Method for controlling the firing rate of combustion installations

A method for controlling the firing rate of combustion installations, in particular refuse combustion installations comprising the steps of:

• depositing combustible material at the beginning of a fire grate;
• subjecting the combustible material on said fire grate to a stoking and forward motion;
• and
• removing resulting slag at the end of the fire grate,
• the stoking and forward motion of the combustible material being at least influenced as a function of the permeability to combustion air of fire grate and firebed,
• a control signal corresponding to a permeability to combustion air being determined by recording a free air outlet area of a total combustion air resistance body, composed of grate surface structure and firebed, and an experimentally determined flow coefficient which depends on a flow velocity of the combustion air, in accordance with an equation
• R.sub.K=F:.alpha.
• in which R.sub.K is a correct control signal, F is a fire air outlet area, .alpha. is a flow coefficient, and the free air outlet area is calculated from an equation ##EQU9## where V is a flow velocity through a combustion air resistance body, composed of the grate surface structure and the firebed, and which is calculated from an equation ##EQU10## where g is the gravitational acceleration, .gamma..sub.L is a specific weight of the air under the operating conditions and .DELTA.p is a static pressure difference between an undergrate zone and a furnace space.