ALEXANDRIA, Va., June 6 -- United States Patent no. 12,281,791, issued on April 22, was assigned to Explo Engineering AG (Niederlenz, Switzerland), MARTIN GmbH fur Umwelt- und Energietechik (Munich), Hans Ruegg (Waltenschwil, Switzerland) and Kanadevia Inova AG (Zurich, Switzerland).

"Device and method for producing pressure waves of high amplitude" was invented by Paul Muller (Greppen, Switzerland) and Harald Herz (Baden, Switzerland).

According to the abstract* released by the U.S. Patent & Trademark Office: "A device for generating pressure waves of high amplitude, in particular for boiler cleaning, has a pressure-resistant container (21, 40) with a combustion chamber (121) inserted therein, which can be filled with a flowable burn-off...