The performance of a fluidized particulate feeding system with multiple discharge sections

Abstract

A particulate feeding system based on air flluidization principles was developed at the Thermal and Fluids Engineering Group at EESC-USP. The system is basically formed of a cylindrical chamber comprising two levels of fluid bed distributor plates. The performance of the system was addressed. Repeatability experiments were performed in order to check out for the possibility of solids feeding control through a sphere valve which controls the air feed rate. Silica sand particles of three different size were used, with mean diameters of 152, 287 and 484 µm. Experiments showed that the total particulate discharge depends on the primary air feeding rate, the distance between the exit of the feeding hopper and the primary air distributor plate, and the particulate diameter, but independs on the secondary air feeding rate. The system was observed to be of difficult control and showed poor repeatability. However, the system was found to be an excellent device for distributing the flow of solids throughout several discharge sections. For the operational conditions considered and air volumetric flowrates above 3×10-3 m3/s the deviation on the particulate mass flowrate through a given discharge section related to the average value through the four sections of the injector was always below 5 %.