(19)

(11)

EP 4 341 611 A2

(12)

(88) Date of publication A3: 29.12.2022 (43) Date of publication: 27.03.2024 Bulletin 2024/13 (21) Application number: 22805224.7 (22) Date of filing: 13.05.2022

(51) International Patent Classification (IPC):  F23C 3/00(2006.01) F23D 14/22(2006.01) F23D 11/40(2006.01) (52) Cooperative Patent Classification (CPC): F23D 14/02; F23D 14/64; F23D 2900/14021; F23D 2900/14042 (86) International application number: PCT/US2022/029325 (87) International publication number: WO 2022/245674 (24.11.2022 Gazette 2022/47)

(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR Designated Extension States: BA ME Designated Validation States: KH MA MD TN (30) Priority: 19.05.2021 US 202163190606 P 11.06.2021 US 202163209918 P (71) Applicant: ClearSign Technologies Corporation Tulsa, Oklahoma 74133 (US)	(72) Inventors: KENDRICK, Donald Bellevue, Washington 98008 (US) SANTANA, William A. Maple Valley, Washington 98038 (US) (74) Representative: Meissner Bolte Partnerschaft mbB  Patentanwälte Rechtsanwälte Postfach 10 26 05 86016 Augsburg 86016 Augsburg (DE)