Abstract: This invention refers to a burner for fluid fuels comprising an essentially cylindrical burner housing having an open end and a closed end, the open end being connectable to an exhaust pipe, a fuel supply means in the closed end in the longitudinal center axis of the housing, a combustion air supply passage in the peripheral wall of the housing, a tubular combustion chamber arranged co-axially within the housing, an annular space between said combustion chamber and the inner peripheral wall of the housing an annular space, said space being closed towards the open end of the housing, said air supply passage opening into said annular space.

Abstract: Burner units for fluid fuels such as oil or gas include a combustion chamber, a prechamber, means to enable combustion gases to recirculate from the combustion chamber to the prechamber, a mixing chamber in communication with the prechamber and the combustion chamber, a fuel nozzle for distributing fuel into the recirculated combustion gases and means including an air nozzle for supplying combustion air to the mixture of fuel and combustion gases whereby the energy of the air jet emerging from the air nozzle forms at least partially the means for recirculating the combustion gases.

Abstract: Apparatus for producing protective reducer gas, for use in plant having main and auxiliary burners for burning liquid or gaseous fuels, and designed either for heating purposes or for ore reduction processes. The apparatus includes a common cooling chamber into which the hot waste gases from the main and/or auxiliary burners can be fed selectively, the auxiliary burner being located immediately above the chamber with a combustion pipe extending downwards into the cooling chamber. Cooling water is injected directly into the upper part of the cooling chamber and withdrawn from the lower end. The waste gases from the main burner are admitted through a pipe terminating between the levels of two outlets in a side wall of the cooling chamber, the lower one having a valve closure, to control the level of the cooling water and so form a water seal for the waste gas inlet. The protective gas outlet is in the upper part of the cooling chamber.