US3596839A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Slurry particle size determination
Assignee: Westinghouse Electric Corp
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Filing: 1969-12-10
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Granted: 1971-08-03
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Expires: 1989-12-10
Abstract
Abstract Method and apparatus for determining the particle size distribution in a slurry in a grinding circuit with the method and apparatus operative in an online manner and at frequent intervals for effecting this determination. A high-speed computer is used to better control the operation of the circuit. Such particle size distribution, obtained through a determination of the cumulative percentage of solids in the grinder output slurry, is regulated in relation to the infeed of slurry material into the grinder as a predetermined function of the weight of new material introduced into the grinder unit circuit, the known particle size distribution of that new material from classifiers returned as infeed to the grinder and the calculated particle size distribution of that overflow material.
Inventors
- 👤 Richard E J Putman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:22
CPC Classifications
B; B02; B02C; B02C25/00; G; G01; G01N; G01N15/00; G01N15/02; G01N15/0255
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
173 words
In a system for controlling the particle size distribution from a grinder supplying an output slurry to a measurement device, the combination of means for sensing predetermined flow and density conditions relative to a first operation of said grinder and for sensing said predetermined flow and density conditions relative to a second operation of said grinder, means for establishing a first cumulative percentage of solids in the slurry leaving said measurement device in accordance with said flow and density conditions for said first operation of said grinder and for establishing a second cumulative percentage of solids in the latter said slurry leaving said measurement device in accordance with said flow and density conditions for said second operation of said grinder, means for establishing the particle size modulus of said output slurry in accordance with a predetermined relationship between said first cumulatiVe percentage of solids and said second cumulative percentage of solids, and means for controlling the particle size distribution of said output slurry from said grinder in accordance with said particular size modulus.
Claim 2
Dependent Claim
165 words
In a control system for a grinding device supplying an output slurry to a classifier device, the combination of, first means operative with said output slurry from the grinding device for determining at least one of a first flow characteristic and a first density characteristic of the slurry supplied to said classifier device, second means operative with the slurry leaving said classifier device for determining at least one of a second flow characteristic and a second density characteristic of the slurry leaving said classifier device, third means operative with said first and second means for establishing the percentage of solids relationships in said output slurry in accordance with a predetermined relationship between at least said one of said first flow characteristic and said first density characteristic and said predetermined relationship between at least said one of said second flow characteristic and said second density characteristic, and control means operative to control the operation of said grinding device in accordance with said percentage of solids relationship.
Claim 3
Dependent Claim
79 words
The control system of claim 1 with said measurement device being a measurement cyclone classifier and with said grinding apparatus including a production cyclone classifier, with said measurement cyclone classifier being operative with the output slurry from the grinding apparatus which appears in the overflow slurry from said production cyclone classifier, and with said third means for establishing the particle size modulus being operative in relation to the percentage of solids in the overflow from said production cyclone classifier.
Claim 4
Dependent Claim
78 words
The control system of claim 3, with said grinding device having a portion of said output slurry returned to said grinding device and including a new material supply, with said third means being operative to determine the particle size distribution in at least the slurry returned to said grinding device and with said control means being operative to control said new material supply to maintain a predetermined particle size distribution in the slurry supplied to said grinding device.
Claim 5
Dependent Claim
72 words
The control system of claim 1, with said grinding apparatus including a plurality of production cyclone classifiers, said combination including overflow slurry sampling means operative to supply said output slurry to said measurement device for sequentially sampling the overflow slurry from each one of the respective production cyclone classifiers, and with said fourth means being operative in response to said particle size modulus to control the particular production cyclone classifier being sampled.
Claim 6
Independent Claim
99 words
The method of controlling a grinding system including a grinding device connected to supply an output slurry to a classifier device, the steps of determining a first flow and a first density of the slurry leading to said classifier device, determining a second flow and a second density of the slurry leaving said classifier device, establishing the particle size modulus of said output slurry in accordance with a predetermined relationship between said first and second flow and said first and second density, and controlling the particle size distribution of said output slurry in response to said particle size modulus.
Claim 7
Dependent Claim
85 words
The method of claim 7 with said classifier device being a measurement classifier device and with said grinding system including a plurality of production particle size classifiers, said method including the steps of determining in sequence the particle size modulus of a sample of the output slurry from each selected one of the respective production classifiers, and controlling the particle size distribution of the output slurry from the selected production clasSifier corresponding with the particular sample for which the particle size modulus has been determined.
Claim 8
Dependent Claim
156 words
In a control system for a grinding device connected to supply an unknown slurry to a classifier device having an output slurry, the combination of first flow-sensing means and first density-sensing means operative with the unknown slurry from the grinding mill for determining respectively the inlet flow F1 and the inlet density D1 of the slurry supplied to said classifier device, second flow-sensing means and second density-sensing means operative with the output slurry of said classifier device for determining respectively the output flow F2 and the output density D2 of the output slurry of said classifier device, third means operative with said flow and density sensing means for establishing a percentage of solids relationship phi in said output slurry in accordance with the predetermined formula and control means responsive to said percentage of solids phi in accordance with formula for controlling of operation of said grinding device to provide a desired operation of said grinding device.
Claim 9
Dependent Claim
101 words
The control system of claim 1, with said measurement device being a measurement cyclone classifier, with said grinding apparatus being operative with a production cyclone classifier, and with said measurement cyclone classifier being operative with said output slurry from the grinding apparatus which appears in the overflow slurry from said production cyclone classifier, the combination including said third means being further operative to calculate the particle size modulus in relation to the particle size distribution in said overflow slurry, and with said fourth means being responsible to said particle size modulus to control the particle size distribution from said grinding apparatus.
Claim 10
Dependent Claim
76 words
The control system of claim 1, with said grinding apparatus having a portion of said output slurry returned to said grinding apparatus and including a new material supply, with said third means being further operative to determine the particle size distribution in at least said output slurry returned to said grinding apparatus and being operative to control said new material supply to maintain a predetermined particle size distribution in said output slurry from said grinding apparatus.
Claim 11
Dependent Claim
65 words
The control system of claim 3, with said grinding device including a plurality of production cyclone classifiers, said combination including overflow slurry sampling means operative with said first means for sequentially sampling the overflow slurry from each one of the respective production cyclone classifiers, and with said control means being operative to control the particle size distribution of the particular production cyclone classifier being sampled.
Claim 12
Independent Claim
79 words
The method of controlling a grinding system connected to supply an output slurry to a classifier device, the steps of determining at least one of the flow and density of the slurry leading to said classifier device, determining at least one of the flow and density of the slurry leaving said classifier device, establishing the particle size modulus of said output slurry, and controlling the particle size distribution of said output slurry in response to said particle size modulus.
Claim 13
Dependent Claim
92 words
The method of claim 13 with said classifier device being a measurement classifier device and with said grinding system including a plurality of production particle size classifiers, said method including the steps of determining in sequence the particle size modulus of a sample of the output slurry from each one of the respective production classifiers and controlling the particle size distribution of the output slurry from each one of said production classifiers in sequence before performing the same operation on a sample of the output slurry from the next sequence production classifier.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |