Thursday, August 31, 2017

HAZARDOUS AREA CLASSIFICATIONS Part 1


Now a day’s safety has been taken important role in industry but Understanding of safety terms are still matter of experience as Engineers learns about safety through experience. There is no basic and fundamental course in Graduation about safety which can make an Engineering graduate understood about the industrial safety. An Engineer slowly learns about safety whenever he attends some safety workshop or meeting. 

Discipline Engineers directly do not come across the safety courses except the safety training which are most of the time done as a formality so their lack of understanding taken undue advantage to safety engineers. So below is the few important that can help you to understand the safety jargons and can boost your confidence while attending the meeting or workshop on a project.

One of the most important outputs of SAFETY is to done HAZARDOUS AREA CLASSIFICATIONS
So we understand about this first but before that lets have look on famous FIRE Triangle which says

Fire Occurs due to combinations of :
  1.  Flammable gas or dusts,
  2. Air / Oxygen  &
  3. Ignition source





Below are some Properties of Gases / Vapors for deciding Degree & Extend of Hazard.:
  1. Density, 
  2.  LEL(LFL) / HEL(UFL)
  3. Auto Ignition Temp.
  4. Gas Groups
  5.   Storing / processing temp.
  6. Volume
  7. Storing / processing pressure
Note:  Search on Google for Gases - Explosive and Flammability Concentration Limits for your case.

Now We come to the point :


1.        
What is an Hazardous Area ?
          An Area in which flammable substance in the form of gas, vapor or dust when mixed with the air, is present in such a proportions that it can explode when in contact with an ignition source.
          In such cases there is necessity to eliminate sources of ignition such as sparks, hot surfaces or static electricity which may ignite these mixtures.
          The mixture must be between the lower flammable limit & upper flammable limit in order to occur an explosion.( Refer Above Figure for LEL and HEL
          In order for ignition to occur, certain amount of energy is needed.
          The minimum ignition energy is the smallest possible amount of energy which is converted during the discharge of a capacitor and is just enough to ignite the most ignitable mixture.
 
Next part 02

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