EVALUATION AND SELECTION OF THE FOURNIER ROTARY PRESS FOR DEWATERING OF TREATMENT RESIDUALS IN A UNIQUE NEW COASTAL COMMUNITY

Charleston Commissioners of Public Works (CPW) needed to replace a pair of 20 year-old, 2 meter, belt de-watering presses at its Plum Island Wastewater Treatment Facility. In addition, a second wastewater plant was in need of expansion to meet the rapidly-growing, planned development and unique community growth conditions on Daniel Island. As part of this expansion, a mechanical de-watering process will be required. After initially piloting and selecting centrifuge technology for both plants, CPW's wastewater engineers and operators became aware of and began the evaluation of rotary press technology by Fournier Industries of Quebec, Canada. A pilot scale study demonstrated high cake solids capability and favorable operating characteristics for both treatment plants.This detailed evaluation consisted of comparing pilot testing of both centrifuge technology and Fournier press technology, and included extended observation of the Fournier pilot study mobile unit, which uses full-sized components. Moreover, CPW made visits to the rotary press installations in Murfreesboro, Tennessee and Montreal, Quebec. Accordingly, the rotary press was selected to replace the Plum Island belt presses due to its robust design, slow operating speeds, low energy consumption, reduced requirements for structural reinforcement of sludge-handling buildings, and easier installation in an area at Plum Island which had poor accessibility for construction. The suitability of the rotary press for round-the-clock operation and automation were additional considerations in anticipation of a future thermal sludge process at Plum Island.The rotary press was selected for new installation at the Daniel Island facility for many of the same reasons as for the Plum Island plant. Quietness of operations and odor containment were additional factors in this selection in consideration of the environmentally pristine, resort-like development of the Daniel Island community. By April 2004, both de-watering facilities should be under construction. As an added benefit, Fournier has demonstrated solid customer support in the evaluation and design phases, and references confirm good support after installation.