US3630836A - Controlling the cutting to hydration ratio in the refining of pulp - Google Patents

Controlling the cutting to hydration ratio in the refining of pulp Download PDF

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Publication number
US3630836A
US3630836A US863618A US3630836DA US3630836A US 3630836 A US3630836 A US 3630836A US 863618 A US863618 A US 863618A US 3630836D A US3630836D A US 3630836DA US 3630836 A US3630836 A US 3630836A
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United States
Prior art keywords
signal
stock
drying
rate
paper
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Expired - Lifetime
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US863618A
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English (en)
Inventor
Charles R Bietry
Earl D Hogan
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Eastman Kodak Co
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Eastman Kodak Co
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Publication of US3630836A publication Critical patent/US3630836A/en
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    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
    • D21G9/00—Other accessories for paper-making machines
    • D21G9/0009—Paper-making control systems
    • D21G9/0018—Paper-making control systems controlling the stock preparation
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S162/00—Paper making and fiber liberation
    • Y10S162/09—Uses for paper making sludge
    • Y10S162/10—Computer control of paper making variables

Definitions

  • the invention permits the preselection and maintenance of a given quality for paper being manufactured.
  • the invention employs a computer that effectively calculates the cutting to hydration ratio (C/I-I) of refined pulp, i.e., stock, used in paper manufacturing, thereby to control paper formation (with respect to paper strength). It has been found that the rate at which stock dries into paper during paper manufacture is a reflection of its hydration: the greater the hydration, the lower the rate at which such stock dries, and vice versa. Thus, for a given stock (and drying temperature) the drying rate thereof will vary directly with the cutting thereof, and inversely with the hydration thereof.
  • the error therebetween may be used to controleither manually or automaticallythe adjustment of the pulp refiner, thereby to maintain the desired paper formation.
  • the drying rate for stock is determined from the moisture content of such stock before and after such stock respectively enters and exits from a paper drying stage.
  • drying stage should not be one wherefrom bone dry" paper exits, this being because no moisture is removed from such paper for part of its passage through such drier; and so, the entering and exiting moisture measurements would lead to a false indication of the drying rate.
  • the drying rate for stock is dependent not only on the cutting to hydration ratio, but is also directly dependent on the drying temperature, i.e., d S(C/H), where S is some temperature dependent variable such as the pressure of steam within the drying stage.
  • the cutting to hydration ratio is more properly reflected in terms of stock drying rate per units of temperature (d/s); and in the presently preferred form of the invention, the instantaneous d/s is equated with a reference Zi,sl,for quality control purposes.
  • An object of the invention is to provide improved apparatus and methods for manufacturing paper.
  • Another object of the invention is to provide apparatus and methods for controlling the quality of paper during manufacture thereof.
  • Another object of the invention is to detect, and correct for, inefficient operation of a pulp refiner.
  • Another object of the invention is to provide control of a pulp refiner in accordance with the cutting to hydration ratio of pulp stock processed thereby.
  • Another object of the invention is to provide a way to determine the cutting to hydration ratio for pulp stock from its drying rate.
  • FIG. 1 is a diagram useful in describing the invention
  • FIG. 2 is a block diagram illustrating a presently preferred form of the invention.
  • a family of three curves illustrates the relationships among stock drying rate (ii); drying temperature (S), and paper formation (C/I-I).
  • S drying temperature
  • C/I-I paper formation
  • raw pulp is passed through a refiner 10 such, for example as a jordan.
  • the refiner I0 typically, has parts 12 and 14, which are relatively rotatable about a common axis by means of a motor 16.
  • the stock output of the refiner is, in conventional manner, passed through a paper-forming fourdrinier 18, after which such stock is dried (22,24) into a bone dry paper web, calendered (26), and rolled (28).
  • the driers 22, 24 are steam (30) operated; and the stock drying rate, as presently preferred, is determined as follows:
  • a first beta gauge 32 for producing a signal (MA) representing the stock moisture content per unit of web area, is situated at the entrance of the driver 22; and a second beta gauge 34, for producing a signal (M'IA) representing the stock moisture per unit of web area is situated at the exit of the drier 22.
  • the moisture levels (MIA) and (M'IA) are compared (subtraction device 38) to produce a loss in moisture signal (MM/A), which when multiplied (40) by the web speed (tachometer 42) and web width (selector 44) produces a signal (3,) representing the actual rate at which the stock dries into paper.
  • steam pressure is analogous with the drying temperature of the driers (22,24), it is used to drive, via a diaphragm actuator 46, the wiper 48 of a pickoff potentiometer 50, thereby to product a signal (S,,) representative of the actual temperature of the driers 22,24.
  • a divider 52 is provided to produce the quotient signal (fl /S which is directly related to the cutting to hydration ratio (C/I'I) for the paper being manufactured. See the equations of FIG. 1.
  • a comparator 54 equates the signal (Zi /S with a preselected fonnation signal (2i,/S,selector 56-the error therebetween being applied to control the operation of a motor 58.
  • the motor 58 relatively positions axially the parts 12,4 of the refiner 10, thereby to close (or open) the bite of the refiner.
  • An error signal produced by the comparator 54 evidences a dulling of the refiner parts 12,14, and which dulling would be reflected in a degraded product formation were it not for the fact that, in accordance with the invention, the bite of the refiner I0 is taken up to cancel such error signal, thereby to maintain product formation.
  • c. means producing a signal dependent on the difference between said signal that varies directly with said drying rate and said reference signal, said difference dependent signal being said control signal.
  • said signal that varies directly with said drying rate is a signal that varies as a direct function of the rate of drying for said stock and as an inverse function of the stock drying temperature.
  • a lead device may be employed between the comparator 54 and motor 58 to compensate for the delay (fourdrinier 18, drier 22) between the time the refiner first starts to produce stock with a low cutting to hydration ratio and the time such cutting to hydration ratio is computed; or application of the signal output from the comparator 54 may be applied to adjust the bite of the refiner in discrete increments, etc.
  • said adjustable means is a pulp refiner
  • said signal is applied to adjust said pulp refiner in proportion thereto.
  • said signal producing means includes:

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US863618A 1969-10-03 1969-10-03 Controlling the cutting to hydration ratio in the refining of pulp Expired - Lifetime US3630836A (en)

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US86361869A 1969-10-03 1969-10-03

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US3630836A true US3630836A (en) 1971-12-28

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US (1) US3630836A (fr)
BE (1) BE748038A (fr)
FR (1) FR2020505A1 (fr)
GB (1) GB1330675A (fr)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4498137A (en) * 1982-04-21 1985-02-05 Beloit Corporation Programmable refiner controller with horsepower-days per ton scaling
US5853543A (en) * 1997-01-27 1998-12-29 Honeywell-Measurex Corporation Method for monitoring and controlling water content in paper stock in a paper making machine
US5928475A (en) * 1996-12-13 1999-07-27 Honeywell-Measurex, Corporation High resolution system and method for measurement of traveling web
US5944955A (en) * 1998-01-15 1999-08-31 Honeywell-Measurex Corporation Fast basis weight control for papermaking machine
US6006602A (en) * 1998-04-30 1999-12-28 Honeywell-Measurex Corporation Weight measurement and measurement standardization sensor
US6072309A (en) * 1996-12-13 2000-06-06 Honeywell-Measurex Corporation, Inc. Paper stock zeta potential measurement and control
US6076022A (en) * 1998-01-26 2000-06-13 Honeywell-Measurex Corporation Paper stock shear and formation control
US6080278A (en) * 1998-01-27 2000-06-27 Honeywell-Measurex Corporation Fast CD and MD control in a sheetmaking machine
US6086716A (en) * 1998-05-11 2000-07-11 Honeywell-Measurex Corporation Wet end control for papermaking machine
US6087837A (en) * 1996-12-13 2000-07-11 Honeywell-Measurex Compact high resolution under wire water weight sensor array
US6092003A (en) * 1998-01-26 2000-07-18 Honeywell-Measurex Corporation Paper stock shear and formation control
US6099690A (en) * 1998-04-24 2000-08-08 Honeywell-Measurex Corporation System and method for sheet measurement and control in papermaking machine
US6149770A (en) * 1998-04-14 2000-11-21 Honeywell-Measurex Corporation Underwire water weight turbulence sensor
US6341522B1 (en) 1996-12-13 2002-01-29 Measurex Corporation Water weight sensor array imbedded in a sheetmaking machine roll

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2699095A (en) * 1953-11-10 1955-01-11 Honeywell Regulator Co Control apparatus for pulp refiners
US3196072A (en) * 1962-06-12 1965-07-20 Ibm Control system for paper-making machines
US3490689A (en) * 1966-09-23 1970-01-20 Beloit Corp Automated machine system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2699095A (en) * 1953-11-10 1955-01-11 Honeywell Regulator Co Control apparatus for pulp refiners
US3196072A (en) * 1962-06-12 1965-07-20 Ibm Control system for paper-making machines
US3490689A (en) * 1966-09-23 1970-01-20 Beloit Corp Automated machine system

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4498137A (en) * 1982-04-21 1985-02-05 Beloit Corporation Programmable refiner controller with horsepower-days per ton scaling
US6341522B1 (en) 1996-12-13 2002-01-29 Measurex Corporation Water weight sensor array imbedded in a sheetmaking machine roll
US5928475A (en) * 1996-12-13 1999-07-27 Honeywell-Measurex, Corporation High resolution system and method for measurement of traveling web
US6204672B1 (en) 1996-12-13 2001-03-20 Honeywell International Inc System for producing paper product including a compact high-resolution under wire water weight sensor array
US6072309A (en) * 1996-12-13 2000-06-06 Honeywell-Measurex Corporation, Inc. Paper stock zeta potential measurement and control
US6087837A (en) * 1996-12-13 2000-07-11 Honeywell-Measurex Compact high resolution under wire water weight sensor array
US5853543A (en) * 1997-01-27 1998-12-29 Honeywell-Measurex Corporation Method for monitoring and controlling water content in paper stock in a paper making machine
US5944955A (en) * 1998-01-15 1999-08-31 Honeywell-Measurex Corporation Fast basis weight control for papermaking machine
US6076022A (en) * 1998-01-26 2000-06-13 Honeywell-Measurex Corporation Paper stock shear and formation control
US6092003A (en) * 1998-01-26 2000-07-18 Honeywell-Measurex Corporation Paper stock shear and formation control
US6080278A (en) * 1998-01-27 2000-06-27 Honeywell-Measurex Corporation Fast CD and MD control in a sheetmaking machine
US6149770A (en) * 1998-04-14 2000-11-21 Honeywell-Measurex Corporation Underwire water weight turbulence sensor
US6099690A (en) * 1998-04-24 2000-08-08 Honeywell-Measurex Corporation System and method for sheet measurement and control in papermaking machine
US6126785A (en) * 1998-04-24 2000-10-03 Honeywell-Measurex Corporation System and method for sheet measurement and control in papermaking machine
US6168687B1 (en) 1998-04-24 2001-01-02 Honeywell-Measurex Corporation System and method for sheet measurement and control in papermaking machine
US6006602A (en) * 1998-04-30 1999-12-28 Honeywell-Measurex Corporation Weight measurement and measurement standardization sensor
US6086716A (en) * 1998-05-11 2000-07-11 Honeywell-Measurex Corporation Wet end control for papermaking machine

Also Published As

Publication number Publication date
GB1330675A (en) 1973-09-19
FR2020505A1 (fr) 1970-07-17
BE748038A (fr) 1970-08-31

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