Length-based hydrodynamic fractionation of highly networked fibers in a mini-channel

Thomas Schmid; Jakob D. Redlinger-Pohn; Stefan Radl

doi:10.1515/npprj-2018-0086

Published by De Gruyter March 23, 2019

Length-based hydrodynamic fractionation of highly networked fibers in a mini-channel

Thomas Schmid , Jakob D. Redlinger-Pohn and Stefan Radl

From the journal Nordic Pulp & Paper Research Journal

https://doi.org/10.1515/npprj-2018-0086

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Abstract

Fractionation of cellulose fibers is performed within a circular mini-channel (diameter 7 mm) to realize a novel fractionation principle. We show that fractionation within a single-floc regime relies on the formation of a rigid network in cases where the crowding number is chosen to be greater than 60. Fractionation is performed for channel Reynolds numbers Re> 10,000, and unlike the situation in larger channels, fractionation is found to be relatively independent of Re. Experiments show a high dependency of the radial aperture velocity and aperture width on fractionation performance associated with fibers that are longer than 200 µm. By contrast, fibers shorter than 200 µm are only influenced by the volumetric flow rate through the aperture. Our results suggest that fibers smaller than 200 µm are mobile in the near wall region. Fibers longer than 200 µm are, dependent on their length, drawn out of the network by hydrodynamic forces acting on them as a result of the radial fluid velocity caused by the accept flow through the aperture. Our results support a novel fractionation hypothesis that is in contrast to previous findings, which were based on dilute flows and were demonstrated in channels having a larger size.

Keywords: fiber network; fibers; grade efficiency; hydrodynamic fractionation; mini-channel

Funding statement: The authors gratefully acknowledge the industrial partners Sappi Austria Produktions-GmbH & Co KG, Zellstoff Pöls AG and Mondi Frantschach GmbH, and the Competence Centers for Excellent Technologies (COMET), promoted by BMVIT, BMDW, Styria and Carinthia and managed by FFG, for their financial support of the K-project FLIPPR² (Future Lignin and Pulp Processing Research – PROCESS INTEGRATION).

Acknowledgments

We gratefully acknowledge the help of Gregor Schaub in performing pressure drop experiments.

Conflict of interest: The authors declare no conflicts of interest.

Appendix A Experimental data

Table A.1

Experimental data, i. e. fiber sort, feed flow rate, accept flow rate, Reynolds number, accept ratio, slot width, radial fractionation velocity, feed consistency and corresponding crowding number for investigation of network effects on fractionation.

Exp-no.	Pulp	V˙Feed	V˙Accept	Re	ϕ+	s	uFrac	Cfeed	NCW

		(ml/min)	(ml/min)	–	(%)	(mm)	(m/s)	(%)	–
70-1	CP	6,126	123	18,572	2.0	1.6	2.0E-02	0.49	62
70-2	CP	6,128	121	18,576	2.0	1.6	2.0E-02	0.58	73
70-3	CP	6,051	123	18,342	2.0	1.6	2.0E-02	0.67	85
139-0	CP	6,100	119	18,492	2.0	1.6	1.9E-02	0.21	27
140-0	CP	6,062	121	18,377	2.0	1.6	2.0E-02	0.08	10
141-0	VP1	5,988	122	18,152	2.0	1.6	2.0E-02	0.29	19
142-0	VP2	6,168	115	18,698	1.9	1.6	1.9E-02	0.40	55
144-0	VP3	6,111	121	18,525	2.0	1.6	2.0E-02	0.35	91

Table A.2

Exp-no.	Pulp	V˙Feed	V˙Accept	Re	ϕ+	s	uFrac	Cfeed	NCW

		(ml/min)	(ml/min)	–	(%]	(mm)	(m/s)	(%)	–
62-1	CP	8,460	81	25,647	1.0	1.6	1.3E-02	0.47	60
62-2	CP	8,550	86	25,920	1.0	1.6	1.4E-02	0.63	80
62-3	CP	8,409	84	25,492	1.0	1.6	1.4E-02	0.50	63
63-1	CP	8,400	173	25,465	2.1	1.6	2.8E-02	0.64	81
63-2	CP	8,410	183	25,494	2.2	1.6	3.0E-02	0.65	83
63-3	CP	8,526	171	25,846	2.0	1.6	2.8E-02	0.57	72
64-1	CP	8,400	348	25,465	4.1	1.6	5.6E-02	0.49	62
64-2	CP	8,400	335	25,465	4.0	1.6	5.4E-02	0.76	97
64-3	CP	8,352	343	25,318	4.1	1.6	5.6E-02	0.62	79
66-1	CP	7,414	306	22,477	4.1	1.6	5.0E-02	0.56	71
66-2	CP	7,403	290	22,441	3.9	1.6	4.7E-02	0.53	67
66-3	CP	7,424	297	22,506	4.0	1.6	4.8E-02	0.57	72
67-1	CP	7,457	151	22,606	2.0	1.6	2.4E-02	0.59	75
67-2	CP	7,354	144	22,294	2.0	1.6	2.3E-02	0.55	69
67-3	CP	7,425	148	22,509	2.0	1.6	2.4E-02	0.54	69
68-1	CP	7,457	75	22,606	1.0	1.6	1.2E-02	0.56	71
68-2	CP	7,405	69	22,450	0.9	1.6	1.1E-02	0.61	78
68-3	CP	7,397	75	22,425	1.0	1.6	1.2E-02	0.60	76
69-1	CP	6,130	63	18,584	1.0	1.6	1.0E-02	0.51	65
69-2	CP	6,103	62	18,501	1.0	1.6	1.0E-02	0.62	79
69-3	CP	6,101	66	18,496	1.1	1.6	1.1E-02	0.63	80
70-1	CP	6,126	123	18,572	2.0	1.6	2.0E-02	0.49	62
70-2	CP	6,128	121	18,576	2.0	1.6	2.0E-02	0.58	73
70-3	CP	6,051	123	18,342	2.0	1.6	2.0E-02	0.67	85
71-1	CP	6,126	254	18,572	4.1	1.6	4.1E-02	0.49	63
71-2	CP	6,082	243	18,438	4.0	1.6	3.9E-02	0.53	68
71-3	CP	6,111	243	18,525	4.0	1.6	3.9E-02	0.66	83
72-1	CP	4,687	191	14,208	4.1	1.6	3.1E-02	0.59	74
72-2	CP	4,737	186	14,360	3.9	1.6	3.0E-02	0.63	79
72-3	CP	4,876	196	14,783	4.0	1.6	3.2E-02	0.63	80
73-1	CP	4,718	93	14,303	2.0	1.6	1.5E-02	0.48	61
73-2	CP	4,844	91	14,684	1.9	1.6	1.5E-02	0.54	69
73-3	CP	4,774	96	14,472	2.0	1.6	1.5E-02	0.48	60
74-1	CP	4,700	46	14,248	1.0	1.6	7.5E-03	0.58	73
74-2	CP	4,805	46	14,568	0.9	1.6	7.4E-03	0.59	75
74-3	CP	4,760	48	14,429	1.0	1.6	7.8E-03	0.59	75
75-1	CP	3,826	38	11,599	1.0	1.6	6.2E-03	0.56	71
75-2	CP	3,736	38	11,326	1.0	1.6	6.2E-03	0.54	69
75-3	CP	3,799	42	11,516	1.1	1.6	6.8E-03	0.51	65
76-1	CP	3,826	78	11,599	2.0	1.6	1.3E-02	0.50	64
76-2	CP	3,887	79	11,782	2.0	1.6	1.3E-02	0.57	72
76-3	CP	3,955	81	11,990	2.1	1.6	1.3E-02	0.44	56
77-1	CP	3,831	164	11,613	4.3	1.6	2.7E-02	0.45	57
77-2	CP	3,810	159	11,551	4.2	1.6	2.6E-02	0.51	65
77-3	CP	3,794	149	11,501	3.9	1.6	2.4E-02	0.47	59

Table A.3

Exp-no.	Pulp	V˙Feed	V˙Accept	Re	ϕ+	s	uFrac	Cfeed	NCW

		(ml/min)	(ml/min)	–	(%)	(mm)	(m/s)	(%)	–
69-1	CP	6,130	63	18,584	1.0	1.6	1.02E-02	0.51	65
69-2	CP	6,103	62	18,501	1.0	1.6	1.00E-02	0.62	79
69-3	CP	6,101	66	18,496	1.1	1.6	1.06E-02	0.63	80
70-1	CP	6,126	123	18,572	2.0	1.6	1.99E-02	0.49	62
70-2	CP	6,128	121	18,576	2.0	1.6	1.96E-02	0.58	73
70-3	CP	6,051	123	18,342	2.0	1.6	1.99E-02	0.67	85
71-1	CP	6,126	254	18,572	4.1	1.6	4.11E-02	0.49	63
71-2	CP	6,082	243	18,438	4.0	1.6	3.93E-02	0.53	68
71-3	CP	6,111	243	18,525	4.0	1.6	3.93E-02	0.66	83
112-1	CP	6,107	65	18,515	1.1	0.6	2.80E-02	0.53	67
112-2	CP	6,120	60	18,553	1.0	0.6	2.61E-02	0.52	66
112-3	CP	6,092	62	18,468	1.0	0.6	2.66E-02	0.65	82
113-1	CP	6,114	120	18,534	2.0	0.6	5.17E-02	0.72	91
113-2	CP	6,073	127	18,412	2.1	0.6	5.51E-02	0.56	72
113-3	CP	6,073	121	18,411	2.0	0.6	5.23E-02	0.70	89
114-1	CP	6,165	246	18,690	4.0	0.6	1.06E-01	0.74	94
114-2	CP	6,137	244	18,603	4.0	0.6	1.05E-01	0.64	81
114-3	CP	6,025	240	18,266	4.0	0.6	1.04E-01	0.62	79
115-1	CP	6,080	522	18,432	8.6	0.6	2.26E-01	0.654	83
115-2	CP	6,087	492	18,452	8.1	0.6	2.13E-01	0.63	80
115-3	CP	6,188	489	18,758	7.9	0.6	2.11E-01	0.58	74
116-1	CP	6,206	834	18,814	13.4	0.6	3.60E-01	0.626	79
116-2	CP	6,215	802	18,840	12.9	0.6	3.46E-01	0.58	74
116-3	CP	6,202	780	18,802	12.6	0.6	3.37E-01	0.68	86
117-1	CP	6,156	62	18,663	1.0	2.6	6.15E-03	0.62	78
117-2	CP	6,087	62	18,452	1.0	2.6	6.19E-03	0.52	66
117-3	CP	6,160	64	18,675	1.0	2.6	6.40E-03	0.69	87
118-1	CP	6,138	128	18,606	2.1	2.6	1.28E-02	0.66	83
118-2	CP	6,054	119	18,353	2.0	2.6	1.18E-02	0.54	69
118-3	CP	6,083	123	18,441	2.0	2.6	1.23E-02	0.61	77
119-1	CP	6,104	242	18,505	4.0	2.6	2.42E-02	0.52	66
119-2	CP	6,097	240	18,483	3.9	2.6	2.39E-02	0.82	104
119-3	CP	6,074	248	18,414	4.1	2.6	2.47E-02	0.70	89
120-1	CP	6,076	484	18,419	8.0	2.6	4.82E-02	0.62	79
120-2	CP	6,094	500	18,474	8.2	2.6	4.98E-02	0.52	66
120-3	CP	6,112	461	18,528	7.5	2.6	4.60E-02	0.66	84
121-1	CP	6,025	803	18,264	13.3	2.6	8.01E-02	0.631	80
121-2	CP	6,149	801	18,639	13.0	2.6	7.98E-02	0.6	76
121-3	CP	6,192	801	18,771	12.9	2.6	7.98E-02	0.54	69
122-1	CP	6,171	30	18,706	0.5	0.6	1.30E-02	0.48	61
122-2	CP	6,120	31	18,553	0.5	0.6	1.34E-02	0.65	83
122-3	CP	6,164	31	18,687	0.5	0.6	1.32E-02	0.51	64
145-1	CP	6,099	120	18,489	2.0	0.3	1.15E-01	0.742	94
145-2	CP	6,133	124	18,593	2.0	0.3	1.19E-01	0.77	97
145-3	CP	6,153	126	18,653	2.1	0.3	1.21E-01	0.56	70
146-1	CP	6,126	57	18,572	0.9	0.3	5.51E-02	0.7	89
146-2	CP	6,048	60	18,335	1.0	0.3	5.76E-02	0.72	91
146-3	CP	6,116	60	18,542	1.0	0.3	5.74E-02	0.55	70
147-1	CP	6,129	247	18,580	4.0	0.3	2.37E-01	0.615	78
147-2	CP	6,012	245	18,226	4.1	0.3	2.35E-01	0.66	84
147-3	CP	6,097	243	18,483	4.0	0.3	2.33E-01	0.63	80
150-1	CP	6,130	461	18,585	7.5	0.3	4.43E-01	0.62	79
150-2	CP	6,073	479	18,410	7.9	0.3	4.60E-01	0.69	88
150-3	CP	6,110	479	18,523	7.8	0.3	4.60E-01	0.6	76
151-1	CP	6,135	763	18,598	12.4	0.3	7.32E-01	0.58	73
151-2	CP	6,085	720	18,446	11.8	0.3	6.91E-01	0.65	82
151-3	CP	6,164	729	18,687	11.8	0.3	6.99E-01	0.61	77
157-1	CP	6,111	491	18,527	8.0	1.6	7.96E-02	0.58	74
157-2	CP	6,088	474	18,457	7.8	1.6	7.69E-02	0.58	74
157-3	CP	6,088	478	18,454	7.9	1.6	7.75E-02	0.58	73
158-1	CP	6,176	733	18,722	11.9	1.6	1.19E-01	0.6	76
158-2	CP	6,092	750	18,468	12.3	1.6	1.21E-01	0.63	81
158-3	CP	6,000	741	18,189	12.3	1.6	1.20E-01	0.77	97

References

Abbasi Hoseini, A., Lundell, F., Andersson, H.I. (2015) Finite-length effects on dynamical behavior of rod-like particles in wall-bounded turbulent flow. Int. J. Multiph. Flow 76:13–21.10.1016/j.ijmultiphaseflow.2015.05.015Search in Google Scholar

Bergström, R. Fibre Flow Mechanisms. Royal Institute of Technology, Stockholm, 2005.Search in Google Scholar

Cotas, C., Branco, B., Asendrych, D., Garcia, F., Faia, P., Rasteiro, M.G. (2017) Experimental study and computational fluid dynamics modeling of pulp suspensions flow in a pipe. J. Fluids Eng. 139(7):071303.10.1115/1.4036165Search in Google Scholar

DIN 66142-3:1982-09 (n. d.) Representing and characterizing the separation of disperse materials; Selection and determination of parameters for industrial separation processes.Search in Google Scholar

Duffy, G.G. (2003) A new method of fibre fractionation. In: Appita Annu. Conf. Exhib., Melbourne. pp. 453–458.Search in Google Scholar

Duffy, G.G., Abdullah, L. (2003) Fibre suspension flow in small diameter pipes. Appita J. 56(4):290–295.Search in Google Scholar

Duffy, G.G., Ramachandra, S. (2005) Validation of flow mechanisms of fibre suspensions in small diameter pipes. Appita J. 58(5):374–377.Search in Google Scholar

Duffy, G.G., Titchener, A.L., Lee, P.F.W., Moller, K. (1976) The mechanisms of flow of pulp suspensions in pipes. Appita J. 29(5):363–370.Search in Google Scholar

Fock, H., Claesson, J., Rasmuson, A., Wikström, T. (2011) Near wall effects in the plug flow of pulp suspensions. Can. J. Chem. Eng. 89(5):1207–1216.10.1002/cjce.20471Search in Google Scholar

Fock, H., Rasmuson, A. (2008) Near wall studies of pulp suspension flow using PIV. Nord. Pulp Pap. Res. J. 23(1):120–125.10.3183/npprj-2008-23-01-p120-125Search in Google Scholar

Forgacs, O.L., Robertson, A.A., Mason, S.G. (1958) The hydrodynamic behaviour of paper-making fibres. Pulp Pap. Mag. Can. 117–128.Search in Google Scholar

Gooding, R.W. The Passage of Fibres Through Slots in Pulp Screening. University of British Columbia, 1986.Search in Google Scholar

Gooding, R.W., Kerekes, R.J., Salcudean, M. (2001) The flow resistance of slotted apertures in pulp screens. In: 12th Fundam. Res. Symp.Search in Google Scholar

Haavisto, S., Cardona, M.J., Salmela, J., Powell, R.L., McCarthy, M.J., Kataja, M., Koponen, A.I. (2017) Experimental investigation of the flow dynamics and rheology of complex fluids in pipe flow by hybrid multi-scale velocimetry. Exp. Fluids 58(11):1–13.10.1007/s00348-017-2440-9Search in Google Scholar

Hubbe, M.A. (2007) Flocculation and redispersion of cellulosic fiber suspensions: a review of effects of hydrodynamic shear and polyelectrolytes. BioResources 2(2):296–331.10.15376/biores.2.2.296-331Search in Google Scholar

Jäsberg, A. Flow Behaviour of Fibre Suspension in Straight Pipes: New Experimental Techniques and Multiphase Modeling. University of Jyväskylä, 2007.Search in Google Scholar

Jäsberg, A., Koponen, A., Kataja, M., Timonen, J. (2000) Hydrodynamical forces acting on particles in a two-dimensional flow near a solid wall. Comput. Phys. Commun. 129(1):196–206.10.1016/S0010-4655(00)00107-7Search in Google Scholar

Karinkanta, P., Laitinen, O. (2017) Use of tube flow fractionation in wood powder characterisation. Biomass Bioenergy 99:122–138.10.1016/j.biombioe.2017.02.011Search in Google Scholar

Kerekes, R.J., Schell, C.J. (1992) Characterization of fibre flocculation regimes by a crowding factor. J. Pulp Pap. Sci. 18(1):32–38.Search in Google Scholar

König, J. Experimental Study of Separation of Fines from Fiber Suspensions with Hydrodynamic Filtration. University of Technology Graz, 2016.Search in Google Scholar

Kumar, A. Passage of Fibres Through Screen Apertures. University of British Columbia, 1991.Search in Google Scholar

Laitinen, O., Kemppainen, K., Stoor, T., Niinimäki, J. (2011) Fractionation of pulp and paper particles selectively by size. BioResources 6(1):672–685.10.15376/biores.6.1.672-685Search in Google Scholar

Madani, A. Fractionation of Particle Suspensions in a Viscoplastic Fluid: Towards a Novel Process. University of British Columbia, 2011.Search in Google Scholar

Martinez, D.M., Buckley, K., Lindström, A., Thiruvengadaswamy, R., Olson, J.A., Ruth, T.J., Kerekes, R.J. (2001) Characterizing the mobility of papermaking fibres during sedimentation. In: Sci. Papermak. 12th Fundam. Res. Symp. 16 (September 2001). pp. 225–254.Search in Google Scholar

Mason, S.G. (1950) The flocculation of pulp suspensions and the formation of paper. Tappi J. 33(9):440–444.Search in Google Scholar

Medhi, B.J., Ashok Kumar, A., Singh, A. (2011) Apparent wall slip velocity measurements in free surface flow of concentrated suspensions. Int. J. Multiph. Flow 37(6):609–619.10.1016/j.ijmultiphaseflow.2011.03.006Search in Google Scholar

Olson, J.A. The Effect of Fibre Length on Passage Through Narrow Apertures. University of British Columbia, 1996.Search in Google Scholar

Olson, J.A. (2001) Fibre length fractionation caused by pulp screening, slotted screen plates. J. Pulp Pap. Sci. 27(8):255–261.Search in Google Scholar

Olson, J.A., Wherrett, G. (1998) A model of fibre fractionation by slotted screen apertures. J. Pulp Pap. Sci. 24(12):398–403.Search in Google Scholar

Pettersson, A.J., Wikström, T., Rasmuson, A. (2006) Near wall studies of pulp suspension flow using LDA. Can. J. Chem. Eng. 84:422–430 (August).10.1002/cjce.5450840403Search in Google Scholar

Redlinger-Pohn, J.D., Bauer, W., Radl, S. (2017a) Fractionation of fibre pulp in a hydrodynamic fractionation device: influence of reynolds number and accept flow rate. In: Trans. 16Th Fundam. Res. Symp. (Oxford, September 2017). pp. 209–228.Search in Google Scholar

Redlinger-Pohn, J.D., König, J., Radl, S. (2017b) Length-selective separation of cellulose fibres by hydrodynamic fractionation. Chem. Eng. Res. Des. 126:54–66 (Institution of Chemical Engineers).10.1016/j.cherd.2017.08.001Search in Google Scholar

Robertson, A.A., Mason, S.G. (1957) The flow characteristics of dilute fiber suspensions. Tappi J. 40(5):326–334.Search in Google Scholar

Sha, J., Nikbakht, A., Wang, C., Zhang, H., Olson, J. (2015) The effect of consistency and freeness on the yield stress of chemical pulp fibre suspensions. BioResources 10(3):4287–4299.10.15376/biores.10.3.4287-4299Search in Google Scholar

Soszynski, R.M., Kerekes, R.J. (1988) Elastic interlocking of nylon fibers suspended in liquid. Part 2. Process of interlocking. Nord. Pulp Pap. Res. J. 3(4):180–184.10.3183/npprj-1988-03-04-p180-184Search in Google Scholar

Steenberg, B., Wahren, D. (1960) Concentration gradients in boundary layers of streaming fibre suspensions. Sven. Papp.tidn. 63(11):347–355.Search in Google Scholar

Tamura, A., Sugaya, S., Yamada, M., Seki, M. (2011) Tilted-branch hydrodynamic filtration for length-dependent sorting of rod-like particles. In: 15th Int. Conf. Miniaturized Syst. Chem. Life Sci. (c). pp. 1343–1345.Search in Google Scholar

Vollmer, H., Fredlund, M., Grundström, K.-J. (2001) Characterization of fractionation equipment. In: Ecopapertech Conf. 3. pp. 27–35.Search in Google Scholar

Walmsley, M., Atkins, M. (2003) Comparing fibre length fractionation of a laboratory flow channel to an industrial pressure screen. In: Proc. 57th Appita Annu. Gen. Conf. Exhib. pp. 369–376.Search in Google Scholar

Weber, A.P., Legenhausen, K. (2014) Characterization of a classification or separation process. Ullmann’s Encycl. Ind. Chem. pp. 1–11.10.1002/14356007.b02_02.pub3Search in Google Scholar

Received: 2018-12-17

Accepted: 2019-03-03

Published Online: 2019-03-23

Published in Print: 2019-05-26

Length-based hydrodynamic fractionation of highly networked fibers in a mini-channel

Abstract

Acknowledgments

Appendix A Experimental data

References

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