miun.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Ferritsius, Olof
Publications (10 of 27) Show all publications
Ferritsius, O., Ferritsius, R., Rundlöf, M., Engberg, B. A. & Engstrand, P. (2018). The Independent State of Fibres in Relation to the Mechanical Pulping World. In: IMPC 2018: . Paper presented at International Mechanical Pulping Conference (IMPC) 2018, May 27-30, 2018, Trondheim, Norway. Trondheim, Norway
Open this publication in new window or tab >>The Independent State of Fibres in Relation to the Mechanical Pulping World
Show others...
2018 (English)In: IMPC 2018, Trondheim, Norway, 2018Conference paper, Published paper (Refereed)
Abstract [en]

Paper and wood are highly inhomogeneous materials. When describing the mechanical pulp itself, we allcommonly ignore that it is an inhomogeneous material. We have realized that just a very small fraction of stifffibres are enough to impair the printability of the product. In this paper we share some of our reflections andattempts how to describe the inhomogeneous nature of mechanical pulps. A method denoted BIN is underdevelopment based on independent common factors and paying attention to the inhomogeneity of the material.The method may give the possibility to describe the nature of TMP/CTMP/SGW in a more relevant way comparedto todays practice. Hence the paper and board makers may be able to deliver more uniform products at “goodenough” level at lower costs. We have realized that because a method or opinion is well spread (sometimes usedby almost everybody) it does not necessarily mean that it is relevant. A couple of myths have been reflected uponand in our opinion they remain just myths. By putting more attention to reality and describing mechanical pulp asan inhomogeneous material we hope to be able to rid ourselves and the mechanical pulping community of someother myths circulating (some still to be discovered).

Place, publisher, year, edition, pages
Trondheim, Norway: , 2018
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:miun:diva-34680 (URN)
Conference
International Mechanical Pulping Conference (IMPC) 2018, May 27-30, 2018, Trondheim, Norway
Available from: 2018-10-09 Created: 2018-10-09 Last updated: 2018-10-09Bibliographically approved
Ferritsius, R., Ferritsius, O., Hill, J., Karlström, A. & Eriksson, K. (2018). TMP properties and refiner conditions in a CD82 chip refiner at different operation points. Part II: Comparison of the five tests. Nordic Pulp & Paper Research Journal, 33(1), 82-94
Open this publication in new window or tab >>TMP properties and refiner conditions in a CD82 chip refiner at different operation points. Part II: Comparison of the five tests
Show others...
2018 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 33, no 1, p. 82-94Article in journal (Refereed) Published
Abstract [en]

This paper is part two of a study on a CD 82 TMP chip refiner where relations between changes in the process conditions and changes in the properties of the produced pulp are investigated. Focus is on the ratio between tensile index and specific energy consumption when results from five tests are compared. Pulp properties were measured for composite pulp samples taken from the refiner blow line. Residence times and pulp consistencies were estimated by use of the extended entropy model. Clearly, an increase in specific energy does not necessarily implicate an increase in strength properties of the pulp produced. It is of high importance to have access to information about the refining zone conditions when searching for an optimal operation point in terms of the ratio between tensile index and specific energy. In these tests, this ratio had a maximum at about 55 % measured blow line consistency. Unfavourable operating conditions were identified at high pulp consistencies, especially after the FZ, where pulp consistencies well above 70 % were observed. The estimated residence time for each refining zone responded differently when applying changes in production rate, plate gaps and dilution water flow rates. In conclusion, the results associated with estimated pulp consistencies where easier to interpret compared with results for residence times, implying that additional tests are required for the latter variable. In addition to tensile index, pulp properties like freeness, Somerville shives and light scattering coefficient were included in the analysis. 

Keywords
CD 82 refiner, entropy model, fibre properties, handsheet properties, plate gap, pulp quality, residence time, specific energy, temperature measurements, TMP refiners
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-34543 (URN)10.1515/npprj-2018-3003 (DOI)2-s2.0-85048002264 (Scopus ID)
Available from: 2018-09-27 Created: 2018-09-27 Last updated: 2018-09-27Bibliographically approved
Ferritsius, R., Ferritsius, O., Hill, J., Karlström, A. & Eriksson, K. (2018). TMP properties and refining conditions in a CD82 chip refiner. Part I: Step changes of process variables, description of the tests. Nordic Pulp & Paper Research Journal, 33(1), 69-81
Open this publication in new window or tab >>TMP properties and refining conditions in a CD82 chip refiner. Part I: Step changes of process variables, description of the tests
Show others...
2018 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 33, no 1, p. 69-81Article in journal (Refereed) Published
Abstract [en]

The study explores how changes in process variables, residence time and pulp consistency in refining influence the pulp properties. The equipment utilized in this study was a conical disc chip refiner (RGP82CD) producing thermomechanical pulp (TMP). The focus was on the ratio between tensile index and specific energy consumption. Pulp properties were measured for composite pulp samples taken from the refiner blow line. Residence times and pulp consistencies were estimated by use of the extended entropy model. This showed that the CD-refiner, with the flat and conical refining zone, has a process performance similar to that of a two-stage refiner set-up, and that the consistency in both refining zones is of high importance. Comparing different periods revealed that even if the values of measured blow line consistency are similar, significant differences in the estimated consistency in the flat zone can prevail. Therefore, only monitoring blow line consistency is not enough. Specifically, it was found that the pulp consistency after the flat zone could be very high, considerably higher than in the blow line, and this could have negative effects on tensile index and fibre length. 

Keywords
conical disc refiner, energy, entropy model, fibre properties, pulp consistency, pulp properties, residence time, temperature profile, TMP
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-34542 (URN)10.1515/npprj-2018-3002 (DOI)2-s2.0-85047997941 (Scopus ID)
Available from: 2018-09-27 Created: 2018-09-27 Last updated: 2018-09-27Bibliographically approved
Sandberg, C., Ferritsius, O. & Ferritsius, R. (2017). Energy efficiency in mechanical pulping. In: : . Paper presented at 10th Fundamental Mechanical Pulping Research Seminar, Jyväskylä, Finland, 13–14 of June, 2017.
Open this publication in new window or tab >>Energy efficiency in mechanical pulping
2017 (English)Conference paper, Published paper (Refereed)
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:miun:diva-34661 (URN)
Conference
10th Fundamental Mechanical Pulping Research Seminar, Jyväskylä, Finland, 13–14 of June, 2017
Available from: 2018-10-09 Created: 2018-10-09 Last updated: 2018-10-09Bibliographically approved
Ferritsius, O., Ferritsius, R., Hill, J., Karlström, A., Ferritsius, J. & Eriksson, K. (2017). Process considerations and its demands on TMP property measurements - A study on tensile index. Nordic Pulp & Paper Research Journal, 32(1), 45-53
Open this publication in new window or tab >>Process considerations and its demands on TMP property measurements - A study on tensile index
Show others...
2017 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 32, no 1, p. 45-53Article in journal (Refereed) Published
Abstract [en]

As a vital component in the strive towards improved energy efficiency in the operation of TMP refining processes, this work highlights the importance of well- designed procedures when collecting and analysing pulp properties with respect to process conditions. Process data and pulp from a CD82 chip refiner have been used to show that tensile index has strong covariance with fibre residence time calculated by the extended entropy model. A combination of theoretical and practical analysis methods has shown that, in order to assure representative, reliable results, pulp sampling procedures should comprise composite pulp samples collected during a sampling period of about three minutes. In addition, at least four subsequently collected composite pulp samples should be included in the analysis to effectively dampen effects from fast process variations as well as from slow process drift. An in-depth study on tensile index measurements clarifies that 40-60 strips should be used in the case we studied regardless if machine made paper or handsheets are considered.

Keywords
Accuracy, Composite pulp samples, Pulp sampling procedure, Residence time, Tensile index, TMP
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-30666 (URN)10.3183/NPPRJ-2017-32-01-p045-053 (DOI)000398384400006 ()2-s2.0-85016389492 (Scopus ID)
Available from: 2017-04-26 Created: 2017-04-26 Last updated: 2017-06-09Bibliographically approved
Johansson, O., Fernando, D., Fenitsius, R., Daniel, G. & Ferritsius, O. (2016). Advancements in optical analysis yields new insight to mechanical pulping processes in an efficient and inexpensive way. In: International Mechanical Pulping Conference 2016, IMPC 2016: . Paper presented at International Mechanical Pulping Conference 2016, IMPC 2016; Jacksonville; United States; 26 September 2016 through 28 September 2016 (pp. 267-276). TAPPI Press
Open this publication in new window or tab >>Advancements in optical analysis yields new insight to mechanical pulping processes in an efficient and inexpensive way
Show others...
2016 (English)In: International Mechanical Pulping Conference 2016, IMPC 2016, TAPPI Press, 2016, p. 267-276Conference paper, Published paper (Refereed)
Abstract [en]

Operating costs, pulp quality, and loss of markets continue to dominate the concern of mechanical pulp producers. The search for process improvements, new products, and cost reductions requires significant amount of pulp testing to find out how improvements or new products can be achieved. Unfortunately, the required testing comes at a significant cost due to the time consuming and labor intensive preparation of each sample. For example, a detailed analysis which requires fractionation, hot disintegration, hand sheets, etc. may cost in excess of a thousand dollars. Thus, for an in-depth study where one compares different processes or operating conditions, the cost is significant. At the IMPC conference in Helsinki 2010, 2014 Fernando & Daniel showed how a modern variation of Simon staining can be used to gain information about the fiber wall conditions. This idea has now been expanded further by combining traditional fiber morphology measurements with the information gained from the measurement of color and intensities. In this paper, we will demonstrate a new approach to evaluate mechanical pulps using a special optical analyzer with the ability to process images in color or image intensities. The additional information gained from the color of the images is discussed. For the study, we have been comparing results from three modem commercial installations. The results from these trials are discussed using traditional testing methods in an earlier paper by Ferritsius et al., (2016). We will continue the discussion and show how these pulp samples were analyzed with a new optical device involving minimal sample preparations.

Place, publisher, year, edition, pages
TAPPI Press, 2016
Keywords
Automatic pulp tesfing, New approach to evaluating pulp quality, Process improvements
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-29833 (URN)2-s2.0-85006513310 (Scopus ID)9781510830738 (ISBN)
Conference
International Mechanical Pulping Conference 2016, IMPC 2016; Jacksonville; United States; 26 September 2016 through 28 September 2016
Available from: 2017-01-09 Created: 2017-01-09 Last updated: 2017-07-04Bibliographically approved
Eriksson, K., Ferritsius, R., Ferritsius, O. & Hill, J. (2016). Benefits from improved stability in process conditions and pulp properties-a double disc refiner case study. In: International Mechanical Pulping Conference 2016, IMPC 2016: . Paper presented at International Mechanical Pulping Conference 2016, IMPC 2016; Jacksonville; United States; 26 September 2016 through 28 September 2016 (pp. 317-327). TAPPI Press
Open this publication in new window or tab >>Benefits from improved stability in process conditions and pulp properties-a double disc refiner case study
2016 (English)In: International Mechanical Pulping Conference 2016, IMPC 2016, TAPPI Press, 2016, p. 317-327Conference paper, Published paper (Refereed)
Abstract [en]

The purpose of this case study was to explore the potential for reduced energy consumption by improved process control. The application was HC post-refining of TMP in double-disc refiners. Based on data from both continuous production and from step-response tests, a thorough analysis of process performance was conducted. It was found that a significant proportion of the process disturbances, as reflected in the refiner motor load, could be successfully dampened through stabilizing measures on the basic control level. The remaining disturbances was found to be generated inside the refiner itself. In order for these disturbances to be dampened, measurements that can characterize the conditions inside the refining zone are necessary. Given the present design and instrumentation of the process, dynamic modelling of refiner motor load was performed and for fiber properties, muhivariate modeling methods were used to derive expressions for the independent variables Fl and F2. Taken together, evaluation of the models gave directions on how to further improve the process stability and indicated a potential for reduced energy consumption.

Place, publisher, year, edition, pages
TAPPI Press, 2016
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-29832 (URN)2-s2.0-85006380402 (Scopus ID)9781510830738 (ISBN)
Conference
International Mechanical Pulping Conference 2016, IMPC 2016; Jacksonville; United States; 26 September 2016 through 28 September 2016
Note

Funding details: Swedish Research and Development program

Available from: 2017-01-09 Created: 2017-01-09 Last updated: 2017-01-09Bibliographically approved
Ferritsius, R., Sandberg, C., Ferritsius, O., Rundlöf, M., Daniel, G., Mörseburg, K. & Fernando, D. (2016). Development of Fiber Properties in Full Scale HC and LC Refining. In: TAPPI conference proceedings: . Paper presented at 2016 International Mechanical Pulping (IMPC) Conference. TAPPI Press
Open this publication in new window or tab >>Development of Fiber Properties in Full Scale HC and LC Refining
Show others...
2016 (English)In: TAPPI conference proceedings, TAPPI Press, 2016Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
TAPPI Press, 2016
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:miun:diva-34668 (URN)
Conference
2016 International Mechanical Pulping (IMPC) Conference
Available from: 2018-10-09 Created: 2018-10-09 Last updated: 2018-10-09Bibliographically approved
Eriksson, K., Ferritsius, J., Ferritsius, O., Ferritsius, R., Hill, J., Karlstrorrp, A. & Merseburg, K. (2016). Proper pulp sampling pre-requisite to any pulp property assessment. In: International Mechanical Pulping Conference 2016, IMPC 2016: . Paper presented at International Mechanical Pulping Conference 2016, IMPC 2016; Jacksonville; United States; 26 September 2016 through 28 September 2016 (pp. 1-11). TAPPI Press
Open this publication in new window or tab >>Proper pulp sampling pre-requisite to any pulp property assessment
Show others...
2016 (English)In: International Mechanical Pulping Conference 2016, IMPC 2016, TAPPI Press, 2016, p. 1-11Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
TAPPI Press, 2016
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-29837 (URN)2-s2.0-85006434746 (Scopus ID)978-151083073-8 (ISBN)
Conference
International Mechanical Pulping Conference 2016, IMPC 2016; Jacksonville; United States; 26 September 2016 through 28 September 2016
Note

Conference Paper

Available from: 2017-01-09 Created: 2017-01-09 Last updated: 2017-01-09Bibliographically approved
Karlström, A., Hill, J., Ferritsius, R. & Ferritsius, O. (2016). Pulp property development Part II: Process non-linearities and their influence on pulp property development. Nordic Pulp & Paper Research Journal, 31(2), 287-299
Open this publication in new window or tab >>Pulp property development Part II: Process non-linearities and their influence on pulp property development
2016 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 31, no 2, p. 287-299Article in journal (Refereed) Published
Abstract [en]

It is shown in this paper that knowledge of the spatially measured temperatures inside the refining zone in TMP refiners is essential in describing non-linear dynamics of high consistency refining. By expanding the pulp and handsheet properties using piece-wise linear functions into the time domain, an auto-regressive model can be applied to verify that the tempera-ture and the consistency profiles, in combination with the motor load and production rate, are key input candidates when modeling changes in different pulp properties. The model accuracy is analyzed using process information captured at different time and operating conditions. It is also shown that it is more complex to estimate and validate the tensile index than the mean fiber length and Somerville shives content, especially close to refiner operating limits where a shift in the process gain may occur. This type of switched dynamics in tensile index estimation at a specific consistency is related to non-linear behaviors where the fiber pad distribution most likely undergoes a local collapse.

Keywords
Fiber distribution, Fiber network, Pulp quality, Refining models, System identification
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-28939 (URN)000378442300015 ()2-s2.0-84977493495 (Scopus ID)
Note

Funding Details: Norske Skog

Available from: 2016-09-27 Created: 2016-09-27 Last updated: 2017-11-21Bibliographically approved
Organisations

Search in DiVA

Show all publications