降低旋风筒阻力的一种新方法

通过试验研究，提出了一种旋风筒降阻新方法———粗糙壁面降阻。结果表明：对相同规格的旋风筒，采用合适的旋风筒器壁粗糙度可以使阻力降低约２０％～３５％，而分离效率仅下降约２％～３％。同时，对旋风筒器壁粗糙度降阻机理进行了探讨。     

旋风预热器导流板的优化研究

在冷模试验条件下探讨了两种导流板安装角度与旋风筒阻力损失、分离效率的相关规律。研究表明,随着安装角度的增大,旋风筒阻力系数ξ是逐渐减小的,当α增大到30°以后,阻力系数几乎不再变化。而分离效率随着安装角度Ⅸ的增大有所降低。     

导流板对旋风分离器内气固两相分离性能的影响

通过数值模拟对环形空间设有导流板的旋风分离器进行了研究. 与常规单入口旋风分离器相比,设置导流板显著改善了旋风分离器内的非轴对称流动,使流场的旋转中心与分离器的几何中心重合,从而抑制了旋风分离器内的涡核摆动现象. 气固两相模拟结果表明,加入导流板可明显提高旋风分离器的分离效率,尤其是对于粒径为5 mm的小颗粒,分离效率从53.4%提高到94.6%,捕集效率显著提高.     

旋风器进口结构的优化及其性能的试验研究

将旋风器常规进口结构优化改进为带有不同回转通道形式和角度的进口结构 ,并对各种旋风器的性能进行了冷态试验测定。结果表明 ,采用双进口回转通道形式的进口结构可同时降低旋风器阻力和提高分离效率     

旋风筒降阻改造方式优化比选的数值模拟

采用CPFD数值模拟方法对旋风筒降阻的不同方式（扩大进口面积、增大内筒直径）进行了分析,重点考察了其对压力损失和分离效率的影响。结果表明：不同扩大进口面积的方式（外扩、内扩、下扩、上扩）降阻效果差别不大,但内扩和下扩的方法对收尘效率具有一定的负面影响;随着内筒直径的扩大,其阻力和分离效率有着不同程度的减小。     

应用双出风口旋风分离器改造旋风选粉机

传统旋风选粉机因分离效率低而影响粉磨产品的产量和质量，采用导流口可调式双出风口旋风分离器技术取代传统单出风口分离器对传统旋风选粉机改造后，降阻节能作用显著，分离效率明显提高，其提高部分恰是捕集细粉增加部分，因而产品细度改观，比表面积增大。     

四级旋风预热器导流板的改进

我公司烧成一车间2号窑是2000t/d的窑外分解窑,采用了四级旋风预热生产技术,在预热器的各级排风管与各级旋风筒联接处安装有导流板,其作用是降低系统阻力,使物料与热气流交换充分地进行。在实际使用中,导流板刚投入使用时导流效果比较好,但使用三个月后,导流板严重变形,使用半年左右就必须进行处理或更换,特别是二、三级导流板因变形严重而堆积了许多物料,严重阻碍了物料流通,增大了系统阻力,提高了单位熟料的煤耗、电耗,这些都不利于生产。经过几年的生产实践,发现预势器的导流板存在一些问题,具体表现在：(1)原导流板形状…     

圆柱段高度对Stairmand型旋风分离器性能的影响

利用雷诺应力模型(RSM)和离散相模型(DPM)对不同高度圆柱段的4种Stairmand型旋风分离器模型(A1、A2、A3、A4)进行了流场、压降和分离效率的计算分析。结果表明:增加圆柱段高度,压降显著降低,收集效率略有提高;在入口速度为18m/s条件下,与模型A1相比模型A2、A3、A4的压降分别降低了约8. 35%、18. 63%、35. 33%,分离效率分别提高了约4. 9%、2. 6%、4. 1%;同时表明了旋风分离器以其设计入口速度稳定运行的重要性。     

旋风分离器结构优化实验研究

为了在降低旋风分离器压降的同时维持较高的分离效率,设计了一种新型旋风分离器。采用弧形导流板分隔进气的入口结构、渐扩型排气的出口结构、加长型的筒体和锥体的结构,有锥顶过渡段的灰斗结构,并匹配了合理的尺寸。为了验证新型分离器的性能,将新型结构的旋风分离器与基准PV型分离器进行了并联对比实验。以空气为实验介质,实验粉料为滑石粉,在入口气速为14. 2～21. 2 m/s、入口含尘浓度为0. 01 kg/m~3时,同时测量了新型分离器与PV型分离器的效率和压降。对比实验结果表明,相对于基准PV型分离器,新型旋风分离器的平均压降降低了21. 91%,且分离效率基本保持不变。     

旋风分离器内筒减阻装置的试验研究

以理论研究为基础,通过冷模试验研究了不同操作条件下旋风分离器压力损失的变化规律,开发设计了一种针对旋风分离器的内筒高效减阻装置,并对安装内筒减阻罩的旋风分离器的阻力损失和分离效率进行了试验研究,探讨了不同入口风速、不同固气比条件对旋风分离器的性能影响.对结果进行了理论分析,结果表明:对于相同规格的旋风分离器,内筒减阻罩能起到优化旋风分离器阻降且把分离效率控制在合理数值范围内的作用,不同风速,不同固气比条件下,内筒减阻罩的最大减阻幅度为43.36％,而分离效率最大降幅只有8.78％.     

Development of a symmetrical spiral inlet to improve cyclone separator performance

Three cyclone separators with different inlet geometry were designed, which include a conventional tangential single inlet (CTSI), a direct symmetrical spiral inlet (DSSI), and a converging symmetrical spiral inlet (CSSI). The effects of inlet type on cyclone performance characteristics, including the collection efficiency and pressure drop, were investigated and compared as a function of particle size and flow rate in this paper. Experimental result indicated that the symmetrical spiral inlet (SSI), especially CSSI inlet geometry, has effect on significantly increasing collection efficiency with insignificantly increasing pressure drop. In addition, the results of collection efficiency and pressure drop comparison between the experimental data and the theoretical model were also involved.     

Design and performance evaluation of vacuum cleaners using cyclone technology

A cyclone technology for a vacuum cleaner—axial inlet flow cyclone and the tangential inlet flow cyclone — to collect dusts efficiently and reduce pressure drop has been studied experimentally. The optimal design factors such as dust collection efficiency, pressure drop, and cut-size being the particle size corresponding to the fractional collection efficiency of 50% were investigated. The particle cut-size decreases with reduced inlet area, body diameter, and vortex finder diameter of the cyclone. The tangential inlet twin-flow cyclone has good performance taking into account the low pressure drop of 350 mmAq and the cut-size of 1.5 μm in mass median diameter at the flow rate of 1 m³/min. A vacuum cleaner using tangential inlet twin-flow cyclone shows the potential to be an effective method for collecting dusts generated in the household.     

Characteristics of electrostatic cyclone/bag filter with inlet types (lab and pilot scale)

The main purpose of this study was to investigate experimentally the characteristics of an electrostatic cyclone/bag filter with inlet types (upper and bottom inlet) in order to overcome the low collection efficiency for submicron particles and high pressure drop, which were the main problems of general fabric bag filters. The experiment was performed to analyze the collection efficiency and pressure drop of the electrostatic cyclone/bag filter compared with that of conventional fabric bag filters with various experimental parameters such as the inlet type (upper and bottom), inlet velocity (filtration velocity) and applied voltages. From the results, the upper inlet type showed a slightly higher pressure drop reduction ratio as 40–90% than that of bottom inlet. In addition, the electrostatic cyclone/bag filter represented an increment of over 5% for the collection efficiency of submicron particles (around 1 Μm) in comparison with the general fabric filter. Presented at the Int’/Sym. on Chem. Eng. (Cheju, Feb. 8–10, 2001), dedicated to Prof. H. S. Chun on the occasion of his retirement from Korea University.     

Effect of the Solid Loading on a PFBC Cyclone with Pneumatic Extraction of Solids

This paper presents the effects of solid loading on the performance of a cyclone with pneumatic extraction of solids. The cyclone is a non‐conventional design, especially used for hot‐gas cleaning applications such as pressurized fluidized bed combustors (PFBC). A scaled‐down cold‐flow model was employed for the research. Experiments were conducted at 9–14 m/s inlet gas velocities, inlet solid loadings ranging from 30 to 230 g/kg gas, and bottom gas extraction percentages from 0.3 to 1.5%. Experimental results of pressure drop resistance coefficients and collection efficiency were compared with literature predictions. At PFBC operating conditions, cyclone geometry and solid concentration are the main parameters influencing cyclone pressure drop and collection efficiency. The vortex penetration in dipleg causes lower pressure drop values and higher collection efficiencies than predicted. These parameters can be suitably predicted for PFBC cyclones by introducing a modified penetration length in Muschelknautz's model [1]. For the present cyclone design, a new correlation of pressure drop, including the influence of solid loading, is proposed. A new method for detecting cyclone fouling, not previously addressed, is also presented, based on the evolution of the pressure drop resistance coefficient. An enhanced separation efficiency has been found, related to collection efficiency, which is especially important for particle sizes below 10 μm revealing agglomeration effects.     

3-D computational fluid dynamics for gas and gas-particle flows in a cyclone with different inlet section angles

A three-dimensional computational fluid dynamics (CFD) Reynolds stress model (RSM) was used to describe the gas and gas-solid flow in a cyclone with a scroll inlet duct at three different inlet section angles in relation to the cyclone body. The effects of the inlet section angles on the fluid dynamics inside the cyclone and on the performance parameters (collection efficiency and pressure drop) were analyzed by means of the finite volume method using a computational code and an industrial-sized cyclone for separation of gas-particle phases operated by Votorantim Cimentos Company. The numerical results show that the value for overall collection efficiency in this work increased to 77.2% for the 45° inlet section angle, while that for the normal inlet duct was 54.4% under the same operating conditions.     

天然气净化用多管旋风分离器的分离性能

为了系统评价天然气净化用多管旋风分离器的分离性能,在线测量了入口气速6~24 m/s、入口颗粒浓度30~2000 mg/m3范围内多管旋风分离器的分离效率和分级效率. 结果表明,多管旋风分离器的分离效率和分级效率都随入口气速和入口颗粒浓度增大而提高. 与单管旋风分离器相比,在相同实验条件下,多管旋风分离器的分离效率下降2%~15%;单管旋风分离器基本能除净粒径大于10 mm的颗粒,而多管旋风分离器只能去除15 mm以上的颗粒. 多管旋风分离器的压降主要是内部单管旋风分离器的压降,占整个压降的80%~90%.     

旋风分离器入口结构影响的研究现状与进展

综述了近年来关于入口结构包括入口结构类型、入口截面形状以及入口下倾角度等对旋风分离器性能影响的研究。认为不同的入口结构参数设计对旋风分离器的性能及能耗有较大影响;随着入口数量增多,分离器压降降低,分离效率先升高后减少,双进口分离器的性能较优。入口截面形状采用倒三角形有利于提高分离效率,但压力损失增加;对于矩形入口旋风分离器,增大高宽比有利于提高分离效率,但也会增大压力损失。随着入口截面角的增加,压力损失降低,分离效率先升高后减小,存在有最优的入口截面角;螺旋下倾角能够改善旋风分离器的分离性能,降低压力损失并有效减少上灰环现象的发生。     

单双切向环流式旋风除尘器的比较

以粉煤灰 空气为实验物系 ,测定了单、双切向环流式旋风除尘器的除尘效率和压降。实验结果表明 ,双切向环流式旋风除尘器的除尘效率比单切向环流式旋风除尘器的除尘效率有所提高 ,压降比单切向环流式旋风除尘器的压降低 2 0 0Pa ,处理量有所增大     

Effects of separation space diameter on the performance of a novel reverse flow cyclone

ABSTRACT

A numerical study was carried out to investigate the effect of separation space diameter on the performance of a novel reverse flow tangential inlet cyclone design by using the Eulerian-Lagrangian approach. The design of this cyclone is based on the idea of increasing vortex length and decreasing pressure drop compared with traditional cyclones. This novel cyclone differs from the traditional cyclones with separation space and vortex limiter instead of the conical part. A qualitative numerical study was performed to analyze the effect of separation space diameter on the cyclone performance at different flow rates by evaluating velocity profile, pressure drop, fractional and overall efficiencies. The results show that the collection efficiency of smaller particles increases while pressure drop decreases significantly with the increase in separation space diameter for D₁/D < 0.5.