Saving energy and maintenance headaches by switching to pneumatic unloading
Over the years, we've strived to show you how to optimize pneumatic conveying system performance. Several columns have presented tips for improving an existing pneumatic conveying system's operation. This month's column shows that we practice what we preach: A case study illustrates how we improved the operation of a bulk unloading system at a cement plant.
A cement company approached us for help solving problems with its fly ash unloading operation. The fly ash arrived at the company's plant in 100-ton gravity-flow railcars. To unload a railcar, a trackside mechanical unloader on wheels was moved into place with its inlet under the car. The portable unloader consisted of an enclosed, inclined belt conveyor with a discharge about 20 feet above the ground at the inlet of a screw pump. The screw pump fed the fly ash into a pneumatic conveying system with a 10-inch-diameter line for transfer to a storage silo. The major problems with this operation were the mechanical unloader's poor reliability, the significant amount of labor required to operate and maintain, and the energy costs for the unloading process.