The Babcock & Wilcox Company

Babcock & Wilcox Power Generation Group, Inc.

Timothy E Hicks

John E Monacelli

Larry A Hiner

Steven L Osborne

Steven I Osborne

A method for improving pulp mill steam cycle efficiency includes the steps of providing at least one deaerator tank having a first pressure, and lowering the pressure of said deaerator tank to a second pressure. Feedwater is supplied to a pre-economizer, where it is heated. The water is then delivered to at least one feedwater heater, where it is heated. The water is then delivered to an economizer. By this method boiler steam rate is increased while boiler efficiency is maintained and turbine extraction for deaerator and feedwater heating is minimized.

Steam cycle efficiency improvement with pre-economizer

An enhanced steam cycle utilizing a dual pressure recovery boiler with reheat. A dual pressure designed recovery boiler furnace is provided with a lower furnace and an upper furnace. The lower furnace is operated at a lower temperature to prevent or reduce corrosion of the lower furnace wall tubes. The lower furnace can be either a low pressure natural circulation steam generating (drum) system or economizer. The upper furnace operates as a high pressure natural circulation steam generating (drum) system, or as a once-through supercritical steam generating system at higher temperatures and pressures permitting implementation of higher efficiency reheat steam cycles.

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Orrville, OH, United States of America

Timothy E Hicks