赤芍醇沉颗粒静置沉降特性及沉降速率模型建立

Particle settling characteristics of alcohol precipitation mixture of Paeoniae Radix rubra extract and models establishment of settling velocity

目的：探究赤芍醇沉液的颗粒静置沉降特性，建立其沉降速率模型。方法：通过测定不同工艺条件下赤芍醇沉液静置沉降过程的颗粒沉降曲线，结合颗粒沉降比（PSV）、颗粒体积指数（PVI）和沉降速度（N）等指标分析颗粒沉降特性，并利用统计分析及拟合检验建立赤芍醇沉颗粒的沉降速率模型。结果：赤芍醇沉颗粒的沉降性能受工艺因素影响明显，控制较大的终醇浓度、较大的浸膏密度和较小的初醇浓度，有利于赤芍醇沉颗粒快速沉降。颗粒沉降过程主要可分为匀速和减速两个阶段。匀速阶段沉降速率符合经验模型v0=-0．236 PSV＋0．022 PVI＋7．521，且终醇浓度和浸膏密度越大、初醇浓度越小，匀速沉降越快；减速阶段沉降速率符合活性污泥沉降的经典速率模型v=k（1-n1X）^4 exp（-n2X）／X，模型预测值与实测值吻合良好。结论：掌握赤芍醇沉颗粒的静置沉降特性，有助于全面理解赤芍醇沉过程。建立的沉降速率模型可准确预测赤芍醇沉颗粒的静置沉降速度。

Objective： To understand the particle settling characteristics of alcohol precipitation mixture of Paeoniae Radix rubra extract and establish models of the sedimentation rate. Methods： Focusing on the particle settling characteristics such as particle settling curve, particle settling velocity （ PSV）, particle volume index （ PVI ）, the particle settling process of alcohol precipitation was investigated. The effect of three key process factors on the settling process was discussed and mathematical models for describing the particle settling velocity were developed. Results： Controlling of higher final alcohol concentration, higher density of Paeoniae Radix rubra extract, or lower initial alcohol concentration, was conducive to settlement of alcohol precipitation particles. In the constant speed phase, an empirical calculation formula of vo was established, with both the variables PSV and PVI （ v0 = - 0. 236PSV ＋ 0. 022PVI ＋ 7. 521 ）. Another developed model was applied to predict the settling velocity in decelerated phase and the simulation was very good[v = k（ 1 -n1X）4exp（ -n2X）/X]. Conclusion： The results of this work will contribute to a better control and optimization of alcohol precipitation process, and help to implementation of accuracy control in the manufacture of botanical medicines.