title: Note: A heated-air curtain design using the Coanda effect to protect optical access windows in high-temperature, condensing, and corrosive stack environments.
abstract: We present an air knife design for creating a heated air curtain to protect optical infrared access windows in high-temperature, condensing, and corrosive stack environments. The design uses the Coanda effect to turn the air curtain and to attach the air curtain to the window surface. The design was tested and verified on our 24 m stack and used extensively over a 6 yr period on several release stacks. During testing and subsequent use no detrimental changes to access window materials have been noted. This design allows stack monitoring without significantly affecting the stack flow profile or chemical concentration.
authors.affiliation: National Security Technologies, LLC, Las Vegas, Nevada 89030, USA.
authors.forename: Gustavious Paul
authors.initials: GP
authors.lastname: Williams
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Keenan
authors.forename: James
authors.initials: J
authors.lastname: Herning
authors.forename: Clare
authors.initials: C
authors.lastname: Kimblin
authors.forename: John
authors.initials: J
authors.lastname: DiBenedetto
authors.forename: Glen
authors.initials: G
authors.lastname: Anthony