0
Research Papers: Fundamental Issues and Canonical Flows

Flow Modifiers for Preventing Sedimentation in Heat Exchangers

[+] Author and Article Information
Timo Kulju

Mass and Heat Transfer Process Laboratory, Department of Process and Environmental Engineering,  University of Oulu, P.O. Box 4300, FI-90014 Oulu, Finlandtimo.kulju@oulu.fi

Markus Riihimäki

Mass and Heat Transfer Process Laboratory, Department of Process and Environmental Engineering,  University of Oulu, P.O. Box 4300, FI-90014 Oulu, Finlandmarkus.riihimaki@oulu.fi

Tiina M. Pääkkönen

Mass and Heat Transfer Process Laboratory, Department of Process and Environmental Engineering,  University of Oulu, P.O. Box 4300, FI-90014 Oulu, Finlandtiina.m.paakkonen@oulu.fi

Ossi Vilhunen

 Neste Oil Corporation, Technology Centre, P.O. Box 310, FI-06101 Porvoo, Finlandossi.vilhunen@nesteoil.com

Kyösti Lipiäinen

 Neste Oil Corporation, Technology Centre, P.O. Box 310, FI-06101 Porvoo, Finlandkyosti.lipiainen@nesteoil.com

Esa Muurinen

Mass and Heat Transfer Process Laboratory, Department of Process and Environmental Engineering,  University of Oulu, P.O. Box 4300, FI-90014 Oulu, Finlandesa.muurinen@oulu.fi

Riitta Keiski

Mass and Heat Transfer Process Laboratory, Department of Process and Environmental Engineering,  University of Oulu, P.O. Box 4300, FI-90014 Oulu, Finlandriitta.keiski@oulu.fi

J. Fluids Eng 133(10), 101203 (Sep 27, 2011) (8 pages) doi:10.1115/1.4004942 History: Received June 15, 2010; Accepted August 23, 2011; Published September 27, 2011; Online September 27, 2011

Heat exchangers are commonly used in process industries; however, fouling, such as sedimentation of particulate material is a significant challenge hindering the efficient use of heat exchangers in a wide range of industrial processes. This research studied the prevention of sedimentation in tube heat exchanger header sections, which typically are the critical areas for sediment accumulation. Numerous flow modifiers were explored, of which the most advantageous ones are presented in this paper. The study included construction and analysis of a miniature, validation of the used CFD model, and finally simulating an industrial scale heat exchanger. This research considered both flow fields and wall shear stresses for reducing sedimentation. The study showed that CFD models are capable of describing flow fields and their spatial variations in heat exchangers especially in their header sections. The selected flow modifier setups increased wall shear stresses in critical areas and hence reduced sedimentation. The presented solution consisted of utilizing different flow modifiers, filling elements, and their combinations. Industry should consider utilizing flow modifiers in heat exchangers as a potential solution to prevent sedimentation. Industrial cases are worth analyzing by using miniatures and CFD modeling. Analyses should pay special attention to flow fields and wall shear stresses. Heat exchangers include also other fouling mechanisms beside sedimentation; however, further study is required to clarify how flow modifiers influence these mechanisms.

Copyright © 2011 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Experimental setup in (a) and computational grid (b) of the lab scale setup, where mp0 = initial measurement point and mpL = measurement point at length L

Grahic Jump Location
Figure 2

Flow modifier setups in case of (a) single modifier and (b) modifier combination

Grahic Jump Location
Figure 3

Header section with two turning chambers

Grahic Jump Location
Figure 4

Wall shear stress parameterization by the mean of (a) angle dθ and (b) slice thickness dz

Grahic Jump Location
Figure 5

Industrial scale header section

Grahic Jump Location
Figure 6

Flow modifier setups in industrial size heat exchanger geometry for (a) first chamber with filling, (b) second chamber with a filling and flow modifier, (c) third chamber with a flow modifier, and (d) fourth chamber with a filling

Grahic Jump Location
Figure 7

Flow fields from the simulations in (a) original setup, (b) single flow modifier, and (c) two flow modifiers

Grahic Jump Location
Figure 8

Velocities from measurements/simulations without flow modifiers

Grahic Jump Location
Figure 9

Velocities from measurements/simulations with a single flow modifier

Grahic Jump Location
Figure 10

Velocities from measurements/simulations with two flow modifiers

Grahic Jump Location
Figure 11

Velocities from measurements/simulations with two turning chambers

Grahic Jump Location
Figure 12

Wall shear stresses at the bottom of the header section of the miniature

Grahic Jump Location
Figure 13

Velocity fields from the original setups (upper figure) with problematic areas circulated and the modified geometries (lower figure) in (a) first, (b) second, (c) third, and (d) fourth chamber. Wall shear stresses at the bottom of the header section of the miniature.

Grahic Jump Location
Figure 14

Wall shear stresses at the second chamber with (a) original setup and (b) flow modifier and filling combination

Grahic Jump Location
Figure 15

Wall shear stresses in the fourth chamber with (a) original setup and (b) inserted filling at the lower part of the chamber

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In