Page 342 - Wastewater Solids Incineration Systems

Appendix B Incineration Subsystems 303

FIGURE B.3 A shaftless screw conveyer (courtesy of Schwing Bioset, Inc.).

3.0 BLOWERS AND FANS
Blowers and fans are used to supply combustion air (positive pressure in burner or
incinerator) to remove exhaust gases (negative pressure in incinerator). Some MHFs
have been retrofitted to include an exhaust gas recirculation system that conveys hot
exhaust gas from exhaust breeching to lower hearths for NOx control.

3.1 Blowers
Blowers are used in fluidized bed incinerators to provide fluidizing air and purge air.

3.1.1 Fluidizing Air Blower
Fluidizing air systems consist of multistage centrifugal blowers, intake filter
silencers, and a control system. Fluidizing air blowers are capable of producing pres-
sures of 34 to 55 kPa (5 to 8 psig). Intake filters clean the air and remove debris that
could damage or clog the blower. The silencer reduces noise transmission through
the filter. The multistage blower consists of a series of radial and backward inclined