风选技术在建筑废弃物资源化中的应用

Application of Air-classification Technology in the Utilization of Construction Waste

随着城市化进程的加快,城乡建设中大量建筑废弃物的产生、堆放和填埋,造成了城乡结合地区大量农林用地被侵占,严重污染土壤、大气、水体,破坏了区域农林生态环境,这势必促使我国走上建筑废弃物资源化的道路。目前,我国建筑废弃物资源化利用率不到5%,主要制约因素是再生骨料中杂质分选不净,再生产品品质低劣。介绍了建筑废弃物的组成及危害、结合水平与垂直流场的风选特征,建立任意倾斜角度的风选流场模型,应用计算机模拟技术得到建筑废弃物再生骨料的最佳风选参数:风速为15～30 m/s、风向为30°～60°。将风选应用到建筑废弃物资源化分选环节中,为解决废弃物再生骨料分选难题提供参考依据,对提高建筑废弃物利用率,缓解土地资源损耗与农林生态破坏具有重大意义。

With the accelerated pace of urbanization,a grate deal of construction waste is generated,piled and landfilled in the process of urban and rural construction.As a result,a large number of agricultural and forest lands are invaded and occupied.The serious pollution of soil,air and water destroys the regional forestry ecological environment,which is bound to promote our country towards the path of construction waste resources recovery.At present,less than 5% of construction waste is recycled in China.The main restriction is the separation of impurities in recycled aggregate,as well as the poor quality of recycled products.This paper introduces the composition and the hazards of waste solids,based on the feature of the horizontal and vertical air flow field,an air classification model of any inclined angle is established.The technology of computer simulation is applied to represent the feature of the orbit of recycled aggregate in theory,the result shows the optimum parameters of air classification of recycled aggregate： the speed of air classification is from 15 to 30 m/s,the best angles is between 30°and 60°.The application of air classification in the classification process of solid waste utilization provides the reference basis for solving the conditional problems.It is of great significance to improve the utilization of construction waste and alleviate the loss of land resources and the ecological destruction of agriculture and forestry.