Compact filter design for gas treatment centers

Abstract

The footprint occupied by the GTC is an increasing concern since roadways, alumina handling and storage fill the courtyard, the area between pot rooms. This area is further congested by high draft systems and collector ducting. The application of new heat exchangers has been recently discussed because it has the potential to reduce the footprint in two ways 1) by causing a reduction of the actual flow through the filters by eliminating the controlled ingress of dilution air and 2) the reduction in gas temperature reduces the “actual” volumetric flow rate to the baghouse [1]. This paper describes a different approach taken by Danieli Corns to develop a compact filter module design that is aimed to reduce the overall footprint and capital costs of a GTC. Dubbed as the “Chinook” module, the design comprises of two low pressure rotating pulse systems combined into a single filter module thereby reducing the total number of modules and required associated equipment. Computational Fluid Dynamic (CFD) modeling was applied and confirms that while maintaining industrial standards on air/cloth ratio and can velocity, the footprint potentially is reduced by 25–30%. Placing the circular bag array of the low pressure pulse system into a square filter housing eliminates any concerns regarding the can velocity since the majority of gas flow migrates to the open areas around the filters. Modules can be upgraded to longer filter bags and/or to filter bags with extended surface without the need to increase the cross sectional area of the module itself. Future developments also include a positive pressure concept to the Chinook module with an exhaust fan upstream of the module and one independent stack on top of each module. Combined with the design aspects discussed, the positive pressure concept has the potential to further reduce the GTC footprint to about 60% in total.