İSKİ Tuzla Sludge Dryer Plant

Project Description

Kuzu Group completed the second-phase construction of and commissioned the sludge drying facilities at Tuzla Wastewater Treatment Plant in 2009. Previously, there were three paddle dryers, each with 100 tons/day capacity, which were used for thermal drying of mechanically dewatered wet sludge (25% DM to 98% DM) in the decanter. However, as the amount of sludge increased, it became necessary to build an additional dryer with 150 tons/day capacity.

Under this project, Kuzu Group set up additional sludge storage and conveyor facility with a volume of 50 m³, in an annex building next to the existing decanter. In collaboration with the US company Komline Sanderson, the Group manufactured (80% domestic) and installed a sludge dryer with 150 tons/day capacity – complete with steam, condenser, odor removal and dry product conveyor lines. Much like the former ones, the new dryer, which has a capacity of 150 tons, dries sludge by using steam (at 12 bars and 190°C) from waste heat exhausted from the cogeneration gas turbines that burn biogas. Dried products then pass through cooling conveyors and are transferred to dry product storage silos through the dried sludge conveyor system. Since the drying system has an air-tight structure and sludge is dried with direct contact on hot metal surfaces, the amount of foul-smelling gas produced is much less compared to other drying technologies; also, these gases are transmitted to the odor control system after passing through the condenser. Based on past experiences with Tuzla sludge, the paddles and the shaft of the dryer were manufactured using abrasion-resistant special alloys to extend the dryer’s life cycle significantly.