rail.

ii) INDIVIDUAL PUMP SYSTEM :

In this system, each cylinder of the engine is provided with an individual injection valve, a high -pressure pump and a metering device. It is quite compact but since at all operating loads and speeds each pump in this unit should very precisely match its companions, extremely close tolerances are required during manufacturing. Therefore, it involves higher costs.

Comments

ELECTRICAL COMPARATORS AND ITS WORKING

Electrical Comparators are used as a means of detecting and amplifying small movements of a work contacting elements. An electrical comparator consists essentially of a pick-up head or transducer for converting a displacement into a corresponding change in current and a meter or recorder connected in the circuit to indicate the electrical change, calibrated to show in terms of displacement. Generally, an amplifier is needed to provide the requisite sensitivity and to match the characteristics of different parts of the circuit. Electrical comparators can be classified according to the electrical principle used in the pick-up head. Most of the comparators use either a differential transformer, an inductance bridge, a strain gauge or a capacitor as a means of detecting movement of the gauging element. There are different types of electrical comparators. One kind called an electrolimit gauge is used to check or measure the outside diameter of a roll. The objec...

TOP POLLUTION RECORDED IN WORLD

CHERNOBYL NUCLEAR DISASTER (NUCLEAR POLLUTION) : In April 26,1986, the melt down of the Chernobyl nuclear reactor , in Russia, has leaked out the radioactive rays and radioactive materials. Effects : 1. In this Pollution nearly 2000 persons have been killed by the accident. 2. People suffered due to the illness such as, degeneration of the cells, severe bleeding, anemia, skin cancer. 3. Animals, Plants are also affected by nuclear radiation. MINAMATA EPIDEMIC (1953) : MARINE POLLUTION ( CASE STUDY ) Minamata is a small coastal village in Japan. The Chisso Chemical Company , which produces vinyl polymer plastics used organomercurial compound. The industry released its effluent into Minamata sea. The effluent containing mercury ions is converted into methyl mercury, which is highly toxic. The marine organisms like phytoplankton and zoo-planktons easily absorb the toxic methyl mercury compound. These organisms are consumed by small fishes and these are in ...

MELTING FURNACES FOR FERROUS METALS : CUPOLA AND ITS WORKING

Various types of melting furnaces are used in different foundry shops, depending upon the quantity of metal to be melted at a time, and the nature of work that is carried out in the shop. The primary objective in cupola is to produce iron of desired composition, temperature and properties at the required rate in the most economical manner. Besides, this furnace has many distinct advantages over the other types, e.g., simplicity of operation, continuity of production, and increased output coupled with a high degree of efficiency. Description Of a Cupola : The Cupola Furnace consists of a vertical, cylindrical steel sheet, 6 to 12 mm thick, and lined inside with acid refractory bricks or acid tamping clay. The refractory bricks or the tamping clay used consist of silicon oxide acid (SiO2) and alumina (Al2O3). The lining is generally thicker in the lower where the temperatures encountered are higher than in the upper region. The shell is mounted either on a brick work fo...

Mechinopedia For Mechanical Engineers

Search This Blog