Development of the Pressure Screen Foil

Topics: Efficient energy use, Mass flow rate, Volumetric flow rate Pages: 17 (5503 words) Published: January 21, 2013
Saimaa University of Applied Sciences Technology, Imatra Paper Technology

Loan Dinh

Development of the Pressure Screen Foil

Bachelor’s Thesis 2012

Abstract
Loan Dinh Development of the Pressure Screen foil, 60 pages, 12 appendices Saimaa University of Applied Sciences Technology, Imatra Paper Technology Bachelor’s Thesis 2012 Instructors: Mr Ari Pelkiö, Chief Technology Manager, Andritz Mr Pekka Karppinen, Product Manager, Andritz Mr Jarkko Männynsalo, MSc, Senior Lecturer, Saimaa UAS Mr Tapio Tirri, Director, MUAS FiberLaboratory Mr Jari Käyhkö, Research Director, MUAS FiberLaboratory

The purpose of the research was to develop new foils model for headbox screen on higher consistency level of the feed flow than foil that is used today with target feed/accept consistency being approximately 2.0%. However, energy consumption and pulsation level should be in same range as today’s foil type has. The study was commissioned by Andritz. The study was carried out at Fiber-Laboratory in Savonlinna. The work was divided into four parts. First part was the test of Dolphin D foil and Bump foil. Second part was the test of new foil with different position on the rotor. Third part was the test of three new foils which were designed from new original foil. Last part was the test of new HB foil. The purpose was to find out which one has the best condition for using in headbox screen of the paper machine. The data for this thesis were collected from the control room of the laboratory. The information was gathered from literature, newspapers, journal, theses and the internet. The final result of this thesis was that Bump had the most suitable condition for working in headbox screen. However, if concentrating on the results of new foil, new designed foils and HB foil, No8 (new designed foil with two cutting edges) had the most suitable condition with low pulsation, good runnability, low thickening factor and low power consumption.

Keywords: pressure screen, headbox screen, pressure pulsation, power consumption, screening, foil

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Contents
1 Introduction .............................................................................................................................. 5 Theoretical part ........................................................................................................................... 6 2 Pressure screen’s structure and principle ........................................................................... 6 3 Screening parameters ............................................................................................................ 7 3.1 Design parameters .......................................................................................................... 7 3.1.1 Feed construction ..................................................................................................... 7 3.1.2 Rotor design .............................................................................................................. 7 3.1.2 Screen cylinder design ............................................................................................ 9 3.2 Operational parameters ................................................................................................ 11 3.2.1 Aperture velocity ..................................................................................................... 11 3.2.2 Rotor tip speed and rotor frequency .................................................................... 12 3.2.3 Feed consistency ................................................................................................... 12 3.2.4 Volumetric reject rate ............................................................................................. 13 3.3 Furnish parameters ....................................................................................................... 13 3.3.1 Temperature and pH...


References: Andritz Pulp and Paper. ModuScreen HBE. Bliss, T. Screening in Pulp and Paper Manufacture, Volume 6 Stock Preparation. 1992. TAPPI, pp. 234-235 Feng, M. 2003. Numerical simulation of the pressure pulses produced by a pressure screen foil rotor. Univ. British Columbia. Dept. Mech. Eng. M. A. sc. Thesis. Feng, M., Olson J.A., Ollivier-Gooch, C.F., Xia J., and Gooding, R.W. 2003. Acomputational fluid dynamic (CFD) tool for advanced pulp screen foil roto design. ABTCP Conf, San Paulo, Brazil. Gonzalez, J.A. 2002. Characterization of design parameters for a tree foil rotor in a pressure screen. Univ. British Columbia. Dept. Mech. Eng. M.A. Sc. Thesis. Gooding, R.W., & Kerekes R.J. 1989. The motion of fibres near a screen slot. JPPS 15(2), pp. 59-62. Gooding, R.W. 1986. The passage of fibres through slots in pulp screening. University of British Columbia, Vancouver, Canada. M.A.Sc. Thesis. Halonen, L., Ljokkio, R., & Peltonen, K. 1990. Improved screening concepts. TAPPI Conference Proceedings, Atlanta, pp. 207-212. Karvinen, R., & Halonen, L. 1984. The effect of various factors on pressure pulsation of a screen. Paperi ja Puu 66(2), pp. 80-83. Kemppainen, J. 2011. Development of the pressure screen foil. Lappeenranta University of Technology. Degree Programme in Chemistry. Master’s Thesis. Kubat, J. & Steenberg, B. 1955. Screening at low particle concentrations. Svensk. Papperstidning 58(9), pp. 319-324. Kumar, A. 1991. Passage of fibres through screen apertures. University of British Columbia, Vancouver, Canada. Ph.D. Thesis. Levis S.H. 1991. Screening of secondary fibers. Progress in Paper Recycling 1(1), pp. 31-45. Martin A., Michael W., Zuben W. 2005. Internal fibre length concentration in a pressure screen. University of Waikato, New Zealand. Appita. McCarthy C.E. 1988. Various factors affect pressure screen operation and capacity. Pulp & Paper 62(9), pp. 233-237.
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Niinimäki, J. 1998a. On the fundamentals of pressure screening, an experimental study of conditions and phenomena in the screen basket. University of Oulu. Niinimäki, J. 1998b. Phenomena affecting the efficiency of a Pressure screen. University of Oulu. Niinimäki, J., Ämmälä, A., Dahl, O., Kuopanportti, H. & Nissilä, S. 1998. The settings of hydrofoils in a pressure screen. Proc. International Symposium on Filtration, Las Palmas, Canary Islands, pp. 71-78. Olson, J.A., Pflueger, C.D., Delfel, S., Ollivier-Gooch, C., Martin, P., Vaulot, F., and Gooding, R.W. 2007. High performance foil rotor improves de-ink pulp screening. Dept. Mech. Eng., Univ. British Columbia, Canada. Paul, T., Chen, D., Duffy, G., & Walmsley, M. 1999. Improved screening performance with viscous media. Proc. 53 rd Appita Annual Conference, Rotorua, New Zealand, pp, 821-824. Pflueger, C.D., Olson, J.A., and Gooding, R.W. The performance of the EP Rotor in de-ink pulp screening, preprints 2007 Appita Conf., 8p. Repo, K. & Sundholm, J. 1995. The effect of rotor speed on the separation of coarse fibers in pressure screening with narrow slots. Proc. International Mechanical Pulping Conference, Ottawa, Canada, pp. 271-275. Sanya Wedge Wire Factory. Welded Wedge Wire http://www.wedgewire.org/wedgewire/weldedwedgewirescreen.html Screen.
Sealey, R. & Miller, G. 1981. Modified screen basket geometry improves pressure screen operation. Pulp & Paper 55(6), pp. 97-100. Seifert, P. 1993. Understanding screening of secondary fiber. Proc. TAPPI Engineering Conference, Orlando, FL, USA, pp. 429-438. Vitori, C.M., & Philippe, I.J. 1989. New technology for improved performance and longer wear life in contour-Surface slotted-screen cylinders. Proc. TAPPI Pulping Conference, Seattle, USA, pp. 707-714. Wakelin, R.F., Blackwell, BG., & Corson, SR. 1994. The influence of equipment and process variables on mechanical pulp fractionation in pressure screens. Proc. 48th Appita Annual Conference, Melbourne, Australia, pp. 611-621. Wakelin, R.F., & Paul, S.T. 2000. Effects of some process variables on screen fractionator performance. Proc. 54th Appita Annual Conference, Melbourne, Australia, pp. 153-160. Yu, C.J. 1994. Pulsation measurement in a screen. Proc. TAPPI Engineering Conference, San Francisco, CA, USA, pp. 767-782. Yu, C.J., & Defoe, R.J. 1994a. Fundamental study of screening hydraulics. Part 1: Flow patterns at the feed-side surface of screen baskets; mechanism of fibermat formation and remixing. TAPPI Journal 77(8), pp. 219-226.
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Yu, C.J., & Defoe, R.J. 1994b. Fundamental study of screening hydraulics. Part 2: Fiber orientation in the feed side of a screen basket. TAPPI Journal 77(9), pp. 119-124. Yu, C.J., & Crossley, B.R. 1994. Fundamental study of screening hydraulics. Part 3: Model for calculating effective open area. TAPPI Journal 77(9), pp. 125131. Zhao, RH., & Kerekes, R.J. 1993. The effect of suspending liquid viscosity on fiber flocculation. TAPPI Journal 76(2), pp. 183-188. Ämmälä, A. 1997-2000. Fractionation of thermomechanical pulp in pressure screening. University of Oulu. Department of Process and Environmental Engineering. Master’s Thesis.
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