板框过滤实验中滤饼压缩性指数为负的原因分析

Exploration the Reason Why Negative Filter Cake Compression Index Appears in the Plate-and-Frame Filtration Experiments

2020秋季学期,学生基于实验测量数据计算出的滤饼压缩性指数s全部为负数,这与理论上s值应介于0~1不符。笔者重复实验,并在操作过程中消除了文献资料中已报道的导致s为负的原因,分别在几组不同的恒定过滤压强条件下测量过滤数据,通过对实验过程的观察和数据处理结果的分析,发现漩涡泵没有及时清洗是引起s值为负的原因。基于所找到的原因,完善了板框过滤实验的操作步骤和注意事项,实现了滤饼压缩性指数的实验测量值符合理论上的取值范围。

During the autumn semester of 2020,the obtained compression index s of filter cake was negative based on the experimental data in our university,which is obviously against the range of(0,1)predicted in theory.Authors repeated the experiments carefully and those reported possible reasons causing the abnormal phenomena were avoided during our experiments.The filtration data was obtained under several different pressures.Based on the observation of the experimental process and the analysis of experimental data,the reason why negative filter cake compression index appears can be attributed to the failure to wash those sediment in the vertex pump in time.So,the operation steps and precautions have been improved to ensure that the abnormal phenomena will not happen again.