二元颗粒的旋风分离效率

Separation efficiency for cyclone separator of binary particles

为了揭示二元颗粒的分离特性,以较难分离的沥青和滑石粉为母体粉料,以容易分离的煤粉和石油焦为添加粉料,两两形成4种差异二元颗粒体系,并以直径300 mm的PV型旋风分离器为模型,比较分离效率。结果表明:沥青颗粒、煤粉和石油焦的加入均能促进其分离效率,添加比例越大,效率提高越明显,且煤粉的促进作用比石油焦的更大;滑石粉、煤粉和石油焦的加入降低其分离效率,添加比例越大,分离效率降低越明显,且煤粉的抑制作用也更大;提出稳定团聚促进颗粒分离的观点,建议采用团聚相对稳定度来判断添加颗粒的促进或抑制作用,且采用团聚相对稳定度可从定性和定量两方面解释二元颗粒旋风分离的特殊现象。

Four kinds of powders, including asphalt, talcum,petrol coke and coal fines, were chosen to prepare four different binary particles. The asphalt and the talcum were used as the principal powder, and the petrol coke and coal fines as the assistant powder. A model PV cyclone with a diameter of 300 mm was employed as the test cyclone to demonstrate the difference of separation performance between unitary and binary particles. The results show that for the asphalt powder, the addition of either the petrol coke or coal fines improve the asphalt＇s separation and the coal fines is better than the petrol coke in separation promotion.For the talcum powder, however, either the petrol coke or coal fines reduce the separation efficiency of the talcum powder. It is assumed that if a stable agglomerate is formed due to the particle collision and agglomeration, the particle separation is improved.To further determine whether the addition of the assistant powder enhances or reduces the separation of the principal powder, a quantity called relative agglomerate stability, AR, is put forward which is the product of the particle agglomerate stability and the particle collision number. It is shown that with the use of AR, the special separation performance of binary particles can well be explained both qualitatively and quantitatively.