Explosion VS Implosion in Boiler
Numerous conditions can arise in connection with the operation of a boiler that produces explosive conditions. The most common of these are as follows.
a) An interruption of the fuel or air supply or ignition energy to the burners, sufficient to result in momentary loss of flames, followed by restoration and delay re-ignition of an accumulation.
b) Repeated unsuccessful attempts to light off without appropriate purging, resulting in the accumulation of an explosive mixture.
c) The accumulation of an explosive mixture of fuel and air as a result of flame is at one or more burners in the presence of other burners, operating normally or during lighting of additional burners.
d) The accumulation of an explosive mixture of fuel and air as a result of a complete furnace flame out and the ignition of the accumulation by a spark or other ignition source, such as could occur where attempting to light a burner(s).
A furnace implosion is the result of the occurrence of excessively low gas side pressure, which causes equipment damage. Two conditions that have caused furnace implosion include:
a) A mal-operation of the equipment regulating the boiler gas flow, including air supply and flue gas removal, resulting in furnace exposure to excessive induced draft fan head assembly.
b) The rapid decay of furnace gas temperatures and pressure resulting from either a
rapid reduction in fuel input or a master fuel trip.