Modular Pulse Jet Fabric Filter

Abstract

A modular design for large pulse jet fabric filters (PJFF) is divided into similar compartments, which are each “shop-fabricated” in quarter sections prior to delivery to the power plant site. The quarter sections of the compartments are modular and sized so that they can be fabricated at a shop located away from the power plant site and transported by truck over public roads to the power plant site. Once delivered to the site, the quarter sections are bolted together and seal welded to form a PJFF compartment, without requiring additional internal fabrication or welding. The assembled compartment is then lifted onto the support structure as an assembled unit and bolted and / or welded in place. The additional components of the PJFF may also be shop-fabricated offsite to further the benefits of the modular design.

Description

CROSS-REFERENCE TO RELATED CASES[0001]This application is a divisional of U.S. patent application Ser. No. 13 / 748,651, filed on Jan. 24, 2013, pending, which is incorporated by reference herein in its entirety.BACKGROUND[0002]Pulse jet fabric filters (PJFFs) are industrial filter buildings located at coal-fired and other types of power plants that produce heave particulate loads in the furnace exhaust gas. The furnace may also be referred to as a boiler (even though the furnace need not generate steam for the present invention to be applicable), and the exhaust gas may be referred to as flue gas for descriptive convenience. The PJFF is used to remove the particulates from the flue gas as part of the “scrubber” exhaust air cleaning system. The PJFF typically contains thousands of long, tubular filter bags in the approximate range of 4 to 10 inches across and 15 to 33 feet (5 to 10 meters) long. The boiler exhaust gas is directed through the filters to remove the particulates from the...

AI Technical Summary

Benefits of technology

[0008]The quarter sections can therefore be efficiently fabricated at the off-site shop and transported to the job site where they are assembled to form the complete compartments. In cases where the transportation economics are in its favor, the ash hoppers may be shop-fabricated as part of the quarter sections. If this approach is not feasible, for example due to public road transportation length limitations, the hoppers are also fabricated in sections and shipped to the site, bolted and seal welded in place, without requiring additional structural welds in the field. Once the compartment has been assembled, it is lifted into position onto a structural steel frame previously erected on-site using a crane and secured with bolts and / or welds. This modular fabrication technique provides higher quality and reliability, shorter field erection time, and lower installed costs relative to the conventional PJFF fabrication approaches.

[0009]The quarter sections of the filter compartments are thus designed to maximize the structural welding and fabrication at the shop location, while keeping overall dimensions within the envelop required for over-the-road transportation. This modular fabrication technique reduces the number of steel parts requiring fabrication in the field to erect a large PJFF, thereby reducing the field erection labor costs and time to erect the PJFF. This approach also reduces the linear seal weld length required in the field to erect the PJFF. The modular design also maximizes shop welding, which is more reliable and less costly than welding in the field. The modular design of the PJFF maximizes shop-fabricated portions of the steel portions on the PJFF while minimizing expensive field welding and fabrication requirements. The modular design thus provides a unique solution to the problem of expensive field fabrication of PJFF designs that require extensive, expensive and time consuming field fabrication and welding.

Problems solved by technology

If this approach is not feasible, for example due to public road transportation length limitations, the hoppers are also fabricated in sections and shipped to the site, bolted and seal welded in place, without requiring additional structural welds in the field.

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