New Control Head Design for Hyperbaric Disk Filter Gives Better Performance and Longer Life-Time

Abstract

For ultimate mechanical dewatering in coal beneficiation plants hyperbaric disk filtration (HBF) represents the best available technology to achieve low residual moisture. HBF is a continuous operation with high throughputs as needed in coal industry. Three zones are located on the respective disks and passed through consecutively, i.e., cake formation, drying and cake release. The disk is segmented by so called filter elements. Once such a filter element is entirely submerged in the slurry, access to the filtrate receiver is granted. This is also accompanied with a sudden pressure difference between the elevated pressure in the vessel and ambient air resulting in a two phase flow which causes abrasion. While the pressure difference across the filter increases, filter cake starts building up. When separating this venting stage from the cake formation, this vented air can be handled separately to reduce abrasion, as already proven in large scale HBF application in highly abrasive applications. Since most of the air is already released before the majority of cake formation starts, filtrate flow is at ease which improves cake formation and thus the throughput is increased. This is a quite simple measure for substantially improving performance also for existing installations.