近年我国精细化工行业使用的新型粉体混合设备

就我国精细化工行业目前使用的新型粉体混合设备的主要结构和性能特点作了简要叙述，这些设备有对称型双螺旋锥形混合机，单螺旋锥形混合机，对称型三螺旋锥形混合机，非结称形双螺旋锥形混合机，带式螺旋锥形混合机，犁刀式混合机，无重力粒子混合机和改良型滚筒混合机等八种。     

复合推进剂成型与发动机总装集成工艺技术创新

分析了大型发动机连续装药工艺,采用大型立式混合机混合,设计了连续注入(螺杆)挤压注射浇灌工艺技术试验装置。为解决国外SME(塑型"高聚物黏结炸药")工业化存在的问题(配方组分化合物进给、固体粉料(高氯酸铵)干摩擦的安全性等),提出了建设性见解;对输送推进剂药浆并排除气体而不产生烟火风险,在螺杆连续出料口直接浇注推进剂药柱技术问题等,提出了创新性设计思路论证和实施方法。研讨了大型发动机连续浇注成型/总装工程化设计思路。     

拼混染料的理想设备——DSH型悬臂非对称双螺旋锥形混合机

六十年代以前,我国染料拼混设备大都采用滚筒式混合机。自七十年代起,浙江省化工研究院针对日本单螺旋锥形混合机的缺点,研究开发了 SLH 型双螺旋锥形混合机见图1)。该机无论在混合均匀度、混合速度、能耗,还是噪音、粉尘污染等方面都大大优于滚     

DSH型双螺旋锥形混合机

DSN型双螺旋锥形混合机是目前行星螺旋锥形混合机中最新的一种产品。本文就其混合机理、结构特征、主要技术参数、混合效率、能耗等方面的先进性进行了综合的评述。     

1M~3双螺旋锥形混合机混合试验

一、概述混合是一种重要的单元操作。在我国,混合设备大多处于生产效率低,混合精度差,操作条件恶劣的落后状态。我们在兰溪农药厂和上海中药制药一厂的协助下,研制成功1M~3双螺旋锥形混合机(又称SLH型混合机)。据国外资料报导,双螺旋比单螺旋锥形混合机具有混合时间短和效率高、可改善机械受力、节省动力消耗、维修方     

浙江省一九八○年化工、炼油科技成果简报

(一)SLH型双螺旋锥形混合机研制单位浙江省化工研究所上海中药制药一厂 SLH型双螺旋锥形混合机是我国自行研制的一种新型高效粉体混合设备。其特点是由两根对称排列的螺旋杆沿圆锥筒壁作公转和自转的行星运动,使物料快速而均匀混合。与目前国内较先进的仿日本“细川/NAVTA”型单螺旋混合机相比,效率提高3～4倍,动力消耗减少2/3以上,混合质量也有了提高。     

国内外染料后处理设备发展水平(Ⅳ)——混合、包装设备

一、国外设备的发展现状及未来趋势从最近几年国外混合设备的发展方向看,基本以单螺旋锥形混合机、双螺旋锥形混合机、桨叶式混合机、V型混合机、滚筒式混合机等为主体,其发展趋势是进一步提高混合均匀度和混合速度,开发比重差大、粘性大、易发生偏析现象、难混合物料的高效、高精度混合器。混合设备的规模有向大型化发展的趋势。     

SLH型双螺旋锥形混合机

SLH型双螺旋锥形混合机(简称SLH型)是一种新型高效的粉体混合设备。由浙江省化工研究所仿照国外NAUTA型单螺旋混合机的基础上,研制开发成功的新产品。目前已开发出型号为SLH-1,SLH-2,SLH-K_2,SLH-6,SLH-10五种产品,并通     

用于塑料混合的双螺为混合机螺杆底轴承的优化设计

本文详叙了用于塑料混合的双螺旋混合机螺杆底轴承的一种优化设计，克服了原设计的结构缺陷，延长了底轴承的使用寿命。     

螺杆混合机

<正> 本文介绍一种螺杆式的混合机,其结构与塑料螺杆挤出机基本相同,只是螺杆的结构加以改进。这种混合机可以很好地混合粉料或粒料、微粒固体,也可以混合固体及液体及不相容的两种液体。本文叙述关于固体在液体中的物理规律、去附聚(deagglomera-tion)、混合不相容的液体的物理规律等。对小研磨性质的剪切力、剪切速度、界面张力等     

LHSY-11.5N双螺旋锥形混合机的研制

介绍了ＬＨＳＹ １１．５Ｎ双螺旋锥形混合机的特性、结构及主要零部件的设计、制造，同时还阐述了整机的组装、试车等技术问题     

Experimental study of the mixing kinetics of binary pharmaceutical powder mixtures in a laboratory hoop mixer

As increasingly commented by the literature during the last 5 years, estimating the homogeneity of a powder mixture and following powder mixing processes is not a simple task. In this paper, we present the development and statistical validation of a sampling methodology for defining the number of samples required to provide a reasonable estimation of the homogeneity attained in a laboratory scale tumbler mixer. This method is then used to follow the mixing kinetics of a dilute binary powder mixture in a hoop mixer. Special attention is paid to the statistical meaning of the values obtained and the influence of the physical characteristics such as particle size and shape. The role of the particle shape of the majority powder is particularly emphasised and it is quantitatively demonstrated that spherical particles are harder to mix and more ready to segregate than particles with irregular shapes. The different mixing mechanisms at play are identified; the practical limits of use of such tumbler mixers with pharmaceutical powders are discussed.     

风粉混合器内气固两相流动的模拟及试验研究

煤粉工业锅炉系统中风粉混合器是实现煤粉与一次风快速均匀混合的关键设备,测量及计算风粉混合器内煤粉、一次风气固两相流流场,对于优化风粉混合器结构,强化风粉混合效率及提高一次风粉的均匀稳定供给具有重要意义。笔者针对竖直结构及倾斜结构的2种风粉混合器,开展了数值计算及现场工程试验研究。基于几何拓扑学知识,采用ICEM软件针对2种风粉混合器划分了合适的三维网格;多相流理论模型中,多相连续介质模型中的双流体模型各相视为相互渗透、耦合但又保持各自运动特征的连续介质,相比于单流体模型,双流体模型考虑了固相的湍流输运以及气固两相间相互滑移引起的阻力,使得计算结果更接近实际情况;冷态双流体模型基本方程由守恒方程、相间耦合方程以及封闭方程构成,其中相间耦合方程用于表征气固相动量之间的耦合;为了探究不同停留时间下风粉混合器内气固两相的流场特征,采用非稳态数值计算方法,利用Fluent软件开展数值计算。基于两相流模型及Schilller-Naumann曵力系数模型研究了不同结构下风粉混合器内煤粉浓度分布随停留时间变化特征,采用德图testo425热敏风速仪测量了不同煤粉落料量下风粉混合器内负压变化规律。结果表明,竖直结构的风粉混合器内停留时间由0.25 s增至1 s时,混合器底部颗粒沉积的现象一直存在,即存在较长时间的颗粒流动死角区域;而对于倾斜结构的风粉混合器,当停留时间大于0.3 s,混合器内颗粒浓度基本降为0,较好避免了颗粒在混合器底部的沉积,该结构对于强化混合器内风粉混合及降低供料波动具有重要意义。不同落料量下的现场工程试验结果表明,高落料量下竖直结构的风粉混合器内平均负压偏小,几乎接近正压,且存在间断正压喷粉的现象,故该风粉混合器在高落料量下负压不足,易造成供料波动较大;高落料量下倾斜风粉混合器负压平均值仍大于-1 000 Pa,且无喷粉现象。相比于竖直结构,倾斜风粉混合器具有稳定且较宽的负压变化范围,能较好地克服供料波动大的现象。     

基于液桥效应圆筒制粒机的铁矿粉制粒机理研究

针对圆筒制粒机中存在有不同量级粒径颗粒的制粒问题，本工作对现有的液桥力计算式进行了修正，建立了相对应的离散元模型，通过实验测试与仿真相结合，探讨了修正系数对颗粒运动的影响，得到了修正系数以0.6适宜；以铁矿粉混合料的堆积角为参考，通过仿真和实验测试得到了混合料的物性参数，以此为基础，探讨了铁矿粉混合料颗粒的运动规律与团聚机理及其团聚体的分布，结果表明，团聚体颗粒的自旋速度越大、所受剪切力越小，则越有利于制粒；团聚体粒径沿圆筒的径向呈现先增大后减少的变化，且在靠近混合料表层下存在一个“高效制粒区”，在该区域团聚体的粒径最大、剪切力最小、自旋速度较大，同时建议可采用颗粒碰撞频率或能量损失作为判据来终止颗粒的团聚，以达到节能降耗的目的，所得结论可为铁矿粉圆筒制粒机的研发提供设计依据。     

Effect of operating conditions and design parameters in a continuous powder mixer

An experimental investigation was carried out to study the mixing performance and flow behavior in a continuous powder mixer for a typical pharmaceutical mixture. Blender performance, characterized by the relative standard deviation (RSD) of composition of blend samples taken at the blender discharge and by the variance reduction ratio (VRR) of the blender, was measured as a function of impeller rotation rate, flow rate and blade configuration. The flow behavior in the continuous mixer was characterized using the residence time distribution (RTD) and powder hold-up measurements. To quantify the strain applied to the powder in the blender, the number of blade passes experienced by the powder in the blender was calculated using the residence time measurements. The relationship between different experimental parameters and mean residence time and mean centered variance was examined. The mixing performance was largely dominated by the material properties of the mixture, which had a larger effect than the ingredient flow rate variability contributed by the feeders. Holdup was strongly dependent on impeller rotation rate; as impeller rotation rate increased, holdup (and therefore, residence time) decreased sharply. As a result, intermediate rotation rates showed the best mixing performance. Blade configuration affected performance as well; blade patterns where some of the blades push the powder backwards improved the mixing performance.     

The effect of humidity on the production of ordered mixtures

The rate of formation of ordered powder mixtures has been investigated, under various humidity conditions, in a revolving cube mixer with an internal agitator. The rate at which a 1:1000 mixture of salicylic acid and sucrose formed an ordered mixture was found to be the same at 0%, 55% and 84% relative humidity. This result is discussed in terms of the kinetics of ordered mixture formation and the adsorption forces giving rise to the ordered unit.     

Manufacture of Powder Coatings by Spraying of Gas‐Enriched Melts

An alternative process for the manufacture of powder coatings was developed. The continuously operated process is applicable to new (low‐melting and fast‐reacting) and conventional powder coating systems and allows to produce coatings with improved properties. The process uses the solubility of compressed gases in melts of coating polymers at pressures up to 220 bar. The single components of a powder coating mixture are melted in separated tanks and are dosed to a static mixer by means of high‐pressure pumps. In the mixer the melts are homogenized and simultaneously compressed carbon dioxide is dissolved. The so‐formed solution is depressurized directly afterwards over a nozzle into a spray tower. Thereby, the melt is atomized into fine droplets and cooled by the expanding gas. The droplets reach the solidification point of the melt and fine solid particles are formed. The particle size, particle size distribution and the morphology of the powders could be adjusted by the operating parameters of the plant.     

精准配料和高效均化装备在分别粉磨系统中的应用

将分别粉磨后的熟料粉、混合材粉按照不同比例进行配比，可比较灵活、快速地切换水泥品种，以适应市场对产品需求的变化，选用精确配料装备和高效均化装备是保证成品水泥质量的重要前提。KXT计量系统可保证物料给料连续性和计量准确性；多级模块化的组合式立式混料机可解决粉料大流量、低能耗混料难题。计量系统与均化设备有机结合为分别粉磨高效配制水泥成品提供了保障。     

Influence of stirrer type on mixture homogeneity in continuous powder mixing: A model case and a pharmaceutical case

Continuous powder mixers offer a viable alternative to batch processes, but have received very little attention in scientific literature and in the industrial world. Mixer design is still very empirical and is not based on assessed methodologies. In this paper, we report experiments that aimed to compare two very different types of stirrers for a pilot-scale continuous powder mixer, and for two types of mixtures: a model mixture and a real pharmaceutical mixture. The first stirrer A is of the frame type with inclined paddles and internal transporting screw, the other stirrer B is of the shaft type with paddles mounted on it. Results are first presented from the viewpoint of bulk powder flow by hold-up determination and correlation with operating conditions. General relationships are derived which show that the mobile B leads to higher hold-ups, which may be an important drawback. The study of mixture homogeneity globally confirms these findings, especially in a dense phase flow regime. In the fluidised regime, where the stirrer B can be used, attention is drawn to the negative effect of excessive rotational speeds on the quality of the mixtures.     

PP/PA6合金增容母料的研究

通过多单体熔融接枝改性聚丙烯来增容聚丙烯/尼龙6混合物,从而制得相容性比较好的聚合物合金.首先,将聚丙烯、尼龙6在干燥箱中烘干,将聚丙烯粒料、苯乙烯及丙烯酸和少量的聚丙烯粉末加入混合器中,然后经挤出做成母料,将制得的母料加入到聚丙烯、尼龙6初混物中,再经挤出注塑,得到聚合物合金.并通过测试其性能及接枝率从而找到最佳的组分配方.