Control of burners

Control means for the reactant flow ratio for at least one burner comprising separate valve means for the control of flow of fuel and of air to a burner, a variator associated with each valve for the setting of the position thereof, sensing means associated with each valve for the sensing of the position thereof, a memory device for holding data pertaining to the characteristics of the control means, said memory device having initially stored therein data representing a calculated parameter related to an optimum condition of combustion and data representing control information for the flow of fuel and air to the burner corresponding to said calculated optimum parameter, a computing device for controlling the variators to adjust the positions of said valves in accordance with the calculated data in the memory device, and detector means associated with the or each burner for the detection of the actual value of said parameter related to the optimum condition of combustion, both said sensing and detector means being connected to the memory device, said memory device further including means for continually and automatically up-dating said data stored in the memory to that data which is detected by said detector and sensing means only when the system achieves a condition of combustion which is an improvement over a previously determined optimum condition of combustion, such that the computing device automatically optimises the performance of the control means on the basis of the feedback of information from the said detector means and sensing means.