Abstract: The present invention relates to air-cooled grate bars, in particular for mechanically conveying mechanical grates such as pivot step grates, comprising a cap of U-shape which is provided over the respective grate bar and is in particular welded on and which forms with the grate bar disposed therebelow passages extending longitudinally of the grate bar, the cap being led at the bearing-side end of the grate bar up to shortly before the curvature end and the cap and thus the passages being in each case sealed at the end face at the curved cap end.

Abstract: A step grate including feeding means, distributor, step grate elements and combustion grate, comprising a stationary flat grate on which the distributor acts, and at least one further flat grate associated therewith on which a further distributor acts, in each case with combustion air supply, this being followed by the combustion grate, and the stationary flat grate steps may be followed by pivot grate bars, said stationary flat grates being divided in two and downwardly up to 80% completely sealed.