ALEXANDRIA, Va., March 19 -- United States Patent no. 12,253,282, issued on March 18.
"Double-circuit electric boiler (variants)" was invented by Kostiantyn Leonidovych Serebrenykov (Kharkov, Ukraine) and Fedir Mashutovych Magasumov (Kharkov, Ukraine).
According to the abstract* released by the U.S. Patent & Trademark Office: "The invention is a double-circuit electric boiler for boiling a warming heat-carrying agent and a residential hot water. A hot water supply circuit first container and a second container with an electric heater for the heat-carrying agent of a warming circuit are arranged in a housing. Outer surfaces of inner walls of the warming circuit second container are in a contact with the water of the hot water supply circui...