{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,2]],"date-time":"2025-10-02T10:25:19Z","timestamp":1759400719493,"version":"3.40.5"},"reference-count":19,"publisher":"Walter de Gruyter GmbH","issue":"1","license":[{"start":{"date-parts":[[2019,1,30]],"date-time":"2019-01-30T00:00:00Z","timestamp":1548806400000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2019,3,26]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:p>The purpose of this work was to study the influence of pulp fiber suspensions refining operating variables on energy efficiency coefficient. Three chemical pulps with different average morphological characteristics were used, obtained from bleached kraft <jats:italic>Pinus sylvestris<\/jats:italic>, <jats:italic>Eucalyptus globulus<\/jats:italic> and <jats:italic>Betula verrucosa<\/jats:italic>. The final objective was to establish the chemical pulps refining efficiency parameters. Refining hydromechanics and energy consumption profiles were analyzed. Average normal and tangential forces on pulp suspension in the gap clearance, resulting rotor-stator distance and no-load and refining conditions power consumption were obtained. The refining trials took place in a laboratory Valley beater, and the manipulated variables were charge on the roll and rotor rotation speed. Global relationships for tangential stress and energy efficiencies in terms of rotation speed and rotor-stator gap were obtained. A relationship between energy efficiency and shear stress was obtained. The results have shown that in a Valley beater increased rotor-stator gaps reduce energy efficiency, concomitantly increasing apparent viscosity and reducing shear stress. No-load power was seen to increase with crowding factor, and thus with flocculation. Inversely, crowding factor and ultimately flocculation had an adverse effect on energy efficiency.<\/jats:p>","DOI":"10.1515\/npprj-2018-0009","type":"journal-article","created":{"date-parts":[[2019,1,30]],"date-time":"2019-01-30T09:51:21Z","timestamp":1548841881000},"page":"67-74","source":"Crossref","is-referenced-by-count":2,"title":["Energy efficiency in low consistency refining: a study using a Valley beater"],"prefix":"10.1515","volume":"34","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8505-8209","authenticated-orcid":false,"given":"\u00c1lvaro","family":"Vaz","sequence":"first","affiliation":[{"name":"Fiber Materials and Environmental Technologies (FibEnTech) Research Unit , Universidade da Beira Interior , Covilh\u00e3 , Portugal"}]},{"given":"Ant\u00f3nio","family":"Esp\u00edrito-Santo","sequence":"additional","affiliation":[{"name":"Department of Electromechanical Engineering , Universidade da Beira Interior , Covilh\u00e3 , Portugal"}]},{"given":"Pedro","family":"Ara\u00fajo","sequence":"additional","affiliation":[{"name":"Department of Computer Science , Universidade da Beira Interior , Covilh\u00e3 , Portugal"}]},{"given":"Rog\u00e9rio","family":"Sim\u00f5es","sequence":"additional","affiliation":[{"name":"Fiber Materials and Environmental Technologies (FibEnTech) Research Unit , Universidade da Beira Interior , Covilh\u00e3 , Portugal"}]},{"given":"Jacques","family":"Silvy","sequence":"additional","affiliation":[{"name":"Fiber Materials and Environmental Technologies (FibEnTech) Research Unit , Universidade da Beira Interior , Covilh\u00e3 , Portugal"}]}],"member":"374","published-online":{"date-parts":[[2019,1,30]]},"reference":[{"key":"2023040407420744434_j_npprj-2018-0009_ref_001","unstructured":"Attala, R., Wahren, D. 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DOI: 10.13140\/RG.2.1.4008.3921."},{"key":"2023040407420744434_j_npprj-2018-0009_ref_010","unstructured":"Lundin, T., L\u00f6nnberg, B. (2005) Energy balance in low consistency refining. In: 8th Pira International Refining Conference, Barcelona, Spain, March 1\u20133. Pira Intl., UK. pp.\u20091\u20136. DOI: 10.13140\/RG.2.1.4413.8962."},{"key":"2023040407420744434_j_npprj-2018-0009_ref_011","unstructured":"Lundin, T., Wurlitzer, F., Park, S.W., Fardim, P. (2009) Energy Analysis in low consistency refining of softwood. O Papel 70(10):41\u201360."},{"key":"2023040407420744434_j_npprj-2018-0009_ref_012","doi-asserted-by":"crossref","unstructured":"Nasab, N.R., Olson, J.A., Heymer, J., Martinez, M.D. (2014) Understanding of no-load power in low consistency refiners. Can. J. Chem. Eng. 92:524\u2013535. 10.1002\/cjce.21818.","DOI":"10.1002\/cjce.21818"},{"key":"2023040407420744434_j_npprj-2018-0009_ref_013","unstructured":"Radoslavova, D. (1996) Mod\u00e9lisation Hydrodynamique du processus de Raffinage des P\u00e2tes a Papier. PhD Thesis, Institut National Polytechnique de Grenoble. France, 67\u201393."},{"key":"2023040407420744434_j_npprj-2018-0009_ref_014","unstructured":"Radoslavova, D., Roux, J.C., Silvy, J. (1997a) Energy efficiency in refining. In: 4th Pira International Refining Conference, 18\u201320 March 1997, Fiuggi, Italy. Pira International, Leatherhead, UK."},{"key":"2023040407420744434_j_npprj-2018-0009_ref_015","unstructured":"Radoslavova, D., Roux, J.C., Silvy, J. (1997b) Hydrodynamic modelling of the behaviour of the pulp suspensions during beating and its application to optimizing the refining process. In: The Fundamentals of Papermaking Materials, Proceedings of the 11th Fundamental Research Symposium, Cambridge. Ed. Baker, C.F., Pira International, UK. pp.\u2009607\u2013639. ISBN: 0 9541126 0 1."},{"key":"2023040407420744434_j_npprj-2018-0009_ref_016","unstructured":"Roux, J.C. (2001) Stock preparation part 1: pulp treatment processes. In: The Science of Papermaking, Proceedings of the 12th Fundamental Research Symposium, 17\u201321 September 2001, Cambridge. Ed. Baker, C.F., Pira International, UK. pp.\u200919\u201380. ISBN: 0 9541126 0 1."},{"key":"2023040407420744434_j_npprj-2018-0009_ref_017","unstructured":"Roux, J.C., Franc, N., Duffy, G.G., Fabry, B. (2001) Shear Factor: a new way to characterize fiber suspension shear. Tappi J. 84(8):46\u201363."},{"key":"2023040407420744434_j_npprj-2018-0009_ref_018","doi-asserted-by":"crossref","unstructured":"Van den Akker, J.A. (1957) Energy considerations in the beating of pulp. In: Fundamentals of Papermaking Fibers, Proceedings of the 1st Fundamental Research Symposium, Cambridge, September 1957. Ed. Bolam, F., Pira International, UK. pp.\u2009435\u2013479. 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