Patent US3962029A successfully refreshed from Google Patents.
US3962029A
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Method of controlling the amount of chemicals in liquids used within the cellulose industry and related industries
Assignee: Mo och Domsjo AB
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Filing: 1974-10-17
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Granted: 1976-06-08
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Expires: 1994-10-17
Abstract
Abstract A method is provided for controlling the amount of oxidizing bleaching agents in liquors used within the cellulose industry, as in the bleaching of sulphite, sulphate, mechanical, chemimechanical, semichemical or similar cellulose pulps, and in related industries, and particularly for controlling the addition of oxidizing bleaching agents to the system during the bleaching of cellulose pulp by mixing such liquor with at least one chemiluminescent reagent which reacts with the oxidizing bleaching agents in a manner to emit light. The amount of oxidizing bleaching agents in the liquor is then determined by comparison of the light intensity thus obtained with the light intensity for previously measured calibration values corresponding to known quantities of such oxidizing bleaching agents, and then from such determination controlling the addition of such oxidizing bleaching agents to the liquor.
Inventors
- 👤 Karl Gustav Gunnar Wettermark
- 👤 Per Ulf Isacsson
- 👤 Bengt Goran Hultman
- 👤 Per Henrik Otto Johan Norberg
- 👤 Bo Nils Olof Lindahl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:19
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/10; D21C9/1026; D21C9/1052; G; G01; G01N; G01N21/00; G01N21/75; G01N21/76; G05; G05D; G05D21/00; G05D21/02; Y; Y10; Y10S; Y10S162/00; Y10S162/09; Y10S162/10
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
131 words
A process for controlling the quantity of oxidizing bleaching agent in a liquor for treating cellulosic material, which comprises continuously mixing such liquor containing such oxidizing bleaching agent with at least one chemiluminescent reagent selected from the group consisting of 1,3-aminophthalic acid hydrazide, N,N'-dimethylacridinium dinitrate, and 2,4,5-triphenyl imidazole, which reacts oxidatively therewith in a manner to emit light; continuously measuring the intensity of such light; determining the amount of such oxidizing bleaching agent in the liquor by comparison of the light intensity thus obtained with the light intensity for previously measured calibration values corresponding to known quantities of such oxidizing bleaching agent; and then from such determination controlling the addition of such oxidizing bleaching agent to the liquor, to maintain a desired quantity of such oxidizing bleaching agent in the liquor.
Claim 2
Dependent Claim
131 words
A process for controlling the quantity of oxidizing bleaching agent in a liquor for treating cellulosic material, which comprises continuously mixing such liquor containing such oxidizing bleaching agent with at least one chemiluminescent reagent selected from the group consisting of 1,3-aminophthalic acid hydrazide, N,N'-dimethylacridinium dinitrate, and 2,4,5-triphenyl imidazole, which reacts oxidatively therewith in a manner to emit light; continuously measuring the intensity of such light; determining the amount of such oxidizing bleaching agent in the liquor by comparison of the light intensity thus obtained with the light intensity for previously measured calibration values corresponding to known quantities of such oxidizing bleaching agent; and then from such determination controlling the addition of such oxidizing bleaching agent to the liquor, to maintain a desired quantity of such oxidizing bleaching agent in the liquor.
Claim 3
Dependent Claim
41 words
A process according to claim 1, in which a portion at least of the emitted light is impinged upon a photoelectric detector, to induce a signal whose response is related to the quantity of the oxidizing bleaching agent in the liquor.
Claim 4
Dependent Claim
25 words
A process according to claim 1, in which the liquor is a cellulose bleaching liquor, and the oxidizing bleaching agent is a cellulose bleaching agent.
Claim 5
Dependent Claim
15 words
A process according to claim 3, in which the bleaching agent is a chlorine compound.
Claim 6
Dependent Claim
13 words
A process according to claim 4, in which the chlorine compound is chlorine.
Claim 7
Dependent Claim
14 words
A process according to claim 4, in which the chlorine compound is a hypochlorite.
Claim 8
Dependent Claim
14 words
A process according to claim 4, in which the chlorine compound is chlorine dioxide.
Claim 9
Dependent Claim
38 words
A process according to claim 1, in which the liquor is a cellulose bleaching liquor and the oxidizing bleaching agent is a per compound selected from the group consisting of organic and inorganic peroxides, perborates and per acids.
Claim 10
Dependent Claim
24 words
A process according to claim 1, in which the liquor is a cellulose bleaching liquor and the oxidizing bleaching agent is oxygen or ozone.
Claim 11
Dependent Claim
72 words
A process according to claim 1, in which the chemiluminescent reagent is caused to react with at least two oxidizing bleaching agents present in the liquor to emit light, the oxidizing bleaching agents being reactive therewith under different conditions and measuring the light intensity from the reactions of the respective oxidizing bleaching agents at different times after mixing the reagent with liquor separately to determine the amounts of such oxidizing bleaching agents.
Claim 12
Dependent Claim
25 words
A process according to claim 10 in which the oxidizing bleaching agents are chlorine and chlorine dioxide, and the chemiluminescent reagent is 1,3-aminophthalic acid hydrazide.
Claim 13
Dependent Claim
72 words
A process according to claim 10 in which several chemiluminescent reagents are caused to react with several oxidizing bleaching agents present in said liquor, each reagent being specific for a specific oxidizing bleaching agent, and reacting therewith under different conditions; and measuring the light intensity from the reaction of such oxidizing bleaching agents under different conditions after mixing the reagents with the liquor separately to determine the amounts of oxidizing bleaching agents.
Claim 14
Dependent Claim
15 words
A process according to claim 1, in which the chemiluminescent reagent is 1,3-aminophthalic acid hydrazide.
Claim 15
Dependent Claim
15 words
A process according to claim 1, in which the chemiluminescent reagent is N,N' -dimethylacridinium dinitrate.
Claim 16
Dependent Claim
14 words
A process according to claim 1, in which the chemiluminescent reagent is 2,4,5-triphenyl imidazole.
References Cited (Backward Citations)
US3366572A
Cited
US3539794A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-08 | 1979-12-08 | 1980-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-08 | 1983-12-08 | 1984-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-08 | 1987-12-08 | 1988-06-08 | $7700.00 | Window Closed / Lapsed |