The Case for Replacing Multiple Hearth Incinerators with Fluidized Bed Incinerators

The Multiple Hearth Incinerator (MHI) has been the workhorse for publicly owned treatment works (POTWs) for many years to burn dewatered solids for volume reduction. Built in the 1970s and 1980s, many of these units are undergoing upgrades to keep them running. In other cases, POTWs that currently incinerate using MHIs are faced with a decision to renew their MHIs or replace them with fluid bed incinerators (FBIs). This paper will compare the processing capacity and operational requirements for MHI and FBI incineration, and will address the environmental, social and economic viability, the triple bottom-line, for continuing to incinerate wastewater solids with renewed MHIs or replacing them with new FBIs. This paper concludes that with increased regulations applied to incineration in the future, new FBIs will better position a POTW for that future.