交流变频调速在转炉煤气回收中的应用

在济钢第一炼钢厂转炉煤气回收加压站系统改造中，采用交流变频器对煤气加压机进行调速，控制煤气流量，实现了回收煤气与总管煤气并网，年节电效益19．35万元。     

煤气加压风机控制系统变频调速技术改造实践

分析煤气加压机的工艺流程特点,利用变频调速技术对煤气加压机的控制系统进行改造,充分发挥了变频技术的节电效果。     

煤气加压系统优化改造

由于历史原因导致莱钢小型区域煤气加压站存在设备分散及加压前煤气管道腐蚀严重的缺陷，分别采取了加压机移机改造和加压前焦炉煤气管道异地改造的措施，实现了加压机的统一管理，提高了设备运行的安全性。     

变频调速在焦炉煤气加压机控制系统中的应用

分析焦炉煤气加压的工艺流程特点，运用变频调速技术对焦炉煤气加压机运行控制系统进行改造，从而实现对煤气加压机与运转的自动调节，有效稳定焦炉煤气主管压力，保证安全运行，并且收到节约能源的效果。     

莱钢转炉煤气系统研究与优化

针对莱钢炼钢厂转炉煤气系统扩容后回收量增加带来的煤气含尘浓度高、煤气输出能力有限、管网系统设计不合理等问题,对系统进行了适应性优化设计,完成了转炉煤气自产自用、系统管网改造、煤气精除尘改造、煤气加压机升压改造,使吨钢煤气回收量达到60m3,煤气含尘量降至1 4mg/m3,年直接经济效益达1053万元。     

2008/435型煤气加压机润滑系统的改造

某公司动力厂的煤气站加压机是该厂的关键性设备之一。其作用是将煤气发生炉所产煤气加压，经管道输送至各用户使用，其状态直接影响煤气站的安全运行和用户生产。现投入运行的3台煤气加压机为2008/435型离心风机。转速为2980r/min，叶轮直径870mm，轴承座内有左右两个轴承盒，每个轴承盒内装有两套面对面安装的角接触球轴承，型号为7022ACM，轴承的润滑方式为油浴润滑。     

宣钢东区大小高炉煤气并网及控制的探讨

对宣钢东区大高炉(1260m~3)与小高炉((300m~3)煤气并网,使用微机、变频调速装置控制煤气,多余时进柜储存,不足时加压机自动运转抽取煤气柜的煤气送入管网,互补余缺,调节煤气供应与使用中的高峰及低谷做了探讨。     

轴端氮气密封在煤气加压机上的应用

在D400-13煤气加压机应用轴端氮气密封替代原迷宫式密封，以充分利用叶轮前后压差，消除轴向推力，减少机械磨擦，从而保证密封效果，改善风机性能，提高密封寿命。使用表明，改造后消除了煤气外泄现象，提高了设备开机率，年直接经济效益15．22万元。     

低频声波清灰装置在煤气加压机叶轮清灰中的应用

济钢高炉煤气经湿法除尘后煤气中部分粉尘附着于煤气加压机叶轮与机壳上,人工清理费时、费力,影响生产。为此,以氮气为气源,采用低频声波清灰装置可对加压机进行在线清灰,应用表明,加压机平均运行周期由30天延长至99天。     

离心式煤气加压机故障的分析与处理

针对新钢公司冷轧混合煤气加压站5台离心式转炉煤气加压机在运行过程中出现振动大的现状,从设备检修和运行方式调整方面采取一系列改造和优化,大大提高了加压机的运行时间,确保了岗位生产和运行安全,促进了新钢公司的节能降耗工作。     

集成PWM控制器在挤塑机上的使用

本文介绍了利用集成控制器SG1525组成PWM控制器在挤塑机上的使用,并分析介绍该系统的应用方式及技术特点.     

治理高炉炉底跑煤气的实践

分析了宣钢2#高炉炉底跑煤气的原因及特点,并采取了炉体压浆封堵技术进行了治理。在保证高炉炉体金属外壳无裂缝漏点的前提下,利用塑相密封理论,在炉体内壳处压入高炉塑性密封材料,完全充填炉皮与冷却壁间的空隙及煤气窜漏通道,有效治理了炉底跑煤气问题,保证了高炉的安全生产和炉缸的长寿。     

Effects of sample storage time, temperature and syringe type on blood gas tensions in samples with high oxygen partial pressures

BACKGROUND: Although plastic arterial sampling syringes are now commonly used, the effects of sample storage time and temperature on blood gas tensions are poorly described for samples with a high oxygen partial pressure (PaO2) taken with these high density polypropylene syringes. METHODS: Two ml samples of tonometered whole blood (PaO2 86.7 kPa, PaCO2 4.27 kPa) were placed in glass syringes and in three brands of plastic blood gas syringes. The syringes were placed either at room temperature or in iced water and blood gas analysis was performed at baseline and after 5, 10, 20, 40, 60, 90, and 120 minutes. RESULTS: In the first 10 minutes measured PaO2 in plastic syringes at room temperature fell by an average of 1.21 kPa/min; placing the sample on ice reduced the rate of PaO2 decline to 0.19 kPa/min. The rate of fall of PaO2 in glass at room temperature was 0.49 kPa/min. The changes in PaCO2 were less dramatic and at room temperature averaged increases of 0.47 kPa for plastic syringes and 0.71 kPa for glass syringes over the entire two hour period. These changes in gas tension for plastic syringes would lead to an overestimation of pulmonary shunt measured by the 100% oxygen technique of 0.6% for each minute left at room temperature before analysis. CONCLUSIONS: Glass syringes are superior to plastic syringes in preserving samples with a high PaO2, and prompt and adequate cooling of such samples is essential for accurate blood gas analysis.     

THE DISPLACEMENT OF GAS FROM POWDERS DURING COMPACTION

Abstract

A soap-bubble method was used to observe in detail the flow of gas out of powder masses during and immediately after compaction. The effects of powder material and size distribution, die size, pressing speed, and degree of compaction were investigated. The amount of gas trapped in the compact at completion of pressing varied from 12 to 83% of the initial amount of gas present in the spaces between the powder particles, over the range of compaction conditions studied. As expected, the amount trapped increased with increase in die size, with increase in pressing speed, and with decrease in particle size. Very little gas escaped during the later stages of compaction, even at slow pressing speeds. The effect of a small punch/die clearance was examined in typical cases, and shown to be minor, except with a coarse powder pressed at a high speed.

That trapped gas can produce cracks was demonstrated by making compacts containing varying amounts of trapped gas, other conditions remaining constant. With the particular powder used, once the amount of trapped gas had passed a certain level, the compacts tended to be fairly badly cracked. It appears, however, that cracks due to gas pressure alone tend to occur only when powders are rapidly compacted to very high densities.     

利用循环氨水清洗煤气初冷器工艺改进

在焦化生产过程中,煤气中的焦油、萘类物质在初冷器内的换热管上遇冷凝结,导致煤气通道变小,系统阻力升高,冷却效果变差。分析认为：高温氨水是清洗初冷器换热管间焦油类物质既经济又有效的介质。经过对煤气初冷器的清洗喷洒系统进行改造,增加了外送泵和液位观察槽,初冷器阻力由3～4 kPa降至1 kPa,提高了清洗效果。     

电弧炉底吹搅拌熔池表面突起高度的模拟研究

模拟实验测定了气体搅拌能、喷嘴孔径及孔数、液体深度对液体表面突起高度的影响，回归得到各因素间的关系式，并由此推算了电弧炉底吹的条件。     

蓄热式燃烧技术在韶钢三轧厂加热炉上的开发应用

韶关钢铁集团有限公司为了节能降耗、减少污染，充分利用自产的低热值高炉煤气，在国内首次用蓄热式燃烧技术在本轧厂线材在线加热炉应用成功后，又对三轧厂2＃开坯加热炉进行了改造，改造后取得了明显效果和良好的经济效益，本文阐述了此两座蓄热式加热炉的技术性能、系统结构和技术特点。     

High temperature deformation behavior and processing map of hot isostatically pressed Ti-47.5Al-2Cr-2Nb-0.2W-0.2B alloy using gas atomization powders

The hot compressive deformation behavior of hot isostatically pressed Ti-47.5Al-2Cr-2Nb-0.2W-0.2B al-loy using gas atomization powders was systematically investigated and the processing map was obtained in the temperature range of 1323-1473 K and strain rate range of 0.001-0.5 s-1 .The calculated activa-tion energy in the above variational ranges of temperature and strain rate possesses a low activation energy value of approximately 365.6 kJ/mol based on the constitutive relationship models developed with the Ar-rhenius-type constitutive model respectively considering the strain rate and deformation temperature.The hot working flow behavior during the deformation process was analyzed combined with the microstructural evolution.Meanwhile, the processing maps during the deformation process were established based on the dynamic material model and Prasad instability criterion under different deformation conditions.Finally, the optimal hot processing window of this alloy corresponding to the wide temperature range of 1353-1453 K and the low strain rate of 0.001-0.1 s-1 was obtained.     

提高罗泾转炉煤气回收综合措施

转炉煤气作为炼钢过程的副产品,是重要的二次能源和清洁能源,提高转炉煤气回收率是负能炼钢和降低工序能耗的重要环节,是一项重要节能减排工作。由于COREX-3000铁水成分波动,易造成转炉喷溅,影响转炉煤气的正常回收,因此,为了稳定煤气回收并减少高硅铁水冶炼的喷溅问题,研究了如何减缓化学反应速率和提高强脱碳期炉渣熔点,探索了高硅铁水冶炼模式和操作要领;同时,结合罗泾煤气回收生产实际经验,为减少铁水成分对煤气含量波动的影响,分时段控制煤气回收、优化了回收连锁条件,罗泾转炉煤气回收取得良好效果。     

唐钢高炉煤气高效利用生产实践

为降低能源成本,增加发电量,2010年唐钢炼铁厂北区新建1套25 MW发电机组和1座75 t/h锅炉。为满足新建锅炉高炉煤气用量的需要,系统分析了各工序高炉煤气的使用情况,针对高炉煤气使用过程中普遍存在的利用效率低的问题,提出改进措施,达到了高炉煤气的供需平衡,实现了预期目标。