Friday, 2 August 2019

Questions related on Fire and Safety By P Mohan ., Sr.Faculty NIFS


Q1) WHAT IS FIRE?
ANS) FIRE IS THE VISIBLE PROCESS OF CHEMICAL REACTION (COMBUSTION REACTION) BETWEEN OXYGEN IN THE AIR AND ANY COMBUSTIBLE MATERIAL (FUEL) RELEASING HEAT.

Q2) WHAT ARE THE ELEMENTS INVOLVED IN FIRE?
ANS)  THEY ARE THREE ELEMENTS INVOLVED IN FIRE
             SOLID LIQUID OR GAS COMBUSTIBLE MATERIAL ALSO CALLED FUEL,
             OXYGEN TAKEN FROM SURROUNDING AIR,
             HEAT

Q3) WHAT IS FIRE TRIANGLE?
ANS)  THEY ARE THREE ELEMENTS INVOLVED IN FIRE
             SOLID LIQUID OR GAS COMBUSTIBLE MATERIAL ALSO CALLED FUEL,
             OXYGEN TAKEN FROM SURROUNDING AIR,
             HEAT
THESE THREE ELEMENTS ARE CALLED FIRE TRIANGLE, WHICH ARE REPRESENTED AT THE SIDES OF TRIANGLE

Q4) WHAT IS DIFFERENCE BETWEEN STARTING OF FIRE AND PROPAGATION OF FIRE?
ANS)   1 ) FIRE STARTS WHEN HEAT ENERGY IN THE FORM OF IGNITION (SPARK, FLAME) STARTS A CHEMICAL REACTION BETWEEN OXYGEN IN THE AIR AND COMBUSTIBLE  MATERIAL (FUEL).THIS IS CALLED FIRE STARTING OR FIRE INITIATION.
                2) AFTER FIRE STARTS THE CHEMICAL REACTION BETWEEN OXYGEN AND FUEL GENERATES HEAT, WHICH PROVIDES THE REQUIRED TEMPERATURE TO CONTINUE REACTION BETWEEN OXYGEN AND FUEL, THIS IS CALLED FIRE PROPAGATION

Q5) WHAT IS FLASHPOINT AND FIRE POINT?
ANS)   1 ) THE FLASH POINT IS THE LOWEST TEMPERATURE AT WHICH THE LIQUID GIVES OFF ENOUGH VAPOR TO FORM IGNITABLE MIXTURE IN AIR,  BUT  VAPOR FORMED CANNOT SUSTAIN THE FIRE WHEN THE IGNITION SOURCE IS REMOVED
                2) THE FIRE POINT IS THE LOWEST TEMPERATURE AT THE WHICH THE VAPOR FROM THE LIQUID CAN CONTINUE TO BURN FOR ATLEAST 5 SECONDS AFTER THE IGNITION HAS STARTED        
               
Q6) WHAT ARE TWO MAIN CLASSES OF VOLATILE LIQUIDS BASED ON FLASHPOINT?
ANS) THE TWO MAIN CLASSES OF VOLATILE LIQUIDS BASED ON FLASH POINT ARE FLAMMABLE LIQUIDS AND COMBUSTIBLE LIQUIDS

Q7) WHAT IS DIFFERENCE BETWEEN FLAMMABLE AND COMBUSTIBLE?
ANS) 1) LIQUIDS WHICH HAVE FLASHPOINT OF LESS THAN (140°F) or (60°C) ARE CALLED FLAMMABLE
         2) LIQUIDS WHICH HAVE FLASHPOINT OF ABOVE (140°F) or (60°C) ARE CALLED COMBUSTIBLE

Q8) WHAT IS DIFFERENCE BETWEEN FLAMMABLE AND COMBUSTIBLE LIQUIDS?
ANS) 1) LIQUIDS WHICH HAVE FLASHPOINT OF LESS THAN 37.8°(100°F) ARE CALLED FLAMMABLE
         2) LIQUIDS WHICH HAVE FLASHPOINT OF ABOVE 37.8°(100°F) ARE CALLED COMBUSTIBLE

Q9) WHAT IS DIFFERENCE BETWEEN DEFLAGRATION AND DETONATION?
ANS) 1) A SURFACE PHENOMENON OF RAPID AUTO COMBUSTION OF PARTICLES RESULTING IN A SHOCK WAVE MOVING AT A SPEED LESS THAN SOUND IS KNOWN AS DEFLAGRATION.
                 2) A RAPID, SELF PROPAGATING, DECOMPOSITION OF  AN EXPLOSIVE RESULTING IN A HIGH TEMPERATURE – PRESSURE SHOCK WAVE MOVING AT A SPEED MORE THAN THE SPEED OF SOUND IS CALLED DETONATION 

Q10) WHAT IS DIFFERENCE BETWEEN FIRE AND EXPLOSION?
ANS) 1) IN EXPLOSION THE HEAT ENERGY IS RELEASED AT A VERY FAST RATE DURING COMBUSTION PROCESS INVOLVING THE LIBERATION AND EXPANSION OF LARGE VOLUME OF GAS.
2) IN FIRE THE HEAT ENERGY IS RELEASED AT A VERY SLOW RATE DURING COMBUSTION PROCESS

Q11) WHAT IS MEANT BY SMOTHERING, COOLING, STARVATION IN STOPPING FIRE?
ANS)      1) SMOTHERING - CUTTING OFF OXYGEN SUPPLY TO FIRE.
               2) COOLING - REMOVAL OF HEAT FROM THE BURNING SUBSTANCE.
               3) STARVATION – REMOVAL OF FUEL FROM TEH BURNING SUBSTANCE.

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