TULSA, Okla., April 30, 2024 /PRNewswire/ -- ClearSign Technologies Corporation (Nasdaq: CLIR) ("ClearSign" or the "Company"), an emerging leader in industrial combustion and sensing technologies that improve energy, operational efficiency and safety while dramatically reducing emissions, today announces the receipt of two purchase orders to complete the detailed engineering of burners for the fitting of two additional process heaters in a California refinery for a total of four burners. "We are grateful an ...