Beringer Wine Estates, St. Helena, Calif., improved filtration effectiveness in its diatomaceous earth (DE) unloading and winery waste filtration area by an automated bulk bag unloader and flexible screw conveyor. The winery replaced a manual DE unloading setup with this automated, enclosed unloading and conveying method from Flexicon Corporation.
The automated bulk bag unloader lifts 1,000-lb. bulk bags of DE by an electric hoist and trolley at the top of its 16-foot-high cantilevered I-beam frame. Aided by flow promotion devices, the unloader fully discharges bulk bags into the 30* hopper below. From the hopper, a flexible conveyor, at a 45° angle, moves the DE to two 12-foot-high, 1,500-gallon slurry tanks of winery waste.
Filtration efficiency was optimized by the bulk bag unloader’s loss-in-weight control that precisely meters diatomaceous earth into the two 1,500-gallon slurry tanks. The bulk bag unloader is mounted on load cells that transmit loss-of-weight information to a controller. As the flexible conveyor feeds the slurry tank, the controller, on reaching the set weight, slows the speed to a dribble before stopping the conveyor, delivering the target dose.
"Dispensing accuracy gives us more filtration runs per amount of DE consumed," said John Pepe, director of cellar operations. "Otherwise, adding too little DE would allow effluent to plug the filters following the slurry tanks, or too much DE would clog the filters. Both situations would prompt more filtration runs than needed."
Beringer Wine Estates recouped its investment for the automated system in less than three years out of savings from the dispensing accuracy and buying DE in bulk bags rather than 50-lb. hand sacks that workers previously had to manually open and dump.
In installing the bulk bag unloader, Flexicon modified an existing bulk bag frame from an earlier attempt by Beringer at automated bulk bag unloading. The former system metered the diatomaceous earth to a horizontal screw auger. The unloader was controlled based on timing rather than weight.
Flexcon added an agitator to the new system to eliminate bridging and caking of DE in the hopper and changed the conveyor screw to its Bevcon design to exert less compression on the material.
The system has since run with no problems.