US3679782A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of globular powder
Assignee: Olin Corp
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Filing: 1969-11-20
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Granted: 1972-07-25
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Expires: 1989-11-20
Abstract
Abstract A method of preparing globular propellant powder wherein presized lacquer particles are entrained in a liquor suspending medium and forced to flow through a long section of tubing until the propellant grains are dewatered and rounded into spherical shape. The spherically shaped powder globules are then passed into a flash evaporator having a pressure lower than that in the dewatering and shaping conduit so that a portion of the solvent within the globules volatilizes. The remaining solvent is removed by passing the slurry through a final hardener consisting of several chambers. Each of these chambers are individually heated to increase the temperature of the slurry of powder granules as it moves through the column. The temperature gradient between adjacent chambers in the latter stages may be increased.
Inventors
- 👤 Eugene A Andrew
- 👤 Henry J Halverson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:05
CPC Classifications
C; C06; C06B; C06B21/00; C06B21/0033; C06B21/0066
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
153 words
In the art of making powder grains, the method comprising continuously passing a lacquer of a smokeless powder base and a solvent therefor through at least one extrusion orifice, cutting said lacquer into discrete particles after it passes through said orifice, entraining said discrete particles in a liquor suspending medium which is a non-solvent for said powder base and substantially immiscible with said solvent to form a slurry, continuously passing said slurry through conduit means of a predetermined length and at a predetermined rate to shape said particles into spherical or near spherical shape, passing the resulting slurry of suspending medium and shaped lacquer particles through a first heating zone having a lower pressure than said line and a temperature above the boiling point of said solvent and thereafter continuously passing the remaining slurry through a series of heating zones at east some of which have a higher temperature than the preceding zone.
Claim 2
Independent Claim
28 words
The method of clam 2 wherein the lacquer is cut into cylinders having a length to diameter ratio of about 1 to 1 t form said discrete particles.
Claim 3
Dependent Claim
35 words
The method of claim 2 wherein the temperature of said conduit means is maintained at a temperature above the boiling point of the solvent and under a pressure sufficient to prevent vaporization of the solvent.
Claim 4
Dependent Claim
27 words
The method of claim 2 wherein at least half of the solvent is removed from the shaped lacquer particles during the passage thereof through said first zone.
Claim 5
Dependent Claim
32 words
The method of claim 2 wherein said suspending medium contains a dewatering salt to cause migration of any aqueous medium from said lacquer articles as said particles pass through said conduit means.
Claim 6
Dependent Claim
13 words
The method of claim 6 wherein said suspending medium is an aqueous medium.
Claim 7
Dependent Claim
166 words
In the art of making powder grains from a lacquer of a nitrocellulose based powder and a solvent therefor, the method comprising passing said lacquer through an extrusion plate, cutting said extruded lacquer into discrete particles, entraining said lacquer particles in a liquor suspending medium which is a non-solvent for said powder base and substantially immiscible with said lacquer to form a slurry, passing said slurry through conduit means for a time and temperature sufficient to shape said lacquer articles into a substantially spherical shape while maintaining said slurry at a pressure above atmospheric, passing the resulting slurry of shaped lacquer particles and suspending medium through a first evaporator at Atmospheric pressure and at a temperature above the boiling point of the solvent, and thereafter passing said slurry through a series of heating zones all maintained at atmospheric pressure, at least some of said zones having a higher temperature than the zone immediately preceding it, and thereafter separating said hardened powder grains fro said suspending medium.
Claim 8
Dependent Claim
175 words
In the art of making powder grains, the method comprising preparing a lacquer of smokeless powder base and a solvent therefor, preparing a liquor of an aqueous medium, a protective colloid and a dewatering salt, extruding said lacquer through an extrusion plate having at least one opening of predetermined size, cutting the extruded lacquer into lengths such that the length to diameter ratio of the resulting particles is about 1 to 1, immediately entraining said particles in said liquor to form a slurry and passing said slurry through a conduit for a time sufficient to cause migration of any aqueous medium from said lacquer particles and to permit said particles to assume a substantially spherical shape, passing said slurry through an evaporator at atmospheric pressure and at a temperature above the boiling point of said solvent, and thereafter passing said slurry through a series of heating zones all having a temperature higher than said evaporator and at least some of said zones having a temperature greater than the temperature of the zone immediately preceding it
Claim 9
Dependent Claim
73 words
The method of claim 14 wherein a first group of heating zones of said series of zones is maintained at a temperature about 2* to 4* C. above that of said first zone, the next zone is maintained about 2* to 4* C. above said evaporator, the next zone about 4* to 6* C. above that of the previous zone, and the final zone about 8* to 9* C. above the previous zone.
References Cited (Backward Citations)
US2740705A
Cited
US3014246A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |