Experimental Study On Mixing Behavior Between Coal And Ash In Down Flow Of Coal Topping Process

"Coal topping process"is a new technology combined heat, power, gas and oil, it combine CFB technology with coal conversion technology together. In the process, hot circulating ash from CFB is used to heat coal rapidly, and promote coal pyrolysis fast. Homogeneous between hot circulating ash and coal after mixing directly effect on the heat transfer efficiency of heating medium and coal, and it is the important factor that effect on pyrolysis temperature. So, adopting reasonable and suitable mixing manner is of great important to improve pyrolysis efficiency, avoid cohesion of semicoke, and improve productivity of gas and oil.Compared to general powder mixing, mixing between coal and ash has characteristics such as high temperature(650℃-850℃), inert atmosphere, continuous, fast and so on. Baffle-mixing way meets the requirement. In this paper, mixing behavior between coal and circulated hot ash is studied at self-made experimental table of solid-solid mixing."Coal-glass beads"manner and"Baking soda-glass beads"manner were used to study the mixer structure and mixture discharge effect on mixing result successively during experiment, mixing effect is judged by homogeneous M. It was show that as baffle angle went bigger, mixing effect went worse first and better then, and reached minimum value when it is 55°, it went better again when it reached 60°; mixing result went better as baffle number got more; changing baffle structure improved mixing result greatly, especially, baffle structure is with horizontal bar shape, mixing result is good, and its design is simple, that is, the structure is suitable to be used at engineering project. Besides, mixing result went better as mixture discharge went more, however it is not clear.