浅谈球磨机吸声降噪技术

钢球磨煤机本身的筒体内反复反射声、电机噪声、齿轮传动噪声、排粉风机噪声等相互作用,且钢球磨煤机房墙体、地面及设备表面等为噪声的强反射面,造成钢球磨煤机及室内噪声为强混响声场。在钢球磨煤机噪声治理中,单纯靠隔声或阻尼减振方法等措施,难以达到满意的效果,必须辅助以吸声处理技术。     

山东胜利发电厂双进双出磨煤机的调试

双进双出钢球磨煤机是近些年投产机组中普遍使用的磨煤机,文中详细论述了山东胜利发电厂BBD 3854型双进双出钢球磨煤机的主要特点及运行情况,重点介绍该种磨煤机及料位测量系统调试过程、调试中出现的主要问题及处理.     

220t/h煤粉炉磨煤机噪声治理

广州石化动力事业部三台220t/h煤粉炉六台钢球磨煤机噪声治理工程采用隔声墙加吸声板的处理方法,使磨煤机室外噪声明显下降.     

采用绝声套法控制钢球磨煤机噪声

采用绝声套法控制钢球磨煤机噪声吕玉恒，郑和平（中国船舶工业总公司第九设计研究院）（上海柘林环保设备厂）１．前言火力发电厂广泛使用的钢球磨煤机，俗称球磨机，其噪声一般高达１１０～１２０ｄＢ（Ａ），严重危害着操作者的身心健康，同时给周围环境带来噪声污染。...     

筒型粉磨设备本体部位质量的控制

介绍DTM型筒式钢球磨煤机因散件到现场,因而在安装时易发生的质量问题及相应解决措施.     

MTZ3560筒式钢球磨煤机端盖的轴颈加工

产品MTZ3560筒式钢球磨煤机适用于粉磨各种硬度的煤炭,它广泛应用于热电厂加工固体燃料——煤粉,是制粉系统中的主要设备。筒式钢球磨煤机是由传动部、主轴承部、转动部、基础部、电器部、给料部、出料部等几部分组成,其中端盖是筒式钢球磨煤机上的主要部件,该部件的轴颈不但精度要求很高,而且加工表面的粗糙度要求也很高,这就迫使我们要采用一种新的、高效节能的加工方法——砂带磨削来解决生产关键问题,以满足图纸的要求,并取得了良好的效果。     

钢球磨煤机故障分析和解决办法

通过对钢球磨煤机存在的故障进行分析,提出了一些切实可行的改进措施,如基础重新浇灌、衬板螺栓改型、加装自动喷油和断油保护装置、加装隔音罩等,经一系列处理后,确保了磨煤机设备安全稳定的运行,取得良好的经济效益。     

600MW电厂双进双出磨煤机的运行特点

阜阳华润电力有限公司一期工程运用的是上海重型机器厂引进法国ALSTOM公司的技术生产的BBD-4360型双进双出钢球磨煤机,自投产以来,运行稳定,煤种适应性强,为公司的发展奠定了良好的基础,现对我厂磨煤机的分析总结如下：     

钢球磨煤机端盖裂纹修复技术

对某电厂钢球磨煤机出口端盖出现长度达5100mm的贯穿性的裂纹进行分析,主要详细讲述裂纹修复技术,对球磨机使用单位的检修工作起到一定借鉴作用。     

钢球磨煤机的噪声治理

针对发电厂主要噪声污染源钢球磨煤机，通过现场测试分析，识别其噪声产生的根源和频谱特性。结合测试结果和现场实际，制定出有效的综合治理方案，实施后效果显著。     

基于信息融合的球磨机料位分级与检测研究

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。     

Effect of mill speed and slurry filling on the charge dynamics by an instrumented ball

In the ball mill, the motion of charge is a complex system, especially under wet grinding. It is difficult to measure the charge physical quantities and hard to validate the correctness of charge motion simulation. To this end, an instrumented ball which is capable of measuring the charge physical quantities was designed. The laboratory ball mill was lined with 12 pieces of trapezium lifters and filled with J_b = 25% grinding balls. An iron ore was used to prepare the slurry at 50% solid concentration by mass. A series of tests were carried out to investigate the charge dynamics at different mill speeds and slurry filling. The average rotational kinetic energy, average applied force and mill power were measured and analyzed. The results showed that the average rotational kinetic energy increases with mill speed, whereas the average applied force first increases and then decreases. The average rotational kinetic energy and applied force first increases and then decreases by the increase in slurry filling. Furthermore, there exists a slurry filling U = U^* that the mill power has a maximum value.     

滚动轴承球磨机的应用

分析了球磨机采用滑动轴承存在摩擦阻力大的弊端。采用滚动轴承代替滑动轴承降低了磨机能耗,解决了大负荷下的轴承寿命、轴承密封等问题,磨机配用电动机功率可减少17％～23％。     

Fabrication of ultrafine W – Cu powders by mechanical alloying

Abstract

Ultrafine composite powders of W – 15 wt-%Cu, W – 25 wt-%Cu, and W – 35 wt-%Cu have been fabricated by mechanical alloying. The effects of type of mill, process control agent, temperature of milling, and ball/powder ratio on the final products have been evaluated. The results show that the planetary ball mill possesses a higher impact energy intensity than that of the vibratory ball mill. The optimum milling time is confirmed by the formation of a nanocrystalline microstructure in the planetary ball mill after optimisation of the milling parameters. A steady state between cold welding and fracture is attained with a milling time of up to 25 h in the planetary ball mill under optimised conditions. Crystallites with sizes of 7 – 8 nm for W – Cu composite powders have been obtained after 25 h of ball milling. The powders obtained after mechanical alloying have been characterised in terms of their size, shape, phase constitution, and microstructural features using X-ray diffraction and scanning electron microscopy.     

大型节能水泥粉磨技术的发展

归纳总结了当前国内外大型节能的水泥粉磨的发展动态 ,指出以辊压机或特殊结构的立磨作为预粉磨机与球磨机组成的水泥粉磨系统是当前的主要流行方式 ,另外用粉磨效率高的立磨或辊压机代替球磨机的水泥终粉磨方式在国外也有一定发展 ,但采用终粉磨系统要注意水泥质量问题     

Application of TUSSIM with a variable Tromp curve for predicting optimal operation of multi-compartment mills with various ball size distributions

A true unsteady-state simulator (TUSSIM) for ball milling was integrated with a variable Tromp curve for classification to simulate and optimize closed-circuit, multi-compartment cement ball milling. Using representative model–operational parameters from available literature, we first investigated the system dynamics for a two-compartment mill. Then, various simulations examined the impacts of closed-circuit vs. open-circuit operation, number of compartments, and various ball size distributions. Our results suggest that integrating an air classifier into an open-circuit ball mill can increase the production rate by 15% or increase the cement-specific surface area by 13%. A single-compartment mill entails a pre-milled feed for proper operation, whereas a two-compartment mill yields a finer cement product than a three-compartment mill. Uniform mass distribution of balls led to slightly finer product than uniform surface area or number distributions, while the impact of a classifying liner was negligibly small. Finally, we identified optimal ball mixtures in a two-compartment mill using a combined global optimizer–DAE solver, which suggests 14% capacity increase with desirable cement quality. Overall, TUSSIM’s results are not only in line with limited, full-scale experimental studies and industry best practices, but also provide fundamental process insights, while enabling process optimization with tailored ball mixtures in different compartments.     

基于N4SID子空间辨识的轧机系统性能改进分析

利用N4SID子空间辨识方法对南钢2800 mm中厚板精轧机系统的性能进行了分析。选取轧机的测量信号构成辨识对,利用子空间辨识方法,得到轧机在工作时的高阶动态数学模型。机架在0.63 Hz处有一振动频率,当轧辊旋转频率与该频率一致或接近时容易激发机架振动,对板形和设备正常运转影响较大。实际生产中,精轧机应避免在上述振动频率对应的转速范围36.0~39.0 r&;#8226;min-1内进行轧制,速度调整后板形得到很好控制,表明模型在轧机系统性能改进分析中是有效的。     

A Study of Mill Power as a Function of Media Type and Shape

ABSTRACT

The mill power of a laboratory scale tumbling media mill was determined for the different shapes of media which are used industrially for dry grinding of quartz to produce silica flow. The tested media were ceramic balls and cylinders of high density alumina, and natural flint pebbles; tests were performed over ranges of filling levels and rotational speeds, with and without lifters in the mill. The experiments showed that ceramic balls at low levels of ball charge slipped excessively against the mill wall when the mill interior was smooth and without lifters. The use of lifters gave a consistent tumbling action and, under otherwise comparable conditions, mill power was linearly proportional to media density. Equations were developed which enable the comparison of mill conditions which give the same mill power draw for the different shapes and densities. Combined with studies of grinding kinetics, this enables comparison of the grinding efficiencies for different media shapes.     

Effect of ball mill grinding parameters of hydrated lime fine grinding on consumed energy

The influence of several grinding parameters such as charged material volume, ball filling ratio, and mill rotation speed on energy efficiency of fine grinding of hydrated lime and the product fineness of hydrated lime was studied experimentally using a laboratory scale ball mill. The product size and surface area of the ground samples were determined with respect to the above variables, and changes in energy input during the grinding were described in detailed. Finally, the optimum conditions for the grinding of the hydrated lime with the ball mill were obtained. The results from this study showed that the ball mill load and mill speed are the most important parameters rather than ball mill charged material volume for the fine grinding of the hydrated lime using the ball mill in terms of energy efficiency associated with external surfaces.     

Enhancing the capacity of large-scale ball mill through process and equipment optimization: An industrial test verification

The production capacity of the large-scale ball mill in the concentrator is a crucial factor affecting the subsequent separation and the economic benefits of the operation. The main aim of this study is to improve the processing capacity of the large-scale ball mill. Taking a Φ5.49 × 8.83 m ball mill as the research object, the reason for the low processing capacity of the ball mill was explored via process mineralogy, physicochemical analysis, workshop process investigation, and the power consumption method. Based on this framework, a series of laboratory grinding optimization tests were conducted and verified via industrial tests. The results show that the ore primarily contained hematite and magnetite, the disseminated particle size of magnetite was primarily a coarse-grained inlay that was easy to separate from gangue, while the disseminated particle size of hematite was primarily an uneven and medium-sized inlay, which increased the grinding difficulty. Under optimum conditions of +6.0 mm material suitable for a 100 mm ball diameter, −6.0 + 2.0 mm material suitable for an 80 mm ball diameter, −2.0 mm material suitable for a 70 mm ball diameter; medium ratio of Φ90 mm 34.62%, Φ70 mm 26.92%, Φ60 mm 23.08%, Φ40 mm 15.38%; filling ratio of 32%; material ball ratio of 1.0; rotation speed rate of 80%; and grinding concentration of 78%, the −0.074 mm content in the grinding product increased from 55.10% to 58.86% and the processing capacity of the ball mill increased from 310 to 320 t/h to 350 t/h. Scanning electron microscopy/energy dispersive X-ray spectrometry (SEM-EDS) micrograph analysis shows that the fineness of the ore and dissociation degree of useful minerals were apparently improved by optimizing the process and equipment.