Boiler blowdown

 

Original creation :25/8/2011

Boiler Safety

There are three things which are required for successful firing of Boiler.

• Admission of fuel –Atomized or as per design (including correct viscosity/temperature etc)
• Sufficient Air to ensure Combustion—
• Both above are in a proper Ratio (stoichiometric Ratio) and designed to mix  as per design.
• Ignition to kick start the Firing.

The above happen at a particular sequence with meticulously calculated time intervals

The entire process is Automated by Boiler

Misfiring of a Boiler –results when one of the above gets disturbed.

When there is a failure of complete of Fuel admission – Not much Harm might occur –except for the Boiler Not Firing.

However if there is a Failure of admission of AIR or IGNITION , fuel would be inserted into the boiler furnace which eventually never could be ignited .So Accumulation of Fuel Takes place which may leads to Furnace explosion when an attempt is made to fire again.

To avoid this, The Burner combustion control program always allows for a thorough Purge cycle.. a few minutes of Purging the Combustion Chamber with air which  removes all Fuel oil Vapors prior to admission of fresh Fuel and Ignition.

This does take some time and people run out of Patience due to operational demands and pressure. Thus the Extremely dangerous  practice of Bypassing the Purge sequence takes place . This is usually done by people putting the Firing to MANUAL MODE and starting the Firing sequencing. This practice has often resulted in serious injuries and fatalities.

Even in the manual mode ( when there is some problem with the Combustion program , Purging should be carried out manually by allowing 5~10 Minutes supply of Fresh air by the FD fan .Misfiring often results in the ignitor tips getting wet with oil.

may get wet with oil If they are  not properly positioned after Overhaul of Burners.

Apart from the serious Consequences, repeated trials after misfiring without investigating and rectifying the root cause often results in Burn out of the Ignition Rods or Failure of the Ignition transformer.

Another usual wrong Practice adopted on board is – Bypassing the flame sensor. This is also equally dangerous and may result in undesirable consequences.

Safety is of paramount importance and proper maintenance of Burning equipment is a must.