高含水率中药渣的带式压滤机压滤脱水试验

摘要

分析中药渣中的水分,阐述中药渣受挤压作用时的脱水机理,结合中药渣的特性和带式压滤机的脱水工艺,对压滤机的布料器进行改造,增加两级分料螺旋,改善压滤效果,使其适用于中药渣脱水试验,增加物料处理量,减少溢料现象,降低污水含固率,减少运行人员劳动强度.采用控制变量法,试验研究压滤机的不同脱水段、压力、带速、中药渣初始含水率等 4 个因素对脱水效果的影响,结果表明:物料初始含水率越大,不同脱水段的脱水率越大,滤饼的含水率越大;Ⅰ级脱水辊对物料脱水效果影响最大,楔形预压段对物料脱水效果影响最小;中药渣的初始含水率不宜超过80.16%;Ⅰ级脱水辊压力选择0.2～0.6MPa较合适;带速在0.3～0.5m/s范围内时,滤饼的含水率在65%～66%之间,脱水效果较好.%The water content in Chinese medicine residue was analyzed, and the mechanism of the dehydration of the Chinese medicine residue was analyzed. The characteristics of the Chinese medicine residue and the dehydration process of the belt filter press were used to transform the distributing device of the filter press. Two-stage feed screws were increased, improving the filter effect, making it suitable for Chinese medicine residue dehydration test. The amount of material handling was increased,the phenomenon of flash material was reduced,the solid content of sewage was reduced, the labor intensity of operating personnel was reduced. The influence of the different dehydration sections,pressure,belt speed of the filter press and the initial moisture content on the dewatering effect was studied by using the control variable method. The test results showed that the greater the initial water content of the material,the greater the dehydration rate of the different dehydration section,the greater the water content of the filter cake. The effect of the first grade dewatering roller on the material dehydration is the biggest, and the wedge dewatering section has the least effect on the material dehydration effect. The effect of the grade Ⅰ dewatering roller on the material dehydration is the biggest, and the wedge preloading section has the least effect on the material dehydration effect. The initial moisture content of Chinese medicine residue is not easy to exceed 80.16%.The gradeⅠdewatering roller pressure selection between 0.2MPa and 0.6MPa is more appropriate.When the belt velocity is in the range of 0.3—0.5m/s, the moisture content of the filter cake is between 65% and 66%, and the dehydration effect is better.