A combustion apparatus and process for improved flue gas recirculation wherein the recirculation line penetrates into an exhaust duct, such as the exhaust stack for capturing and directing a portion of said flue gas through the recirculation line which is connected to an air fan inlet which provides induction of the flue gas into the combustion unit. The pressure-reducing valve brings about a pressure drop which depends upon a pilot-pressure signal that is sent thereto by a pilot solenoid valve. The outer rim has a crown cap-like overall shape such that it includes, in the region of each cage pocket, a constriction that extends axially into the cage pocket and is in supporting contact with an end face of the rolling elements, and, in the region of each pocket web, a section corresponding to the outer diameter of the axial cage. Preferably, the item is one of a textile, a tile, a wallpaper, or a carpet.