The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 08, 1992
Filed:
Jan. 23, 1990
Douglas C Myhre, Eden Prairie, MN (US);
Richard J O'Brien, Burnsville, MN (US);
David Y Pui, Plymouth, MN (US);
Chuen-Jinn Tsai, St. Paul, MN (US);
Rosemount Inc., Eden Prairie, MN (US);
Abstract
A purging air flow system that causes air to pass over a pyrometer lens or window to keep it clean and free from particulate contaminants has an annular, continuous slot for air inlet around the periphery of the lens to permit flow of air across the lens without any obstructions in the path of flow inwardly from the outer edge of the lens. An asymmetric flow pattern is established across the lens surface, either by having a differential size slot at different peripheral portions of the peripheral edge of the lens or window, or by providing a radial swirl about the axis of the window so that when the air goes through the slot, the tangential velocity creates a moving asymmetric flow pattern on the window surface.