Carbon type differentiation technique for diagnosing pulverised coal injection efficiency

Coal injection is a common practice for coke replacement in current blast furnace (BF) operations. The amount of coal that can be injected and successfully replace large coke is determined by the extent of coal gasification, which is a function of both the combustion environment in the tuyere/raceway region and combustibility of the injected coal. A new carbon type differentiation (CTD) technique was developed at CanmetENERGY for quantifying the amount of unburnt pulverised coal injection (PCI) residue that is carried in the furnace top gas for diagnosing the extent of injected coal gasification. This technique utilises the combustion characteristics of solid carbonaceous material generated during rapid pyrolysis and partial combustion of coal. The CTD technique developed was transferred to ArcelorMittal Dofasco and successfully implemented in the industrial environment. Using this technique, AM Dofasco established a PCI efficiency baseline for each of its three BFs, which will be used as a reference point for comparison in future trials. The capability of the CTD technique in diagnosing and understanding the effect of BF operating parameters on PCI burnout efficiency was demonstrated upon examining the effect of blast temperature decrease during a recent BF stove repair.     

高炉喷吹煤粉性能研究

提高高炉喷煤量对于降低炼铁焦比和成本有着重要影响。选择安钢高炉喷吹用煤煤源进行了可磨性、燃烧性实验。对安钢喷吹煤粉的物理特性以及煤粉粒度、富氧率、风温对燃烧率的影响进行了分析研究。     

无烟煤J在高炉喷吹的应用研究

主要分析了某无烟煤J的工艺性质及其在宝钢高炉喷吹应用的实践。该煤的灰分、硫分和挥发分较低,其燃烧特性优于常用的无烟煤A,低位热值与无烟煤A接近;其可磨性较低,需与可磨性好的喷吹煤混合制粉才能满足高煤比制粉要求。从工艺性质分析看,该煤可部分替代无烟煤A在高炉中的使用。在高炉喷吹实践中配入该煤后,高炉各项操业指标表现良好,具有较高的理论置换比,可有效替代焦炭的部分作用。     

高煤比条件下高炉风口前现象的取样研究

阐述了宝钢应用风口取样技术,对高炉在高煤比冶炼条件下风口前现象、焦炭劣化、煤粉燃烧、炉芯透液性等重要问题的研究成果.这些结果对监控焦炭质量、指导炼焦配煤、提高喷煤效果、延长炉缸寿命具有重要意义和技术价值.     

Research on Utilization Factor of Injected Pulverized Coal into BF at Large PCI Rate

The carbon mass fraction of blast furnace (BF) dust (gravitational dust and sludge) was determined under normal production conditions in industrial tests. The mass fraction of unconsumed coal and coke particles in BF dust at different PCI rates was obtained based on microscopic and chemical analysis. A relationship between PCI rate and mass fraction of unconsumed coal in BF dust was derived. The amount of unconsumed coal and coke particles in BF dust at different PCI rates was obtained. The utilization factor of injected pulverized coal into BF was determined under different PCI rates at Baosteel. This result provides a necessary analysis method at large PCI rate in BF.     

韶钢750 m3高炉喷煤系统技术进步

韶钢750m^3高炉喷煤系统采用了自动配煤、中速磨制粉、低压长袋收粉器收粉、浓相输送等国内先进技术．喷煤系统投产后，高炉煤比达到了150kg／t以上，入炉焦比降到400kg／t以下，取得了良好的经济效益．     

高炉大量喷吹煤粉的探讨

通过煤粉燃烧研究成果和喷煤实践的分析得出如下初步认识：煤粉在高炉风口区燃烧过程与一般工业炉不同，因风速高，煤粉停留时间短，煤粉在风口前端很难达到较高燃烧率；氧煤枪对延长煤粉停留时间的作用有限，据国内外多数大喷煤量高炉的实践，２００ｋｇ／ｔ以下喷煤量不一定要使用氧煤枪，风口未燃煤粉并不可怕，因其气化率比焦炭高若干倍，能优于焦炭参加还原反应，有利于改善矿石高温性能，减少焦炭粉化和高炉顺行，粒煤具有节约     

A Modified Model for Calculating Theoretical Flame Temperature in Blast Furnace and Its Application

The theoretical flame temperature(TFT)before tuyere,always highly concerned by blast furnace(BF)operators,is one of the most important parameters for evaluating the thermal state of hearth.However,some influencing parameters,for example,the SiO2 reduction by carbon,were always neglected or inaccurate when calculating the TFT.According to the definition of TFT,the temperature of coke into raceway and the reduction rate of SiO2 in ash of coke and pulverized coal were obtained by analyzing the samples before tuyere in blast furnace.Taking full account of different factors,a modified model for calculating the TFT in blast furnace was established.The effects of the oxygen enrichment rate,the reduction rate of SiO2 in raceway,the ash content in coke and pulverized coal and the pulverized coal injection(PCI)rate on TFT were determined quantitatively.The modified model was applied to selecting the used coal for PCI in blast furnace.Considering the different SiO2 contents of mixed coal,the calculated TFT remained a stable level.This showed that the selected coal could be suitable for PCI in blast furnace.     

3D model study of coal/coke combustion in a blast furnace effects of coal properties

A three-dimensional mathematical model of the combustion of pulverized coal and coke has been developed.The model is applied to the blowpipe-tuyere-raceway-coke bed region in an ironmaking blast furnace in one computational domain,which includes two parts:pulverized coal combustion model in the blowpipe-tuyere-raceway cavity and the coal/coke combustion model in the surrounding coke bed.The effects of coal properties are examined comprehensively,in terms of coal burnout and gas species distributions.The ...     

Influence of conveyance methods for pulverised coal injection in a blast furnace

Pulverised coal injection (PCI) is a widely adopted industry practice for reducing blast furnace coke rates. The conditions under which pulverised coal (PC) is injected and combusted, including the co-injection of natural gas (NG), can lead to complex combustion phenomena inside the blast furnace, which must be understood to provide improved furnace performance. This research examines computational simulations of the co-injection phenomena, as well as the industrial drivers behind the project. A wide-ranging parametric study was conducted utilising numerous variations in furnace operating conditions, as well as a new technique for the conveyance of PC. It was found that utilising NG as the carrier gas for PCI could increase coal burnout across the raceway region from about 71% to approximately 87% without altering the design of the tuyere/blowpipe region, with an increase to 96% possible if a shift to a dual lance design for NG injection is considered.     

基于T-S模型的高炉喷煤协同优化控制策略研究

高炉炼铁过程通过增煤减焦实现节能减排目标,针对人工操作模式存在主观性、粗糙性和滞后性难以实现增煤减焦的问题,采用上下协同优化控制方法,一方面通过上部提前匹配减焦方式维持高温区热平衡,另一方面通过富氧鼓风保证下部喷入煤粉的高消化率,使煤粉在风口回旋区充分燃烧.进而从控制角度解析描述增煤减焦过程,将铁水温度的稳定控制问题转...     

Measures to dealwith low strength coke for Basteel's 2500 m~3 BF

The production indexes were deteriorated due to quality coke,Utilization Factor 2.0 t/m~3·d,PCI 100 kg/T,According to Analysis the Mechanism of Production of low hot strength coke quality on Blast Furnace Smooth,The coke cold strength retained M_(10)<6.3 over a long period of time in order to insure coke granularity and permeability index in cohesive zone;A_(ad)<12 and granularity tranquilization is useful BF production.The PCI protect coke hot strength by high rate bituminous coals;high rate H_2 in BF g...     

高炉下部气固湍流和煤粉燃烧的数值模拟与优化研究

高炉喷吹煤粉时,由于煤粉的不完全燃烧,在回旋区处会产生未燃煤粉,影响高炉的透气性。建立了气固两相湍流和煤粉燃烧的三维数学模型,并且验证了该模型的可靠性。用所建模型对由直吹管、风口、回旋区和焦炭床构成的高炉下部区域进行了喷吹煤粉流动与燃烧现象的模拟研究。模拟结果揭示了高炉炉内气固流动和煤粉燃烧的基本性质和特点;通过正交试验方法研究不同操作因素对评价指标煤粉燃尽率的影响,得到4个操作因素对燃尽率的影响程度依次分别为喷煤量、富氧率、鼓风量和鼓风温度。而工况(喷煤量1 25kg/t,鼓风量1 950m3/min,鼓风温度1 523K,富氧率5.0%)为最佳优化工况,可实现提高喷煤量和煤粉燃尽率的效果。     

高炉高煤比操作的实践

从理论上解析了宝钢高煤比操作的实践成果。实践表明：在1．5％左右较低的鼓风富氧率下煤比可达到200kg／t以上,煤比165kg／t以下可以不富氧;煤比超过200kg／t时焦炭劣化加剧,高炉透气性明显下降,高煤比操作需要高质量原燃料特别是高热强度的焦炭作支撑,要更加重视焦炭在炉内粉化状况和焦炭热性能指标（CRI、CSR）的跟踪分析;宝钢根据自己的操作理念控制气流合理分布,增强了大喷煤的接受能力和炉况稳定性,从而实现长期高煤比操作。     

莱钢1~#1 880m~3高炉炉况长期稳定顺行生产实践

莱钢1#1880m3高炉自投产以来,经不断探索和完善炉内操作,加强原燃料管理和基础管理,确保了高炉长期稳定顺行。通过保证炉缸均匀活跃,控制合理的煤气流分布、合理的理论燃烧温度、合理的焦批,实施低硅冶炼,适当提高炉渣碱度等,建立了完善的炉内操作制度;通过控制原燃料质量、确保布料精确等,严把原燃料入炉关;通过加强设备管理、炉前出铁管理等,强化基础管理。高炉取得了良好的技术经济指标,煤比168 kg/t,焦比355 kg/t,燃料比523 kg/t。     

安钢7~#高炉喷煤节焦生产实践

介绍了安钢7#高炉喷煤节焦的生产实践情况。通过优化喷煤工艺、改善原燃料质量、优化高炉操作、加强炉外管理等措施,取得了煤比180kg/t、综合焦比500kg/t的好指标。     

高炉喷吹石油焦的可行性研究

选用石油焦替代部分高炉喷吹用煤,并通过对其着火点、反应性、燃烧性能、可磨性及输送性能的系统研究发现,高炉喷吹石油焦可改善煤粉的燃烧性能、降低能耗。综合考虑输送性能及高炉所能承受的硫负荷,高炉喷吹石油焦的配比不宜过高。     

武钢高炉经济性喷煤研究

为了使武钢高炉达到经济性喷煤的目标,通过煤资源调查,掌握了适合武钢喷吹用煤的煤源情况;通过对高炉大煤比条件下的风口理论燃烧温度进行计算,分析了影响高炉喷煤的主要因素;通过对武钢高炉炉尘中的残碳量及其来源进行分析,发现目前操作条件下炉尘中源自煤粉的碳量占总碳量的10%左右,此结果已用于研究未燃煤粉在炉内的利用状况及评估高炉喷吹煤粉的燃烧情况;通过对高炉操作指标进行统计分析,发现煤比在160~170 kg/t时,高炉燃料比较低。实践结果表明,上述经济性喷煤技术在5号高炉应用后,在煤比仅略增加0.8 kg/t的情况下,焦比降低了9.7 kg/t。     

邯钢东区3200mm~3高炉无计划停煤操作实践

邯钢3200 m3高炉因突发事故无计划停煤长达8 h,通过快速变停煤焦比、合理控制各项参数,协调理论燃烧温度与炉温的关系,避免了炉况与炉温的大幅度波动。     

高炉理论燃烧温度计算的研究

 理论燃烧温度是判断高炉炉缸热状态的重要参数之一。 在深入分析现有理论燃烧温度计算模型存在问题的基础上,提出修正建议 ：绝热系统内除煤气之外还应包括燃料燃烧后的残留物及未燃煤粉;所有物质的比热容应是温度的函数;焦炭的温度应为高温区热平衡计算所得;同时,考察了这些修正因素对理论燃烧温度计算值的影响。