粉煤灰计量技术与应用

1概述 粉煤灰是一种流动性极好、容重较轻的干粉状物料，多年来，粉煤灰掺量的准确计量和定量控制一直是水泥厂面对的难题。由于没有理想的计量技术和装置可供选择，只能采用螺旋电子秤、冲量流量计（冲板式或溜槽式）、失重秤、皮带秤、转子秤，甚至双管螺旋给料机及刚性叶轮给料机等传统的计量手段或给料设备，使用效果均难以满足生产要求，普遍存在计量不准，给料不稳，冲料、跑料问题，或受计量设备本身结构局限，无法用于大流量粉煤灰计量环节。计量不准会导致粉煤灰添加量失控，或掺量不足影响经济效益，或掺量超标致使出厂水泥质量不合格。此外，冲料、     

几种选矿厂计量仪表

目前国内外选矿厂的计量,按物料的干湿程度分为矿石(包括矿粉)计量和矿浆计量;按物料的状态又可分为静态计量和动态计量。静态计量有轨道衡、汽车地中衡或分批式漏斗称。动态计量有皮带秤(机械秤、电子秤、核幅射秤)、冲量流量计、秤重给料机、管道流量计和浓度计、移动台秤等。 静态计量的精度主要取决于秤重仪表传感器的精度,而动态计量的精度除了秤重仪表传感器的精度外,还与系统工艺关系密切。     

DEL／DEM型称重给料机

中国建材装备公司组织合肥水泥研究设计院、南京水泥工业设计院、四川建材设计院和承德自动化计量仪器厂、常熟机械总厂以及成都科学仪器厂,从联邦德国申克(Schenck)公司引进“水泥厂连续计量设备设计与制造技术”,其内容包括DEL/DEM型称童给料机、DLM型固体(溜槽)流量计、DLD型流量喂料机、FLK型煤粉流量计、PSS型失重秤、DPH型裙板式称重给料机、BMP型电子皮带秤、BMK型链斗输送机电子秤和FCR568型磨机控制系统。为了使用户对这些设备有所了解,本刊准备对这些设备作概要介绍,以便用户选择使用。     

2 500 t/d生料制备下料系统的改进

我厂2号生产线(2 500 t/d水泥熟料)生料制备下料系统配用了四台定量给料机(电子皮带秤),分别计量石灰石、砂岩、铁粉及粉煤灰等原料.在生产期间,铁粉秤、粉煤灰秤常出现堵塞、冲料等现象,生料质量不稳定,熟料煅烧质量差.为稳定下料系统的正常运行,我们成功地对其进行了改进.     

磨机喂料设备的最新发展

在水泥生产中,磨机的喂料离不开喂料计量设备。已为我们熟知的喂料设备有圆盘喂料机、电磁振动给料机、电子皮带秤、斗式电子秤和螺旋电子秤。此外,电机振动喂料机、板式喂料秤、称重喂料仓、冲击式固体流量计等喂料计量设备在磨机喂料系统中也都逐渐有所应用。尽管在喂料设备中大都引入了计算机技术,使喂料计量技术有了新的发展,但都仍存在着一些不尽人意的地方。例     

立窑企业生产过程自动控制技术

由于水泥立窑受其生产工艺、投资规模、台时产量的影响，生产过程中的计量与自动控制技术发展相对缓慢．也走了很多弯路。在计量方面，物料计量从斗式秤、圆盘秤到失重秤，从恒速秤、间歇式皮带秤到直流、变频调速式皮带秤，从螺旋秤、冲击流量计到转子秤；水流量计量从转子流量计、涡街流量计到克里奥流量计。在自动化方面，     

水泥配料系统计量设备选型及注意事项

<正>1调速皮带秤的选型及注意事项随着新型给料计量设备的完善和成熟,水泥工业中一些技术落后、计量控制精度低、工作不够稳定可靠和污染环境的给料设备(如简易料斗秤和简易皮带秤、恒速定量给料秤、双悬臂电子皮带秤、减量法斗式秤、圆盘秤和核子皮带秤等)已经逐步淘汰,     

M91型失重配料秤常见故障及处理方法

我厂特种水泥生产线扩建工程的生料系统,选用了山东临朐微机所研制生产的M9l型失重秤微机配料控制系统.现就该秤使用过程中常见故障及处理方法介绍如下,供参考.1.系统结构及工作原理M91型失重秤微机配料控制系统主要由工业控制计算机、拉力传感器、信号放大器、可控硅电源控制器、计量仓(失重仓)和上下料给料机等部分组成.系统开始工作时,首先由计算机发出上料控制信号,启动可控硅电源控制器,使上料给料机开始快速向计量仓上料.悬挂于计量仓上的3只拉力传感器将仓内瞬时重量以mV方式反映出来.该电压信号经信号放大器放大后,送入计算机进行A/D转换.     

提高水泥配料皮带秤精度和稳定性的措施

皮带秤作为水泥配料中重要的计量设备,配料系统通过PID控制,以恒定的给料流量连续不断地输送散状物料,实现定量给料、自动计量和累计等功能。本文介绍皮带秤误差源,皮带秤使用维护过程中秤架准直性校准、减少零点漂移、减少环境影响、减少测速误差、标定等改善措施,有效提高水泥配料皮带秤的准确性和稳定性。     

水平回转式稳流定量给料装置的应用

1 概述 在现代工业生产中,粉体物料的稳定给料一直被视为生产控制的一个重要环节。就水泥工业而言,生料、煤粉及水泥的稳流给料,目前大多数采用叶轮给料机、螺旋给料机等装置。叶轮给料机的稳料、锁风效果不太理想,特别是安装在库底或大仓下     

圆管带式输送机的发展及其关键技术

圆管带式输送机是一种特种带式输送机。在介绍圆管带式输送机工作原理基础上，分析了该种输送机的优点和缺点；对国内国外发展水平和研究现状进行了分析，指出了我国圆管带式输送机发展过程中的问题。同时讨论了圆管带式输送机的设计计算方法、输送带结构设计、托辊组及其辅助设施与布置、新型结构机身的设计等关键技术．提出了针对不同类型物料输送参数研究、定量给料装置的研制等需要进一步研究的课题。     

Generating a representative signal of coal moisture content to anticipate combustion control in thermal power stations

This article describes the possibilities of continuously measuring coal moisture in the boiler feeding circuit of a thermal power station so that the measurement can be used as a signal for the boiler combustion control system. To do so, in the first place, the point through which coal would be fed into the boiler was chosen. After studying the different parts of the circuit, the feeder was selected. Then, an installation was designed, at semi-industrial scale, faithfully reproducing the operation of a belt conveyor. In order to measure the moisture content, a microwave system was installed, and a large number of coal samples with different ranks and grain sizes was tested showing eventually the likelihood of the objective.     

高气密耐磨关风器与低温真空干燥简仓

关风器是气力输送、真空输送系统中不可或缺的设备，有旋转阀、星型给排料机、密闭旋转叶片给排料机等多种名称。减小关风器漏气量、延长使用寿命是本产品的难点；减小叶轮工作状态各封闭腔体压力差。选用复合耐磨自润滑材料是达到关风器漏气量小、使用寿命长的有效途径。真空干燥筒仓有多种结构，但适合做大产量连续干燥的不多。研制一种工作状态设备外壳静止、仓内单位容积换热面积大的筒仓，有利于降低设备制造总成本。     

炼油废白土在水泥厂燃煤自备电厂中再利用的实践

本项目主要研究和实现了工业废白土在BAYAH燃煤自备电厂中的再利用,实现变废为宝,减少了环境污染,同时为企业创造了一定的经济效益。针对废白土的特性,对燃料输送系统给煤机、皮带机、煤仓、下料溜子和排渣系统进行了改造。通过修改操作规程消除废白土对锅炉运行的影响。     

电子皮带秤测量误差的分析及改进

通过对电厂输煤系统皮带秤在使用过程中存在问题的分析,找出影响皮带秤计量准确度的多种原因,根据现场实际工况,提出具体的改进方案,并进行论证,阐明实物校验的方法是皮带秤量值溯源的可靠方法,选配了皮带秤的实物校验装置。方案实施后效果显著,运行良好。     

煤焦输送系统自动运转作业控制方法

针对宝钢焦化一期计算机皮带系统运转控制,在一定的优先算法下,选择最优化的连续输送方案,制定了动态生成运转作业计划,从而实现了计算机控制方式下的皮带系统运转机制。该软件的应用,既提高了皮带系统的输送效率,又保证了焦炉炼焦用煤的稳定。     

Prediction of screw conveyor performance using the Discrete Element Method (DEM)

Screw conveyors are used extensively in agriculture and industry for transporting and/or elevating bulk materials over short to medium distances. They are very effective conveying devices for dry particulate solids, giving good control over the throughput. Despite their apparent simplicity, the mechanics of the transportation action is very complex and designers have tended to rely heavily on empirical performance data. The performance of a screw conveyor is affected by the operating conditions, such as: the rotational speed of the screw; the inclination of the screw conveyor; and the volumetric fill level of the bulk material. In this paper we examine how these operating conditions influence the performance of a screw conveyor by applying the Discrete Element Method (DEM) to simulate a single-pitch screw conveyor with periodic boundary conditions. The DEM modelling gives predictions of screw conveyor performance in terms of variations of: particle speeds, mass flow rate, energy dissipation and power consumption, due to changes in the operating conditions.     

选煤厂煤泥干燥系统及设备优化

针对新型煤泥传导式间接干燥系统和设备在实际应用中出现的滑架断裂、螺旋给料机处理量小、干燥机和布料螺旋负荷过大、输送机衬板磨损等问题,通过技术分析,采取了平衡滑架受力、增加支撑、降低煤泥下料距离等措施,有效保障了该系统及设备运行的持续稳定。     

Analysis of Regime Transitions and Flow Instabilities in Vertical Conveying of Coarse Particles Using Different Solids Feeding Systems

The transition between dense and dilute flow in vertical conveying of Geldart D particles were investigated for risers of different diameters using a spouted bed as a solid feeding system. The transition and choking velocities were identified by combining analyses of pressure gradient versus air velocity diagrams, pressure fluctuation signals and voidage values. Experimental data were used to evaluate the effect of particle and riser diameters on the pressure gradient, mean mixture voidage, the regime transition and choking velocities. The transition velocity from dilute to dense phase could be identified, as well as the onset of the choking condition, which appeared as the air velocity was further reduced. Data obtained in the same experimental apparatus facility using a screw conveyor and a gravitational system as solid feeding devices have been used as a reference to be compared to those obtained using the spouted bed feeder.     

Influence of the Entrance Configuration on the Performance of a Non-Mechanical Solid Feeding Device for a Pneumatic Dryer

The solids feeder is an important component of a dryer, since it is responsible for introducing the moist material at controlled, specified rates. The purpose of this paper is to investigate the effects of solids feeding configuration on the fluid dynamic behavior of a 53-mm-diameter vertical pneumatic conveyor with a loop of 180°, aiming at further applications in drying granular materials. A non-mechanical solid feeding system constituted by a hopper connected to an inclined pipe was applied to feed type D particles in the conveying line. This simple feeding apparatus was modified through the insertion of different flow restriction devices at the air inlet, namely a reduction nozzle and a Venturi device. This was aimed at studying how the solids flow rates and the fluid dynamics of the whole conveying line are affected by the entrance configuration and inlet devices. The use of inlet devices combined with the non-mechanical inclined valve affected significantly the performance of the valve when operating with type D particles in a pneumatic conveying line. When using inlet devices, an increase in the conveyed solid flow rates at a given air velocity was observed. The reduction nozzle yielded a range of solids loading ratios similar to that of the inclined valve with no inlet device, and introduced some pressure instabilities at the entrance region. The Venturi device allowed operation at a wider range of solids loading ratios and no pressure instability was detected in the conveying line. For the conditions investigated, neither the gas velocity nor the loading ratio affected the extent of entrance length. The inlet devices may be successfully applied to modify and improve the performance of the inclined valve as a solids feeder in pneumatic dryers.