Today in 1943, US Patent 2322749 A was issued, an invention of John F. Silhavy, for his “Heating and Treating Wort.” There’s no Abstract, although in the description it includes this summary:

This invention relates to heating and boiling wort and more particularly relates to heating and boiling wort by using submerged combustion and passing hot products of combustion through the wort or passing gases through the wort while heating it.