单喷颗粒镁与镁基复合喷吹铁水脱硫喷吹系统的区别

单喷颗粒镁脱硫和镁基铁水脱硫是最常见的铁水脱硫技术,由于各自铁水脱硫工艺过程的特点,其喷吹系统也存在区别。通过对单喷颗粒镁脱硫与镁基复合喷吹脱硫喷吹系统的比较,分析了单喷颗粒镁脱硫与镁基复合喷吹脱硫喷吹系统的主要区别和设计中需要注意的问题。     

钝化石灰在复合喷吹铁水脱硫工艺中的应用

对钝化石灰在复合喷吹铁水脱硫工艺中的脱硫机理及各阶段中的作用进行了分析,结合山西太钢不锈钢股份有限公司80 t复合喷吹铁水脱硫生产实践,得出复合喷吹脱硫工艺中的钝化石灰可以提高镁粉利用率和脱硫率,加强深脱硫能力,减少温降、回硫量和扒渣铁损,降低脱硫成本。以铁水初始硫质量分数0.02%~0.03%,终点硫质量分数小于0.003%为例,复合喷吹脱硫剂消耗比单喷颗粒镁降低了2.96元/t,扒渣铁损降低了1.08元/t,扒渣剂消耗减少了0.23元/t,合计降低了脱硫成本4.02元/t。     

单喷颗粒镁脱硫与镁基复合喷吹脱硫喷吹系统的区别

单喷颗粒镁脱硫和镁基铁水脱硫是最常见的铁水脱硫技术,对单喷颗粒镁脱硫与镁基复合喷吹脱硫喷吹系统进行了比较,主要区别在于:单喷镁脱硫系统要求的镁颗粒较大,球形度好,采用机械给料的方式精确给料,料罐容积小,利于实现设备的小型化,但是喷枪需要设置气化室,结构复杂;复合喷吹铁水脱硫通过调节动力学参数来调节镁粉喷吹速率。     

宣钢单喷颗粒镁铁水预处理技术的应用

介绍了单喷颗粒镁铁水预脱硫技术的优势,在正常的铁水条件下,宣钢采用单喷颗粒镁铁水预脱硫技术,镁粉喷吹速率平均4．5kg／min,可保证脱硫扒渣能力110万t／年,达到了规定的终点脱硫效果。     

300 t 铁水罐喷吹颗粒镁脱硫的生产实践

结合生产实践,从工艺技术角度介绍了在铁水罐中喷吹钝化颗粒镁脱硫反应的基本原理,并探讨了影响镁脱硫效率和脱硫效果的因素,以及该技术在武钢三炼钢应用一年多来,为防止品种钢转炉终点回硫而采取的各种有效措施所取得的显著效果.     

单喷颗粒镁脱硫工艺优化实践

介绍了承钢150 t铁水脱硫工艺概况,生产初期存在脱硫效率低、回硫严重等问题,不能满足大板坯以优质钢种为主的生产需求。通过在喷吹过程中顶加石灰、优化扒渣操作、改善脱硫反应的动力学条件等措施,改善了铁水包内铁水的搅拌效果,顶加的石灰将脱硫产物固定在顶渣中且稠化了脱硫终渣,扒渣效果得到有效改善,提高了钝化镁粒的有效利用率,有效防止了铁水回硫。镁粒的脱硫效率提高了24.2%,回硫率降低了32.2%。     

铁水罐喷吹颗粒镁高效化脱硫的研究

结合湘钢铁水罐喷吹颗粒镁脱硫的理论研究与生产实践,对喷吹颗粒镁脱硫工艺作了简要介绍;分析了脱硫量与耗镁量之间的关系、影响脱硫率的因素和颗粒镁脱硫成本;对铁水罐喷吹颗粒镁脱硫提出了一些建议。     

螺旋外导流槽式脱硫喷枪的数值模拟及应用研究

针对常规直通式单口喷枪喷吹金属颗粒镁铁水脱硫存在的脱硫反应动力学条件差的问题,提出了螺旋外导流槽式脱硫喷枪,并对其喷吹过程进行了数值模拟研究。通过对比发现,螺旋导流槽式脱硫喷枪能够有效提高气体对熔池的搅拌作用,同时减弱铁水喷溅。某钢厂250 t铁水罐的铁水金属颗粒直接喷吹脱硫工业性试验与应用表明,铁水喷溅与渣面金属镁蒸气逃逸燃烧明显降低,脱硫剂平均单耗降低6.0%,喷枪平均寿命达180炉/支,应用效果优良。     

插入深度与载气流量对铁水颗粒镁脱硫影响的数值模拟

在CFD软件平台上进行喷吹颗粒镁铁水脱硫数值模拟,通过改变喷枪插入深度、载气流量等参数,探究其对脱硫过程中铁水罐内流场以及混匀死区的影响。结果表明,在一定条件下,增大喷枪插入深度、适当降低载气流量均可改善喷吹颗粒镁的动力学条件,增强脱硫效果。     

提高单喷颗粒镁脱硫效率的工艺实践

介绍吉林建龙钢铁有限责任公司单喷颗粒镁脱硫站的工艺现状,并结合本厂的历史数据,从影响单喷颗粒镁脱硫的热力学、动力学及脱硫率的各种因素着手,通过优化颗粒镁的安息角、监督铁水成分及温度变化、优化脱硫渣组成等手段,可以将喷吹强度稳定控制在10 kg/min以上,钝化镁单耗控制在0.5 kg/t以内,脱硫站的处理周期缩短至30...     

论从实践理解世界的物质性和自然世界的先在性

马克思主义唯物论是一种物本主义形态的唯物论,还是一种超越物本主义形态、从实践理解世界的本质相关问题的实践的唯物主义的唯物论?这是一个我们必须搞清楚的有关马克思主义唯物论的本质规定性和精神实质的重大问题.在考察物本主义的唯物论及其思维方式的局限性的基础上,揭示了马克思主义唯物论是现代的、实践的唯物主义,并重点研讨了马克思主义唯物论关于从实践理解世界的物质性和自然世界的先在性的原理,以期为马克思主义唯物论进一步阐明人类世界的实践性原理奠定基础.     

Effect of cyproheptadine on the ultrastructure of the neurons of the arcuate nucleus in the hypothalamus of the rat

The data are presented on changes in the rat arcuate nuclear neuron ultrastructure after using cyproheptadine (peritol, Egyt Pharmaceutical Works, Hungary) in a water suspension at a dose of 20 mg/kg once daily during 7 successive days and twice a day within 10 days. It was shown that cyproheptadine decreases the functional activity of the arcuate nuclear neurons, depending on the total amount of the drug used. Cyproheptadine-induced inhibition of the forming neurohormone release from neurons is likely to be one of the mechanisms of its therapeutic effect in Itsenko-Cushing's disease.     

Characteristics of the sympathetic innervation of the nictitating membrane and of the vasculature of the nose and tongue of the cat

Vasomotor responses from the nasal mucosa and tongue, and contractions of the nictitating membrane, were recorded on stimulation of the cervical sympathetic or internal carotid nerves. Preganglionic sympathetic nerve fibres which elicited a membrane response possessed a lower threshold than those which evoked nasal vasoconstriction, while the latter displayed a lower threshold than fibres which evoked tongue vasoconstriction. The sympathetic vasodilator fibres to the tongue whose activity was revealed after alpha-receptor blockade, had a similar threshold to the vasoconstrictor fibres. Membrane contraction, nasal vasoconstriction and occasionally tongue vasoconstriction could be evoked by stimulating the internal carotid nerve. The postganglionic fibres innervating the nasal mucosa had a similar threshold to those of the nictitating membrane, which may indicate that there are small myelinated fibres innervating the mucosa. The preganglionic compound nerve action potential had four major components, S1-S4. S1, S2 and usually S3 fibres were associated with membrane contraction; S2, S3 and sometimes S1 fibres were associated with nasal vasoconstriction; and S3, usually S2 and occasionally S1 fibres were associated with vasoconstriction in the tongue. It is concluded that each of these three groups of nerve fibres, but not S4 fibres, may include fibres associated functionally with the three effectors. There was a considerable difference between the relative amplitude of the responses of the three effectors elicited by stimulation of the cervical sympathetic nerve at frequencies between 0.2 and 2 Hz. Vasoconstrictor responses were relatively larger than membrane contractions suggesting differences in the mechanisms of neurotransmission at the neuroeffector junctions.