A method for adjusting a supply of gaseous medium to a fluidized bed boiler
performing a combustion process and including a pipe grate comprising a
plurality of pipes. An active area of the pipe grate is adjusted to form
at least one inactive bed area that is out of use by shutting off the
supply of gaseous medium to some of the pipes of the pipe grate utilizing
pipe-specific control means included in at least some of the pipes of the
pipe grate. Cooling medium is conducted through cooling channels located
in the pipes in the at least one inactive bed area at least during the
combustion process.
