Static Mixing Spacers for Spiral Wound Modules

Membranes play a critical role in many separation processes ranging from nitrogen production to desalination. Membranes are used most commonly in the form of fine hollow fibers or sheets. The sheet form is used to produce spiral wound modules that permit the efficient contacting of process streams with the membrane in a compact form. Spiral wound modules are the dominant form used in reverse osmosis and Nanofiltration membrane processes.Spacers are used in spiral wound modules to create feed and permeate flow channels and to enhance mass transfer rates by reducing concentration polarization. Most spacers possess a ladder or mesh structure and rely on the generation of turbulence and eddies to enhance mass transfer. The literature contains numerous experimental and theoretical studies of how pressure drop and mass transfer rates depend on the geometry of these spacers.We present a new spacer paradigm. The spacer acts as a static mixer for planar flow channels and effect mixing without generating turbulence and eddies. Simulations of flow and mass transfer with the new spacer were performed using the computational fluid dynamics program, FLUENT. Flow visualizations clearly show how the spacer mixes the fluid. Furthermore, spacer prototypes were constructed and evaluated for mass transfer performance and pressure drop-flow rate characteristics. Significant enhancement in mass transfer was observed by experimental measurements for fabricated static mixer spacer. Experimental results were compared for the static mixer spacer, a commercial spacer and an empty channel and results in terms of Sherwood number, Power number and friction factor. Future works are proposed to have a better comparison for experimental and simulation results.

Name thesis:degree_name

Master of Science in Chemical Engineering

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Chemical Engineering

Grantor dc:publisher

University of Toledo

Year dc:date

2012

Author dc:creator

• Iranshahi, Ashkan

Contributors dc:contributor

• Lipscomb, Glenn

• Chemical Engineering
• Membrane
• Spacer

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=toledo1352121892

OAI identifier oai:identifier

oai:etd.ohiolink.edu:toledo1352121892