Influence of nozzle design on flow, mixing, and fluidisation in a bubbling bed fluidised by a single nozzle

In this paper we apply, for the first time, positron emission particle tracking (PEPT) to a fluidised bed in which gas is injected through a nozzle-type distributor. The detailed, three-dimensional data obtained provide direct insight into how the angle of the orifices through which gas is injected affects the fluidisation, mixing, and flow patterns observed within the bed. Our results show that the fastest and most consistent recirculation of material – an indicator of good mixing – as well as the most complete fluidisation may be achieved by using a nozzle with horizontal- or near-horizontal outlets.