Claims
- 1. A process of manufacturing a gas generating material comprising the steps of:
- preparing a hot solution at a temperature T.sub.1, of a metal azide with metal oxide particles suspended in the solution,
- precipitating the metal azide from the solution onto the metal oxide particles by cooling the hot solution to a temperature T.sub.2, said cooling being by indirect heat exchange with a cooling fluid, and thereafter,
- removing the metal azide precipitate and the metal oxide particles from the solute, the temperatures T.sub.1, and T.sub.2 providing a ratio of precipitated metal azide to suspended metal oxide which is effective for reaction of the metal azide with the metal oxide.
- 2. The process of claim 1 wherein the metal azide is an alkali metal azide and the solvent is water, the hot solution of metal azide being saturated.
- 3. The process of claim 2 wherein said azide is sodium azide and the temperature T.sub.1 is greater than about 200.degree. F. and the temperature T.sub.2 is less than about 40.degree. F.
- 4. The process of claim 3 wherein said metal oxide is iron oxide, and the assay of dissolved sodium azide in the hot solution is about 34.6% and the assay of the dissolved sodium azide of the cooled solution is about 21%.
- 5. The process of claim 1 wherein the heating is performed in a closed heating chamber.
- 6. The process of claim 1 performed on a continuous basis including a heating zone for preparing the hot solution, a cooling zone for cooling the hot solution, a separation zone for removing the precipitate and metal oxide particles from the solute, and a mixing zone for providing a feed to said heating zone, further including the step of continuously recycling solute from the separation zone to the mixing zone.
- 7. The process of claim 6 wherein said process is essentially a closed chamber process except the mixing zone further including the step of maintaining the mixing zone at a temperature below the boiling point of hydrozoic acid.
- 8. A continuous process of manufacturing a gas generating material comprising the steps of:
- preparing a hot solution of a metal azide in a heating zone at a predetermined assay with metal oxide particles at a predetermined concentration suspended in the solution,
- continuously maintaining said solution at said metal azide assay and said metal oxide concentration;
- continuously feeding said solution to a cooling zone,
- continuously precipitating the metal azide onto the metal oxide particles from said solution by cooling the hot solution in said cooling zone, said cooling being by indirect heat exchange with a cooling fluid and, thereafter,
- continuously removing the metal azide precipitate and the metal oxide particles from the solute in a separation zone.
- 9. The process of claim 8 including the step of continuously recycling the solute to said heating zone.
- 10. The process of claim 8 wherein the temperature of the solution in said heating zone is above about 200.degree. F. and in the cooling zone is below about 40.degree. F.
- 11. The process of claim 10 wherein the solvent of said solution is water, said metal azide is sodium azide and the assay of the dissolved sodium azide in said heating zone is about 34.6% and the assay of the dissolved sodium azide in said cooling zone is about 21%.
- 12. The process of claim 8 wherein the ratio of metal oxide in said cooling zone to precipitated sodium azide is that effective for substantially complete reaction of the metal azide with the metal oxide.
- 13. The process of claim 12 wherein the metal oxide is iron oxide and the metal azide is sodium azide and the weight ratio of metal oxide to metal azide is about 40/60.
- 14. The process of claim 8 including a mixing zone wherein the first heating zone is continuously fed from said mixing zone and the solute from the separation zone is continuously recycled to the mixing zone.
- 15. The process of claim 14 which is a closed chamber process except for the mixing zone, and the solvent of said solution is water, including the step of maintaining the mixing zone at a temperature below the boiling point of hydrozoic acid.
- 16. An essentially closed chamber process of manufacturing a gas generating material comprising the steps of:
- preparing a hot solution of a metal azide with metal oxide particles suspended in the solution in a closed heating zone,
- precipitating the metal azide from the solution onto the metal oxide particles in a closed cooling zone by cooling the hot solution, said cooling being by indirect heat exchange with a cooling fluid, and, thereafter,
- removing the metal azide precipitate and the metal oxide particles from the solute in a closed separation zone.
- 17. The process of claim 16 wherein the heat transfer in said heating zone is indirect.
- 18. The process of claim 16 wherein said process in continuous.
- 19. The process of claim 18 including a mixing zone and further including the steps of providing a continuous feed from said mixing zone to said heating zone and a continuous recycle of solute from said separation zone to said mixing zone.
- 20. The process of claim 19 wherein the solvent of said solution is water, said mixing zone is open to atmosphere, and is maintained at a temperature below the boiling point of hydrozoic acid.
- 21. The process of claim 16 wherein the metal azide is sodium azide and the temperature of the solution in said heating zone is above about 200.degree. F. and in said cooling zone below about 40.degree. F.
- 22. The process of claim 21 wherein the assay of the dissolved sodium azide in said heating zone is about 34.6% and the assay of the dissolved sodium azide in the cooling zone is about 21%.
- 23. The process of claim 22 wherein the metal oxide is iron oxide and the ratio of precipitated sodium azide to iron oxide in the cooling zone is that effective for substantially complete reaction of the metal azide with the metal oxide.
- 24. A process of manufacturing a gas generating material comprising the steps of:
- a) forming a metal azide by a process which includes making wet metal azide,
- b) adding metal oxide particles to the wet metal azide,
- c) maintaining the metal azide wet from the inception of the metal azide until after performing said step of adding metal oxide particles,
- d) preparing a hot solution of metal azide with the metal oxide particles suspended in the solution,
- e) precipitating the metal azide from the solution onto the metal oxide particles by cooling the hot solution, said cooling being by indirect heat exchange with a cooling fluid, the ratio of precipitated metal azide to suspended metal oxide being that effective for reaction of the metal azide with the metal oxide, and thereafter,
- f) separating the metal azide precipitate and metal oxide particles from the solute.
- 25. The process of claim 24 wherein said steps d), e) and f) are performed on a continuous basis, the temperature in step d) is greater than 200.degree. F., the temperature in step e) is less than 40.degree. F., and the flow rate during cooling is about 100 lbs./minute.
- 26. The process of claim 25 wherein the solvent of said solution is water and wherein the steps d), e), and f) are performed in essentially closed chambers, the temperature in steps b) and c) being below the boiling point of hydrozoic acid.
- 27. The process of claim 3 wherein the flow rate during cooling is about 100 lbs/minute.
- 28. The process of claim 10 wherein the flow rate during cooling is about 100 lbs/minute.
- 29. The process of claim 21 wherein the flow rate in the cooling zone is about 100 lbs/minute.
Parent Case Info
This is a continuation of application Ser. No. 07/595,047, filed on Oct. 10, 1990, now abandoned.
US Referenced Citations (6)
Foreign Referenced Citations (1)
Number |
Date |
Country |
1087852 |
Oct 1980 |
CAX |
Continuations (1)
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Number |
Date |
Country |
Parent |
595047 |
Oct 1990 |
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