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:
Apr. 13, 1993
Filed:
Jan. 30, 1989
Didier-Werke AG, Wiesbaden, DE;
Abstract
A refractory gas permeable injection device for introducing gas into a metallurgical vessel containing molten metal has a surface to be exposed to and progressively worn away by the molten metal during operation of the vessel. The device includes an outer body and an inner body within the outer body, at least the inner body being formed of a fireproof refractory material. A gas permeable space extends through the device in the direction of wear thereof, and the space has a plurality of different geometric shapes spaced in such direction. Upon the metallurgical vessel being emptied, and with the device still relatively hot, gas is caused to flow through the space such that the gas will create on the surface an optically recognizable image in a particular geometric shape as a function of the relative degree of wear of the device.