烟草除尘过程中节能减排优化研究

使用全面试验法,对除尘风机的空转时间进行研究,分析了风机空转的原因,并通过增加"制丝需求启动信号"逻辑控制建立了切丝工序与除尘风机的联动程序。本研究对企业产生了一定的经济效益,并可为同领域其他方面的节能减排提供参考和方法。     

Hybrid H2/Ti dust explosion hazards during the production of metal hydride TiH2 in a closed vessel

The explosibility of hybrid H₂/Ti dust in the production of metal hydride TiH₂ was simulated and studied using a 20-L spherical vessel. The influential factors for the explosion performance of hybrid H₂/Ti dust, including particle size distribution and polydispersity, humidity, temperature, hydrogen content, inert gas and degree of reaction, on hybrid explosion were investigated. Results showed that both the mean particle sizes and particle size polydispersity had significant effects on the dust severity of hybrid H₂/Ti dust. The explosion severity of hybrid H₂/Ti dust was enhanced at a higher temperature in a certain range, and it presented a trend of increasing at the early stage and then decreased both for the increasing humidity and hydrogen pressure. Explosion inhibition effects of typical inert gases for hybrid H₂/Ti dust increased in the following order: argon < helium < nitrogen. The values of (dP/dt)_ex and V_f decreased along with the reaction process, while the value of P_ex kept stable, which showed that the hydrogen state had no obvious impact on P_ex but significantly affected the explosion risk of hybrid H₂/Ti dust, and special attention should be paid to the initial stages of the production process of TiH₂.     

接地极雾化电晕放电除尘器的研究

随着经济的快速发展和排放标准的日益严格,粉尘的去除一直是研究的热点。设计了一种新型的接地极雾化电晕除尘器。该除尘器在放电过程中,对颗粒物荷电的同时使线电极表面液体雾化,从而有效去除粉尘。在试验过程中,首先设定进气的气流速度为1 m/s和3 m/s,改变线电极表面覆盖液体流量及气流方向,研究了接地极雾化负电晕放电伏⁃安特性。其次,设定线电极表面覆盖液体流量为25 mL/min,研究了接地极雾化负电晕放电装置中顺向气流和逆向气流下气流速度对除尘效率的影响。最后,为了研究接地极雾化电晕放电除尘器对高比电阻粉尘的除尘能力,在气流速度为1 m/s的逆向气流中,将比电阻为1.2×1012 Ω·m的水泥粉尘作为高比电阻粉尘进行了试验。结果表明,随着气流速度的增加,除尘效率降低。当气流速度较大的条件下,气流逆向流动时的放电电流比顺向流动时大;在线电极表面覆盖液体流量为25 mL/min时,接地极雾化负电晕放电的电流最大。接地极雾化电晕放电除尘器最优条件为：线电极表面覆盖液体流量为25 mL/min,逆向气流速度为1 m/s。相对于传统的干式电晕放电反应器,接地极雾化电晕放电除尘器对高比电阻粉尘具有更高的除尘效率。     

排尘口直径对旋风分离器壁面磨损影响的数值模拟

基于计算流体动力学(Computational fluid dynamic,CFD)的数值模拟方法,在FLUENT软件平台上,应用雷诺应力模型、离散相模型和磨损值计算模型系统地研究排尘口直径对旋风分离器壁面磨损的影响。计算结果表明,旋风分离器壁面磨损的整体变化趋势不随排尘口直径的改变而变化,都呈现局部磨损的形态。排尘口直径减小,环形空间壁面磨损值保持不变,分离空间壁面磨损值有不同程度的增加,在锥体末端附近增加幅度最大,而这种变化主要是由于排尘口直径变化后分离器内部流动结构的变化引起的。分离空间锥体末端附近壁面的严重磨损主要受气固两相的旋转速度、颗粒浓度、旋进涡核和颗粒受力情况的影响。通过研究揭示合理地进行结构设计在减少磨损中的重要作用,为旋风分离器壁面的防磨提供数值试验方法和依据。     

炼铁厂出铁口烟尘综合利用的研究

本文分析了炼铁厂出铁口烟尘的性质,并用选矿方法对烟尘进行提纯,通过重选、磁选、浮选的试验研究,结果表明;“分级一磁选”效果最好,可获得铁品位为68．78％的超级铁精矿,回收率为66．22％;另一铁精矿品位为57．93％,回收率为32．86％;尾矿铁损失率仅为0．92％。文章还对后续深加工提出了具体建议。     

Consideration of the stress dependence of the bulk density in silo storage of dusts from dry off-gas cleaning

In this study the influence of the consolidation stress on the bulk density of dusts separated from the off-gas of a broad variety of industrial processes was investigated. With the exception of very small values of the stress this dependence can be approximated very well by a simple function. One coefficient in this function correlates very well with the bulk density measured according to EN ISO 60, while the other coefficient shows a good correlation with a function, combining several dust properties. Using this approximation function equations for the vertical stress and bulk density in the shaft of a cylindrical silo as a function of the distance from the surface were derived. The results for the vertical stress and the mass of the bulk obtained with these equations were compared with those acquired on the basis of Janssen’s equation assuming constant bulk density according to EN ISO 60 and a constant average bulk density. Up to a certain distance from the surface of the bulk the values for the stress and for the mass were between the results obtained by the two variants with constant bulk density, whereas for greater distances the resulting values were higher.     

Synthesis and performance measurement of a modified polymer dust suppressant

In order to address the problem of dust pollution formed during coal production processes, we chemically modified sodium alginate (SA), an environmentally friendly macromolecule polymer, to achieve a grafted product. IR and NMR were employed to investigate the structure of the grafted products. A contact angle experiment was used to select surfactants with good wettability, which were subsequently combined with the water-retaining agent CMS and SAE–XG–3, to fabricate an environmentally friendly dust suppressant. A high–resolution scanning electron microscope (SEM) was used to analyze the morphology of the cured film that formed on the surface of coal dust. A spraying test was performed to measure the dust suppressant’s performance. The experimental results demonstrated that the environmentally friendly dust suppressant possessed good water retention, viscosity, and wettability, and could achieve suitable dust bonding and settlement performance. In addition, the newly developed dust suppressant is environmentally friendly and has economic benefits.     

电荷对粉尘和病原体团聚影响的数学模型研究

由于封闭畜禽舍内聚集了大量的粉尘和病原体,将影响到动物和饲养人员的呼吸道健康,因此迫切需要研究去除粉尘和病原体的方法。以粉尘和病原体的结合体为研究对象,利用蒙特卡罗法及相关概率模型,研究电荷对粉尘和病原体团聚影响。通过研究粉尘和电荷间的附着模型,确定其附着受粒子半径、电荷情况、风速等因素影响;之后,进一步构建粉尘、病原体间以及病原体、电荷间的附着模型。结合数值化运算设定边界条件,得出三者间的结合率可达到15%。粉尘、病原体与电荷相互之间模型的建立能有效的了解到畜禽舍除尘的方法,提高除尘效率,并为高压静电除尘的推广和应用提供了理论基础。     

袋式除尘器在水泥工业中的应用状况及研究进展

从袋式除尘器的滤料、清灰方式、清灰状态等几个方面论述了袋式除尘器的发展及应用情况,并且涉及实际应用中出现的问题及解决方法以及袋式除尘器最近几年发展的新技术。     

塑料厂除尘系统的设计分析

除尘系统是捕集、输送、净化含尘气体直至干净气体排放的整个系统,它由集气吸尘罩、除尘管路、除尘设备、除尘风机等组成。提出了除尘系统的设计原则和计算方法,为正确选择、合理配置除尘系统提供了设计依据