Research On The Flow Characters Of Fluidized Beds In Pipe-distributed Condition And Industrial Applying For Dealing With The Solid Waste

Solid waste has been becoming a serious environmental problem in the world. One of the promising methods to deal with solid waste is incineration because of maximum volume/quantity reduction and energy recovery. The technique of fluidized bed (FB) incineration compared with other incineration methods was proposed in China. The new pipe-distributor FB technique predigesting pre-process system and promoting slag remove was investigated to deal with solid waste with difficult components, especially with high quotient non-combustible waste aiming at the problem of fluidized bed incineration in this paper.In this thesis, the studies as follows:(1) The axis and radial flow field distribution of CFB were analyzed by the particle flow visualization software, and the criterion of turbulence to circulation fluidization situation was reported.(2) Pipe resistance, critical fluidized gas velocity and fluidization characteristics including pipe control zone, space control zone, stable critical fluidized height and two layer pipe distribution were investigated under different operation conditions.(3) Residence time of three different kinds of non-combustible wastes simulated by steel, stone, and glass balls with different diameters were studied with different operation conditions in cold circulating fluidized bed. Residence time of the mixture of non-combustibles was also studied.(4) Based on the experimental theory, the performances of industrial scale incinerator with pipe-distributor under different operation conditions were analyzed at the end of the paper.In summary, the flow characteristics separated into fluidized characteristics and slag remove characteristics of FB were studied in this paper. The results showed that the radial mixture was very intense which satisfy the condition of sufficiency mixture between bed materials and waste, so waste can be incinerated drastically. In two layers pipe distributed condition, the flow field in FB presents "horizontal on top, vertical in bottom" distribution. It is advantaged to deal with the high quotient non-combustibles waste. At last, the result of practical industrial applying showed this new type FB technique successful.