US4963229A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System and method for continuous measurement of pulp consistency in a blowline of a continuous pulp digester
Assignee: International Paper Co
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Filing: 1985-07-02
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Granted: 1990-10-16
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Expires: 2005-07-02
Abstract
Abstract A system and method to continuously determine the pulp consistency in the discharge blowline (112) of a continuous pulp digester (100) having a gamma gauge (116) disposed adjacent to the blowline (112) for continuous measurement of the intensity of gamma radiation attenuated by the pulp slurry passing through the blowline (112), a density gauge (118) disposed adjacent to a cold blow liquor line (102) for continuous measurement of the density of the cold blow liquor in the cold blow line (102) independent of variations in the gamma radiation mass-attenuation coefficient of the cold blow liquor in the cold blow liquor line (102), a gamma gauge (120) disposed adjacent to the cold blow liquor line (102) for measuring the intensity of gamma radiation attenuated by the cold blow liquor passing through the cold blow liquor line (102) and a computer (122) for receiving signals output from the first gamma gauge (116), the density gauge (118) and the second gamma gauge (120) indicative of intensity of gamma radiation attenuated by pulp slurry, the density of the cold blow liquor and the intensity of gamma radiation attenuated by the cold blow liquor respectively, and calculating the pulp consistency in the pulp slurry based on these received signals.
Inventors
- 👤 Khaim Lisnyansky
- 👤 H. Heinz Walbaum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:15
CPC Classifications
G; G01; G01N; G01N23/00; G01N23/02; G01N23/06; G01N23/12; Y; Y10; Y10S; Y10S162/00; Y10S162/09; Y10S162/10
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
278 words
A system for continuously determining pulp consistency in a discharge blowline of a continuous pulp digester having a cold blow liquor line for providing cold blow liquor to the digester to wash the pulp by substantially replacing strong black liquor in the pulp slurry with cold blow liquor prior to discharging the pulp slurry into the discharge blowline of the digester comprising: a first measurement means disposed adjacent to the blowline for continuous measurement of the intensity of attenuated gamma radiation by the pulp slurry passing through the blowline; a second measurement means disposed adjacent to the cold blow liquor line for continuous measurement of the density of the cold blow liquor passing through the cold blow liquor line independent of variations in the gamma radiation mass-attenuation coefficient of the cold blow liquor and for continuous generation of signals indicative of the density of the cold blow liquor independent of variations in the gamma radiation mass-attenuation coefficient of the cold blow liquor; a third measurement means disposed adjacent to the cold blow liquor line for continuous measurement of the intensity of attenuated gamma radiation by the cold blow liquor passing through the cold blow liquor line; and a computing means connected to the first, second and third measurement means for calculating pulp consistency in the pulp slurry passing through the blowline based on the continuous signals received from the first, second and third measurement means which are indicative of the attenuation of gamma radiation by the pulp slurry, cold blow liquor density independent of variations in the gamma radiation mass-attenuation coefficient of the cold blow liquor, and the attenuation of gamma radiation by the cold blow liquor, respectively.
Claim 2
Independent Claim
278 words
A system for continuously determining pulp consistency in a discharge blowline of a continuous pulp digester having a cold blow liquor line for providing cold blow liquor to the digester to wash the pulp by substantially replacing strong black liquor in the pulp slurry with cold blow liquor prior to discharging the pulp slurry into the discharge blowline of the digester comprising: a first measurement means disposed adjacent to the blowline for continuous measurement of the intensity of attenuated gamma radiation by the pulp slurry passing through the blowline; a second measurement means disposed adjacent to the cold blow liquor line for continuous measurement of the density of the cold blow liquor passing through the cold blow liquor line independent of variations in the gamma radiation mass-attenuation coefficient of the cold blow liquor and for continuous generation of signals indicative of the density of the cold blow liquor independent of variations in the gamma radiation mass-attenuation coefficient of the cold blow liquor; a third measurement means disposed adjacent to the cold blow liquor line for continuous measurement of the intensity of attenuated gamma radiation by the cold blow liquor passing through the cold blow liquor line; and a computing means connected to the first, second and third measurement means for calculating pulp consistency in the pulp slurry passing through the blowline based on the continuous signals received from the first, second and third measurement means which are indicative of the attenuation of gamma radiation by the pulp slurry, cold blow liquor density independent of variations in the gamma radiation mass-attenuation coefficient of the cold blow liquor, and the attenuation of gamma radiation by the cold blow liquor, respectively.
Claim 3
Dependent Claim
199 words
The system as recited in claim 1, wherein the computing means continuously determines pulp consistency in the pulp slurry passing through the blowline according to the equation: ##EQU10## where C F =the pulp consistency in the blowline, a=the intercept of a regression analysis curve of a graph of pulp slurry liquor density vs. cold blow liquor density, b=the slope of a regression analysis curve of a graph of the density of the liquor in the pulp slurry vs. cold blow liquor density, ρ L2 =the density of the cold blow liquor in the cold blow line measured by the second measurement means, ##EQU11## in which I.sub.γ1 is the intensity of the gamma radiation attenuated by the pulp slurry of I.sub.γ10 is the intensity of unattenuated gamma radiation as measured by the first measurement means, d 1 =the diameter of the blowline, ρ F =the density of cellulose fiber, μ F =the gamma radiation mass-attenuation coefficient of cellulose fiber, d 2 =the diameter of the cold blow liquor line, ##EQU12## in which I.sub.γ2 is the intensity of the gamma radiation attenuated by the cold blow liquor and I.sub.γ20 is the unattenuated gamma radiation as measured by the third measurement means.
Claim 4
Dependent Claim
17 words
The system as recited in claim 1, wherein the first and third measurement means are gamma gauges.
Claim 5
Dependent Claim
16 words
The system as recited in claim 1, wherein the second measurement means is a density gauge.
Claim 6
Independent Claim
204 words
A system for continuously determining pulp consistency in a discharge blowline of a continuous pulp digester having a cold blow liquor line for providing cold blow liquor to the digester to wash the pulp by substantially replacing strong black liquor in the pulp slurry with cold blow liquor prior to discharging the pulp slurry into the discharge blowline of the digester comprising: a first measurement means disposed adjacent to the blowline for continuous measurement of the density of the pulp slurry passing through the blowline and for continuous generation of signals indicative of the pulp slurry density; a second measurement means disposed adjacent to the cold blow liquor line for continuous measurement of the density of the cold blow liquor passing through the cold blow liquor line to predict the density of pulp slurry liquor in the discharge blowline and for continuous generation of signals indicative of the density of the cold blow liquor; and a computing means connected to the first and second measurement means for calculating pulp consistency in the pulp slurry passing through the blowline based on the continuous signals received from the first and second measurement means which are indicative of pulp slurry density and cold blow liquor density, respectively.
Claim 7
Independent Claim
204 words
A system for continuously determining pulp consistency in a discharge blowline of a continuous pulp digester having a cold blow liquor line for providing cold blow liquor to the digester to wash the pulp by substantially replacing strong black liquor in the pulp slurry with cold blow liquor prior to discharging the pulp slurry into the discharge blowline of the digester comprising: a first measurement means disposed adjacent to the blowline for continuous measurement of the density of the pulp slurry passing through the blowline and for continuous generation of signals indicative of the pulp slurry density; a second measurement means disposed adjacent to the cold blow liquor line for continuous measurement of the density of the cold blow liquor passing through the cold blow liquor line to predict the density of pulp slurry liquor in the discharge blowline and for continuous generation of signals indicative of the density of the cold blow liquor; and a computing means connected to the first and second measurement means for calculating pulp consistency in the pulp slurry passing through the blowline based on the continuous signals received from the first and second measurement means which are indicative of pulp slurry density and cold blow liquor density, respectively.
Claim 8
Dependent Claim
122 words
The system as recited in claim 5, wherein the computing means continuously determines pulp consistency in the pulp slurry passing through the blowline according to the equation: ##EQU13## where C F the pulp consistency in the blowline, ρ p =the density of the pulp slurry in the blowline as measured by the first measurement means, a=the intercept of a regression analysis curve of a graph of pulp slurry liquor density vs. cold blow liquor density, b=the slope of a regression analysis curve of a graph of pulp slurry liquor density vs. cold blow liquor density, ρ L2 =density of cold blow liquor in the cold blow liquor line as measured by the second measurement means, ρ F =the density of cellulose fiber.
Claim 9
Dependent Claim
16 words
The system as recited in claim 5, wherein the first measurement means includes a gamma gauge.
Claim 10
Dependent Claim
16 words
The system as recited in claim 5, wherein the second measurement means includes a gamma gauge.
Claim 11
Dependent Claim
16 words
The system as recited in claim 5, wherein the second measurement means includes a density gauge.
Claim 12
Independent Claim
263 words
A method of continuously determining pulp consistency in a discharge blowline of a continuous pulp digester having a cold blow liquor line for providing cold blow liquor to the digester for washing the pulp by substantially replacing strong black liquor in the pulp slurry with cold blow liquor prior to discharging the pulp slurry into the discharge blow line of the digester comprising the steps of: continuously measuring the intensity of the attenuated gamma radiation by the pulp slurry in the blowline and continuously generating signals indicative of the intensity of the attenuated gamma radiation by the pulp slurry in the blowline, continuously measuring the density of the cold blow liquor passing through the cold blow liquor line independent of variations in the gamma radiation mass-attenuation coefficient of the cold blow liquor and continuously generating signals indicative of the density of the cold blow liquor independent of variations in the gamma radiation mass-attenuation coefficient of the cold blow liquor; continuously measuring the intensity of the attenuated gamma radiation by the cold blow liquor passing through the cold blow liquor line and continuously generating signals indicative of the density of the cold blow liquor; and continuously computing the pulp consistency of the pulp slurry passing through the blowline with a computer based on continuous signals received by the computer indicative of the intensity of attenuated gamma radiation by the pulp slurry, the density of the cold blow liquor uninfluenced by variations in the gamma radiation mass-attenuation coefficient of the cold blow liquor and the intensity of attenuated gamma radiation by the cold blow liquor.
Claim 13
Independent Claim
263 words
A method of continuously determining pulp consistency in a discharge blowline of a continuous pulp digester having a cold blow liquor line for providing cold blow liquor to the digester for washing the pulp by substantially replacing strong black liquor in the pulp slurry with cold blow liquor prior to discharging the pulp slurry into the discharge blow line of the digester comprising the steps of: continuously measuring the intensity of the attenuated gamma radiation by the pulp slurry in the blowline and continuously generating signals indicative of the intensity of the attenuated gamma radiation by the pulp slurry in the blowline, continuously measuring the density of the cold blow liquor passing through the cold blow liquor line independent of variations in the gamma radiation mass-attenuation coefficient of the cold blow liquor and continuously generating signals indicative of the density of the cold blow liquor independent of variations in the gamma radiation mass-attenuation coefficient of the cold blow liquor; continuously measuring the intensity of the attenuated gamma radiation by the cold blow liquor passing through the cold blow liquor line and continuously generating signals indicative of the density of the cold blow liquor; and continuously computing the pulp consistency of the pulp slurry passing through the blowline with a computer based on continuous signals received by the computer indicative of the intensity of attenuated gamma radiation by the pulp slurry, the density of the cold blow liquor uninfluenced by variations in the gamma radiation mass-attenuation coefficient of the cold blow liquor and the intensity of attenuated gamma radiation by the cold blow liquor.
Claim 14
Dependent Claim
143 words
The method as recited in claim 10, wherein during the computing step pulp consistency is computed by the computer according to the equation: ##EQU14## where C F =pulp consistency in the blowline, a=the intercept of a regression analysis curve of a graph of pulp slurry liquor density vs. cold blow liquor density, b=the slope of a regression analysis curve of a graph of pulp slurry liquor density vs. cold blow liquor density, ρ L2 =density of the cold blow liquor independent variations in the gamma radiation mass-attenuation coefficient, ##EQU15## in which I.sub.γ1 is the intensity of the gamma radiation attenuated by the pulp slurry and I.sub.γ10 is the intensity of unattenuated gamma radiation, d 1 =the diameter of the blowline, ρ F =the density of cellulose fiber, d 2 =the diameter of the cold blow liquor line, ##EQU16## in which I.sub.γ2 is the
Claim 15
Independent Claim
172 words
A method of continuously determining pulp consistency in a discharge blowline of a continuous pulp digester having a cold blow liquor line for providing cold blow liquor to the digester for washing the pulp by substantially replacing strong black liquor in the pulp slurry with cold blow liquor prior to discharging the pulp slurry into the discharge blowline of the digester comprising the steps of: continuously measuring the density of the pulp slurry passing through the blowline and continuously generating signals indicative of the intensity of the pulp slurry; continuously measuring the density of the cold blow liquor passing through the cold blow liquor line to predict the density of pulp slurry liquor in the discharge blowline and continuously generating signals indicative of the density of the cold blow liquor; and continuously computing the pulp consistency of the pulp slurry passing through the blowline with computing means based on continuous signals received by the computing means indicative of the density of the pulp slurry and the density of the cold blow liquor.
Claim 16
Independent Claim
172 words
A method of continuously determining pulp consistency in a discharge blowline of a continuous pulp digester having a cold blow liquor line for providing cold blow liquor to the digester for washing the pulp by substantially replacing strong black liquor in the pulp slurry with cold blow liquor prior to discharging the pulp slurry into the discharge blowline of the digester comprising the steps of: continuously measuring the density of the pulp slurry passing through the blowline and continuously generating signals indicative of the intensity of the pulp slurry; continuously measuring the density of the cold blow liquor passing through the cold blow liquor line to predict the density of pulp slurry liquor in the discharge blowline and continuously generating signals indicative of the density of the cold blow liquor; and continuously computing the pulp consistency of the pulp slurry passing through the blowline with computing means based on continuous signals received by the computing means indicative of the density of the pulp slurry and the density of the cold blow liquor.
Claim 17
Dependent Claim
102 words
The method as recited in claim 12, wherein during the computing step pulp consistency is computed by the computer according to the equation: ##EQU17## where C F =pulp consistency in the blowline, ρ p =the density of the pulp slurry in the blowline, a=the intercept of a regression analysis curve of a graph of pulp slurry liquor density vs. cold blow liquor density, b=the slope of a regression analysis curve of a graph of pulp slurry liquor density vs. cold blow liquor density, ρ L2 =density of cold blow liquor in the cold blow line, ρ F =the density of cellulose fiber.
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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) | 1993-10-15 | 1994-04-16 | 1994-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-15 | 1998-04-16 | 1998-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-15 | 2002-04-16 | 2002-10-16 | $7700.00 | Window Closed / Lapsed |