What is the function of the Baffles in a Boiler ?

Baffles are used in Boilers to reduce turbulence in the flow of the hot combustion gases over the boiler tubes.  The baffles maintain proper velocity of the gases which enables efficient energy transfer.

Baffles also guide the fly ash and slag to the proper place for deposition from where they an be easily removed.  

If the Baffles are damaged, it will result in overheating at certain places and poor heating in others.