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Fabric Filtration

Lawrence K. Wang, Clint Williford, and Wei-Yin Chen

CONTENTS
INTRODUCTION
PRINCIPLE AND THEORY
APPLICATION
ENGINEERING DESIGN
OPERATION
MANAGEMENT
DESIGN EXAMPLES AND QUESTIONS
NOMENCLATURE
REFERENCES
APPENDICES

1. INTRODUCTION
Fabric filtration is a physical separation process in which a gas or liquid containing
solids passes through a porous fabric medium, which retains the solids. This process
may operate in a batch or semicontinuous mode, with periodic removal of the retained
solids from the filter medium. Filtration systems may also be designed to operate in a
continuous manner. As with other filtration techniques, an accumulating solid cake per-
forms the bulk of the filtration. Importantly, an initial layer of filter cake must form at
the beginning of the filtration operation (1,2).
Fabric filtration effectively controls environmental pollutants in gaseous or liquid
streams. In air pollution control systems, it removes dry particles from gaseous emissions;
in water pollution control, filtration removes suspended solids; in solid-waste disposal,
filtration concentrates solids, reducing the landfill area required. Often, filtration pro-
cesses simultaneously reduce air, water, and solid-waste disposal problems. An air
pollution control system might, for example, remove particles and/or gases from an
emission source and might consist of a scrubbing device that removes particulates by
impaction and the gases by chemical absorption. The reaction products of gases and
chemicals can produce a crystalline sludge. A fabric filter may also be used to remove
solids from water so that the water can be recycled. As a result, effluent slurry does not
present a water pollution problem. Effective use (optimization) of a fabric-filter sys-
tem would minimize problems with waste disposal.
From: Handbook of Environmental Engineering, Volume 1: Air Pollution Control Engineering
Edited by: L. K. Wang, N. C. Pereira, and Y.-T. Hung © The Humana Press, Inc., Totowa, NJ
59