Latest developments for dry and wet dedusting systems for converter steel making

Environmental requirements world wide and in the P.R.of China in particular have increased and authorities are increasing the pressure on steelmakers to comply with always more stringent limits and standards. Modern converter steel making goes along with the innovation and new developments not only for the primary converter process itself but even more for the dedusting technologies.This paper describes the benefits and latest development of advanced off gas cleaning and recovery systems based on dry type cleaning with electrostatic precipitation and wet type gas cleaning based on wet scrubbers.Modern converter dedusting is based on suppressed combustion systems in order to reduce off gas amounts and to be able to use the gas for gas recovery.The dry type primary off gas treatment system based on electrostatic precipitator technology is the most advanced environmental solution available for converter steel making.Dry dedusting has been introduced in China successfully with a significant contribution by Siemens VAI being the market leader for converter dry dedusting systems.Siemens VAI has introduced several design improvements over the last years such as CFD modeling of flow conditions in evaporation cooler,design of chains for dust conveyors,design of ESP inlet,design and thickness of discharge electrodes and operation in energy saving mode.Additionally the DDS process has been successfully implemented in China for the De-P process.The gas recovery system for DDS has been optimized over the years with high quality equipment and integrated automation and control systems.Wet type dedusting for converter gas is a well proven technology for many years and is still widely used due to the simplicity of the process and the lower investment costs.SVAI has continuously improved it's wet dedusting technologies to provide highly energy efficient systems which can achieve lowest levels of clean gas dust while still maintaining a moderate water and energy consumption with simplified process control and standardized process control packages.Main design and process improvements include expansion joints for connection of scrubber to cooling stack,new type of droplet separator,advanced hood pressure control package,ID fan washing system,ID fan speed control system etc.The focus for wet type gas recovery systems is still on maximum safety and reliability.SVAI has also successfully improved the technological packages for converter gas recovery for wet type dedusting systems.The comparison between the two system shows the advantages of dry dedusting mainly being the lowest clean gas dust content, lower operating costs,easier handling for recycling of residuals and no need for a water treatment plants.Wet type dedusting has it's main advantages in the simple process and operation of the system,the flexible layout solutions inside the steel shop as well as generally lower investment costs.An overview on the numerous reference installations for dry- and wet type dedusting systems in China as well as world wide is given.

Experimental Study and Analysis on Performance and Dedusting Efficiency of Frothing Generator

By simulating test and study in laboratory, the structure and performance offrothing generator were determined. The relative curves between the frothing volume and gas velocityof foaming net, supplying liquid volume and the content of foaming agent were obtainedrespectively. There were an optimum gas-velocity of foaming net, an optimum supplying liquid volumeand an optimum content of foaming agent under the condition of the given material quality and shapeof foaming net and spraying form. The spraying froth is of a great assistance in collectingrespirable dust.

Clean and efficient-optimization of EAF dedusting systems

Most of the electric arc furnace(EAF) dedusting systems installed worldwide have been designed and built with the mere intention to comply with certain environmental regulations and limiting values for a determined process and production capacity- and this usually works as long as those variables are fix.But reality shows thatever since the recent financial crisis- steel producers are perpetually forced to adapt their steelmaking process in order to meet the requirements of the market and properly react to its fluctuations(e.g.by flexible use of input materials).Many installed dedusting systems cannot live up to this challenge.Badische Stahl-Engineering GmbH (BSE) optimizes dedusting systems to meet various process requirements and thus increase the overall productivity and cost efficiency- along with the strict compliance with all environmental standards and local legislations.This paper further describes the basic considerations to be taken and the BSE approach to deal with these challenges, emphasizing it by examples of our latest projects world wide.

The Application of Cold Banding Technology for Dust Removed From BOF Gas Using Dry Dedusting Technology

Firstly, physical and chemical properties of dust removed from BOF gas are analyzed, and then the cold banding technology of dust removed from BOF gas and its application are introduced. Tests have proved that using cooled agglomerated pellets made of the dust removed from BOF gas and small amounts of modified starch as a coolant and slagging agent in steel production can bring about considerable economic, social and environmental benefits.

Research and application of inertia-gravity dedusting and noise reduction technology in mine airshaft outlet

Massive dust of exhausted airflow easily diffuses to the industrial square while hoisting shaft is used as return shaft in the retrograde ventilation,and certainly there is a problem of dust scattering and noise exceeding standard. In order to solve the problem,the coupled technology of dedusting and noise reduction in airshaft outlet was investigated and the device with the function of Dedusting and noise Reduction(DR) was originated. The device is named as DR diffuser,which comprehensively utilizes mechanisms of inertia-gravity dedusting and absorption-insulation sound. The DR diffuser has been applied to Xingdong Coal Mine,and the testing results show that:a. the resistance of DR diffuser is lower than 60 Pa;b. the noise level reaches to 49.2 dB(A);c. the dedusting efficiency of above 50 μm is higher than 85 %;d. dynamic pressure recovered from the outlet of main fan is larger than 50 Pa. The above measured data illustrates that comprehensive benefit of the DR diffuser is good,and the device is worth of applying to engineering site.

宝钢股份高炉煤气干法除尘与湿法除尘的选择

对高炉煤气除尘系统是选择干法除尘还是湿法除尘进行了探讨。以宝钢股份高炉煤气干法除尘与湿法除尘运行数据为基础,重点分析比较了煤气干法除尘与湿法除尘的TRT发电量及发电效率,提出了煤气干法除尘TRT发电效率低于湿法除尘的新观点。认为,传统观念中煤气干法除尘的发电量比湿法除尘增加30%,是建立在炉顶温度适宜,且TRT发电效率保持湿法除尘水平的基础上;宝钢股份高炉的运行数据表明,与煤气湿法除尘相比,干法除尘TRT电能转化效率低,同等条件下的发电量仅增加15.9%,而TRT发电效率低9.33%。

基于CPFD方法的生物质燃气旋风分离陶瓷膜一体化除尘器仿真

为缩短高温燃气除尘工艺,提高除尘效率,提出了一种耦合复合陶瓷膜组的一体化旋风除尘器。在温度为573 K的条件下对陶瓷膜的流动阻力进行了实验研究,考察了流量和压力对单个陶瓷膜过膜压降的影响,得到过膜压降与流速之间的关系式,基于计算颗粒流体力学(CPFD)方法模拟了除尘器内部的气固两相流动特性,探讨了生物质燃气除尘过程中内部颗粒的分布规律、速度和停留时间,探究了复合陶瓷膜组对除尘器压降和效率的影响。结果表明:在入口温度为573 K、压力为111325 Pa、进口气体积流量为7909 m^(3)/h的条件下,较之无陶瓷膜组的除尘器,一体化除尘器内部粉尘颗粒的停留时间更长,其对粉尘颗粒捕集效率更高,颗粒聚集性能更好,除尘效率从91.2%提升至99.7%,然而总体压降增大了78 Pa。

南美某钢厂100t电炉除尘系统改造案例分析

相比于转炉炼钢而言,电炉炼钢具备较大的灵活性,或将成为未来发展的趋势。分析南美某钢厂100t电炉的除尘改造案例,对比国内外电炉除尘系统的差异,为工程化应用提供参考。采用炉内排烟(一次烟气)、导流板与屋顶罩相结合的烟气捕集方式,一次烟气通过绝热烟道进入水雾急冷塔,出来后与屋顶罩烟气混合降温并进入布袋除尘器净化。除尘系统的处理风量为220万m^(3)/h,净化后的颗粒物排放浓度控制在≤20 mg/m^(3)(标准),二英排放浓度控制在≤0.2ng-TEQ/m^(3)。改造完成后明显改善了作业场所的卫生条件且满足大气污染排放要求。

大型转炉烟气超净处理及回收装备技术

概述了我国钢铁工业为实现“双碳”目标而研发的大型转炉炼钢烟气超净处理及其资源回收利用装备系统。针对大型转炉炼钢过程中产生的大量废气和固体废物问题,中国重型机械研究院股份公司研制了超大型圆筒形电除尘装备、多功能智能型喷雾除尘冷却器、定频泵恒压供水技术、煤气柔性精细调节设备以及智能化控制模型等多项关键技术。这些技术的应用显著提高了除尘效率,降低了能耗,并确保了烟气的超低排放,同时实现了高品质资源的循环利用。大型转炉烟气超净处理及回收整体技术达到国际先进水平,为我国钢铁行业的绿色低碳转型提供了重要支撑。

酒钢选矿厂含铁除尘灰资源化利用研究

以酒钢选矿厂含铁除尘灰为研究对象,研究环境除尘灰和烟气除尘灰的选矿技术经济指标,进行除尘灰用于水泥生产物料性质测试,分析用作铁质校正剂的可行性。通过不同应用途径的可行性和经济性分析,为选矿厂合理处置除尘灰提供了依据。

转炉一次湿法除尘遗留问题治理

针对转炉一次湿法除尘升级改造后存在的风机转速波动、放散塔冒烟及溢流水箱安全隐患等问题,分析了问题产生的原因,采取了加强排水能力,调整环缝开度及压差并取消溢流水箱的措施,实现了风机稳定运行,烟尘排放指标减低到30 mg/m3以内,提高了转炉一次湿法除尘效果,保证了生产的安全稳定运行。

转炉除尘水质优化实践

对马钢长材事业部转炉除尘水硬度高、悬浮物多、粗颗粒分离差导致的除尘水恶化问题进行分析,通过粗颗粒分离机与优化药剂处理的实践运用,优化了转炉除尘水质,提升了运行效果。

双巷干式除尘成套装置研制及试验研究

针对双巷掘进工艺特点,研制了以高负压矿用干式除尘器、除尘风筒联动三叉、除尘风筒气动伸缩装置等组成的双巷干式除尘成套装置。构建试验装置,对干式除尘器除尘效率、配套90 m风筒后的吸风量、模拟井下供风条件对巷道综合除尘效果进行了模拟试验,并在煤矿井下进行了使用。对干式除尘器主机进行高负压设计,采用3级对旋风机,相比传统2级对旋风机,除尘吸风量提高40%,压力提升45%;除尘风筒三叉采用风门联动控制,避免了人为操作失误的可能;采用除尘风筒气动伸缩装置,可实现除尘风筒随连采机作业自动伸缩,在截割粉尘源头进行吸尘,提高掘进面除尘效果。

防风抑尘网减风抑尘效果数值模拟研究

依托洋浦港三期散货码头工程,对35个堆垛的防风(抑尘)网各布置方案进行数值模拟,计算其在布置防风(抑尘)网前后堆场的起尘量、敏感点的TSP浓度值及降尘量,并通过比选推荐出经济、合理的防风(抑尘)网布置方案。通过数值模拟表明,防风(抑尘)网的减风效果与网高的设置有关,防风(抑尘)网的抑尘效果与布置有关。本项目的建设和研究成果可供国内同类港口工程借鉴,对我国环保事业的发展起到推动作用。

袋式除尘系统的节能措施

分析袋式除尘系统各环节对系统能耗的影响,提出节能措施。

干熄焦检修技术的创新与实践

随着干熄焦在焦化企业的快速推广,延长干熄焦系统的使用寿命、快速维护,将使其具有更加广泛的市场。金牛天铁煤焦化有限公司通过对干熄焦系统运行过程中在线检修技术的创新与实践,保证了生产安全运行,达到了延长干熄焦系统使用寿命的效果。

矿用摄像仪智能自清洁系统的研究与应用

针对综采工作面现有摄像仪球罩容易附着煤尘或煤泥,影响视频监控的效果、且需要人工擦拭的问题,提出了采用具有疏水涂层的聚碳酸酯光学球罩,通过在现有的摄像仪壳体上增加喷水自清洁装置,自清洁装置连接支架喷雾系统,由自清洁装置对摄像仪球罩进行除尘清洁,开发出可以通过地面监控中心进行远程控制的摄像仪自清洁系统,并在煤矿井下进行了工业性试验。经验证,摄像仪自清洁系统满足现场需求,极大地节省了人力,解决了综采工作面摄像仪“看得见”、“看得清”的问题,为实现智能化无人开采奠定了基础。

拦焦车集尘除尘装置的研究及应用

在煤化工中,炼焦作为污染较严重的活动,需要借助有效的集尘、除尘装置,控制生产中的烟尘污染,保证煤化工过程的绿色性。基于此,介绍了焦炉及拦焦车的基本情况及要求,并提出集尘除尘装置的设计依据及运行指标。对集尘装置的主要装置(U型管和水封式集尘干管)进行结构、功能的分析,对除尘系统的主要装置(除尘风机、脉冲喷吹袋式除尘器)进行结构、特点的研究。对拦焦车集尘、除尘装置的效果进行验证,其烟尘的捕集效率至99%,可有效控制烟尘的污染。

大柳塔三盘区露天矿煤尘旋风除尘特性的数值模拟研究

露天煤矿的生产中会产生大量的煤尘,为研究煤尘在旋风除尘设备中的运动规律,使用数值模拟的方法进行研究。研究结果表明,随着入口气流速度的增加,高压区域的压力在增加,整个高压场的分布在下移,高压区域的面积在增加。从旋风除尘设备的下部到上部,都存在着1个条形的压力条带,随着入口气流速度的增加,“摆尾状”的摆动更加明显,呈现明显的S型曲线。随着入口气流速度的增加,内部的颗粒群条带在变宽,且颗粒群条带和除尘设备内部壁面第一次接触的拐点在上移,颗粒群的条带更加清晰可视,螺旋运动的螺距在减小。

除尘脱硝一体化滤料的制备及其性能研究

以硝酸铈、偏钒酸铵等为主要原料,通过加热搅拌混合制备催化剂前驱体浆料,并采用表面浸渍法将浆料负载到基材滤料,通过压延、干燥、煅烧形成除尘脱硝一体化滤料。研究了浸渍方式、过滤风速和负载量对除尘脱硝效率的影响,并验证了滤料的催化剂稳定性、耐磨性能和抗水、抗硫、抗碱、中毒性能。通过SEM、XRD表征分析,结果表明:在二步浸渍法负载滤料负载量为352 g/m2,过滤风速为0.4 m/min时,在160℃~220℃温度区间内,脱硝效率为60%~95%,0.6 MPa的喷吹压力下,表面催化剂损失率仅1.1%。滤料的耐磨性能和过滤性能优于常规滤料(在1μm粉尘粒径过滤下,过滤效率可达99.87%),具备良好的抗水、抗硫、抗碱金属性能。