Flow Behaviour of Shredded Solid Waste in a Rotary Kiln Hazardous Waste Incinerator

摘要

Rotary kilns are widely used for incineration of hazardous waste with complex chemical compositions and physical forms. The solid waste used to be burnt through containers in the rotary kiln, which leads to serious process instability. Recently AVR-Chemie, a hazardous waste incineration company in the Netherlands has implemented a solid waste homogenisation plant where the containerised solid waste is shredded into small particles. The shredded solid waste is incinerated subsequently in the kiln so as to get better combustion efficiency and smoother process operation. It is obvious that the particle trajectory and the mixing of the solid particles with combustion air depend very much on the design and operation parameters. But the solid particle behaviour under current furnace and operating conditions is so far not clear. Thus, process simulation and optimisation are conducted to study the flow and mixing behaviour of the shredded solid waste so as to assist an optimal design of the feeding system. The current paper addresses the recent results in modelling the solid particle flow and mixing behaviour, by using computational fluid dynamics (CFD) technique. The knowledge gained will be used for the design optimisation in an industrial scale rotary kiln incinerator at AVR-Chemie.