US3854882A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system in an apparatus for reacting silicon with nitrogen
Assignee: Saint Gobain Abrasives Inc
•
Filing: 1973-01-17
•
Granted: 1974-12-17
•
Expires: 1993-01-17
Abstract
Abstract Apparatus for nitriding silicon with means for controlling the flow of nitrogen into a reaction chamber as a function of the pressure in the chamber. The rate of flow of nitrogen is also measured, this being a measure of the reaction rate, and is used as a means for controlling the operation of the apparatus. When this nitrogen flow rate reaches a predetermined amount the apparatus provides for flooding the reaction chamber with an inert gas for a predetermined set period. The automatic on and off cycling of inert gas and nitrogen provides high yields of nitrided product while preventing run away reaction.
Inventors
- 👤 M Washburn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:30
CPC Classifications
G; G05; G05D; G05D27/00; C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/591; F; F23; F23N; F23N1/00; F23N1/08
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
179 words
IN AN APPARATUS FOR REACTING SILICON WITH NITROGEN AT ELEVATED TEMPERATURE IN A HEATED REACTION CHAMBER, WHICH INCLUDES A SOURCE OF INERT GAS, A CONDUIT FOR INTRODUCING INERT GAS INTO THE REACTION CHAMBER, A FIRST VALVE MEANS IN SAID INERT GAS CONDUIT, A NITROGEN SOURCE, A CONDUIT FOR INTRODUCING SAID NITROGEN INTO THE REACTION CHAMBER, AND A SECOND VALVE MEANS IN SAID NITROGEN CONDUIT FOR CONTROLLING THE FLOW OF NITROGEN INTO SAID REACTION CHAMBER, THE IMPROVEMENT WHICH COMPRISES MEANS FOR CONTROLLING SAID SECOND VALVE MEANS AS A FUNCTION OF THE PRESSURE IN THE REACTION CHAMBER, MEANS FOR MEASURING THE RATE OF FLOW OF NITROGEN THROUGH THE CONDUIT AND INTO THE CHAMBER, A TIMING MEANS, AND MEANS RESPONSIVE TO A PREDETERMINED RATE OF NITROGEN FLOW INTO SAID REACTION CHAMBER: A. TO ACTUATE THE SECOND VALVE MEANS TO REDUCE THE FLOW OF NITROOGEN TO THE REACTION CHAMBER, B. TO ACTUATE THE FIRST VALVE MEANS TO INTRODUCE INERT GAS INTO THE REACTION CHAMBER, AND C. TO ACTUATE SAID TIMING MEANS, SAID TIMING MEANS BEING EFFECTIVE AFTER A PREDETERMINE INTERVAL, TO REOPEN THE
Claim 2
Dependent Claim
179 words
IN AN APPARATUS FOR REACTING SILICON WITH NITROGEN AT ELEVATED TEMPERATURE IN A HEATED REACTION CHAMBER, WHICH INCLUDES A SOURCE OF INERT GAS, A CONDUIT FOR INTRODUCING INERT GAS INTO THE REACTION CHAMBER, A FIRST VALVE MEANS IN SAID INERT GAS CONDUIT, A NITROGEN SOURCE, A CONDUIT FOR INTRODUCING SAID NITROGEN INTO THE REACTION CHAMBER, AND A SECOND VALVE MEANS IN SAID NITROGEN CONDUIT FOR CONTROLLING THE FLOW OF NITROGEN INTO SAID REACTION CHAMBER, THE IMPROVEMENT WHICH COMPRISES MEANS FOR CONTROLLING SAID SECOND VALVE MEANS AS A FUNCTION OF THE PRESSURE IN THE REACTION CHAMBER, MEANS FOR MEASURING THE RATE OF FLOW OF NITROGEN THROUGH THE CONDUIT AND INTO THE CHAMBER, A TIMING MEANS, AND MEANS RESPONSIVE TO A PREDETERMINED RATE OF NITROGEN FLOW INTO SAID REACTION CHAMBER: A. TO ACTUATE THE SECOND VALVE MEANS TO REDUCE THE FLOW OF NITROOGEN TO THE REACTION CHAMBER, B. TO ACTUATE THE FIRST VALVE MEANS TO INTRODUCE INERT GAS INTO THE REACTION CHAMBER, AND C. TO ACTUATE SAID TIMING MEANS, SAID TIMING MEANS BEING EFFECTIVE AFTER A PREDETERMINE INTERVAL, TO REOPEN THE
Claim 3
Dependent Claim
42 words
The apparatus of claim 1 wherein said second valve means includes two valves in series, one of said valves being controlled as a function of pressure in the chamber and the other being controlled as a function of rate of nitrogen flow.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-16 | 1978-06-17 | 1978-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-16 | 1982-06-17 | 1982-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-16 | 1986-06-17 | 1986-12-17 | $7700.00 | Window Closed / Lapsed |