Abstract: In order to carry out the method for controlling the firing rate of the combustion installation, the fire grate is equipped with a plurality of undergrate zones. In order to determine the control signal, the undergrate zone at the beginning of the main combustion zone is equipped with the corresponding measurement devices, namely a temperature sensor and a pressure sensor and the associated air supply line is equipped with an airflow measuring device. A further pressure sensor is provided in the furnace space so that the static pressure difference between the undergrate zone and the furnace space can be determined. The measured values from this measurement equipment are supplied to a central computer ZR which outputs, if necessary taking account of a flow coefficient .alpha.

Abstract: For determining the average radiation of a surface region of a burning bed, an infrared camera is used in a firing installation, which camera is aligned with this region and is equipped by means of appropriate flame filters in such a way that it operates at the minimum of the interfering radiation emanating from the flame, whereby this interfering radiation is already largely eliminated. In order then also to eliminate the solids radiation from moving particles and thus to obtain a temperature measurement of the burning bed, recordings are made successively at short intervals of time by means of the infrared camera and these are evaluated in the evaluation and control device.