My Exam Notes
  • Home
  • CURRENT AFFAIRS
  • GENERAL AWARENESS
    • Child Category 1
  • BIHAR PSC
  • Home
  • CURRENT AFFAIRS
  • GENERAL AWARENESS
  • BIHAR GK
  • RAJASTHAN GK
  • MECHANICAL NOTES

Sunday, November 2, 2014

CARBURETION AND IGNITION IN INTERNAL COMBUSTION ENGINE

 Saurabh     6:09 AM     I C ENGINE     No comments   


 CARBURETION OF INTERNAL COMBUSTION ENGINE


As we know that engine works on fuel (may be petrol, diesel or any other gasoline product).
The fuel is supplied into the combustion chamber of engine where it is burned under high pressure.

Now a question arises that can engine breathe any amount of fuel and air mixture to its cylinder?
The answer is NO. This is because an engine work efficiently only at certain ratio of fuel and air mixture.

Hence carburetion is technique of providing exact amount of fuel and air mixture to combustion chamber of cylinder of an engine, and the device used for it is called carburetor.


Fig:-Carburetor

DESCRIPTION:-

The air from the atmosphere is sucked in air filter chamber and filtered. Then it passes through choke valve. The air then comes to narrow passage called venturi.The venturi section increases the speed of air (as the diameter decreases at the section). This enables good quality carburetion effect.At this point the air is mixed with fuel which is coming from another channel having nozzle at the tip. The fuel channel has a device called float,which regulates the amount of fuel entering the chamber.

The fuel-air mixture is then passed through the throttle valve. This valve regulates the amount of fuel-air mixture entering the engine cylinder and finally the mixture is released in combustion chamber.

VARIOUS FACTOR THAT AFFECT CARBURETION

Factor that has influence over carburetion are as fallows:-
  • Air temperature at inlet.
  • Fuel properties and its nature.
  • Operational speed of engine.
  • Shape,size,outline or blueprint of carburetor.
As the temperature of inlet air increases good quality of carburetion is achieved. This is because with increase in temperature, vaporization of fuel occurs and good homogeneity is obtained.The fuel properties has vast effect on carburetion process. The properties like melting point, boiling point, viscosity etc effect vaporization and intern proper carburetion.When engine operates at high speed, large amount of air-fuel mixture is to be supplied from carburetor.The construction of carburetor is also a major criteria where performance of device lies. The construction should be such that it should be most efficient in making exact mixture and in exact amount.

The best mixture ratio of air/fuel is 12/1.
 According to the demand of engine a carburetor should must fulfill the fallowing criteria. These are:-

  • During high power (full load) and ideal (no load) condition it should provide enriched mixture of air and fuel.
  • It should be economical and safe.

IGNITION IN INTERNAL COMBUSTION ENGINE




Curiously you would be imagining how combustion is initiated inside engine cylinder.
The process of ignition is initiated by propagation of flame which provides enough energy for beginning of burning of fuel till combustion gains momentum.

Suppose there are two electrodes,a spark is introduced between them at high voltage. This spark has capability to ignite the entire fuel and air mixture. There is critical voltage beyond which only spark is produced. This critical voltage is based on:-

  • Air-fuel ratio.
  • Gap between two electrodes.
  • Gas pressure.
Requirement of good ignition system:-

  • Should produce spark at correct time. This will help to reduce ignition delay or pre ignition. Hence will effect efficiency of engine.
  • Work over varying engine speed.
  • Easy to use and low in cost.
TYPES OF IGNITION SYSTEM
  • Older ignition system.
  1. Battery ignition system.
  2. Magneto ignition system.
  • Modern ignition system.
  1. Electronic orTransistorized ignition system.
  2. Capacitive type system.
1.  BATTERY IGNITION SYSTEM:-

BATTERY USED IN THIS TYPE OF SYSTEM
  • ALKALINE BATTERY used in commercial vehicle (heavy duty).
  • LEAD ACID BATTERY used in light vehicle (light duty).


FIG:-BATTERY IGNITION SYSTEM

CONSTRUCTION:-
The basic parts of battery ignition system are:-
  • Battery
  • Coil for ignition
  • Breaker
  • Distributor
  • Spark plug
The battery provides constant power (6V-12V) without any variation.The source is connected to a coil which acts as transformer.When the circuit is complete,the current flows through the circuits and enters into the coil.

The coil has primary and secondary winding, the primary winding is of approx 300 turns and secondary winding is of around 22000 turns. These winding are generally made up of copper. This difference in number of turns produces large potential difference.

Contact breaker is a tungsten made hard switch which is used to break circuit by cutting flow of current coming from ignition coil. It is operated by cam arrangement.

Distributor is a device that has arrangement of spark plug designed to fire in proper sequence and in accurate time.

MAGNETO IGNITION SYSTEM:-

In magneto ignition system there is no need of battery. Current is obtained by magneto system.Such engine requires less space.
No battery discharge problem in this system.




   
  

  • Share This:  
  •  Facebook
  •  Twitter
  •  Google+
  •  Stumble
  •  Digg
Email ThisBlogThis!Share to TwitterShare to Facebook
Newer Post Older Post Home

0 comments:

Post a Comment

MY TRAVEL VLOG-Being Tourist

Popular Posts

  • LATEST CURRENT AFFAIRS SEPTEMBER 2018, सितंबर हिंदी करेंट अफेयर्स 2018 (...
    PDF AT BOTTOM NOTES  International aviation Summit held in New Delhi . it was organised by Ministry of Civil Aviation, international...
  • TURBOMACHINES
                    TURBOMACHINE DEFINATIONAND  EXPLANATION A turbo-machine is a device in which energy transfer takes place between ro...
  • SINGLE PLATE CLUTCH,CONE CLUTCH AND CENTRIFUGAL CLUTCH
                   SINGLE PLATE CLUTCH DESCRIPTION  In the general arrangement it consists of a disc which has frictional material on both its s...
  • ENERGY LOSS IN PIPES, Darcy- weicbach formula, Chezy's formula, minor losses in pipe
    MECHANICAL TIPS AND STUDY MATERIAL When ever there is flow of fluid in pipes there will be resistance which add to energy loss. For our stud...
  • CASING OF CENTRIFUGAL PUMP, ITS TYPES AND PRIMING OF TURBINES
    MECHANICAL TIPS AND STUDY MATERIAL CASING OF CENTRIFUGAL PUMP As we know casing surrounds the impeller and guides the water and also raises ...
  • HYDRAULIC CRANE WITH CONSTRUCTION, WORKING AND NEAT IMAGE
    MECHANICAL TIPS AND STUDY MATERIAL This device has wide application in warehouses, dock slide, work shops etc. It is used for transferring o...
  • METAL INERT GAS WELDING AND TUNGSTEN INERT GAS WELDING
            TUNGSTEN INERT GAS WELDING (TIG) CHARACTERISTICS IN  BRIEF It is known as GAS TUNGSTEN ARC WELDING (GTAW). Also called Argon arc wel...
  • BERNOULLI'S THEOREM AND ITS APPLICATION-PITOT TUBE AND VENTURIMETER
    BER NOULLI'S THEOREM AND APPLICATION In steady flow of fluid, the Bernoulli principle state that at any point of time the sum of all for...
  • BOILING AND CONDENSATION
      Boiling and condensation At constant pressure if the temperature of the liquid is raised to saturation temperature then the liquid boils. ...
  • #MOST IMPORTANT AUGUST CURRENT AFFAIRS 2018 #PDF link #NOTES #अगस्त करें...
    PDF IS BELOW NOTES - Go Down Notes of August Current Affairs- Navlekha a new platform launched by Google .Google has announced pr...

Categories

AUTOMOBILE BASICS BHIHAR PSC BIHAR PSC biology quiz CURRENT AFFAIRS economics FASTEST MACHINES FLUID MECHANICS GEARS GENERAL AWARENESS HEAT AND MASS TRANSFER I C ENGINE JET ENGINES JOB OPENING IN USA MACHINING PROCESSES MANUFACTURING PROCESS MATERIAL SCIENCE mechanical engineering MECHANICAL JOB VACANCY IN INDIA MECHANICAL VIBRATION MISSILES POLITY QUIZ POWER PLANT ENGINEERING RAJASTHAN GK sports STRENGTH OF MATERIAL THERMODYNAMICS TOP COLLEGES TOP SPEED TURBINES WELDING

Pages

  • QUIZ

Featured post

SCIENCE & TECHNOLOGY CURRENT AFFAIRS 2018 (JANUARY - JUNE)विज्ञान प्रौद्...

CBSE (Central Board of indirect taxes) launched which app to check person collecting GST? GST verify National science day was celebrate...

ad code

Copyright © My Exam Notes | Powered by Blogger
Design by Hardeep Asrani | Blogger Theme by NewBloggerThemes.com | Distributed By blogger Templates