Mathematical modeling of gas‐phase biofilter performance

In the present paper, a new mathematical model describing the physical, chemical and biological phenomena involved in the process of contaminant removal in biofilters is developed. In addition to the contaminant, the key components of the present theoretical model are carbon dioxide and oxygen. The model predicts the concentration profile of the key components in the gas phase, the biofilm and the sorption liquid retained in the solid particles composing the filter bed at both steady and transient regimes. The model equations were solved numerically and comparison between theory and experiment showed that the model results for styrene and carbon dioxide concentration profiles were in very good agreement with experimental data for the biofiltration of styrene vapors at steady state. The analysis of oxygen concentration profile in the biofilm predicted by the theoretical model revealed that oxygen limitation does not occur under the operating styrene biodegradation rate in the biofilter. Copyright © 2003 Society of Chemical Industry     

试论空分生产中大型电机降压起动

随着社会发展和工业化程度的提高，大功率电动机的应用越来越普遍，从几千千瓦到几万千瓦，功率级别越来越大，然而大功率电动机的起动问题一直困扰着工程界。探讨了大功率电机起动的方法，并为今后制氧生产所需大功率电机提供了比较可靠的起动模式。     

1000m^3低温氧气球罐设计

1 000 m3低温氧气球罐是目前国内首次自行设计、制造并组焊的最大的氧气球罐.从球罐材料的选择和部分结构的确定等方面论述了该低温球罐的设计工作.     

Reduction of trace oxygen by hydrogen leaking during selective vaporization to produce ultra-pure cadmium for electronic applications

A viable method utilizing leaking of high pure hydrogen gas into the distillation retort ambience maintained at 8.0 × 10^− 3 Torr was devised to minimize the incorporation of trace oxygen in cadmium and the possibility of forming cadmium oxides during purification using selective vaporization. Hydrogen leaking at the rate of 5 standard cubic centi-metre per minute (sccm) during distillation at soaking temperature of 450 °C reduced trace oxygen from 230-350 ppm for raw cadmium of 3N8 (99.98%) purity and from 5-10 ppm for distilled cadmium of 6N purity. This can be compared to the presence of 30-38 ppm oxygen in cadmium distilled under simple-vacuum of 2.1 × 10^− 3 Torr achievable in the system. A detailed comparison between distillation under simple-vacuum and hydrogen leaking is presented with reference to purity, distillation rate, soaking temperature, and mean free path of distillate vapors.     

Modeling the Oxygen Barrier Properties of Nylon Film Intended for Food Packaging Applications

ABSTRACT: We present a mathematical model to predict the oxygen-permeability coefficient of nylon film as a function of the water activity at the upstream and downstream side of the film. To validate the model, oxygen-permeability tests were conducted at 25 °C. The fitting and predictive ability of the proposed model was successfully tested by fitting and predicting the oxygen-permeability coefficient. The obtained results point out the need for a more accurate analysis of the oxygen and water-transport phenomena in the case of water-sensitive packaging films like nylon.     

连续生产型炉窑排烟温度合理性探讨

推导了热效率变化百分率和单产标准煤耗变化百分率的计算公式 ,通过计算说明了连续生产型炉窑依靠高效余热回收而实施高烟温生产操作 ,实际上是增加而不是减少燃料消耗 ,据此 ,指出“三高一低”理论的不完全正确和HTAC技术在此类炉窑上的不可用性。论述了连续生产型炉窑低烟温的合理性 ,并提出基于低烟温的“双高低”理论和“烟混型高温低氧燃烧法” ,促使连续生产型炉窑向高效节能环保方向发展     

Effects of Light, Oxygen, and pH on the Absorbance of 2,2-Diphenyl-1-picrylhydrazyl

ABSTRACT: The absorbance of 2,2-diphenyl-1-picrylhydrazyl (DPPH) at 517 nm in methanol and acetone decreased by 20 and 35% for 120 min at 25 °C under light, respectively; in the dark it did not change significantly for 150 min. Decomposition of DPPH under 21% oxygen after 90 min under light was significantly higher than that under 1% oxygen. Absorbance of DPPH in pH 4 buffer solution in methanol, and in pH 10 buffer solution in acetone, decreased by 55 and 80%, respectively, under light for 120 min. The evaluation of antioxidant activity by the changes of DPPH absorbance should be carefully interpreted since the absorbance of DPPH at 517 nm is decreased by light, oxygen, pH, and type of solvent in addition to the antioxidant.     

宝钢环形加热炉采用富氧燃烧技术的可行性研究

在分析了富氧燃烧理论的基础上，结合宝钢环形加热炉的实际生产状况，通过燃烧过程的数值模拟和优化仿真计算，讨论了在不同富氧率条件下的节能效果，重点分析了采用富氧燃烧技术后的节能降耗效果以及由此产生的经济效益。     

面向过程的无机膜透氧工艺设计

根据无机膜通氧过程的高温特点，并结合工业应用的经济性要求，对机膜道氧过程的工艺路线进行了探索性研究，初步实现了无机膜道氧过程与能量回收和高温过程的藕合，构筑了面向过程的无机膜透氧工艺设计，为实现无机膜透氧过程的工业化应用提供了指南。     

氧化锆氧分析器计量检定不确定度的评定

论述了氧化锆氧气体分析器计量检定过程中不确定度的合成方法，给出了评定结果。