ALEXANDRIA, Va., April 21 -- United States Patent no. 12,607,349, issued on April 21, was assigned to Schwank GmbH (Cologne, Germany).
"Dark radiator" was invented by Edgar Kreis (Freigericht, Germany), Alexander Genzel (Bonn, Germany), Torsten Stohler (Mettmann, Germany) and Thomas Renner (Wesseling, Germany).
According to the abstract* released by the U.S. Patent & Trademark Office: "A dark radiator includes a burner, a fan and a radiant tube which is connected to an exhaust gas discharge line, wherein the burner is connected to a fuel gas supply, wherein the fan is designed to supply the burner with combustion air, wherein the burner is designed to output a flame into the radiant tube, wherein the fuel gas supply is connected to a hydr...