FRP Chimney Liners for Power Plant Flue Gas Desulfurization--A Chimney Supplier's Perspective

The addition of Wet Flue Gas Desulphurization (WFGD) systems to existing coal fired power plants, and at several new plants, has resulted in the installation of over 90 FRP chimney liners during the past 6 years.  The lower flue gas temperatures in power plants with WFGD increases corrosion concerns for chimney lining materials and often leads to the selection of FRP as the liner material of choice. Although the design and manufacture of the FRP liner is usually performed by a specialty FRP supplier, the integration of the liner into the overall chimney design and arrangement, and the prescription of many of the requirements for the design of the FRP liner are the responsibility of the main chimney supplier. This paper explores various features of FRP liners and chimneys, how they relate to each other and the factors affecting decisions made during the design and installation process. Among the features discuss are:

Liner Size / Gas Velocity

Liner Arrangement / Support Levels and Expansion Joint Locations

Liquid Collection and Drainage / Stack Liquid Discharge

Flue Gas Entry (Breeching) Arrangement / Rectangular vs. Elbow

Chimney Shell Deflections for Structural Design

On-site Fabrication / Location and Transportation

Manways, Sampling Ports, and Other Appurtenances

Access for Installation and Field Joining

Airspace Ventilation

Proper, timely coordination and communication of the required information between the chimney supplier and the FRP liner supplier generally results in a well designed and smoothly executed chimney project.