EP0349860A2 - Process for controlling the addition of retention agent during papermaking - Google Patents
Process for controlling the addition of retention agent during papermaking Download PDFInfo
- Publication number
- EP0349860A2 EP0349860A2 EP89111530A EP89111530A EP0349860A2 EP 0349860 A2 EP0349860 A2 EP 0349860A2 EP 89111530 A EP89111530 A EP 89111530A EP 89111530 A EP89111530 A EP 89111530A EP 0349860 A2 EP0349860 A2 EP 0349860A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- retention
- flocculation
- values
- addition
- degree
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
- D21H23/02—Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
- D21H23/04—Addition to the pulp; After-treatment of added substances in the pulp
- D21H23/06—Controlling the addition
- D21H23/12—Controlling the addition by measuring properties of the formed web
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
- D21H23/02—Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
- D21H23/04—Addition to the pulp; After-treatment of added substances in the pulp
- D21H23/06—Controlling the addition
- D21H23/08—Controlling the addition by measuring pulp properties, e.g. zeta potential, pH
-
- 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
- Y10S162/11—Wet end paper making variables
Definitions
- the invention relates to a method for controlling the addition of retention aid in papermaking.
- the paper produced be as uniform as possible, i.e. H. has a good formation.
- the retention and flocculant addition increases. This means that with the control mentioned above, the retention values at which the formation is still acceptable must first be found by preliminary tests. They are then used as setpoints for the control.
- the formation is still dependent on the respective paper stock composition, so that this setting must be carried out for each type of paper running on the paper machine. But even then it is still not certain whether a good formation will be achieved since fluctuations in the quality of the raw materials used cannot be recorded.
- the degree of flocculation of the pulp suspension is first measured in the paper machine.
- the retention is measured with the known systems described above, the degree of flocculation also with known systems, for example with a flocculation sensor according to EP-A-01 57 310.
- the computer continuously receives measurement data of the variable pulp values or quantities, so that for a setpoint value to be entered for the degree of flocculation, namely the maximum permissible degree of flocculation (Y2), the maximum quantity of the variable material components (X i ... X n ) can be determined.
- Control signals for metering devices, for example metering pumps, of these components are then derived from the quantity values.
- the retention (Y1) depends on the variable pulp values (X1 ... X n ), so that there is an optimal combination of the addition quantities of the variable material components influencing the retention, in which there is a setpoint for the degree of flocculation sets a maximum retention.
- the quantity values of these variable components (X i ... X n ) in the instantaneous setting of the paper stock values (X 1 ... X i-1 ) are varied in such a way that a combination of the values is found in which both the equation (II) for the setpoint of the Degree of flocculation (Y2) is met, and a maximum retention (Y1) of the pulp according to equation (I) is achieved.
- the control signals for the corresponding metering devices for the variable substance components are in turn derived from the quantity values obtained in this way.
Abstract
In Abhängigkeit von einem vorgegebenen Flockungsgrad und charakteristischen Werten des Papierstoffsuspension werden mit Hilfe einer mathematischen Beziehung die höchst zugebbaren Mengen der die Retention beeinflussenden variablen Stoffkomponenten bestimmt und aus den Mengenwerten Steuersignale für Dosiereinrichtungen abgeleitet.Depending on a given degree of flocculation and characteristic values of the paper stock suspension, the maximum allowable amounts of the variable material components influencing the retention are determined with the aid of a mathematical relationship and control signals for metering devices are derived from the amount values.
Description
Die Erfindung betrifft ein Verfahren zur Steuerung der Retentionsmittelzugabe bei der Papierherstellung.The invention relates to a method for controlling the addition of retention aid in papermaking.
Für die automatische Steuerung der Zugabe von die Retention und Flockung beeinflussenden, variablen Stoffkomponenten wurden bisher Systeme verwendet, die mit Hilfe entsprechender Sensoren die Gesamtstoff- und Füllstoffkonzentration in der Papierstoffauflaufsuspension und im Siebwasser messen. Aus diesen Meßdaten wurden nach bekannten Formeln die one-pass-Retention des gesamten Stoffes sowie der Faser- und Füllstoffe berechnet. Durch die Steuerung der Zugabe eines oder mehrerer Retentions- und Flockungsmittel wurden dann möglichst hohe Retentionswerte angestrebt. Der Flockungsgrad wurde dabei nicht gemessen und berücksichtigt.For the automatic control of the addition of variable substance components influencing retention and flocculation, systems have so far been used which use appropriate sensors to measure the total substance and filler concentration in the pulp suspension and in the white water. The one-pass retention of the entire substance as well as the fiber and fillers were calculated from these measurement data according to known formulas. By controlling the addition of one or more retention and flocculation agents, the highest possible retention values were then sought. The degree of flocculation was not measured and taken into account.
Außer einer hohen Retention ist es jedoch ebenso wichtig, daß das hergestellte Papier eine möglichst gleichmäßige Durchsicht, d. h. eine gute Formation aufweist. Sie wird jedoch mit zunehmendem Flockungsgrad durch steigende Retentions- und Flockungsmittelzugabe mehr oder weniger verschlechtert. Das bedeutet, daß bei der obenerwähnten Steuerung zunächst durch Vorversuche die Retentionswerte gefunden werden müssen, bei denen die Formation noch annehmbar ist. Sie werden dann als Sollwerte für die Steuerung verwendet. Darüberhinaus ist die Formation noch von der jeweiligen Papierstoffzusammensetzung abhängig, so daß diese Einstellung für jede an der Papiermaschine laufende Papiersorte durchgeführt werden muß. Aber auch dann ist noch nicht sicher, ob dabei eine gute Formation erreicht wird, da Schwankungen in der Qualität der verwendeten Rohstoffe nicht zu erfassen sind.In addition to high retention, however, it is also important that the paper produced be as uniform as possible, i.e. H. has a good formation. However, as the degree of flocculation increases, the retention and flocculant addition increases. This means that with the control mentioned above, the retention values at which the formation is still acceptable must first be found by preliminary tests. They are then used as setpoints for the control. In addition, the formation is still dependent on the respective paper stock composition, so that this setting must be carried out for each type of paper running on the paper machine. But even then it is still not certain whether a good formation will be achieved since fluctuations in the quality of the raw materials used cannot be recorded.
Es bestand daher die Aufgabe, ein Verfahren zur Steuerung der Retentionsmittelzugabe zu entwickeln, durch das die Zudosierung eines oder mehrerer Retentionsmittel in Abhängigkeit von einem vorgegebenen, maximal zulässigen Flockungsgrad und von der Papierstoffzusammensetzung einstellbar ist.It was therefore the task of developing a method for controlling the addition of retention aids, by means of which the addition of one or more retention aids can be set as a function of a predetermined, maximum permissible degree of flocculation and of the paper stock composition.
Die Lösung der Aufgabe besteht erfindungsgemäß darin, daß aus einem vorgegebenen, maximal zulässigen Flockungsgrad (Y₂) und charakteristischen Werten der Papierstoffsuspension (X₁...Xn) mit Hilfe der mathematischen Beziehung
Y₂ = f₂ (X₁...Xi...Xn)
die höchst zugebbaren Mengen der die Retention beeinflussenden variablen Stoffkomponenten (Xi...Xn) bestimmt werden, wobei die tatsächlichen Werte des Flockungsgrades und der Retention durch Messung der Suspension laufend überwacht werden, und aus den Mengenwerten (Xi...Xn) Steuersignale für Dosiereinrichtungen dieser Komponenten abgeleitet werden.The solution to the problem consists in that from a predetermined, maximum permissible degree of flocculation (Y₂) and characteristic values of the pulp suspension (X₁ ... X n ) with the help of the mathematical relationship
Y₂ = f₂ (X₁ ... X i ... X n )
the maximum admissible amounts of the variable substance components influencing the retention (X i ... X n ) are determined, the actual values of the degree of flocculation and the retention being monitored continuously by measuring the suspension, and from the amount values (X i ... X n ) control signals for metering devices of these components are derived.
Das Verfahren nach der Erfindung ist anhand eines Ausführungsbeispiels nachfolgend näher beschrieben.The method according to the invention is described in more detail below using an exemplary embodiment.
Zunächst wird außer der Retention auch der Flockungsgrad der Papierstoffsuspension in der Papiermaschine gemessen. Die Messung der Retention erfolgt mit den bekannten, oben beschriebenen Systemen, die des Flockungsgrades ebenso mit bekannten Systemen, beispielsweise mit einem Flockungssensor nach EP-A-01 57 310.In addition to the retention, the degree of flocculation of the pulp suspension is first measured in the paper machine. The retention is measured with the known systems described above, the degree of flocculation also with known systems, for example with a flocculation sensor according to EP-A-01 57 310.
Dabei werden mit Hilfe statistischer Methoden der Einfluß der variablen Papierstoffwerte (X₁...Xn), wie Zusammensetzung des Faseranteils des Papierstoffes und sein Mahlgrad; pH-Wert der Suspension; Alaun-Menge; Retentionsmittel-Menge; Füllstoff-Menge, auf die Retention und den Flockungsgrad ermittelt und damit empirische Gleichungen
Y₁ = f₁ (X₁...Xi...Xn) (I)
Y₂ = f₂ (X₁...Xi...Xn) (II)
erstellt, die als Steueralgorithmus in einem elektronischen Rechner gespeichert werden. Daneben erhält der Rechner laufend Meßdaten der variablen Papierstoffwerte bzw. -mengen, so daß für einen einzugebenden Sollwert des Flockungsgrades, nämlich den maximal zulässigen Flockungsgrad (Y₂), die höchst zugebbaren Mengen der die Retention beeinflussenden variablen Stoffkomponenten (Xi...Xn) ermittelt werden können. Aus den Mengenwerten werden dann Steuersignale für Dosiereinrichtungen, beispielsweise Dosierpumpen, dieser Komponenten abgeleitet.With the help of statistical methods, the influence of the variable pulp values (X₁ ... X n ), such as the composition of the fiber content of the pulp and its degree of grinding; pH of the suspension; Alum crowd; Amount of retention aid; Filler amount, determined on the retention and the degree of flocculation and thus empirical equations
Y₁ = f₁ (X₁ ... X i ... X n ) (I)
Y₂ = f₂ (X₁ ... X i ... X n ) (II)
created, which are stored as a control algorithm in an electronic computer. In addition, the computer continuously receives measurement data of the variable pulp values or quantities, so that for a setpoint value to be entered for the degree of flocculation, namely the maximum permissible degree of flocculation (Y₂), the maximum quantity of the variable material components (X i ... X n ) can be determined. Control signals for metering devices, for example metering pumps, of these components are then derived from the quantity values.
Wie bereits erwähnt, hängt auch die Retention (Y₁) von den variablen Papierstoffwerten (X₁...Xn) ab, so daß es eine optimale Kombination der Zugabemengen der die Retention beeinflussenden, variablen Stoffkomponenten gibt, bei der sich für einen Sollwert des Flockungsgrades eine maximale Retention einstellt. Hierzu werden im Rechner die Mengenwerte dieser variablen Komponenten (Xi...Xn) bei der augenblicklichen Einstellung der Papierstoffwerte (X₁...Xi-1) so variiert, daß eine Kombination der Werte gefunden ist, bei der sowohl die Gleichung (II) für den Sollwert des Flockungsgrades (Y₂) erfüllt ist, als auch eine maximale Retention (Y₁) des Papierstoffs nach der Gleichung (I) erreicht ist. Aus den auf diese Weise erhaltenen Mengenwerten werden wiederum die Steuersignale für die entsprechenden Dosiereinrichtungen für die variablen Stoffkomponenten abgeleitet.As already mentioned, the retention (Y₁) depends on the variable pulp values (X₁ ... X n ), so that there is an optimal combination of the addition quantities of the variable material components influencing the retention, in which there is a setpoint for the degree of flocculation sets a maximum retention. For this purpose, the quantity values of these variable components (X i ... X n ) in the instantaneous setting of the paper stock values (X 1 ... X i-1 ) are varied in such a way that a combination of the values is found in which both the equation (II) for the setpoint of the Degree of flocculation (Y₂) is met, and a maximum retention (Y₁) of the pulp according to equation (I) is achieved. The control signals for the corresponding metering devices for the variable substance components are in turn derived from the quantity values obtained in this way.
An einer Papiermaschine wurden in einer Versuchsreihe der Mahlgrad des Papierstoffes (X₁), der pH-Wert (X₂), die Alaun-Menge (X₃), die Retentionsmittel-Menge (X₄) und die Füllstoff-Menge (X₅) variiert und aus den Meßdaten mit Hilfe mathematisch-statistischer Methoden die folgenden Gleichungen für die Gesamtstoffretention (Y₁) und den Flockungsgrad (Y₂) erhalten:
Y₁ = 92,33 + 0.18 · X₃ - 19,79 · X₄ - 0,49 · X₅ - 0,26 · X₃² + 0,16 · X₁ · X₄ + 1,02 · X₂ · X₄ + 0,04 · X₂ · X₅ + 0,22 · X₄ · X₅
Y₂ = 2,76 - 0,09 · X₅ - 0,0004 · X₁² - 1,11 · X₄² + 0,001 · X₁ · X₅ + 0,58 · X₂ · X₄ - 0,13 · X₃ · X₄
Mit Hilfe dieser beiden Gleichungen war es dann möglich, für jeden Wert und jede Kombination der oben erwähnten Variablen die Retentionsmittel- bzw. Alaun-Menge so zu wählen, daß ein Flockungsgrad von beispielsweise 1,5 nicht überschritten und jeweils eine maximale Retention erzielt wurde.In a series of experiments on a paper machine, the degree of grinding of the paper stock (X₁), the pH (X₂), the amount of alum (X₃), the amount of retention agent (X₄) and the amount of filler (X₅) were varied and from the The following equations for total substance retention (Y₁) and flocculation (Y₂) are obtained with the aid of mathematical-statistical methods:
Y₁ = 92.33 + 0.18X₃ - 19.79X₄ - 0.49X₅ - 0.26 · X₃² + 0.16 · X₁ · X₄ + 1.02 · X₂ · X₄ + 0.04 · X₂ · X₅ + 0.22 · X₄ · X₅
Y₂ = 2.76 - 0.09 · X₅ - 0.0004 · X₁² - 1.11 · X₄² + 0.001 · X₁ · X₅ + 0.58 · X₂ · X₄ - 0.13 · X₃ · X₄
With the help of these two equations, it was then possible to select the amount of retention agent or alum for each value and each combination of the variables mentioned above in such a way that a degree of flocculation of, for example, 1.5 was not exceeded and maximum retention was achieved in each case.
Claims (2)
Y₂ = f₂ (X₁...Xi...Xn)
die höchst zugebbaren Mengen der die Retention beeinflussenden variablen Stoffkomponenten (Xi...Xn) bestimmt werden, wobei die tatsächlichen Werte des Flockungsgrades und der Retention durch Messung der Suspension laufend überwacht werden, und aus den Mengenwerten (Xi...Xn) Steuersignale für Dosiereinrichtungen dieser Komponenten abgeleitet werden.1. A method for controlling the addition of retention aid in papermaking, characterized in that from a predetermined, maximum permissible degree of flocculation (Y₂) and characteristic values of the pulp suspension (X₁ ... X n ) using the mathematical relationship
Y₂ = f₂ (X₁ ... X i ... X n )
the maximum admissible amounts of the variable substance components influencing the retention (X i ... X n ) are determined, the actual values of the degree of flocculation and the retention being monitored continuously by measuring the suspension, and from the amount values (X i ... X n ) control signals for metering devices of these components are derived.
Y₁ = f₁ (X₁...Xi...Xn)
erreicht ist, wobei aus den Mengenwerten Steuersignale für die entsprechenden Dosiereinrichtungen abgeleitet werden.2. The method according to claim 1, characterized in that in order to optimize the addition of the retention agent, the variable pulp values (X₁ ... X i ... X k ) are selected so that both the mathematical relationship (I) for a maximum permissible degree of flocculation (Y₂ ) is satisfied as well as a maximum retention (Y₁) of the paper stock according to the mathematical relationship
Y₁ = f₁ (X₁ ... X i ... X n )
is reached, control signals for the corresponding metering devices being derived from the quantity values.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3822783 | 1988-07-06 | ||
| DE3822783A DE3822783A1 (en) | 1988-07-06 | 1988-07-06 | METHOD FOR CONTROLLING THE ADDITION OF RETENTION AGENTS IN PAPER PRODUCTION |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0349860A2 true EP0349860A2 (en) | 1990-01-10 |
| EP0349860A3 EP0349860A3 (en) | 1991-05-22 |
Family
ID=6358029
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP19890111530 Withdrawn EP0349860A3 (en) | 1988-07-06 | 1989-06-24 | Process for controlling the addition of retention agent during papermaking |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4952280A (en) |
| EP (1) | EP0349860A3 (en) |
| JP (1) | JPH0247386A (en) |
| DE (1) | DE3822783A1 (en) |
| FI (1) | FI893232A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001055501A1 (en) * | 2000-01-26 | 2001-08-02 | Voith Paper Patent Gmbh | Method for determining a characteristic value for the binding force potential of suspended paper fibers and use of this method |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4237309A1 (en) * | 1992-11-05 | 1993-04-08 | Voith Gmbh J M | |
| SE503386C2 (en) * | 1994-09-30 | 1996-06-03 | Skogsind Tekn Foskningsinst | Procedure for determining the amount of filler in paper |
| US6114171A (en) * | 1997-10-20 | 2000-09-05 | Westvaco Corporation | Additive management system |
| FI103822B (en) | 1998-06-16 | 1999-09-30 | Valmet Corp | A method for optimizing flocking |
| US6363610B1 (en) | 1999-10-21 | 2002-04-02 | Allied Signal, Inc. | Gas turbine rotor bimetallic ring seal and method therefor |
| DE10118508A1 (en) * | 2001-04-12 | 2002-10-17 | Voith Paper Patent Gmbh | Process and plant for producing a fibrous web |
| FI116241B (en) * | 2002-05-06 | 2005-10-14 | Metso Automation Oy | Method and apparatus for determining retention of a wire portion of a paper machine |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1987002396A1 (en) * | 1985-10-18 | 1987-04-23 | Miami University | Papermaking process |
-
1988
- 1988-07-06 DE DE3822783A patent/DE3822783A1/en not_active Withdrawn
-
1989
- 1989-06-14 US US07/366,495 patent/US4952280A/en not_active Expired - Fee Related
- 1989-06-24 EP EP19890111530 patent/EP0349860A3/en not_active Withdrawn
- 1989-06-28 JP JP1164095A patent/JPH0247386A/en active Pending
- 1989-07-03 FI FI893232A patent/FI893232A/en not_active Application Discontinuation
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1987002396A1 (en) * | 1985-10-18 | 1987-04-23 | Miami University | Papermaking process |
Non-Patent Citations (2)
| Title |
|---|
| PAPIER, DAS. vol. 40, no. 10A, Oktober 1986, DARMSTADT DE Seiten 62 - 67; D. HORAND ET AL: "OPTIMIERUNG VON PAPIER- UND KARTONREZEPTUREN" * |
| TA-A- (CHIGAGO) 11-13, 1988 CONTINUOUS RETENTION MONITORING SYSTEM....KORTELAINEN H. * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001055501A1 (en) * | 2000-01-26 | 2001-08-02 | Voith Paper Patent Gmbh | Method for determining a characteristic value for the binding force potential of suspended paper fibers and use of this method |
| US6746572B2 (en) | 2000-01-26 | 2004-06-08 | Voith Paper Patent Gmbh | Method for determining a characteristic value for the binding force potential of suspended paper fibers and use of this method |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3822783A1 (en) | 1990-01-11 |
| US4952280A (en) | 1990-08-28 |
| EP0349860A3 (en) | 1991-05-22 |
| FI893232A (en) | 1990-01-07 |
| JPH0247386A (en) | 1990-02-16 |
| FI893232A0 (en) | 1989-07-03 |
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