Technology Assessment of Carver-Greenfield Municipal Sludge Drying Process

摘要

This project provided a technology assessment of a promising alternative for drying municipal wastewater sludge. Evaluated was the Carver-Greenfield (C-G) process which uses the principle of multiple effect evaporation. The process can dry aqueous solutions or slurries with a wide range of solids content (4-45%). The unique characteristic of the process is the addition of a carrier oil which maintains viscosities at a low enough level to facilitate pumping and heat transfer when the solids content becomes higher as water is evaporated. The process has been used primarily in the food, pharmaceutical, and industrial wastewater treatment industries and has seen limited application for municipal sludge drying. The only municipal application in this country is now under construction for the City of Los Angeles Hyperion Energy Recovery System (HERS) project. The process appears energy and cost effective.