Lowering Economizer Module

PSF replaced the laminar airheaters and economizer on the No. 4 Recovery Boiler at Weyerhaeuser's Springfield, Oregon Mill with a new larger single pass economizer. This retro-fit was performed during a planned twenty day shutdown. We managed subcontract work for: asbestos abatement, concrete, crane service, electrical, instrumentation, insulation, non-destructive examination, painting, scaffolding and fabrication of the structural steel. The work scope included: pre-shutdown work consisting of major structural changes to the building including installation of new platforms, construction of a new FD fan VFD electrical room, opening up the building from the economizer to the roof; installation of the FD fan, three tanks, sweetwater condenser, ash transfer conveyors, and ducting; installation of 6 inch feed water piping, sootblower piping, relocation of the 2 inch fire line; and installation of new electrical wiring, fixtures, receptacles, and new MCC sections; shutdown work consisted of removing the existing economizer and casing, eight sootblowers, existing instrumentation, asbestos containing refractory and insulation, sweetwater condenser, ducting for the air heater outlet and combustion air, ash hopper and flue gas ducting, FD fan and motor, wet ash piping, economizer drains, feedwater piping, and one of the LAH Wheels; installing the new Economizer section and hanger rods, casing, installing new and refurbished sootblowers; complete installation of all platforms and access ways; installation of field mounted instrumentation, power and controling wiring, MCC bus tie, relocate existing burner panel and performing loop check; x-ray header welds and hydro-test boiler. Post-shutdown work consisted of demolition of the remaining LAH Wheel, removing all abandoned piping, condiut, wire and equipment supports, replacing all building steel and closing up the building.

We completed the shutdown two days early, this was due in large part to the meticulous planning done both prior to and during the shutdown. One of the key events permitting our early completion was that our field engineers identified the possiblity of setting the new economizer casing in one piece which allowed shaving substantial time from the schedule.