Abstract: A method for improving the adhesive capacity of a protectively coated steel sheet is proposed, in which, in a continuous process, a protective coating based on Zn—Al—Mg is applied to the steel sheet and, in a further step, the protective coating undergoes a surface treatment in which an aqueous composition is applied in order to modify the natural oxide layer, which contains Al2O3 and MgO, without pickling this natural oxide layer as a result. In order to significantly increase adhesive capacity of the protectively coated steel sheet, the invention proposes skin-pass rolling the protectively coated steel sheet and then reacting the natural oxide layer with an aqueous fluoride-containing composition, reducing its MgO content in order to thus modify the natural oxide layer.

Abstract: A method for improving the adhesive capacity of a protectively coated steel sheet is proposed, in which, in a continuous process, a protective coating based on Zn—Al—Mg is applied to the steel sheet and, in a further step, the protective coating undergoes a surface treatment in which an aqueous composition is applied in order to modify the natural oxide layer, which contains Al2O3 and MgO, without pickling this natural oxide layer as a result. In order to significantly increase adhesive capacity of the protectively coated steel sheet, the invention proposes skin-pass rolling the protectively coated steel sheet and then reacting the natural oxide layer with an aqueous fluoride-containing composition, reducing its MgO content in order to this modify the natural oxide layer.

Abstract: A heating device for burning gaseous fuels comprises an inner shell (3) of U-shaped or C-shaped cross-section which defines a combustion chamber (9) which is bordered by a covering plate (5) and a floor plate (4), can be closed by a door arrangement (6). Gas burner assembly (13) is arranged on a burner base plate (12) and secured to the inner shell (3). Outer shell (2) of U-shaped or C-shaped cross section, on the floor plate. The outer shell (2) is arranged from the inner shell (3) at a distance forming an intermediate space (28). End edges of outer shell (2) and the inner shell (3) are welded together. Openings (27) are arranged in the inner shell between the combustion chamber (9)and the intermediate space (28) which forms a flue gas passage between the openings (27) and the flue outlet (44) region of the covering leading (44) to a smoke pipe connection piece (45). Sheet elements adjacent the outer shell form a convection channel with the outer shell.

Abstract: A furnace for solid fuels is especially for pellets. This furnace includes a combustion chamber, a holder pan for the combustion material positioned in the combustion chamber, and a combustion material transport device located between the holder pan and a fuel container for combustion material. The combustion chamber is surrounded by a convection space, which is closed off towards the outside by a convection mantle, with a blower arranged between the ambient air and the convection space, if necessary. A flue gas blower is arranged between the combustion chamber and a flue gas line. A flue gas channel is arranged in front of at least one rear wall of the combustion chamber on the side facing away from the combustion chamber. This channel extends over at least part of a width and a height of the combustion chamber.