US4514256A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of minimizing slagging in the burning of black liquid
Assignee: Individual
•
Filing: 1983-04-18
•
Granted: 1985-04-30
•
Expires: 2003-04-18
Abstract
Abstract The formation of slag is minimized and the removability of slag is greatly increased, in connection with the furnace burning of black liquor, by applying to the surfaces where slag tends to form a substance which, under black liquor furnace conditions, reacts with the sodium sulfide content of the black liquor ash to oxidize said sodium sulfide and to be itself reduced, such substances preferably comprising sodium persulfate, manganese dioxide, cupric oxide and ferric oxide and mixtures thereof.
Inventors
- 👤 Alfred E. Kober
- 👤 Stanley E. Gilewicz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:29
CPC Classifications
D; D21; D21C; D21C11/00; D21C11/12; C; C10; C10L; C10L10/00; C10L10/04; C10L10/06
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
106 words
The method of minimizing the problem of slag formation in a black liquor furnace which comprises applying to the furnace surfaces above the combustion zone where slag tends to form, substantially progressively as black liquor is burned in the furnace, a substance from the group consisting of sodium persulfate, manganese dioxide, cupric oxide, ferric oxide and mixtures thereof, said substance being introduced essentially solely into the system upstream of said surfaces at a location which permits it to reach said surfaces in essentially unreduced form, said substance then reacting at said surfaces with combustion products of the furnace to oxidize said products and be itself reduced.
Claim 2
Independent Claim
106 words
The method of minimizing the problem of slag formation in a black liquor furnace which comprises applying to the furnace surfaces above the combustion zone where slag tends to form, substantially progressively as black liquor is burned in the furnace, a substance from the group consisting of sodium persulfate, manganese dioxide, cupric oxide, ferric oxide and mixtures thereof, said substance being introduced essentially solely into the system upstream of said surfaces at a location which permits it to reach said surfaces in essentially unreduced form, said substance then reacting at said surfaces with combustion products of the furnace to oxidize said products and be itself reduced.
Claim 3
Dependent Claim
18 words
The method of claim 1, in which said substance is applied substantially continuously as black liquor is burned.
Claim 4
Dependent Claim
32 words
The method of claim 1, in which said substance is applied substantially continuously as black liquor is burned, and in which said substance is applied in the form of finely divided particles.
Claim 5
Dependent Claim
55 words
The method of claim 1, in which said substance is applied substantially continuously as black liquor is burned, and in which said substance is applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned.
Claim 6
Dependent Claim
94 words
The method of claim 1, in which said substance is applied substantially continuously as black liquor is burned, in which said substance is applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned, and in which said substance is initially applied at the rate of about 20-1000 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of from 1 to 4 hours.
Claim 7
Dependent Claim
130 words
The method of claim 1, in which said substance is applied substantially continuously as black liquor is burned, said substance is initially applied at the rate of about 20-1000 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of from 1 to 4 hours, said substance is then applied at the rate of about 20-400 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of about 12 to 48 hours, and in which said substance is then applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned.
Claim 8
Dependent Claim
127 words
The method of claim 1, in which said substance is applied substantially continuously as black liquor is burned, said substance is initially applied at the rate of about 20-1000 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of 1 to 4 hours, said substance is then applied at the rate of about 50-200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of about 24 hours, and in which said substance is then applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned.
Claim 9
Dependent Claim
128 words
The method of claim 1, in which said substance is applied substantially continuously as black liquor is burned, said substance is initially applied at the rate of about 20-1000 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of from 1 to 4 hours, said substance is then applied at the rate of about 100 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of about 24 hours, and in which said substance is then applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned.
Claim 10
Dependent Claim
94 words
The method of claim 1, in which said substance is applied substantially continuously as black liquor is burned, and in which said substance is applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned, and in which said substance is initially applied at the rate of about 100 to 300 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of two hours.
Claim 11
Dependent Claim
125 words
The method of claim 1, in which said substance is applied substantially continuously as black liquor is burned, said substance is initially applied at the rate of about 100-300 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of two hours, said substance is then applied at the rate of about 50-200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of about 24 hours, and in which said substance is then applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned.
Claim 12
Dependent Claim
125 words
The method of claim 1, in which said substance is applied substantially continuously as black liquor is burned, said substance is initially applied at the rate of about 100-300 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of two hours, said substance is then applied at the rate of about 100 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of about 24 hours, and in which said substance is then applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned.
Claim 13
Dependent Claim
92 words
The method of claim 1, in which said substance is applied substantially continuously as black liquor is burned, and in which said substance is applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned, and in which said substance is initially applied at the rate of about 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of two hours.
Claim 14
Dependent Claim
125 words
The method of claim 1, in which said substance is applied substantially continuously as black liquor is burned, said substance is initially applied at the rate of about 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of about two hours, said substance is then applied at the rate of about 100 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor burned for a period of about 24 hours, and in which said substance is then applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned.
Claim 15
Dependent Claim
24 words
The method of claim 1, in which the substance is additionally initially applied to said surfaces when said surfaces are substantially free of slag.
Claim 16
Dependent Claim
38 words
The method of claim 1, in which the substance is additionally initially applied to said surfaces when said surfaces are substantially free of slag, and in which said substance is applied in the form of finely divided particles.
Claim 17
Dependent Claim
38 words
The method of claim 1, in which the substance is additionally initially applied to said surfaces when said surfaces are substantially free of slag, and in which said substance is applied substantially continuously as black liquor is burned.
Claim 18
Dependent Claim
51 words
The method of claim 1, in which the substance is additionally initially applied to said surfaces when said surfaces are substantially free of slag, in which said substance is applied substantially continuously as black liquor is burned, and in which said substance is applied in the form of finely divided particles.
Claim 19
Dependent Claim
74 words
The method of claim 1, in which the substance is additionally initially applied to said surfaces when said surfaces are substantially free of slag, in which said substance is applied substantially continuously as black liquor is burned, and in which said substance is applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned.
Claim 20
Dependent Claim
113 words
The method of claim 1, in which the substance is additionally initially applied to said surfaces when said surfaces are substantially free of slag, in which said substance is applied substantially continuously as black liquor is burned, in which said substance is applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned, and in which said substance is initially applied at the rate of about 20-1000 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of from 1 to 4 hours.
Claim 21
Dependent Claim
147 words
The method of claim 1, in which the substance is additionally initially applied to said surfaces when said surfaces are substantially free of slag, said substance is applied substantially continuously as black liquor is burned, said substance is initially applied at the rate of about 20-1000 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of from 1 to 4 hours, said substance is then applied at the rate of about 20-400 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of about 12 to 48 hours, and in which said substance is then applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned.
Claim 22
Dependent Claim
141 words
The method of claim 1, in which the substance is additionally initially applied to said surfaces when said surfaces are substantially free of slag, said substance is applied substantially continuously as black liquor is burned, said substance is initially applied at the rate of 20-1000 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of 1-4 hours, said substance is then applied at the rate of about 50-200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of about 24 hours, and in which said substance is then applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned.
Claim 23
Dependent Claim
145 words
The method of claim 1, in which the substance is additionally initially applied to said surfaces when said surfaces are substantially free of slag, said substance is applied substantially continuously as black liquor is burned, said substance is initially applied at the rate of about 20-1000 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of from 1 to 4 hours, said substance is then applied at the rate of about 100 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of about 24 hours, and in which said substance is then applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned.
Claim 24
Dependent Claim
112 words
The method of claim 1, in which the substance is additionally initially applied to said surfaces when said surfaces are substantially free of slag, in which said substance is applied substantially continuously as black liquor is burned, in which said substance is applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned, and in which said substance is initially applied at the rate of about 100 to 300 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of two hours.
Claim 25
Dependent Claim
142 words
The method of claim 1, in which the substance is additionally initially applied to said surfaces when said surfaces are substantially free of slag, said substance is applied substantially continuously as black liquor is burned, said substance is initially applied at the rate of about 100-300 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of two hours, said substance is then applied at the rate of about 50-200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of about 24 hours, and in which said substance is then applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned.
Claim 26
Dependent Claim
142 words
The method of claim 1, in which the substance is additionally initially applied to said surfaces when said surfaces are substantially free of slag, said substance is applied substantially continuously as black liquor is burned, said substance is initially applied at the rate of about 100-300 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of two hours, said substance is then applied at the rate of about 100 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of about 24 hours, and in which said substance is then applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned.
Claim 27
Dependent Claim
110 words
The method of claim 1, in which the substance is additionally initially applied to said surfaces when said surfaces are substantially free of slag, in which said substance is applied substantially continuously as black liquor is burned, in which said substance is applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned, and in which said substance is initially applied at the rate of about 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of two hours.
Claim 28
Dependent Claim
142 words
The method of claim 1, in which the substance is additionally initially applied to said surfaces when said surfaces are substantially free of slag, said substance is applied substantially continuously as black liquor is burned, said substance is initially applied at the rate of about 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of two hours, said substance is then applied at the rate of about 100 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned for a period of about 24 hours, and in which said substance is then applied over an extended period of time at a rate between 10 and 200 pounds of dry solids per hour for each 100,000 pounds per hour of black liquor solids burned.
Claim 29
Dependent Claim
41 words
The method of claim 1, in which, during the operation of the furnace in burning black liquor, the surfaces to which the substance is applied are subjected to temperature variations effective to break up the slag which forms on said surfaces.
Claim 30
Dependent Claim
42 words
The method of claim 1, in which said substance is applied substantially continuously as black liquor is burned, and in which the substance is applied to said surfaces prior to as well as during the burning of black liquor in the furnace.
Claim 31
Dependent Claim
23 words
The method of claim 1, in which said substance is introduced into the system at a location where the temperature is relatively low.
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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) | 1988-04-29 | 1988-10-29 | 1989-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-29 | 1992-10-29 | 1993-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-29 | 1996-10-29 | 1997-04-30 | $7700.00 | Window Closed / Lapsed |