细粒煤干法深度筛分技术进展及研究方向

Progress and research direction of dry deep screening technology of fine grained coal

细粒煤干法深度筛分技术在煤炭工业中具有重要作用,已成为当今国内外筛分领域研究热点与难点。目前细粒煤干法筛分粒度界限主要为6和3mm,尤其对于3mm动力煤不经分选可直接用于火力发电。因此,实现6或3mm细粒煤干法深度筛分,不仅能提高粉煤的利用率,也可节约大量分选成本。笔者论述了目前国内外细粒煤干法深度筛分相关理论研究成果,着重阐述了国内外典型细粒煤干法深度筛分设备结构及性能特点,并深入探讨了今后细粒煤干法深度筛分技术的研究方向。目前国外细粒煤干法深度筛分相关理论研究成果主要为概率筛分原理、等厚筛分理论、电磁激振理论,弛张筛分理论、强化筛分理论。论述了黏附细粒物料深度筛分模型,潮湿细粒物料的黏结力计算公式及减少黏结力方法,降低潮湿细粒物料堵孔方法以及双质体共振与网振筛分技术等。国内研究主要为实用概率筛分模型,潮湿细粒物料在筛面上积聚原因和黏附机理及黏附力、黏附厚度的影响因素,克服潮湿细粒原煤深度筛分堵孔、黏孔现象的设计方案,采用筛板振动、筛箱不振动的形式实现难筛物料的筛分,弹性筛面克服堵孔的机理及与刚性筛面筛分效果对比,细粒煤粒度分布模型分布特性研究等。在筛分技术和设备开发上不断创新,目前已开发出的概率筛、等厚筛、博后筛、高幅筛、节肢筛、琴弦筛、弛张筛、抛射筛、谐振式泰勒振动筛、双质体振动筛、电磁高频细筛等细粒煤干法深度筛分设备结构与性能特点各异,且适应于不同用途。基于目前细粒煤干法深度筛分技术发展现状,建议未来应加强筛分理论、关键技术、筛机结构优化、振动参数优化配置、筛板相关技术及多样化等方面研究。

The dry deep screening technology of fine coal plays an important role in the coal industry and has become a hot and difficult study point in the field of screening.At present,the particle size limit of dry screening of fine-grained coal is mainly 6 mm and 3 mm,especially for 3 mm steam coal,which can be directly used for thermal power generation without separation.Therefore,the realization of 6 mm or 3 mm fine grained dry screening method of raw coal can not only improve the utilization rate of coal,but also can save a lot of seperation cost.In this paper,the related theoretical research results of dry deep screening of fine coal were discussed,and the structure and performance characteristics of some typical dry deep screen equipments of fine grained coal were emphatically expounded.In addition,the research direction of the dry deep screening technology of fine grained coal was discussed in depth.At present,the related theoretical research achievements of the dry deep screen theory of fine grained coal abroad include probability screen principle,equal thickness screening theory,electromagnetic excitation theory,relaxation screen theory and strengthening screen theory.In this paper,the model of depth screen of adhesive fine-grained materials,the formula for calculating the adhesion force of moist fine-grained materials and the method of reducing adhesion force,the method of reducing the plugging of wet fine-grained materials and the technique of double plasmid resonance and mesh vibration screen were discussed.The domestic research mainly focuses on the practical probabilistic screening model,the reason for the accumulation of wet fine grained materials on the screen surface and the mechanism of adhesion and the influence factors of the adhesion force and adhesion thickness,and the design scheme of overcoming the phenomenon of wet fine grained raw coal deep screening blocking holes and sticky holes,the screening of difficult materials by means of vibration of sieve plate and non-vibration of sieve box,the mechanism of elastic screen surface overcoming blockage and comparison with the screening effect of rigid screen,and the distribution characteristics and distribution model of fine-grained coal,etc.The screening technology and equipment development are constantly innovated.Recently,the structures and performance characteristics of the developed screen equipments,such as probability screen,equal thickness screen,bo hou screen,high amplitude screen,arthropod screen,string screen,relaxation screen,ejection screen,resonant Taylor screen,double plasmid screen,electromagnetic high frequency fine screen and other dry deep screen equipments of fine coal,are different and suitable for different purposes.Based on the current development status of the dry deep screen technology of fine-grained coal,it is suggested that the deep research direction should be screen theory,key technology,screen structure optimization,optimization configuration of vibration parameters,related technology of screen plate and diversification research in the future.