MATRIX PROJECTS

LIME DRYING AND MILLING

July 1, 2000

Matrix provided the civil, structural and mechanical engineering necessary for designing a lime drying and pulverizing facility with a through-put of 75 tons per hour. The design required a re-furbished rotary kiln dryer fed by a weigh belt and large capacity screw conveyors with a bucket elevator feeding a 65 ft tall milling and screening structure.

The mill was a 200 hp hammermill and vibratory screens and an air separator segregated the lime into two different products with an overs recycle back to the mill. A gas solids injector (GSI) screw pump (or "fuller" type pump) pneumatic conveyor was sized to deliver 60 tons per hours to two different storage silos.

Matrix also provided all of the engineering necessary to properly vent and collect dust off all of the process equipment. A 7500 cfm dust collector was used along with a carefully designed network of collection ductwork to prevent duct clogging. We re-used an existing 18,000 cfm dust collector for the rotary kiln dryer. This provided a challenge since the collector was over 90 ft away from the dryer. A 30" dia grasshopper duct was designed originating from the dryer discharge up to the top of the 65 ft mill structure and back down to the dust collector in the existing process area. The duct angles were kept in excess of 50 deg. to prevent product fall-out and line clogging.