Process for producing furnace atmospheres by deoxygenating non-cryogenically generated nitrogen with dissociated ammonia
US5290480A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1992 |
| Grant date | Mar 1, 1994 |
| Priority date | — |
| Expiry date | Dec 22, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/36
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for producing low-cost furnace atmospheres suitable for annealing and heat treating ferrous and non-ferrous metals and alloys, brazing metals and ceramics, sealing glass to metals, and sintering non-ferrous metal and ceramic powders from non-cryogenically produced nitrogen containing from 0.05 to 5.0% residual oxygen is presented. The disclosed process involves 1) mixing non-cryogenically produced nitrogen with a predetermined amount of dissociated ammonia, 2) passing the mixture through a low-pressure drop catalytic reactor, 3) converting the residual oxygen to an acceptable form such as moisture and reducing the residual oxygen level to below about 10 ppm, and 4) using the resultant gaseous mixture for annealing and heat treating ferrous and non-ferrous metals and alloys, brazing metals and ceramics, sealing glass to metals, and sintering non-ferrous metal and ceramic powders. The key feature of the disclosed process involves the use of a novel low-pressure drop catalytic reactor for converting residual oxygen with dissociated ammonia to moisture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.