共查询到20条相似文献,搜索用时 187 毫秒
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《中国粉体技术》2016,(5):18-21
针对硫磺粉的易燃易爆特性和粉碎要求,对现有分级式冲击磨的结构进行研究;对粉碎、分级和收集系统的操作参数、设备结构以及系统运行过程中出现的静电积聚、粉尘爆炸等问题进行分析探讨和优化改进,通过加工硫磺粉的工业试验,对改进后的分级式冲击磨进行测试。结果表明,控制粉碎主机转速为1 500 r/min,分级机转速分别调为450、600、750 r/min,袋式除尘器过滤风速为0.94 m/min,获得的成品硫磺粉的粒径d97分别为107.79、74.21、46.15μm,产率分别为3.650、2.802、2.205 t/h,单位能耗分别为31.929、43.012、58.095 k W·h/t。 相似文献
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分级轮叶片结构和转速对分级性能影响的仿真 总被引:1,自引:0,他引:1
《中国粉体技术》2015,(4):6-10
运用Fluent软件,采用液-固两相流的数值模拟方法,对超细粉体湿法离心分级机分级腔内流场进行数值模拟仿真;选用重整化群k-ε湍流模型和欧拉多相流模型,利用多重参考坐标系法,在稳态条件下,分析不同形状分级轮叶片分级腔内流体的速度分布情况,研究不同形状分级轮叶片对分级机分级性能的影响;选用离散相模型,在非稳态条件下,分析分级腔内颗粒轨迹的规律,研究分级轮转速对分级粒径的影响。结果表明:相比于直叶片和斜叶片,弧形叶片分级效果更好;采用弧形叶片结构,当分级轮转速为1 000 r/min时,分级粒径大于1μm,分级轮转速为2 000 r/min时,分级粒径接近1μm,当分级轮转速为3 000 r/min时,分级粒径小于1μm,增大分级轮转速有利于减小分级粒径。 相似文献
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建立了FW-Φ150型强制涡卧式涡轮分级机内腔叶片之间气-固两相流的双流体理论模型熏并利用通用的流体力学计算软件进行了数值模拟。结果表明:该涡轮分级机在正常工作状态时,内腔流场遵循强湍流流动规律;粒子群的运动规律是,粒子的粒径越大,越易向叶片外边缘聚集,直至返回分级区;随着转速的增大,流场的涡流现象越来越强,相同粒径的粒子,当转速增大到一定的程度时,出现了反流现象,使已经分离出的细粒又返回到分级区,而影响分级机的分级效率。 相似文献
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针对硫磺粉的易燃易爆特性,采用LNI-330A型氮气保护分级式冲击磨粉碎硫磺,并对其进行工业试验。结果表明:运行过程中,系统压力分布为-1.1~12.8 k Pa时,系统氧含量可稳定在2%左右;调节分级机的转速为150~1 200 r/min,硫磺粉体成品产量为750~1 500 kg/h,粒径d_(50)为15~25μm,单位电耗小于83.601 kWh/t;转速大于450 r/min时,达到橡胶用不溶性硫磺技术指标,即粒径为150μm的筛余物质量分数≤1%;综合考虑工业要求,得到冲击磨制备硫磺粉体的最优分级机转速为450 r/min,成品产量为1 375 kg/h,150μm筛余物质量分数为0.74%,粒径d50为24.50μm,单位电耗为65.77 kW·h/t。 相似文献
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《中国粉体技术》2019,(6)
在现有废旧印刷电路板(WPCBs)机械-物理法回收技术基础上,完善电子元器件(ECs)拆解工艺,利用分级式冲击磨实现粗碎产物的细碎-分离一体化,建立WPCBs回收自动化生产线;分别进行WPCBs拆解试验、废旧印刷电路板基板(WPWBs)粗碎试验和粗碎产物的细碎-金属分离试验;对金属和非金属回收产物进行微观形貌表征;研究分级式冲击磨的分级机转速对金属与非金属回收产物的分离效率的影响;最后对生产线进行了经济性评估。结果表明:该生产线工艺简便,设备投资低,运行能耗低,利润高;产量达到300 kg/h,金属与非金属的分离效率达到94. 4%;回收的铜粉呈球状,其铜品位达95. 4%;符合WPCBs资源化技术的要求,实现WPCBs回收的大规模、工业化生产。 相似文献
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FJW涡轮分级机的分级机理研究 总被引:2,自引:0,他引:2
为了研究涡轮分级机的分级机理对于合理设计分级腔的结构、优化系统操作参数的影响,介绍了一种高效精密分级设备——150FJW型卧式涡轮分级机的结构和工作参数,分析了其分级机理,根据实验探讨了影响其性能的关键因素。研究表明:①颗粒的浓度对分级精度有较大的影响;②分级粒径的大小与涡轮转速、抽风机风量、风压及涡轮结构参数有关;③分析分级精度时要考虑分级机内部紊流的影响。 相似文献
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立磨选粉机操作参数对分级流场影响的数值模拟 总被引:1,自引:1,他引:0
采用离散相流体模型和RNG k-ε湍流模型,对涡轮式立磨选粉机内的气-固两相流场进行数值模拟,对比分析不同操作参数下的速度场、压力场和设备分级效率,获得转笼转速和系统风量对选粉机分级流场的影响规律,并进行相关的试验研究。结果表明,较低的转笼转速和过大的系统风量均会引起叶片间退行面处正漩涡的产生;转笼转速过高或系统风量较小时,分级叶片间的进入面处会出现反漩涡。正、反漩涡的产生均加剧了分级叶片间的速度波动,严重影响了分级流场的稳定性,同时也导致选粉机循环负荷的增加。综合数值模拟与试验分析,系统风量为5 500 m3/min与转笼转速为55 r/min是SMG5500型立磨选粉机的最佳参数匹配。 相似文献
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Benedikt Koeninger Christian Spoetter Stefan Romeis Alfred P. Weber Karl-Ernst Wirth 《Advanced Powder Technology》2019,30(8):1678-1686
Dry grinding of particles to sizes below 10 µm can be realized in fluidized bed opposed jet mills. In these mills the energy for comminution is supplied by pressurized gas, which is introduced through focused nozzles. The gas transports the material towards an internal classifier, which separates the fines from the coarse material. The fines are discharged whereas the coarse material is recycled. Within this study special attention is paid to separation at the classifying wheel. Limestone batch grinding experiments were performed in a fluidized bed opposed jet mill equipped with on-line and in-line probes: The particle size distributions (PSDs) of the product flow and the solid concentration below the classifier were determined on-line. The flow field around the classifier was recorded by a high-speed camera and off-line measurements of the mill inventory and its PSD were performed. Our measurements reveal that the solid transport from the milling zone to the classifier and the classifier performance strongly depend on solid concentration. Increasing the solid feed concentration or the classifier wheel speed leads to unwanted accumulation of product-sized particles inside the mill. In particular, we find high solid loadings of up to 1.05 g?g?1 and strong cluster formation (local zones of high solid concentration) in the vicinity of the classifier blades. Estimated separation efficiency curves of the classifier show a strong “fish-hook effect” which increases with the solid concentration. Our findings are relevant for future process optimization by careful tuning of grinding performance, holdup and classifier speed. 相似文献
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M2 cast high speed steel was inoculated by addition of rare earth(RE)‐Al‐N, network eutectic carbides were eliminated, matrix structures were refined and the segregation of tungsten and molybdenum elements were relieved. In the condition that the hardness did not decrease, impact toughness obviously increased. Quenching at 1180 °C and three‐times tempering at 560 °C, the hardness of M2 cast high speed steel kept 65~66HRC, impact toughness reached 21.3J/cm2. Modified M2 cast high speed steel had excellent thermal fatigue resistance and high temperature wear resistance. Roll made in modified M2 cast high speed steel had excellent service effect using in slit rolling mill stand of hot rolling bar mill. 相似文献
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为在流化床式气流磨进行生产时合理选择喂料速率,以获得较好的产品,通过小型气流磨加工滑石粉实验,分析不同分级轮转速下磨腔料位、产品中位径与喂料速率之间的关系,以及喂料速率对产品粒度的影响。结果表明,提高分级轮转速,可以很明显地减小产品中位径;当物料粉碎过程进入稳定状态以后,分级轮的每一个转速都对应一个喂料速率的临界值,在一定的分级轮转速下,把喂料速率调整到最佳值,可以获得粒度更细、分布更窄的产品;喂料速度控制不好将引起分级轮电机过载,产品粒度不稳定,设备产能降低。 相似文献
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A new type of abrasion-resistant cast boron steel was developed based on the service conditions of the guide roller in the high-speed steel wire-rod mill. The lath martensite was its matrix and the broken Fe2B and dispersive distributed TiB2 were its wear resistant skeleton. The tensile strength, hardness, and impact toughness of cast boron steel quenched at 1000°C excel 750 MPa, 54 HRC, 14 J/cm2, respectively. The guide roller made of this steel has high strength and wear resistance and excellent thermal fatigue resistance and it is reliable to use in the high-speed steel wire-rod mill. Its service life is 1.133 times longer than that of cast high chromium nickel alloy steel and corresponding to that of the sintered-carbide. 相似文献
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火力发电厂锅炉制粉系统的主要设备之一——球磨机的运行状况优劣在一定程度上决定了电厂的经济运行状况好坏。分析了球磨机磨筒内料位的各种影响因素及影响特性,提出了料位分级理论,将料位分为非经济区、优化区与危险区三个区域,解决了数据融合测料位时无法获得大量料位样本的问题。在此基础上,提出了基于BP人工神经网络测量球磨机料位的软测量方法,对球磨机现场数据分析进一步验证了所提方法的有效性。该方法确定了球磨机最佳运行工况的范围,为实现球磨机系统的优化运行和自动控制奠定了基础。 相似文献
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Evaluation of process parameters and performance of planetary mills is considered an important issue in optimization of their predicted efficiencies. The current research deals with a computer simulation based on discrete element method (DEM) employed to evaluate the grinding mechanism of a planetary mill. The effect of rotational speed, the volume percentage of the balls and powders on impact energy, the frequency of the impacts, the abrasion of the balls and the dissipated energy have been investigated. It was realized that by increasing the rotational speed, the impact energy and the number of impacts of ball–ball, ball–container, ball–powder, powder–powder and dissipated energy were increased. By increasing the balls filling ratio, the impact energy value of ball–ball remained almost constant after a critical point while those of ball–powder impact energy and the dissipated energy were slightly increased. With an increase in powders filing ratio, a maximum value was observed for the ball–powder impact energy; however, the ball–ball impact energy remained almost constant and the dissipated energy indicates a reduction in rate. 相似文献