US5198029A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for coating small solids
Assignee: Osram Sylvania Inc
•
Filing: 1992-02-19
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Granted: 1993-03-30
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Expires: 2012-02-19
Abstract
Abstract The present invention is directed to an apparatus useful for fluidizing small particulate solids having a diameter of less than about 50 microns in average particle size, and at least partially enveloping these small solids with a coating material or a precursor thereto. The basis apparatus of this invention includes a cross-current multi-stage fluid bed reactor having N fluid beds in flow communication with one another, wherein N≧2.
Inventors
- 👤 Arunava Dutta
- 👤 Leonard V. Dullea
- 👤 Ernest A. Dale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:24
CPC Classifications
B; B01; B01J; B01J8/00; B01J8/18; B01J8/24; B01J8/36; B01J2/00; B01J2/006; B01J8/26; C; C23; C23C; C23C16/00; C23C16/44; C23C16/442; Y; Y10; Y10S; Y10S118/00; Y10S118/05
Claims Analysis
Total Claims: 49
Claim 1
Independent Claim
342 words
Apparatus for fluidizing small particulate solids having a diameter of less than about 50 microns in average particle size, and at least partially enveloping these small solids with a coating material or a precursor thereto, said apparatus comprising in combination: a cross-current multi-stage fluid bed reactor having N fluid beds, separated by main baffles, said beds being in flow communication with one another, wherein N≧2; a hopper for introducing small solid particles having a diameter of less than about 50 microns in average particle size, to a first bed of said N beds of the reactor, said hopper having an upper section and a lower section having an inclined sidewall for promoting the flow of phosphor into said first bed, at least one duct connected to said lower section for feeding a mixture of gas and small particulate solids into said hopper, means for the exit of gas from the upper section, said gas exit means including a filter for separating gas to be discharged from said small particulate solids; means for introducing a fluidizing gas to the N beds of the reactor, thereby promoting a flow of the small solid particles across the tops of the beds, from the first bed through bed N of the multi-stage fluid bed reactor; means for introducing the coating material or a precursor thereto, to one or more of the N beds of the reactor; means for distributing the coating material or precursor thereto throughout the cross-section of the reactor beds containing the same; means for controlling the residence or contact time of the small particulate solids in the beds containing the coating material or the precursor thereto, including means for maintaining a gas flow across the inner surface of the roof of the apparatus, keeping said roof substantially free of deposited solids, such that the small particulate solids therein are at least partially enveloped by the coating material or precursor thereto; and means for removal of the fluidizing gas and the small solid particles at least partially enveloped by coating material or precursor thereto.
Claim 2
Dependent Claim
342 words
Apparatus for fluidizing small particulate solids having a diameter of less than about 50 microns in average particle size, and at least partially enveloping these small solids with a coating material or a precursor thereto, said apparatus comprising in combination: a cross-current multi-stage fluid bed reactor having N fluid beds, separated by main baffles, said beds being in flow communication with one another, wherein N≧2; a hopper for introducing small solid particles having a diameter of less than about 50 microns in average particle size, to a first bed of said N beds of the reactor, said hopper having an upper section and a lower section having an inclined sidewall for promoting the flow of phosphor into said first bed, at least one duct connected to said lower section for feeding a mixture of gas and small particulate solids into said hopper, means for the exit of gas from the upper section, said gas exit means including a filter for separating gas to be discharged from said small particulate solids; means for introducing a fluidizing gas to the N beds of the reactor, thereby promoting a flow of the small solid particles across the tops of the beds, from the first bed through bed N of the multi-stage fluid bed reactor; means for introducing the coating material or a precursor thereto, to one or more of the N beds of the reactor; means for distributing the coating material or precursor thereto throughout the cross-section of the reactor beds containing the same; means for controlling the residence or contact time of the small particulate solids in the beds containing the coating material or the precursor thereto, including means for maintaining a gas flow across the inner surface of the roof of the apparatus, keeping said roof substantially free of deposited solids, such that the small particulate solids therein are at least partially enveloped by the coating material or precursor thereto; and means for removal of the fluidizing gas and the small solid particles at least partially enveloped by coating material or precursor thereto.
Claim 3
Dependent Claim
26 words
The apparatus of claim 1, wherein the small particulate solids to be fluidized have a diameter of less than about 35 microns in average particle size.
Claim 4
Dependent Claim
26 words
The apparatus of claim 1, wherein the small particulate solids to be fluidized have a diameter of less than about 20 microns in average particle size.
Claim 5
Dependent Claim
23 words
The apparatus of claim 1, wherein N, the number of fluid beds or stages in the multi-stage reactor, is from 2 to 10.
Claim 6
Dependent Claim
20 words
The apparatus of claim 1, wherein N, the number of fluid beds or stages in the multi-stage reactor, is 4.
Claim 7
Dependent Claim
15 words
The apparatus of claim 1, wherein the fluidizing gas comprises at least one non-reactive gas.
Claim 8
Dependent Claim
20 words
The apparatus of claim 6, wherein the fluidizing gas further comprises one or more additional solid, liquid, or gaseous components.
Claim 9
Dependent Claim
15 words
The apparatus of claim 7, wherein the additional components in the fluidizing gas are nonreactive.
Claim 10
Dependent Claim
19 words
The apparatus of claim 7, wherein the additional components in the fluidizing gas comprise one or more reactive components.
Claim 11
Dependent Claim
31 words
The apparatus of claim 1, wherein the means for introducing the fluidizing gas to the N beds of the reactor consists of a distributor with a plurality of gas passageways therein.
Claim 12
Dependent Claim
20 words
The apparatus of claim 10, wherein the distributor is a plate formed from one or more metals, alloys, or ceramics.
Claim 13
Dependent Claim
20 words
The apparatus of claim 10, wherein the distributor is selected from the group consisting of bubble caps, nozzles and pipes.
Claim 14
Dependent Claim
35 words
The apparatus of claim 1, wherein the means for introducing the coating material or precursor thereto, to the beds of the N bed reactor consists of a distributor with a plurality of gas passageways therein.
Claim 15
Dependent Claim
20 words
The apparatus of claim 13, wherein the distributor is a plate formed from one or more metals, alloys, or ceramics.
Claim 16
Dependent Claim
11 words
The apparatus of claim 14, wherein the distributor plate is porous.
Claim 17
Dependent Claim
20 words
The apparatus of claim 13, wherein the distributor is selected from the group consisting of bubble caps, nozzles and pipes.
Claim 18
Dependent Claim
27 words
The apparatus of claim 1, wherein a same distributor plate is employed for the introduction of both the fluidizing gas and the coating material or precursor thereto.
Claim 19
Dependent Claim
30 words
The apparatus of claim 1, wherein distinct and isolated sections of a distributor plate are employed for the introduction of the fluidizing gas and the coating material or precursor thereto.
Claim 20
Dependent Claim
33 words
The apparatus of claim 1, wherein the means for distributing the coating material or precursor thereto throughout the cross-section of the reactor beds containing the same comprises baffle members within said reactor beds.
Claim 21
Dependent Claim
45 words
The apparatus of claim 1, wherein the means for controlling the residence or contact time of the small particulate solids in the beds containing the coating material or the precursor thereto, comprises the positioning of baffle members separating the stages of the fluid bed reactor.
Claim 22
Dependent Claim
42 words
The apparatus of claim 1, wherein the means for controlling the residence or contact time of the small particulate solids in the beds containing the coating material or the precursor thereto, comprises the positioning of baffle members within the said reactor beds.
Claim 23
Dependent Claim
38 words
The apparatus of claim 21, wherein the same baffle members are employed for the distribution of the coating material or precursor thereto and for controlling the residence or contact time of the small particulate solids in said beds.
Claim 24
Dependent Claim
37 words
The apparatus of claim 21, wherein separate baffle members are employed for the distribution of the coating material or precursor thereto and for controlling the residence or contact time of the small particulate solids in said beds.
Claim 25
Dependent Claim
81 words
The apparatus of claim 1, wherein secondary baffles are located directly above the main baffles separating the stages of the fluid bed reactor, the positioning of the former with respect to the reactor top being such as to create a gas flow across the reactor top sufficient to prevent accumulation of fine powder on the same, and the spacing between a main baffle and its secondary counterpart being such as to allow for variations in expanded bed height above the former.
Claim 26
Dependent Claim
64 words
The apparatus of claim 1, wherein there is a provision for a slotted baffle originating at the roof of the reactor and extending at least 10 cm into bed 2, the slots at the baffle top allowing gas to escape to the filter provided above the hopper and the extension into bed 2 preventing short circuiting of powder to the exit means for solids.
Claim 27
Dependent Claim
15 words
The apparatus of claim 1, wherein at least three exit means for solids are present.
Claim 28
Dependent Claim
43 words
The apparatus of claim 26, wherein one exit means for solids is an eductor followed by a gas-solids separating device, the eductor being fed with solids via a tube located at a controllable distance above bed N of the multi-stage fluid bed reactor.
Claim 29
Dependent Claim
28 words
The apparatus of claim 26, wherein one exit means for solids is a bed drain or product withdrawal exit means, suitable for removing solid product from the reactor.
Claim 30
Dependent Claim
38 words
The apparatus of claim 26, wherein one exit means for solids is a transport tube member inclined to the vertical wall of the reactor at an angle greater than the angle of repose for the material being handled.
Claim 31
Dependent Claim
29 words
The apparatus of claim 1, wherein at least one means of sampling of the solids from one or more of the stages of the multi-stage fluid bed reactor exists.
Claim 32
Dependent Claim
29 words
The apparatus of claim 30, wherein the solids sampling means comprises a slotted tube sealed at both ends and inserted through a gas tight feed through into the reactor.
Claim 33
Dependent Claim
35 words
The apparatus of claim 1, wherein the gas exit means are suitable for separating solids from gases, and are selected from the group consisting of cyclones, fabric bag filters and metal alloy blow back filters.
Claim 34
Dependent Claim
42 words
The apparatus of claim 32, wherein the solids are fed by pneumatic means to the hopper at an angle to the hopper wall such that the gas jet axis, when extended, covers the full length of the bag filter for optimum filtration.
Claim 35
Dependent Claim
21 words
The apparatus of claim 32, wherein the hopper walls are coated with a material with a low coefficient of sliding friction.
Claim 36
Dependent Claim
27 words
The apparatus of claim 32, wherein the hopper includes a baffle plate inclined at an angle greater than the angle of repose of the solids being processed.
Claim 37
Dependent Claim
34 words
The apparatus of claim 35, wherein there is a provision for the flow of cooling gas under the baffle of the hopper to cool the solids entrained by the gas leaving the fluid beds.
Claim 38
Dependent Claim
31 words
The apparatus of claim 35, wherein the baffle plate is positioned such that the solids exit the lower end of the plate into bed 1 of the multi-stage fluid bed reactor.
Claim 39
Dependent Claim
27 words
The apparatus of claim 35, wherein the top and bottom surfaces of the baffle plate are coated with a material with a low coefficient of sliding friction.
Claim 40
Dependent Claim
42 words
The apparatus of claim 1, which further includes temperature control means for each of the N fluid beds of the multi-stage fluid bed reactor, said temperature control means providing independently either heating or cooling, or both, to the individual beds as required.
Claim 41
Dependent Claim
23 words
The apparatus of claim 1, wherein there is essentially isothermal behavior in each of the N beds of the multi-stage fluid bed reactor.
Claim 42
Dependent Claim
23 words
The apparatus of claim 39, wherein the heating means is selected from a group consisting of the following means: radiative, convective and conductive.
Claim 43
Dependent Claim
18 words
The apparatus of claim 41, wherein the heating means provides progressively increased temperatures through said N reactor beds.
Claim 44
Dependent Claim
21 words
The apparatus of claim 41, wherein the heating means provides a temperature range from about room temperature to about 1400° C.
Claim 45
Dependent Claim
30 words
The apparatus of claim 41, wherein the heating means comprises a plurality of ceramic electric resistance heating elements, providing a temperature range from about room temperature to about 1000° C.
Claim 46
Dependent Claim
19 words
The apparatus of claim 39, wherein the cooling means is suitable for reducing the temperature to about room temperature.
Claim 47
Dependent Claim
21 words
The apparatus of claim 45, wherein the cooling means consists of the fluidizing gas passing through the beds of the reactor.
Claim 48
Dependent Claim
23 words
The apparatus of claim 45, wherein the cooling means is selected from the group consisting of cooling jackets, cooling coils and refrigerated jackets.
Claim 49
Dependent Claim
34 words
The apparatus of claim 1, wherein the materials of construction of the fluid bed walls and baffles are selected from the group consisting of ceramics, metals, metal alloys and abrasion resistant ceramic coated alloys.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-03-29 | 1996-09-28 | 1997-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-03-29 | 2000-09-28 | 2001-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-03-29 | 2004-09-28 | 2005-03-30 | $7700.00 | Window Closed / Lapsed |