Abstract: This invention relates to a heating device consisting of at least one burner for the combustion especially of a gaseous fuel, at least one radiant tube connecting to the burner, at least one fan generating a negative pressure or an excess pressure in the radiant tube, and at least one exhaust gas recirculation system with at least one exhaust gas recirculation passage through which an exhaust gas produced during the combustion of the primary fuel can be recirculated from the radiant tube to a transition zone from the burner into the radiant tube. In order to further develop a heating device of this type as well as a method for its operation the burner is adapted for being operated in at least two power stages and the exhaust gas recirculation system is controlled in dependence of the power stages of the burner in such a way that the volume flow of the recirculated exhaust gas is reduced with an increasing power stage of the burner.

Abstract: This invention relates to a heating device consisting of at least one burner for the combustion especially of a gaseous fuel, at least one radiant tube connecting to the burner, at least one fan generating a negative pressure or an excess pressure in the radiant tube, and at least one exhaust gas recirculation system with at least one exhaust gas recirculation passage through which an exhaust gas produced during the combustion of the primary fuel can be recirculated from the radiant tube to a transition zone from the burner into the radiant tube. In order to further develop a heating device of this type as well as a method for its operation the burner is adapted for being operated in at least two power stages and the exhaust gas recirculation system is controlled in dependence of the power stages of the burner in such a way that the volume flow of the recirculated exhaust gas is reduced with an increasing power stage of the burner.

Abstract: The present invention relates to a ceramic burner plate for infrared radiators which includes a lithium silicate as a main constituent. The burner plates according to the invention can have a content of lithium oxide within the range of 0.63% by weight to 7.6% by weight and they exhibit a high temperature resistance and are extremely durable.

Abstract: The invention relates to a radiation heater for air/gas admixtures which includes a double-wall housing of a generally trapezoidal transverse cross-section defined by a top wall and downwardly convering side walls. The housing includes a burner plate between a mixing chamber and a radiation grid, and the mixing chamber is fed the air/fuel admixture from an injector nozzle, a mixing tube, a preheated intermediate chamber, and a transition zone or chamber. The injector nozzle and the mixing tube are located at the lower edge of the housing side wall(s) to thereby provide an intermediate chamber extending essentially the length of the side wall(s) along the exterior of which the hot waste gases flow or brush to preheat the fresh admixture of air and fuel in the intermediate chamber thereby effecting reliable operation at low gas pressures and low manufacturing and repair costs.