US3635790A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the thermal oxidation of spent liquor
Assignee: Dorr Oliver Inc
•
Filing: 1969-07-02
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Granted: 1972-01-18
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Expires: 1989-07-02
Abstract
Abstract A partially concentrated spent liquor is introduced into a venturi-type scrubber-evaporator along with combustion gases containing entrained solids from a fluidized bed reactor. From the scrubber-evaporator, the combustion gases are removed with a cyclone separator and the remaining concentrated spent liquor and entrained solids are passed through a comminuting device. Preferably the comminution device is a comminution pump. The comminution device grinds the entrained solids into very fine particles by continuous recycling. The resulting concentrated spend liquor containing finely ground solids can be partially recycled to the venturi-type scrubber-evaporator by mixing a portion of the fine solid containing liquor with the original spent liquor feed to the venturi. The amount of solids fed to the venturi-type scrubber-evaporator can be controlled by varying the amount of find solid containing liquor feed. The remainder of the fine solid containing concentrated spent liquor is fed to the fluidized bed oxidation reactor whereby an ash bed product can be treated for chemical recovery without the problem of scrubberevaportor shutdowns due to large solid particles.
Inventors
- 👤 Thomas K Heath
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:26
CPC Classifications
D; D21; D21C; D21C11/00; D21C11/10; D21C11/103; Y; Y10; Y10S; Y10S159/00; Y10S159/03
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
40 words
The process according to claim 1, wherein said comminution treatment is effected by continuously withdrawing a portion of the mixture from the collecting zone, subjecting said withdrawn portion to comminution, and returning the thus treated mixture to said collecting zone.
Claim 2
Dependent Claim
44 words
The process according to claim 1, wherein a portion of pelletized product is returned into the mixture in said collecting zone, to be reduced to a finely subdivided state along with said entrained solids, providing nuclei for said pelletized product in said fluidized bed.
Claim 3
Dependent Claim
38 words
The process according to claim 1, wherein portion of the pelletized product is subjected to a dry comminuting treatment, and the resulting material is returned into the fluidized bed, providing nuclei for the formation of said pelletized product.
Claim 4
Dependent Claim
30 words
The process according to claim 1, wherein a portion of the mixture in said collecting zone is added to said spent liquor undergoing concentration by contact with said reaction gases.
Claim 5
Dependent Claim
39 words
The process according to claim 1, wherein said mixture is recirculated through pumping from said collecting zone, and delivery back into said collecting zone, and said comminution is effected while in transit between leaving and reentering said collecting zone.
Claim 6
Dependent Claim
19 words
The process according to claim 6, wherein said pumping and said comminution are effected in a single continuous operation.
Claim 7
Dependent Claim
22 words
The process according to claim 1, wherein substantially all of said mixture from the collecting zone is pumped into said fluidized bed.
Claim 8
Dependent Claim
47 words
The process according to claim 1, wherein the dissolved solids concentration in the liquor concentrated in said atomizing stream is continuously monitored, and the dissolved solids concentration is maintained in a predetermined range by controlling the rate of supply of said spent liquor from the monitor indications.
Claim 9
Dependent Claim
38 words
The process according to claim 1, wherein the dissolved solids concentration in said concentrated liquor is continuously monitored and the dissolved solids in said liquor is maintained in a range from about 35 percent to about 50 percent.
Claim 10
Dependent Claim
37 words
The process according to claim 1, wherein the dissolved solids concentration in said concentrated liquor is continuously monitored by refractometer measurements, and said measurements are applied for automatically controlling the rate of supply of said spent liquor.
Claim 11
Dependent Claim
66 words
The process according to claim 1, wherein a stream of said mixture is continuously added to said spent liquor undergoing concentration, and wherein the dissolved solids concentration in said stream is continuously monitored, and the dissolved solids concentration in the liquor feD into said atomizing stream is maintained in a predetermined range by controlling the rate of supply of said spent liquor from the monitor indications.
Claim 12
Dependent Claim
33 words
The process according to claim 1, wherein the rate of supply of said spent liquor is controlled in response to changes in the dissolved solids concentration in the mixture in said collecting zone.
Claim 13
Dependent Claim
29 words
The process according to claim 1, wherein a predetermined dissolved solids concentration in the mixture is maintained by controlling a supply of weak spent liquor to said collecting zone.
Claim 14
Dependent Claim
37 words
The process according to claim 1, wherein the size of the particles constituting the fluidized bed is controlled by controlling the amount and the size of the solids in the liquor being fed to the fluidized bed.
Claim 15
Dependent Claim
68 words
The process according to claim 1, wherein the spent liquor is derived from a neutral sulfite semichemical pulp treatment operation, and wherein the feed liquor to the fluidized bed is of an undissolved solids concentration in a range from 0.5 percent to 1 percent, providing an amount of nuclei for the formation of said pelletized product, sufficient to at least substantially reduce the amount of seeding the reactor.
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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) | 1975-01-17 | 1975-07-19 | 1976-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-17 | 1979-07-19 | 1980-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-17 | 1983-07-19 | 1984-01-18 | $7700.00 | Window Closed / Lapsed |