【目的】煤气化渣提炭分质是实现其减量化、无害化、资源化利用的重要手段,气流分级法因其能够高效处理细粒级物料且无废水、废气排放而具有独特优势。【方法】基于CFD-DEM模拟,研究卧式涡轮气流分级机内气固流动状况,探明进气方向和涡轮转向的匹配关系,明确炭颗粒和灰颗粒的流动机制。优化涡轮气流分级机中进气口方向,预测入口气速和涡轮转速对气化细渣气流分级提炭效率的影响。【结果】结果表明:涡轮气流分级机的进气方向对流场分布和气化细渣提炭效率有显著影响。切向进气口易导致在分级区和淘洗区产生相互干扰的次级漩涡,影响气化渣炭和灰颗粒分离效率。优化切向进气为垂直向上后,避免了淘洗区和分级区相互干扰,消除了涡轮和叶片之间次级漩涡,改善并稳定了分级区内的流场,提高了气化细渣提炭效率。在优化后的涡轮气流分级机中,通过匹配入口气速与涡轮转速,富炭渣产品中的炭含量可达80.95%,炭回收率可达59.83%。

【Purposes】The separation of carbon form coal gasification slag is an important means  to realize its reduction, harmlessness, and resource utilization. The airflow classification method has  unique advantages because of its ability to efficiently process fine-graded particles without waste water  and exhaust gas emmission. 【Methods】 According to CFD-DEM simulation, the gas-solid flow char‐ acteristics of horizontal turbine air classifier were investigated, and the matching relationship between  the air inlet direction and turbine steering was explored. The flow mechanism of carbon and ash par‐ ticles was clarified.On this basis, the air inlet direction in the turbine air classifier was optimized, and  the effects of inlet air velocity and turbine speed on the efficient carbon extraction for gasification slag  in air classifier were predicted. 【Findings】 The results show that the inlet direction of the turbine air  classifier has a significant effect on the flow field distribution and the efficiency of carbon extraction for  gasification slag. The tangential air inlet leads to the generation of secondary vortices in the grading  zone and elution zone that interfere with each other, affecting the separation efficiency of carbon and  ash particles. The optimization of tangential air inlet to vertical upward avoids the mutual interference  between the elution zone and the classification zone. The secondary vortex between the turbine and the  blades is eliminated. The uniform distribution of the flow field in the classification zone is improved  and stabilized. The efficiency of carbon extraction is increased. In the optimized turbine airflow classi‐ fier, by matching the inlet air velocity with the turbine speed, the carbon content in the carbon-rich  product can reach 80.95%, and the carbon recovery rate can reach 59.83%.