垂直螺旋输送机内物料的运动密度研究

垂直螺旋输送机在依靠离心力和螺旋叶片的摩擦力输送物料的同时,高速旋转的螺旋叶片产生的空气动力作用也促进了物料颗粒的输送,输送机内物料的密度分布很复杂.垂直螺旋输送机内输送物料的流动可视为非牛顿流体流动,用FLUENT流体工程仿真软件模拟水泥在垂直螺旋输送机内输送时的流动状态,并对其运动密度进行了描述和分析.     

大长径比卧螺离心机螺旋输送器的有限元分析

应用SolidWorks对大长径比卧螺离心机的转鼓-螺旋输送器系进行了三维建模,采用与SolidWorks无缝衔接的有限元分析插件Simulation对其进行了有限元仿真。通过SolidWorks Simulation对螺旋输送器在正常工况下的整体结构进行了静力分析和模态分析,得到了螺旋输送器前5阶固有频率、应力分布和...     

螺旋破碎松脂法提高松香特级率

福建省尤溪林化厂组织科研小组攻关,并在新成立的林化协会上研讨论证,进行了螺旋破碎法的试验。经过螺旋推进器的使用,对入池前的松脂进行边输送、边破碎操作;由于推进器大,充满系数低、转速较     

动平衡技术在卧螺离心机振动问题中的应用

针对某污水处理厂卧式螺旋离心脱水机出现的振动和异常噪声问题进行了研究,通过拆机检查发现卧式螺旋脱水机的螺旋输送器叶片发生了较大磨损,分析表明振动主要由螺旋输送器磨损造成的不平衡引起。对螺旋输送器叶片维修后进行了动平衡校正,装机后振动明显减小,达到安全运行标准。     

PVC气流干燥装置进料工艺的改进

介绍了改进PVC气流干燥进料工艺的具体措施：①改造螺旋输送器桨叶,②在进料位置下部干燥管增加缩喉,③改变螺旋输送器的进料位置,④在螺旋输送器端部增加吹扫气。改造后彻底解决了气流干燥管底部积料的问题,杂质粒子数单项优等品率有所提高。     

螺旋离心机输送器参数对其强度与变形的影响研究

在诸多参数中,对螺旋离心输送器主要参数:转速、叶片厚、半锥角和导程对其强度和变形的影响进行了分析研究,为已有的卧式螺旋离心机的改造优化和实际应用提供了依据.     

输送固体粒子——选择最佳螺旋给料器的几何形状

螺旋给料器是用来均匀地控制定量物料的流动,是全封闭式的输送器,在选择螺旋给料时,均匀地从料仓或料斗里抽出物料是一主要探寻的问题。安装在料斗下的螺旋给料器有二个作用:     

PVC干燥工段螺旋输送器的改造

2004年8月，山东恒通化工股份有限公司（简称恒通化工）4万t／a PVC项目干燥部分的生产调试中，因螺旋输送器出现问题，严重影响了该项目的及时达标达产。出现的主要问题为：①螺旋输送器频繁地发生过载跳闸；②螺旋输送器容易发生“倒风”；③密封件密封效果差，泄漏严重。恒通化工根据螺旋输送器的实际使用情况，进行了一系列的改造，使PVC干燥生产达到了设计的要求。     

FL—50型粉体螺旋输送器通过技术鉴定

<正> 上海市化工装备研究所研制的FL-50型粉体螺旋输送器于1991年11月29日在宜兴通过技术鉴定,鉴定会由中国化工装备总公司主持,在宜兴液压泵厂召开。与会专家认为此输送器的研制成功,填补了我国粉体输送设备的空白。此输送器为软性轴输送结构,螺旋输送管最小弯曲半径为1.5米,输送能力为1.5米/小时,输送粉体物料时输送器位置可以移动,使     

用于输送固体颗粒的泵

<正> 用于输送粘性,含固量高的浆液和危险性或胶粘物料的传统机械输送设备,例如开式皮带输送器,链式输送器或螺旋输送器,     

Prediction of screw conveyor performance using the Discrete Element Method (DEM)

Screw conveyors are used extensively in agriculture and industry for transporting and/or elevating bulk materials over short to medium distances. They are very effective conveying devices for dry particulate solids, giving good control over the throughput. Despite their apparent simplicity, the mechanics of the transportation action is very complex and designers have tended to rely heavily on empirical performance data. The performance of a screw conveyor is affected by the operating conditions, such as: the rotational speed of the screw; the inclination of the screw conveyor; and the volumetric fill level of the bulk material. In this paper we examine how these operating conditions influence the performance of a screw conveyor by applying the Discrete Element Method (DEM) to simulate a single-pitch screw conveyor with periodic boundary conditions. The DEM modelling gives predictions of screw conveyor performance in terms of variations of: particle speeds, mass flow rate, energy dissipation and power consumption, due to changes in the operating conditions.     

双螺杆挤出实验中影响螺杆填充率的相关因素

利用双螺杆挤出实验中的实验数据曲线,对影响螺杆填充率的诸相关因素进行分析。在螺杆几何结构及螺杆元件组合形式确定之后,不同的操作工况条件下对应有不同的螺杆最大允许填充率,在正常操作中,螺杆的填充率不能大于最大允许值。     

PTA干燥机搅笼轴断裂原因及改进

介绍了PTA装置TA单元干燥机进料搅笼在运行中突然发生的轴断裂事故,从宏观检验、化学成分分析、金相检验、力学试验、宏观断口分析、静强度校核等方面进行了分析,找出了事故原因为疲劳断裂。从搅笼轴的结构和制造工艺上提出了改进方案,取得了良好的经济和社会效益。     

Modeling the solids conveying zone of a novel extruder

On the basis of the theory of relative motions, a novel nested screw extruder was invented in which one rotating outer screw acted as the barrel for an inner screw; the combination of the outer screw and outer barrel was the other extrusion system. It was realized that centrifugal force resulted in the difference between the forces acting on the solids by the screw and by the barrel, which further compacted the solid pellet or powder. These factors benefited the frictional drag of solids and the early melting. This was consistent with the fact that the solids conveying flow rate increased greatly when the barrel and screw rotated oppositely at the same time. Thus, centrifugal force and material compressibility were significant in the feeding zone. A mathematical model was developed to calculate the output, pressure, and velocity of the solids in the screw down‐channel with consideration of the centrifugal force and material compressibility. The predicted pressure distribution and output were better than those by previous models in fitting the experimental data. The simulations revealed that the maximum traction angle was close to 90° ? the helix angle for maximum output in contrast to the maximum traction angle of 90° predicted by the Darnell–Mol theory. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

热管式螺杆及其传热研究

热管应用于挤出机螺杆的热交换，并将热管和螺杆做成一体，提出了热管式螺杆的概念，阐述了热管式螺杆的传热机理，进行了Ｎｕｓｓｅｌｔ分析，指出了影响性能的诸因素，认为热管式螺杆结构简单，传热性能优异。     

Analysis of influence of multiple steel cords on splice strength

Influence to the steel cord conveyor belt strength has many factors. Conveyor belt splice as the weakest link, should be given more attention. In the previous analysis of single steel cord, by comparing the numerical results of splice deformation and maximum pullout force under tension, both simulation and experiment have a good agreement. Based on this, in this paper, we studied the influence of different factors on the strength of splices under multiple steel cords. In addition to the contact surface between the steel cords and the rubber, we should also pay attention to the rubber problem between adjacent steel cords compared to the single steel cord. And we forced on the simulation analysis of the influence strength of splice by two factors of the position and arrangement of the multiple steel cords. The numerical results show that in the total proportion, the pullout force in the middle position of steel cords was about 52%, however, about 47% in the edge position. For the arrangement of the steel cords, with the number of interval steel cords increases, the pullout force of the steel cord increases as well. However, when the interval steel cords with the same number increases, the increase in pullout force does not agree. The above findings are undoubtedly important for us to understand in depth the factors affecting splice strength. And it is guaranteed that we can obtain the maximum splice tensile strength in the most economical way.     

Study of Residence Time Distribution in a Pilot-Scale Screw Conveyor Dryer

The screw conveyor dryer (SCD) finds varied applications in the process industries either as a pre-dryer or for post-drying operation. In certain cases, it can be used as the main dryer. The full potential of SCD has not been exploited for the lack of its understanding. The conveying of paste or particles through a screw conveyor may follow a near plug flow behavior; however, it is essential to ascertain a desired level of inter-particle mixing during the course of drying/conveying so as to obtain the desired drying conditions. The effects of feed rate (15–176 kg/h) and screw speed (10.8–28 rpm) on the RTD were studied for the conveying of sand in a pilot-scale SCD using pulse input of a tracer (dye-coated sand). Two new parameters defining the relative stagnancy and screw effectiveness were introduced to study the flow performance of SCD. The flow in the SCD approaches plug flow with an increase in feed rate or by decrease in the screw speed. A low value of the holdback, a parameter of relative stagnancy, indicates the flow in SCD to be near plug flow. Mean residence time was found to be 3 to 4 times longer than the linear residence time due to lower values of screw effectiveness (0.24–0.32).