关于降低本钢氧气放散率的探讨

介绍了国内特大型钢铁企业近年来氧气放散率情况及本钢氧气放散的经济损失。阐述了本钢氧气放散率高的原因，指出了降低氧气放散应采取的措施。     

浅析降低氧气放散率方法与措施

阐述节能降耗的重要意义,并以本钢氧气厂为例,重点分析造成氧气放散率较高的原因以及降低放散率的可行性方法和措施。     

宝钢氧气系统的现状分析及对策

简要介绍宝钢氧气系统的基本情况,详细地分析了氧气供需平衡关系,找到了宝钢氧气放散率偏高的主要原因,提出了降低氧气放散率的主要对策。     

昆钢氧气供需平衡和动态调整

分析了集团公司氧气供需关系供大于求及造成氧气放散理大的各种因素，阐述了实施氧气供需平衡和动态调整以降低氧气放散率的措施。     

降低氧气放散率的研究和实施简

利用系统资源,根据邯钢铁钢生产以及制氧生产的现状,分析研究了降低氧气放散率的手段,解决了氧气放散率高的问题。     

高炉休风时供氧管网压力对氧气调度的影响

以国内某大型钢铁企业空分厂为研究对象,基于混合整数线性规划方法建立以氧气放散量最小为目标的生产调度模型,并在此基础上以高炉休风期间的氧气生产调度为案例,分析了高炉开始休风期间管网初始压力对氧气放散率的影响.高压管网初始压力大于临界值时,系统出现氧气放散,放散率随初始压力上升呈近线性增大关系,高压管网缓冲容量越大,该线性关系斜率越大.有氧气放散的情况下,对于同一高压管网初始压力,高压管网缓冲容量越大,系统放散率越小.该趋势随着高压管网初始压力增大变得越来越不明显,当初始压力等于最高压力时,高压管网缓冲容量的大小对放散率没有影响.      

宝钢股份公司降低氧气放散率的实践

介绍了宝钢股份公司降低氧气放散率的实践,分析和讨论了利用液化装置控制氧气放散,优化生产组织,强化管理等手段实现氧气零放散的方法。     

宝钢制氧采用优化系统的探讨

目前国内钢铁企业普遍存在着氧气放散率较高的问题，造成大量的能源浪费。根据对宝钢制氧系统的分析研究，提出了降低氧气放散率，采用制氧优化系统的设想。     

大型有色冶金用氧技术优化研究及应用

针对大型有色冶金用氧放散率高的问题,提出氧气供应网络化解决方案,并在网络化供应平台的基础上,通过采用“梯级”减压智能匹配控制技术、氧气生产“自动巡航”控制系统等软件优化控制系统,使氧气放散率进一步降低,获得了良好的经济效益。     

降低氧气放散率生产实践

针对氧气生产中放散率高的问题,天铁集团动力厂充分利用现有的设备和资源,通过采取增设3#调压站、原空分系统与新建空分系统管道联网以及铺设液体真空管道提取液体产品等措施,完善了供氧系统,实现了氧气的灵活调配供应,达到了回收富裕氧气、降低氧气放散率的目的.     

Studies on the mechanical resistance of human erythrocytes under in-vitro conditions

Hemolysis and resistance of erythrocytes were studies in-vitro in experiments on human ACD fresh blood and on heparinized fresh blood after oxygen dispersion, resp. mixed oxygen and carbon dioxide dispersion, and subsequent treatment in the hemoresistometer. Blood alkalinity increases under oxygen dispersion, acidity increases under dispersion with mixed gases. The length of the period of dispersion is more important for hemolysis than the change of pH. The hematocrit value influences the behavior of blood resistance. High values imply enhanced hemolysis. There is no significant difference of actual hemolysis values between oxygen and oxygen/carbon dioxide dispersion. A different behavior appears in the calculation of difference value of hemolysis after treatment in resistometer and the respective actual hemolysis.     

Algal plastid genomes encode homologues of the SRP-associated RNA

To measure the transcorneal dispersion of oxygen into the anterior chamber, dynamic T1-weighted fast-spin-echo MRI (TR=2 seconds, TE=15 msec, 5-mm slice) of the human eye was performed both before and during oxygen supply to a full goggle placed on the face. During the course of the imaging, a significant increase in the signals in the anterior chamber occurred. This indicated that transcorneal dispersion of oxygen into the anterior chamber can be evaluated by this procedure, suggesting that this method may be useful for diagnosing dysfunction of the cornea or aqueous flow.     

Translucence stereoscopy of interictal magnetoencephalographic epileptiform discharge

BACKGROUND: Exercise training is being promoted increasingly for patients with chronic obstructive pulmonary disease (COPD). Many of these patients experience exercise related arterial desaturation but the clinical importance of these hypoxaemic episodes is not known. QTc dispersion is a marker of myocardial repolarisation abnormalities and there has been much interest in its role as a non-invasive predictor of cardiac arrhythmias and sudden death. However, little is known about the dynamic effects that exercise and hypoxaemia have on QTc dispersion in patients with COPD. METHODS: 20 patients with severe COPD (FEV1 < 40% predicted) undertook two 15 minute treadmill tests at a speed calculated to produce a constant workload of 50% maximum oxygen consumption (VO2max) during which they were blindly given either air or 35% oxygen in random order. Physiological measurements taken throughout exercise included 12 lead electrocardiograms from which QTc dispersion values were calculated according to standard criteria. Nine of the patients who desaturated with exercise were studied further. A similar degree of hypoxaemia was induced at rest by giving them a titrated mixture of air and oxygen and the changes in QTc dispersion were recorded. RESULTS: 11 of the 20 patients developed significant hypoxaemia (desaturation by > or = 5% to < 90%) with exercise breathing air. There were no significant changes in QTc dispersion with either exercise or hypoxaemia. There were no significant changes in QTc dispersion when comparing those who did and did not desaturate, and those with and without a high baseline QTc dispersion values (60 ms). Induced hypoxaemia without exercise also failed to worsen QTc dispersion. CONCLUSIONS: No evidence was found to suggest that exercise, even when associated with hypoxaemia, causes myocardial repolarisation abnormalities in patients with COPD.     

Elemental Composition of the Powder Particles Produced by Electric Discharge Dispersion of the Wastes of a VK8 Hard Alloy

The powder fabricated by electric discharge dispersion of the wastes of a VK8 hard alloy is studied by electron-probe microanalysis. This powder formed by electric discharge dispersion in kerosene mainly contains tungsten and carbon and has low contents of oxygen, cobalt, and iron.     

Oxygen Sag Models for Multiorder Biochemical Oxygen Demand Reactions

The empirical biochemical oxygen demand (BOD) equation is expressed as a multiorder reaction equation of order n, then is combined with the dissolved oxygen mass balance equation to give the differential form of an oxygen sag equation for small rivers and streams for which dispersion can be neglected. The value of n in the BOD reaction is restricted to values that are larger than one (first order). The dissolved oxygen sag equation is verified with two published dissolved oxygen sag models by setting n equal to 3/2 (three-halves order BOD reaction), and n equal to 2 (second order BOD reaction). The proposed dissolved oxygen sag equation may be applied to test the BOD and dissolved oxygen models in large, complex numerical models, such as models used in developing total maximum daily load recommendations. Examples show how the BOD reaction order affects the dissolved oxygen sag characteristics of a river.     

Double-pass measurements of retinal image quality in monofocal contact lens wearers

To evaluate the oxygen transporting capability of Hemoglobin vesicles (HbV) the physiological responses to 40% and 90% exchange transfusions with HbV in anesthetized rat were observed. Hb concentration of HbV dispersions is 10 g/dL. HbV dispersed in phosphate buffered saline and HbV dispersed in 5% albumin solution were used as samples for 40% and 90% exchange transfusions, respectively. HbV surface-modified with polyoxyethylene (HbV-Poe) was also used in the 90% exchange transfusion. As controls, phosphate buffered saline, 5% albumin solution, and HbV containing methemoglobin and therefore deprived of oxygen transporting capabilities (metHbV) were administered as non-oxygen carrying fluids and washed rat red blood cells (ratRBC) as an oxygen carrying fluid. Measurements included mean arterial pressure, arterial blood gas analyses, aortic blood flow and renal cortical tissue oxygen tension. At the completion of the exchange transfusion renal cortical tissue oxygen tensions along with oxygen delivery and consumption were sustained almost equally well with the HbV dispersion compared to the washed rat red blood cell dispersion, but declined significantly in the phosphate buffered saline and albumin solutions. These results indicated that the oxygen transporting capability of HbV was almost equivalent to that of rat red blood cells. In the HbV-Poe group, aortic blood flow was sustained higher in comparison to the HbV group. As for the blood gas parameters, pH and venous oxygen tensions in the HbV-Poe group tended to be higher than those in the HbV group.     

Determination of oxygen species in mechanically alloyed oxide dispersion strengthened copper

Abstract

The oxygen content in the process of the production of oxide dispersion strengthened copper by mechanical alloying was traced by carrier gas-hot extraction. First, the usual determination of the total oxygen content was carried out. Second, the analytical method was checked and modified with respect to the selection and detection of different oxygen species in the sample. Applying this analytical approach the relevance of various technological treatments (milling, heat treatment) on the oxygen concentration was evaluated.     

Design Model for COD Removal in Constructed Wetlands Based on Biofilm Activity

Current design criteria for free-water-surface constructed wetlands are based on either empirical relationships or first-order reaction rates and do not emphasize the microbial activity. This study was conducted to evaluate the role of biofilm bacteria present in free-water-surface constructed wetland beds in the removal of organic matter. A kinetic model incorporating the biofilm kinetics and dispersion number was proposed to predict chemical oxygen demand removal in free-water-surface constructed wetlands. The model parameters were determined from laboratory experiments and from the literature. The proposed kinetic model satisfactorily predicted chemical oxygen demand removal efficiencies in a pilot-scale constructed wetland unit located in the tropics. A design chart and a design example based on the kinetic model are given.     

提钒用旋流氧枪喷头的数值模拟

利用Fluent软件模拟旋流氧枪的气体射流和提钒转炉内部的钢液流速,研究常规氧枪以及旋流角分别为5°、8°、10°和13°的旋流氧枪对熔池的搅拌效果和冲击特性.研究发现旋流氧枪射流分布相对分散,流股之间干扰少.增加熔池冲击面积,熔池内部等速线所包围的面积变大.10°旋流氧枪喷头喷吹时,等速线所包围面积最大,其面积约为熔池纵切面面积的75%,钢液的流动速度最大,有利于促进转炉提钒过程钒元素的扩散,从而提高提钒效率.      

Effect of Mg Addition on the Refinement and Homogenized Distribution of Inclusions in Steel with Different Al Contents

To investigate the effect of Mg addition on the refinement and homogenized distribution of inclusions, deoxidized experiments with different amounts of aluminum and magnesium addition were carried out at 1873 K (1600 °C) under the condition of no fluid flow. The size distribution of three-dimensional inclusions obtained by applying the modified Schwartz–Saltykov transformation from the observed planar size distribution, and degree of homogeneity in inclusion dispersion quantified by measuring the inter-surface distance of inclusions, were studied as a function of the amount of Mg addition and holding time. The nucleation and growth of inclusions based on homogeneous nucleation theory and Ostwald ripening were discussed with the consideration of supersaturation degree and interfacial energy between molten steel and inclusions. The average attractive force acted on inclusions in experimental steels was estimated according to Paunov’s theory. The results showed that in addition to increasing the Mg addition, increasing the oxygen activity at an early stage of deoxidation and lowering the dissolved oxygen content are conductive to the increase of nucleation rate as well as to the refinement of inclusions Moreover, it was found that the degree of homogeneity in inclusion dispersion decreases with an increase of the attractive force acted on inclusions, which is largely dependent on the inclusion composition and volume fraction of inclusions.