Flow properties of wood pulp-fiber suspensions in circular pipes
The flow characteristics of wood pulp suspensions in circular pipes have been investigated experimentally. In studying the flow mechanism, we mainly consider the yield shear stress, which represents the fiber-network strength in the flocculation of pulp fibers. The experimental results for five regi...
| Main Authors: | , |
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| Format: | Article |
| Language: | Japanese |
| Published: |
The Japan Society of Mechanical Engineers
2014-12-01
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| Series: | Nihon Kikai Gakkai ronbunshu |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/transjsme/81/823/81_14-00242/_pdf/-char/en |
| _version_ | 1828329927444791296 |
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| author | Masaru SUMIDA Taro FUJIMOTO |
| author_facet | Masaru SUMIDA Taro FUJIMOTO |
| author_sort | Masaru SUMIDA |
| collection | DOAJ |
| description | The flow characteristics of wood pulp suspensions in circular pipes have been investigated experimentally. In studying the flow mechanism, we mainly consider the yield shear stress, which represents the fiber-network strength in the flocculation of pulp fibers. The experimental results for five regimes, into which the flow was classified on the basis of the behavior of pulp fibers and the flow characteristics, as reported in the author's recent work (2010), were correlated with the fiber concentration Cs in equation of the form τ=aCsb where τ is the shear stress on the pipe wall and a and b are constant. The yield shear stresses were determined by the measurement of the pressure loss. They are not dependent so much on the pipe diameter and become large with increase of the pulp-fiber concentration. The flocculation of pulp fibers starts to become loose near the pipe wall when a shear stress exceeding about four times the yield shear stress acts on the suspension. The values of the disruptive and dispersive shear stresses are formulated as simple expressions depending on only the fiber concentration. Furthermore, the corresponding critical and turbulent Reynolds numbers are presented. The pressure loss of the pulp suspension in the turbulent flow becomes smaller than that for water, and the ratio of both can be expressed by a simple empirical equation. |
| first_indexed | 2024-04-13T20:33:22Z |
| format | Article |
| id | doaj.art-9614a964e32c415b8c48123a03aa1b6a |
| institution | Directory Open Access Journal |
| issn | 2187-9761 |
| language | Japanese |
| last_indexed | 2024-04-13T20:33:22Z |
| publishDate | 2014-12-01 |
| publisher | The Japan Society of Mechanical Engineers |
| record_format | Article |
| series | Nihon Kikai Gakkai ronbunshu |
| spelling | doaj.art-9614a964e32c415b8c48123a03aa1b6a2022-12-22T02:31:07ZjpnThe Japan Society of Mechanical EngineersNihon Kikai Gakkai ronbunshu2187-97612014-12-018182314-0024214-0024210.1299/transjsme.14-00242transjsmeFlow properties of wood pulp-fiber suspensions in circular pipesMasaru SUMIDA0Taro FUJIMOTO1Kinki University, Faculty of EngineeringMHI Solution Technologies Co., LTD.The flow characteristics of wood pulp suspensions in circular pipes have been investigated experimentally. In studying the flow mechanism, we mainly consider the yield shear stress, which represents the fiber-network strength in the flocculation of pulp fibers. The experimental results for five regimes, into which the flow was classified on the basis of the behavior of pulp fibers and the flow characteristics, as reported in the author's recent work (2010), were correlated with the fiber concentration Cs in equation of the form τ=aCsb where τ is the shear stress on the pipe wall and a and b are constant. The yield shear stresses were determined by the measurement of the pressure loss. They are not dependent so much on the pipe diameter and become large with increase of the pulp-fiber concentration. The flocculation of pulp fibers starts to become loose near the pipe wall when a shear stress exceeding about four times the yield shear stress acts on the suspension. The values of the disruptive and dispersive shear stresses are formulated as simple expressions depending on only the fiber concentration. Furthermore, the corresponding critical and turbulent Reynolds numbers are presented. The pressure loss of the pulp suspension in the turbulent flow becomes smaller than that for water, and the ratio of both can be expressed by a simple empirical equation.https://www.jstage.jst.go.jp/article/transjsme/81/823/81_14-00242/_pdf/-char/enmulti-phase flowpipe flowpulp fiber suspensionflow propertiespressure dropyield shear stress |
| spellingShingle | Masaru SUMIDA Taro FUJIMOTO Flow properties of wood pulp-fiber suspensions in circular pipes Nihon Kikai Gakkai ronbunshu multi-phase flow pipe flow pulp fiber suspension flow properties pressure drop yield shear stress |
| title | Flow properties of wood pulp-fiber suspensions in circular pipes |
| title_full | Flow properties of wood pulp-fiber suspensions in circular pipes |
| title_fullStr | Flow properties of wood pulp-fiber suspensions in circular pipes |
| title_full_unstemmed | Flow properties of wood pulp-fiber suspensions in circular pipes |
| title_short | Flow properties of wood pulp-fiber suspensions in circular pipes |
| title_sort | flow properties of wood pulp fiber suspensions in circular pipes |
| topic | multi-phase flow pipe flow pulp fiber suspension flow properties pressure drop yield shear stress |
| url | https://www.jstage.jst.go.jp/article/transjsme/81/823/81_14-00242/_pdf/-char/en |
| work_keys_str_mv | AT masarusumida flowpropertiesofwoodpulpfibersuspensionsincircularpipes AT tarofujimoto flowpropertiesofwoodpulpfibersuspensionsincircularpipes |