Municipal solid waste fuel steam generator with waterwall furnace platens

Abstract

A steam generator includes a furnace configured and adapted to generate a stream of furnace exit gases from the combustion of municipal solid waste fuel. At least one superheater is disposed within an upper portion of the furnace or backpass. The superheater is configured and adapted to superheat fluids within the superheater by facilitating heat transfer between fluids within the superheater and furnace exit gases outside the superheater. At least one waterwall furnace platen is disposed within the furnace upstream from the superheater, the waterwall furnace platen is configured and adapted to lower furnace exit gas temperature at the superheater by facilitating heat transfer between fluids within the waterwall furnace platen and furnace exit gases outside the waterwall furnace platen.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application is a divisional of U.S. patent application Ser. No. 11 / 961,654, field Dec. 20, 2007 which claims benefit of priority from U.S. Provisional Application Ser. No. 60 / 976,709, filed Oct. 1, 2007, the disclosures of which are incorporated by reference herein in their entireties.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a municipal solid waste fuel steam generator. Particularly, the present invention is directed to a municipal solid waste fuel steam generator having waterwall furnace platens.[0004]2. Description of Related Art[0005]Waste-to-energy or Energy-from-waste plants generate high-energy steam in boilers by combusting waste materials. Municipal solid waste fuel steam generators use solid municipal waste, such as refuse, as fuel to generate steam. The steam is commonly used to drive high-pressure steam turbines in order to generate electricity or provide steam to a st...

AI Technical Summary

Benefits of technology

The waterwall furnace platen significantly reduces superheater corrosion, extends its usable life, and allows for easier maintenance, while also improving thermal performance and reducing NOx emissions by up to 40% and extending operational periods between cleanings by 33%.

Problems solved by technology

The material demands on the superheater in these extreme temperatures are great.

In municipal solid waste fuel steam generators, however, the combustion gases at the superheater are much more corrosive than in steam generators using coal and other fuels.

This leads to the need for frequent repair or replacement of the superheater, which results in downtime.

However, in order to reduce corrosion of superheaters in existing facilities, it is impractical and extremely difficult to increase the size of the furnace adequately due to space limitations.

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