雾粒粒度测试技术研究

阐述了脱硫塔内喷雾雾场的研究的必要性，分析了雾场的环境条件，应用夫朗和费衍射原理设计制造了适于大雾场内进行测试的仪器，并叙述了仪器的特点，对论了雾粒测定仪进入脱硫塔内测试的有关技术问题，文章还介绍了雾粒测定仪在脱硫塔内测试的情况，分析了测试结果。     

脱硫塔内雾粒测定仪及其测试技术研究

叙述了雾粒粒径测试仪器的设计原理及为进入塔内测试的结构特点。讨论了有关的测试技术问题，特别对仪器动态测试稳定性问题进行了讨论，还对直接影响信号真实度的采样窗口设定问题进行了讨论。文中还讨论用多闪拟合逼近法对雾粒多峰分布的信号进行分析的方法。最后还介绍并讨论了脱硫塔雾场测试的结果，通过一万多小时的实际运行，证实了所测结果的正确性。     

微粒空间运动轨迹测定的一种光学并行处理方法

介绍脱硫塔内离心喷雾雾场中雾粒沿塔体分布的测试结果，指出粒子的运动轨迹测试是一个国际上共同关心的问题。用双曝光散斑图的分析方法来分析微粒运动，其中介绍了双曝光散斑图的分析原理以及如何用全息透镜阵列来分析颗粒在平面内的移动，从垂直两平面获取微粒运动的双曝光图，通过光学并行处理和图象的分析得到颗粒空间运动轨迹的可能性。文中还讨论了一些试验结果和尚待研究的问题。     

微粒空间运动轨迹测定的一种光学并行处理方法

介绍脱硫塔内离心喷雾雾场中雾粒沿塔体分布的测试结果，指出粒子的运动轨迹测试是一个国际上共同关心的问题，用双曝光散斑图的分析方法来分析微粒运动，其中介绍了双曝光散斑图的分析原理以及如何全息透镜阵列来分析颗粒在平面内的移动，从垂直两平面获取微粒运动的双曝光图，通过光学并行处理和图象的分析得到颗粒空间运动轨迹的可能性，文中还讨论了一些试验结果和尚待研究的问题。     

透光率/雾度测定仪原理解析及应用

<正>0引言透光率/雾度测定仪作为光电雾度仪的升级、改进版,其结构原理、参数要求和维护保养还不为大众熟知。本文对WGT-S透光率/雾度测定仪的原理构造进行完整分析,提出日常维护及校准建议,以便使用者清楚认识仪器、熟练掌握方法,从而使仪器运用更规范,数据检测更准确。WGT-S透光率/雾度测定仪现广泛应用于国防科研及工农业生产,可用于测试一切透明、半透明     

百特测试设备服务中心

丹东市百特测试设备服务和心是一个集科研、制造、服务于一体的科技型企业。主要产品有BT－1500型离心沉降式颗粒分布测定义、BT－3000型离心沉降式超细颗粒分布测定仪、BT－930B型激光颗粒分布测定仪；并将陆续推出几种新型的智能颗粒分布测定仪。因此百特中心的颗粒分布测定仪器已经初步形成系列化。此外根据测试需要，中心还开发了液体（悬浮液）分样器、定时超声波分散器、手持电动搅拌器、干粉取样器、液何取样器等附属品，使仪器的配套更加完善，提高了仪器的使用效率和测试质量。颗粒测试仪器是集电子、机械、光学和计算机技术于…     

Y412A型原棉水分测定仪的检修

Ｙ４１２Ａ型原棉水分测定仪的检修王燕（山东省滨州地区计量测试检定所，２５６６１８）Ｙ４１２Ａ型原棉水分测定仪是广泛用于收购、检测棉花的主要仪器之一。它结构简单，携带方便，利于现场使用。现仅就该仪器的检修简述如下：Ｙ４１２Ａ型原棉水分测定仪是以干电池为...     

电厂活性焦干法脱硫吸附塔内烟气流动数值研究

本文采用CFD方法，数值模拟某电厂活性焦干法脱硫吸附塔内的烟气流场，研究机组运行工况和烟气含尘量对塔内烟气流动的影响规律。计算结果表明：烟气含尘量对塔内烟气流动结构和压力分布的影响十分微弱，烟气通过活性焦层产生的压降远大于烟气在烟道内流动的压降，吸附塔承力构件工字钢的存在引起通过烟道人气孔的烟气流量不均匀，但活性焦层内的烟气流量仍十分均匀。     

喷雾半干法脱硫塔内射流卷吸特性的数值模拟

喷雾半干法烟气脱硫塔内射流卷吸特性对塔内烟气与吸收剂的混合以及流场分布均匀有着重要影响。该文通过数值模拟的方法,分析双流体雾化喷嘴的射流卷吸混合特性,得到喷雾半干法烟气脱硫塔内射流流场分布。结果表明：双流体雾化喷嘴在塔内流场呈现中间大两边小的对称分布,并且在靠近塔壁的两侧产生了回流;射流流体与周围气体发生动量交换,对周围气体有明显的卷吸作用,沿着射流轴线方向,射流卷吸量逐渐增加,随着伴随风量的增加,射流卷吸量也逐渐增加。     

智能式屈服强度测定仪原理与设计

智能式屈服强度测定仪是一种采用微处理机技术,由试样总伸长量中分离检测出非比例伸长量,从而实现屈服强度自动测定的新型仪器。本文介绍了仪器的测试原理与结构设计,以及仪器的性能和实用价值。     

Er3Ni磁性蓄冷材料小球成型加工研究

用真空雾化成球设备，研究了Ｅｒ３Ｎｉ蓄冷材料的球形加工方法，得到了球形Ｅｒ３Ｎｉ材料。     

Centrifugal atomization of stainless-steel rotating rods melted by a high-power LASER beam

316L grade stainless steel powders were produced by centrifugal atomization during the melting of a rotating rod heated by a high-power LASER beam. The feasibility has been demonstrated by atomizing a range of stainless steel rods. The atomization process has been observed via high-speed imaging and fragmentation regimes have been identified according to a literature review on the rotating electrode process (REP). Results were compared with literature data and an existing prediction model for such a process. High-speed observation can monitor the present process and it is shown that a solidified layer of metal is formed at the edge of the rod during the process inducing metal flake ejection due to the centrifugal stresses. Effects of incident LASER beam power density, ejection speed and oxygen content of the surrounding atmosphere on the particle size distribution and the sample surface have been studied and compared with literature data on classical REP atomizers. The study focuses on the production of irregular particles during the atomization process and highlights the influence of the oxygen content in the surrounding atmosphere on the fragmentation regime and the resulting particle size distribution.     

Characteristics and atomization behavior of Ti-6Al-4V powder produced by plasma rotating electrode process

In the present research, the characteristics and atomization behavior of Ti-6Al-4V powders produced by plasma rotating electrode process (PREP) with different rotation speeds were investigated. Three kinds of particles in the as-PREPed powders are observed: spherical particles, satellite particles and irregular particles. The mean particle size of the PREP powder decreases and its distribution becomes narrower gradually with increasing rotation speed. PREP powder at higher rotation speed demonstrates lower fractions of both satellite particles and irregular particles. By observing the residual electrode tip, it is considered that the irregular particles with corner or flat shape are possibly caused by the tearing of liquid film under the action of centrifugal force and shear force during the atomization process.     

离心加速场中金属凝固过程温度场分布数值分析

采用有限差分法及MathCad软件首次模拟了二维柱坐标系下自硬砂型离心铸造凝固过程,并就转速、浇温、铸型预热温度、铸型类别等工艺参数对铸件温度场分布的影响规律进行了研究。模拟结果表明,由于采用自硬砂型和灰铁盖,铸件的上下表面首先凝固,然后逐渐向金属液中间推进;随转速、铸型蓄热系数的增加,铸型预热温度与浇注温度的降低,金属凝固加快;在其它条件相同的情况下,型温对温度场的影响最大,转速其次,浇温最小。      

大豆蛋白喷涂液雾化粒子场实验

目的研究大豆蛋白喷涂液雾化场的粒度分布,及喷涂过程中喷涂参数对大豆蛋白液雾化液滴粒径的影响,从而在蔬菜复合纸覆膜成型过程中选择最优喷涂参数。方法利用激光粒度仪测量不同喷涂参数下大豆蛋白液喷涂雾化场的粒度分布,并通过数据分析软件Origin研究喷涂参数对大豆蛋白液喷涂雾化粒度的影响。结果喷涂参数相同时,喷涂雾化场中随着轴向距离的增加,大豆蛋白液液滴粒径先显著减小后趋于稳定;喷涂雾化场中同一轴向位置随着径向距离的增加,大豆蛋白液液滴粒径呈减小趋势。在喷涂雾化场同一测量点,随着喷涂气压的增大,大豆蛋白液液滴粒径逐渐减小;喷涂液压对大豆蛋白液液滴粒径没有显著影响。结论喷涂气压为0.2 MPa,喷涂液压为0.16 MPa,喷涂雾化场轴向30 cm平面内,大豆蛋白液雾化液滴粒径较小且均匀。     

离心真空泵的气动设计探讨

高效率真空泵的设计技术对于工业的节能具有重要意义。根据某真空泵的设计要求,针对真空泵的工作叶轮的形式和设计点参数,分析和探讨了叶片负荷分布形式和分流叶片弦向和周向位置对性能的影响规律,在此基础上完成了该离心真空泵的气动设计。利用三维数值模拟软件对不同叶片扩压器角度情况下的性能曲线和内部流动进行计算。充分考虑真空泵内部流动的非对称性,采用了全通道计算,同时分析了真空泵的离心叶轮、叶片扩压器及蜗壳内部的流动特点。结果表明,叶片负荷分布形式和分流叶片弦向和周向位置对流量、出口气流角和效率均有较大的影响;通过改变叶片扩压器角度使得离心真空泵的特性线平移,使得离心真空泵在整个工作过程中始终工作在高效率区,达到节能的目的。     

利用离心喷雾干燥制备球形粉体的工艺因素研究

研究了铝矾土料浆的离心喷雾造粒过程,考察了料浆固含量、粘度、喷雾头的旋转速度对粉体干燥的影响.从颗粒内部水分迁移的距离、空气进出口温度两方面,分析了蘑菇头颗粒、变形颗粒、球形颗粒和破裂颗粒等颗粒形貌的形成原因,并优化了一组工艺参数:喷雾头转速为12000r/min,料浆固含量为50%,热风入口温度为300℃,废气出口温度为115℃,塔内负压为-350Pa,料浆流速为4L/h,料浆的粘度为14s,在此条件下能制备出球形度高、颗粒粒径集中分布在55μm左右的粉体.     

Experimental and numerical investigations on molten metal atomization techniques – A critical review

Metal powders are highly practical in many applications such as solders, 3D printing, dental activities, etc. Atomization of molten metals and alloys is one of the common mechanisms for the production of powders. In this review, different techniques for the atomizing of molten metals including gas atomization, centrifugal atomization, water/oil atomization, and special atomization are compared and the advantages and disadvantages of each technique are discussed in detail. Furthermore, recent experimental and numerical investigations regarding different atomization techniques are reviewed in different operating conditions and materials for better understanding of the effects of different parameters on powder size. Hybrid atomization, which is the combination of different atomization techniques, is also represented. Finally, some special designs of atomizers for improving the size and quality of powders are introduced.     

一种基于TRNSYS的闭式热源塔冬季工况模拟计算方法

目前所给出的闭式热源塔计算方法主要是针对闭式热源塔的一些特定工况和条件提出的,存在着一定的局限性。本文利用FORTRAN编程语言在TRNSYS模拟平台上建立了闭式热源塔的计算模型,给出了相关结构参数及换热系数的求解过程,通过与其他学者的实测数据及计算数据进行对比,验证该模型的正确性。验证结果表明,干工况、干-湿混合工况以及防霜工况的理论计算结果与实测结果均误差较小,表明本文所建立的计算模型准确度较高,能够满足闭式热源塔全年模拟分析的要求。     

Selective particle size analysis in binary submicron particle mixtures using density dependent differential sedimentation

Particle size characterization of heterogeneous mixtures is a challenging task, as it is not feasible to assign the measured signals to the individual components. Within this framework, the study proposes a method that applies the working principle of differential centrifugal sedimentation (DCS) in order to simultaneously separate and measure the denser component within a binary material mixture of submicron particles. The method was validated using a model system consisting of polyvinyl chloride (PVC) and diamond particles in a size range of 0.5 – 1.5 µm. The results proved that by applying a proper density gradient fluid, the diamond particles can be selectively analyzed by hindering the sedimentation of the lighter PVC component. Furthermore, a very promising application could be found with respect to wet fine grinding processes in stirred media mills. In fact, the approach was utilized to individually determine the particle size distribution of the grinding media wear within an ultrafine organic product. Despite the low quantity of wear particles, it was possible to separate them from the organic product under appropriate density conditions. The size distributions of both the wear and the product particles were validated with SEM images, confirming the feasibility of the method.