Pulp property development Part III: Fiber residence time and consistency profile impact on specific energy and pulp properties

• This paper focuses on the pulp properties obtained from ThermoMechanical Pulp (TMP) CD refiners. Undersampled pulp variables are expanded into an oversampled set of process data, which makes it possible to analyze pulp properties in a dynamic time frame. It is shown that, in order to gain deeper insight into the defibration/fibrillation at a specific energy input, one needs to know the fiber residence time and the consistency profile. Moreover, the fiber residence time in the flat zone (FZ) and conical zone (CD) are intertwined with the consistency out from FZ and CD. Together with an external variable (production), these internal variables are essential for predicting the pulp properties. It is also shown that internal process conditions from different test series can be manipulated in the operating window using a low-frequency gain description obtained from an ARX model. The same mapping procedure can be applied to pulp and handsheet properties (in this paper represented by the tensile index), and this opens for implementation of new optimization routines to find more energy efficient operating points while maintaining pre-specified pulp quality.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Materialteknik -- Pappers-, massa- och fiberteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering -- Paper, Pulp and Fiber Technology (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Kemiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Chemical Engineering (hsv//eng)

Keyword

quality

helich wg

TMP refiners

Piecewise linear functions

tmp refining processes

p78

1972

optimization

Materials Science

v73

Pulp quality models

pulp and paper magazine of canada

Publication and Content Type

art (subject category)

ref (subject category)