气流磨粉碎原理及在钛白粉生产中的应用

引言气流磨作为超细粉碎的一种重要设备,广泛应用于非金属矿物及化工原料的超细粉碎,产品粒度上限取决于混合气流中的固体含量,与单位能耗成反比。气流粉碎产品除粒度细以外,还具有粒度分布窄,颗粒表面光滑、颗粒形状规则,纯度高、活性大、分散性好等特点。由于粉碎过程中压缩气体绝热膨胀产生焦耳-汤姆逊降温效应,因而还适用于低熔点、热敏性物料的超细粉碎。下面就气流磨分类及粉碎原理作一介绍。1气流磨分类工业型气流粉碎自40年代问世以来发展很快,目前工业上应用的气流磨有以下五种类型:1.水平圆盘式(扁平式)气流磨2.循环管式气流磨3.靶式气流磨4.对喷式气流磨5.流化床对喷式气流磨2气流磨粉碎原理气流磨的一般原理:将干燥无油的压缩空气或过热蒸汽通过喷嘴高速喷出,高速射流带动物料作高速运动,使物料碰撞,摩擦而粉碎。被粉碎的物料随气流到达分级区,达到细度要求的物料,最终由收集器收集。没有达到要求的物料,再返回粉碎室继续粉碎,直到达到所需细度并被捕集为止。由于喷嘴附近速度梯度很高,因此绝大多数的粉碎作用发生在喷嘴附近。在粉碎室中,颗粒与颗粒间碰撞的频率远远高于颗粒与器壁的碰撞。也即气流磨中的主要粉碎作用是颗粒之间的冲击或摩擦。虽然气流...     

流化床对撞式气流磨对三七的超细粉碎

利用流化床对撞式气流磨对中药三七进行超细粉碎 ,然后分析粉体颗粒的微观形貌、粒度分布及表面积 ,结果表明 ;粉碎效果良好 ,达到了超细粉碎的目的 ,且粒度分布比较均匀     

气流磨粉碎颗粒分析

为了分析超细粉体颗粒冲击破碎时颗粒破碎与颗粒材料性质之间的关系,运用应力波理论及颗粒材料结构特性对气流磨粉碎进行了定性分析。采用JFC-5气流磨对8种晶体及非晶体材料进行超细粉碎,并用SSX-550电子扫描显微镜分别对8种超细粉体颗粒进行形貌观察。分析发现晶体颗粒的破碎与其晶格构造特点密切相关,被粉碎颗粒形状具有相应明显的晶体特点;非晶体颗粒的破碎则具有很大的随机性,颗粒形状无明显几何特点,无晶界可循。     

流化床气流磨粉碎制备超细SiC片晶的实验研究

超细SiC片晶由于其高强度、高弹性模量和导热系数已成为替代价值昂贵、制备技术复杂SiC晶须的理想的增韧材料。本文中通过对流化床气流磨粉碎机理,以及粉碎腔内工质压强与喷嘴个数对SiC颗粒形貌影响的研究,得出工质压强、喷嘴个数等参数对粉碎的颗粒形貌有很大的影响的结论,其中粉碎腔采用高的工质压强以增加粉碎强度。采用两喷嘴以增加颗粒互相撞击的几率是制备片状SiC粉的有效方法;采用流化床式气流磨加多级涡轮分级机的粉碎系统可以制备产品质量较好的多级别超细SiC片晶微粉。     

关于气流磨机的几个问题（Ⅰ）

关于气流磨机的几个问题（Ⅰ）孙成林蔡玲北京矿冶研究总院１０００４４国家建材局地质研究所１０００２４关键词：粉碎，气流磨，效率１气流（喷射）磨简史高压气流磨或称喷射磨，是一种较成熟的超细粉碎设备。它是利用高速气流（３００～５００ｍ／ｓ）或过热蒸气（３Ｏ...     

粉体设备

<正>国内气流磨在实际应用中的问题以及解决之道我国的粉碎机械是在八十年代中、后期发展起来的。由于工业生产的广泛性,随着国民经济迅速发展而发展迅猛。在粉体生产、应用和设备制造的科研开发过程中,不断有新设备、新产品在市场上出现,气流磨就是众多粉碎设备中的     

流化床式气流磨关键技术及其进展

介绍了流化床式气流磨的工作原理及特点,对喷嘴、粉碎、分级等关键部分相关的技术研究进展分别进行了阐述,表明改进和提高喷嘴、粉碎宝、分级机等核心部件的性能和协调各个部分最优化工作能够使流化床式气流粉碎系统达到最佳工作状态,从而提高产品产量和质量。     

气流磨超细粉碎循环流化床锅炉脱硫灰的试验研究

为提高循环流化床燃煤锅炉脱硫灰在工程上的利用率,利用气流磨对循环流化床脱硫灰进行超细粉碎,通过调节分级机频率大小进行分组实验。结果表明:CaO和SO3组分含量在循环流化床脱硫灰中所占比例大,质量分数分别达26.84%和12.25%;采用气流磨粉碎循环流化床脱硫灰,有效地增大了CaO的比表面积,通过调节分级机的频率可获得窄粒度段分布的超细脱硫灰,获得的超细脱硫灰颗粒表面粗糙,凹凸不平,呈不规则形状。     

气流磨尾尘的超细粉碎

用气流磨加工碳化硅磨料时,约有5%-15%的物料变成了尾尘.这部分碳化硅微粉由于粒度分布范围很宽,无法直接利用.本实验研究对气流磨碳化硅尾尘用搅拌磨粉碎进行了探讨.实验研究了不同研磨时间粉尘的纯度变化;分散剂对粒度变化的影响以及不同研磨时间,微粉的粒度、粒度分布的变化关系,实验结果证明气流磨尾尘经过搅拌磨研磨可以得到分布窄、单峰的理想微细粉体;随着研磨时间的增加,粉体纯度下降;磷酸盐水分散剂可以促进研磨的进程.     

流化床式气流磨制备超微粉的特性

非金属矿深加工是指对原料或其产品进行超细、超高纯、改性、复合等工艺的处理。深加工的非金属矿物除大大拓宽产品本身的应用领域外，还给国家和企业带来可观的经济效益，因此发展非金属矿加工技术得到了世界各国的重视。上海化工机械三厂是化工部粉碎中心、上海市粉体工程中试基地，十多年来长期致力于粉体设备的研制与开发。除了现有扁平式、靶式、对冲式、循环管式等系列气流磨外，近年来成功地开发了流化床式气流磨。气流磨是利用高压气体通过喷嘴产生的高速气流所孕育的巨大的动能，使物料颗粒发生互相冲击碰撞达到粉碎目的。由气体动…     

Thermal optimization and experimental research of high-speed universal pulverizer

Because of high efficiency, energy conservation, simple operation, wide application range, and small size, the high-speed universal pulverizer has been well received by customers. However, its electrical motor can overheat when working, which hinders continuous operation of the pulverizer. In this study, a series of efforts were made to address this problem. Firstly, a detailed analysis of the working principle of the pulverizer was conducted and an optimization plan was proposed, consisting in punching ventilation holes on the surface of the original pulverizer. Simulations of the pulverizer flow field before and after optimization were performed. The hydrodynamic simulation results were used to conduct a steady state thermal analysis of the pulverizer, investigating the influence of the flow field on heat transfer. Additionally, experimental investigations were conducted on the pulverizer before and after optimization in order to measure and compare the parameters (motor working temperature, wind speed and temperature of the motor cooling system, vibration, noise, and pulverizing degree of the material) influencing the performance of the pulverizer. The numerical simulation results showed an increment in heat transfer caused by increment in air flow volume and velocity when air was injected into the pulverizer through bottom and side holes. Experimental results showed that the pulverizer with air injection through holes had the best performance when temperature, vibration, and refinement effect were considered as performance indicators. The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-017-0208-3     

A NOVEL DRY PULVERIZER FOR LOW COST PRODUCTION OF POWDERS

The paper presents the principles of a prototype dry pulverizer particularly suited for industrial applications together with performance tests demonstrating its advantages. The pulverizer offers considerable advantages when compared to commonly used comminution processes, especially in the fine and superfine milling of minerals. The originality of the pulverizer lies mainly in that it allows the variation of the ratio of the shear to the compression forces acting on a particle during its pulverization. The ratio is adjusted to the mechanical requirements of the material to be pulverized. Instead of a single roller or balls, the pulverizer employs several annular rings, thus allowing better grinding of the finer fractions of the original material. The adjustment of the operational conditions to the mechanical properties of the material to be pulverized and the increase of the “active” surface of the pulverizer are examined in terms of ratio of the work done by normal forces to the total work (due to normal and shear forces).     

碗式中速磨煤机运行特性试验研究及应用

为提高制粉系统运行的安全性和经济性,对300 MW锅炉碗式中速磨煤机制粉系统进行了优化调整试验。试验研究了碗式中速磨煤机出力特性、磨煤机分离器挡板特性,调整了磨煤机最佳通风量,获得了磨煤机分离器折向挡板刻度与煤粉细度、磨煤电耗、磨碗差压的关系曲线。试验结果表明：随分离器折向挡板刻度的增大,煤粉细度变小,磨碗差压增大,磨煤机电流增加。根据磨煤机特性试验,提出了磨煤机最佳通风量、磨煤机出力及分离器挡板开度控制范围,并依据磨煤机运行情况提出设备缺陷检修建议,优化试验工况的磨煤机单耗下降8.5%,节能效果比较明显。     

射流冲击冷却系统实验性能研究

对一闭式射流冲击冷却系统的循环冷却性能进行了实验研究,讨论了循环流量和喷射压差对冷却循环系统性能的影响.为了分析射流换热性能的差异,对不同喷射压力和流量的工况进行分析,并通过对喷射腔内的喷射状态观察,与相关的换热试验性能进行了对比分析.     

Analysis of the particle collision behavior in spiral jet milling

Collision behaviors of particles in spiral jet milling were analyzed by using a simulation. The motion of the particles was tracked by the discrete element method (DEM), and the air flow was represented by the computational fluid dynamics (CFD). The DEM was coupled with the CFD by a one-way coupling method. The simulated air flow was validated by comparing the fluid velocity field with the measured one in a model experiment. Furthermore, the air flow and particle behaviors in a spiral jet mill used commercially were analyzed by using the simulation. As a result, the particles with a region balancing between centrifugal and radial drag forces could be mainly ground by the high-speed collisions between the particles circulating near the top and bottom walls of the grinding chamber.     

The Effect of Feeding Mechanism on the Grinding Efficiency of Pulverizers

ABSTRACT

Pulverizers have been used to perform grinding, blending, and dispersing for a wide range of materials in the powder processing industry. In impact pulverizing there have been many modifications to the basic machines in an attempt to achieve the efficient comminution of materials. In this study, feed delivery methods and the stability of the feed rate were investigated in relation to the grinding performance of the pulverizer. Various feeding devices were tested on the Mikro-Pulverizer®. Test results showed that the grinding efficiency of the pulverizer can be improved with the proper feeding mechanism.     

悬摆式磨粉机和立式纵摆磨粉机的研制

讨论悬摆式磨粉机及立式纵摆磨粉机在研磨相同物料及相同粒度的前提下,造成产量差异的理论依据,通过对悬摆式磨粉机和立式纵摆磨粉机的结构分析及参数分析,进一步详细阐明其中的异同;介绍两种摆式磨粉机的优缺点,提出立式纵摆磨粉机磨辊装置(或梅花架总成)中的轴承存在密封可靠性问题,有待于进一步解决。     

Investigation of process parameters influence in abrasive water jet cutting of D2 steel

In the present experimental study, abrasive water jet (AWJ) cutting tests were conducted on D2 steel by different jet impingement angles and abrasive mesh sizes. The experimental data was statistically analyzed using the simos–grey relational method and ANOVA test. In addition, the outcome of influencing cutting parameters, namely jet pressure, jet impingement angle, and abrasive mesh size on the different response parameters, namely, the jet penetration, material removal rate, taper ratio, roughness, and topography, were studied. Micro-hardness test and surface morphology analysis were employed to examine the D2 cut surfaces at different AWJ cutting conditions. The chemical element study was performed to determine the abrasive particle contamination in the AWJ kerf wall cut surfaces. The ANOVA test result indicated the jet pressure and jet impingement angle as the influencing process parameters affecting the various performance characteristics of AWJ cutting. The overall AWJ cutting performance of the D2 steel has been improved through proper identification of the optimal process parameter settings, namely jet pressure 225?MPa, abrasive mesh size #100, and jet impingement angle 70° by the simos–grey relational analysis.     

超脆硬物料粉碎加工设备的研制

超脆硬物料(如金属硅、碳化硅、玻璃等)的粉碎加工,由于硬度高,一般要求无铁污染、粒度集中,目前国内一直缺少节能、高效、高品质的理想加工设备。本文中研制开发了该类物料的粉碎设备—特种盘式磨粉机,介绍了盘式磨的工作机理,讨论了影响盘式磨磨粉质量的生产率的一些因素。     

钢球磨煤机故障分析和解决办法

通过对钢球磨煤机存在的故障进行分析,提出了一些切实可行的改进措施,如基础重新浇灌、衬板螺栓改型、加装自动喷油和断油保护装置、加装隔音罩等,经一系列处理后,确保了磨煤机设备安全稳定的运行,取得良好的经济效益。