基于Fluent的蒸汽动能磨粉碎粉煤灰结构优化设计

Fluent-based Steam Jet Mill Fly Ash Grinding Structural Optimization

蒸汽动能磨技术通过Laval喷嘴可以实现粉煤灰的超细粉碎加工,可高效、经济地制备各种微米尺度的粉煤灰超微粉体。在分析研究过热蒸汽动能磨技术的基础上,通过CFD模拟建立蒸汽动能磨粉碎模型,定量考察了粉碎腔底部、喷嘴数量和粉碎腔长度的影响。模拟计算结果表明:具有粉碎腔底部结构、喷嘴数量在3或4时,喷嘴所在截面平均速度可达80 m/s。另外,当粉碎腔长度从1080 mm增大到1480 mm时,喷嘴所在截面和出口面的平均速度变化小于5 m/s,粉碎腔长度远低于喷嘴数量的影响。该模拟计算模型为基于过热蒸汽动能磨的粉煤灰超微粉碎工业生产线的大规模应用提供了基础。

The steam jet mill technology is intended to realize ultrafine grinding of fly ash through Laval noz⁃zle,resulting in cost-efficient preparation of ultrafine powders from various micron-level fly ashes.By analyz⁃ing and researching the superheated steam jet mill technology and establishing a steam jet mill grinding mod⁃el through CFD simulation,the effect of the grinding cavity bottom structure,number of nozzles and length of grinding cavity are quantitatively evaluated.The simulation result shows that:when the grinding cavity bot⁃tom structure is equipped and there are 3 or 4 nozzles,the average speed on the cross-section where the nozzles are located can reach 80m/s.In addition,when the length of grinding cavity increases from 1,080mm to 1,480mm,the average speed on the cross-section where the nozzles are located and on the outlet surface varies by less than 5m/s.Therefore,the effect caused by the length of grinding cavity is much lower than that of the number of nozzles.The simulation model provides the basis for the extensive application of fly ash ultrafine grinding technology in the industrial production line based on the superheated steam jet mill.