A vertically disposed gas distributor for injection of combustion air into a shaft kiln. The air distributor extends from the upper portion of the shaft kiln to an intermediate combustion zone, and includes at least one cooling water inlet line and at least one cooling water return line. The cooling water inlet and return lines extend along and adjacent to the outer surface of a central gas conduit. The distributor includes an insulation layer covering the central gas conduit and the cooling water inlet and return lines, and includes a baffle member which directs cooling water from the cooling water inlet line around the outlet end of the gas conduit and to the cooling water return line.