US3875273A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hollow pellets and method of making same
Assignee: Coors Porcelain Co
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Filing: 1973-11-26
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Granted: 1975-04-01
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Expires: 1993-11-26
Abstract
Abstract In accordance with the invention, hollow pellets having outer surfaces of one material and inner surfaces of another material are manufactured by dropping drops of liquid into a bed of powder containing the material of which it is desired to make the outer surface portions of the hollow pellets and preferably also a binder, the liquid containing the material of which it is desired to make the inner surface portions of the hollow pellets. When the drops of liquid fall into the powder, the powder immediately forms a spherical shell around each drop so as to form the hollow pellets upon vaporization of the liquid. It is preferred that the powder additionally contain some sodium bicarbonate or the like and that the liquid be an aqueous acid solution such that, upon initial formation of the spherical shell of powder, the acid reacts with the sodium bicarbonate to generate carbon dioxide which causes the spherical shell to expand while yet additional powder coalesces onto the shell. This results in hollow pellets wherein the inner surfaces are formed from material included in the liquid and the outer surfaces are formed from material included in the bed. The method is particularly useful for the manufacture of pellets wherein at least the outer surfaces are of ceramic, there being a firing operation on the pellets after removal from the powder bed so as to sinter the ceramic to monolithic structure.
Inventors
- 👤 Robert M Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:03
CPC Classifications
B; B01; B01J; B01J2/00; B01J13/00; B01J13/02; B01J2/16; C; C04; C04B; C04B38/00; C04B38/009; B01J35/00; B01J35/50; B01J35/51; B01J35/52
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
135 words
A METHOD FOR MAKING HOLLOW PELLETS HAVING INTERIOR SURFACE PORTIONS OF A MATERIAL WHICH IS DIFFERENT THAN THE MATERIAL OF THE EXTERIOR SURFACE PORTIONS, SAID METHOD COMPRISING: SURROUNDING AT LEAST MOST OF THE SURFACE OF DROPS OF A LIQUID WITH POWDER WHICH INCLUDES THE MATERIAL FROM WHICH IT IS DESIRED TO MAKE THE EXTERIOR SURFACE PORTIONS OF THE PELLETS AND WHICH IS INSOLUBLE IN THE LIQUID THEREBY TO FORM A SHELL OF THE POWDER AROUND EACH OF THE DROPS, SAID LIQUID CONTAINING MATERIAL FROM WHICH IT IS DESIRED TO MAKE THE INTERIOR SURFACE PORTIONS OF THE PELLETS, AT LEAST ONE OF SAID LIQUID AND POWDER INCLUDING A BINDER FOR THE POWDER MATERIAL WHICH BINDER IS SOLUBLE IN THE LIQUID; AND THEREAFTER EVAPORATING THE LIQUID THROUGH THE SHELL OF POWDER THEREBY TO PROVIDE THE HOLLOW PELLETS.
Claim 2
Independent Claim
135 words
A METHOD FOR MAKING HOLLOW PELLETS HAVING INTERIOR SURFACE PORTIONS OF A MATERIAL WHICH IS DIFFERENT THAN THE MATERIAL OF THE EXTERIOR SURFACE PORTIONS, SAID METHOD COMPRISING: SURROUNDING AT LEAST MOST OF THE SURFACE OF DROPS OF A LIQUID WITH POWDER WHICH INCLUDES THE MATERIAL FROM WHICH IT IS DESIRED TO MAKE THE EXTERIOR SURFACE PORTIONS OF THE PELLETS AND WHICH IS INSOLUBLE IN THE LIQUID THEREBY TO FORM A SHELL OF THE POWDER AROUND EACH OF THE DROPS, SAID LIQUID CONTAINING MATERIAL FROM WHICH IT IS DESIRED TO MAKE THE INTERIOR SURFACE PORTIONS OF THE PELLETS, AT LEAST ONE OF SAID LIQUID AND POWDER INCLUDING A BINDER FOR THE POWDER MATERIAL WHICH BINDER IS SOLUBLE IN THE LIQUID; AND THEREAFTER EVAPORATING THE LIQUID THROUGH THE SHELL OF POWDER THEREBY TO PROVIDE THE HOLLOW PELLETS.
Claim 3
Dependent Claim
31 words
A method as set forth in claim 1, wherein the combination of said liquid and powder includes material for generating gas within the shell thereby to cause the shell to expand.
Claim 4
Dependent Claim
41 words
A method as set forth in claim 2, wherein one of said liquid and powder includes an acid and the other of said liquid and powder includes a material which reacts with the acid to cause the generation of carbon dioxide.
Claim 5
Dependent Claim
23 words
A method as set forth in claim 3, wherein the liquid is an aqueous acid solution and wherein the powder includes a carbonate.
Claim 6
Dependent Claim
21 words
A method as set forth in claim 1, wherein the powder is heated to approximately the vaporization temperature of the liquid.
Claim 7
Dependent Claim
15 words
A method as set forth in claim 1, wherein the binder is in the powder.
Claim 8
Dependent Claim
24 words
A method as set forth iN claim 1, wherein the powder is prepared by spray drying a slurry containing said material and said binder.
Claim 9
Dependent Claim
34 words
A method as set forth in claim 1, wherein said powder material is sinterable and wherein said pellets, after evaporation of the liquid therefrom, are heated to the sintering temperature of said powder material.
Claim 10
Dependent Claim
14 words
A method as set forth in claim 8, wherein said powder material is ceramic.
Claim 11
Dependent Claim
21 words
A method as set forth in claim 1, wherein the powder with which said drops are surrounded is suspended in gas.
Claim 12
Dependent Claim
20 words
A method as set forth in claim 10, wherein said powder is in the form of a fluidized bed thereof.
Claim 13
Dependent Claim
36 words
A method as set forth in claim 1, wherein said liquid consists predominantly of water and wherein the temperature of the powder with which the drops are surrounded is heated to a temperature of approximately 212*F.
Claim 14
Dependent Claim
21 words
A method as set forth in claim 1, wherein said drops of liquid are dropped into a bed of said powder.
Claim 15
Dependent Claim
31 words
A method as set forth in claim 13, wherein after said drops of liquid are dropped in said bed of said powder additional of said powder is placed over said drops.
Claim 16
Dependent Claim
23 words
A method as set forth in claim 14, wherein the additional powder placed over said drops is sufficient to completely surround the drops.
Claim 17
Dependent Claim
24 words
A method as set forth in claim 14, wherein said powder is prepared by spray drying a slurry containing said material and said binder.
Claim 18
Dependent Claim
48 words
A method as set forth in claim 1, wherein said liquid is an aqueous solution and wherein said powder is prepared by spray drying a slurry containing said powder material, said binder and a material which reacts with the solute of said aqueous solution to generate a gas.
Claim 19
Dependent Claim
14 words
A method as set forth in claim 17, wherein said gas is carbon dioxide.
Claim 20
Dependent Claim
39 words
A method as set forth in claim 1 wherein the said material included in the liquid is in the form of a powder such that the liquid consists of a suspension of the said powder in the liquid ingredients.
Claim 21
Dependent Claim
21 words
A method as set forth in claim 1 wherein the said material included in the liquid is dissolved in the liquid.
Claim 22
Independent Claim
113 words
A method for manufacturing hollow pellets having interior surface portions of a material different than the material of the outer surface portions, said method comprising dropping into a powder suspended in gas drops of a liquid to which the powder adheres thereby to form a shell of the powder around the drop, said powder including material from which it is desired to make the exterior surface portions of the pellets, which material is insoluble in said liquid and said liquid containing material from which it is desired to make the interior surface portions of the pellets, and evaporating the liquid through the shell of the powder material thereby to provide the hollow pellet.
Claim 23
Independent Claim
113 words
A method for manufacturing hollow pellets having interior surface portions of a material different than the material of the outer surface portions, said method comprising dropping into a powder suspended in gas drops of a liquid to which the powder adheres thereby to form a shell of the powder around the drop, said powder including material from which it is desired to make the exterior surface portions of the pellets, which material is insoluble in said liquid and said liquid containing material from which it is desired to make the interior surface portions of the pellets, and evaporating the liquid through the shell of the powder material thereby to provide the hollow pellet.
Claim 24
Dependent Claim
24 words
A method as set forth in claim 21, wherein said powder includes a binder for said material which binder is soluble in said liquid.
Claim 25
Dependent Claim
42 words
A method as set forth in claim 21, wherein said material for the exterior surface portions of the pellets is a sinterable material and wherein said pellets, after evaporation of the liquid therefrom, are heated to the sintering temperature of said material.
Claim 26
Independent Claim
149 words
A method for manufacturing hollow pellets having interior surface portions of a material different than the material of the exterior surface portions thereof, said method comprising dropping drops of a liquid onto a bed of powder, the upper surfaces of said drops being disposed above the surface of said bed, said liquid containing the material from which it is desired to form the interior surface portion of the pellets and said powder containing the material from which it is desired to form the exterior surface portions of said pellets; placing over said drops sufficient additional of said power to cause at least most of the surface of said drops to be surrounded by said powder whereby said powder adheres to each of said drops to form a shell of said powder therearound, and evaporating the vaporizable ingredients of said lIquid through said shells thereby to provide said hollow pellets.
Claim 27
Independent Claim
149 words
A method for manufacturing hollow pellets having interior surface portions of a material different than the material of the exterior surface portions thereof, said method comprising dropping drops of a liquid onto a bed of powder, the upper surfaces of said drops being disposed above the surface of said bed, said liquid containing the material from which it is desired to form the interior surface portion of the pellets and said powder containing the material from which it is desired to form the exterior surface portions of said pellets; placing over said drops sufficient additional of said power to cause at least most of the surface of said drops to be surrounded by said powder whereby said powder adheres to each of said drops to form a shell of said powder therearound, and evaporating the vaporizable ingredients of said lIquid through said shells thereby to provide said hollow pellets.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |