The City of Vancouver, Washington, commissioned its new dewatering and incineration facilities in spring and summer 1999 and completed performance testing in November 1999, as required by the Air Permit. This accomplishment represented continued evolution in solids processing that will
maintain air quality and reliability many years into the future. The design provided for a major expansion to the Westside Water Reclamation Facility (WRF) to increase the plant liquid treatment capacity from 15.2 to 21.3 MGD. In addition to processing solids from the Westside WWTP, the
plant handles wastewater solids from the City's Marine Park WRF. The expansion required a solids processing capacity of 51 dry tons per day. While the plant had been operating a multiple hearth furnace (MHF) for many years, the City decided to look to the future and replace the MHF with
fluidized bed technology. The facility's interim operating permit is based on expected emissions from the fluidized bed furnace (FBF), along with an allowance for operation of the MHF up to 10 percent of the time as a backup. The FBF system includes recuperative preheat of combustion
air, high energy Venturi scrubbing, and ash thickening and dewatering. In addition to sludge, the facility was designed to accept the grit and scum produced by the plant. A hot bed drawoff system was incorporated as a means to maintain the bed depth, given the addition of grit to the feed.
The incorporation of grit and scum feed presented design and operating challenges that are currently being addressed. The performance tests demonstrated emissions significantly below the interim permit levels in all areas. Total particulate emissions averaged 0.24 lb/dry ton of feed.
Carbon monoxide emissions averaged less than 1 ppm and nitrogen oxides (NOx) averaged 34 ppm. In addition, the FBF and overall solids handling system are capable of combustion without the continuous use of auxiliary fuel.
Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed. WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access.