摘要
碱回收蒸发系统新技术的应用,使入炉黑液固含量超过70%,因此有必要研究高固含量黑液的流变性能.NaAlO_2在燃烧法除硅工艺中除硅效果极佳,需要探究其对竹浆黑液膨胀性带来的影响.本文利用AR2000ex动态流变仪,在70℃和98℃高温条件下对固含量为70.19%和79.87%的竹浆黑液的流变特性进行研究,发现在0~100s^(-1)剪切速率范围内竹浆黑液符合假塑性流体的流动特征,且呈现出较强的弹性固体性质.提高温度可以有效降低黑液的表观粘度,减弱黑液的假塑性,削弱其内部结构强度,有助于黑液在碱回收过程中的输送.通过对黑液等温膨胀体积指数(VIE)的测定,发现NaAlO_2添加量为0.5%时,黑液的膨胀率最大,继续加大添加量会抑制黑液的膨胀.
It is necessary to study the rheological properties of black liquor at a high solid content above70wt%due to the development of new technology for the recovery unit in pulp and paper industry.Adding sodium aluminate can ensure high efficiency in the method of black liquor combustion to remove silicon.Nevertheless,the effect of sodium aluminate on the expansion of black liquor should not be ignored.The rheological properties of thick bamboo kraft black liquor(70.19wt%and79.87wt%)at different temperatures(70鈩?and98鈩?were investigated by an AR2000ex rotational rheometer.The results proved that the flowability of the bamboo kraft black liquor obeyed the law of pseudoplastic fluid in the shear rate range of0~100s-1.Thick bamboo kraft black liquor represented strong elastic solid properties.The apparent viscosity of black liquor could be reduced effectively with the increase of temperature.High temperature also weakened the pseudoplastic characteristics of black liquor,as well as the intensity of the molecular structure of black liquor.Therefore,it was benefit for the transportation of black liquor.As an indication of expansion of black liquor,the volumetric isothermal expansivety(VIE)reached the maximum value when the loading of sodium aluminate was0.5wt%.The expansion of the black liquor would be suppressed if the loading was increased continued.
作者
岳小鹏
杜鑫
徐永建
YUE Xiao peng;DU Xin;XU Yong jian(Shaanxi Province Key Laboratory of Papermaking Technology and Specialty Paper, Shaanxi University of Science & Technology, Xi'An 710021, China;College of Mechanical and Electrical Engineering, Shaanxi University of Science & Technology,Xi'An 710021, China)
出处
《陕西科技大学学报》
CAS
2017年第6期1-5,共5页
Journal of Shaanxi University of Science & Technology
基金
国家十二五科技支撑计划项目(2012BAD23B02)
陕西科技大学学术带头人团队基金项目(2013XSD25)
关键词
黑液
流变特性
假塑性
膨胀性
black liquor
rheological properties
pseudoplastic
expansion
