电弧炉直接用煤氧的节能技术

本文叙述了电弧炉炼钢直接用煤氧技术,总结了煤气枪助熔技术、K-ES电炉新工艺和喷煤氧造泡沫渣操作工艺。结合长期从事煤氧枪研究的经验,从理论上分析了“煤氧电炉”的可行性,并阐明了煤氧推广的意义和煤氧炼钢的发展前景。     

Study on Mass Transfer Characteristics in an AOD Converter Bath under Conditions of Combined Side and Top Blowing

The mass transfer characteristics in a steel bath during the AOD refining process with the conditions of combined side and top blowing were investigated. The experiments were conducted on a water model unit of 1/4 linear scale for a 120‐t combined side and top blowing AOD converter. Sodium chloride powder of analytical purity was employed as the flux for blowing, and the mass transfer coefficient of solute (NaCI) in the bath was determined under the conditions of the AOD process. The effects of the gas flow rates of side and top blowing processes, the position arrangement and number of side tuyeres, the powdered flux particle (bubble) size and others on the characteristics were examined. The results indicated that, under the conditions of the present work, the mass transfer coefficient of solute in the bath liquid is in the range of (7.31×10^?5‐3.84×10^?4) m/s. The coefficient increases non‐linearly with increasing angle between each tuyere, for the simple side blowing process at a given side tuyere number and gas side blowing rate. The gas flow rate of the main tuyere has a governing influence on the characteristics, and the gas jet from the top lance decreases the mass transfer rate, the relevant coefficient being smaller than that for a simple side blowing. Also, in the range of particle (bubble) size used in the present work and with all other factors being constant, raising particle (bubble) size increases the coefficient. Excessively fine powder particle (bubble) sizes are not advantageous to strengthening the mass transfer. With the oxygen top blowing rate practiced in the industrial technology, the side tuyere arrangements of 7 and 6 tuyeres with an angular separation of 22.5° and 27° between each tuyere, as well as 5 tuyeres with an angle of 22.5° between each tuyere can provide a larger mass transfer rate in the bath. Considering the relative velocity of the particles to the liquid, the energy dissipation caused by the fluctuation in the velocity of the liquid in turbulent flow and regarding the mass transfer as that between a rigid bubble and molten steel, the related dimensionless relationships for the coefficient were obtained.     

Mathematical Modeling of Fluid Flow in Bath during Combined Side and Top Blowing AOD Refining Process of Stainless Steel: Application of the Model and Results

The mathematical model developed for the molten steel flow in the combined side and top blowing AOD refining process of stainless steel has been used to compute and analyze the flow fields of the liquid phases in the baths of the 120 t AOD converter and its water model unit with a 1/4 linear scale. The influence of the side tuyere number and the angle between each tuyere on the flows has been examined. The results demonstrate that the mathematical model can quite reliably and well model and predict the fluid flow in an AOD bath with the combined blowing. The liquid flow in an AOD converter bath with the combined blowing is resulted from the gas side blowing streams under the influence of a gas top blowing jet. The streams play a governing role on it; and the liquid in the whole bath is in active agitation and circulatory motion during the gas blowing process. The gas jet from the top lance does not change the essential features of the gas stirring and liquid flow in the bath, but can make the local flow pattern of the bath liquid obviously vary and its turbulent kinetic energy enhance. The changes in the tuyere position and number have similarly not altered the basic characteristics and patterns of the gas agitation and liquid flow and turbulent kinetic energy distribution in the bath. At a given tuyere number and gas side blowing rate or a given angular separation between each tuyere and gas side blowing rate, however, the variation of the angle between each tuyere or the tuyere number can locally change them. Using 6 tuyeres with 27° can reach the more uniform flow field and turbulent energy distribution of the liquid in the bath than taking 7 tuyeres with 18° or 22.5° and 6 tuyeres with 22.5°.     

Effects of CeCl3 on Energy Transfer and Oxygen Evolution in Spinach Photosystem Ⅱ

Due to 4f electron characteristics and alternation valence, cerium involved in an oxidation-reduction reaction in plant, closely relating to photosynthesis. Our studies proved that cerium could promote photosynthesis and greatly improve spinach growth. However, the mechanism of promoting energy transfer and conversion by cerium remains unclear. Here we reported that the effects of Ce^3＋ on energy transfer and oxygen evolution in photosystem Ⅱ （PS Ⅱ ） isolated from spinach, which was related to 4f electron characteristics and alternation valence in Ce molecule. The methods of absorption spectrum, fluorescence spectrum were used in the research. Results showed that Ce^3＋ treatment at low concentration could suitably change PS Ⅱ mieroenvironment, increase the absorbance of visible light, improve the energy transfer among amino acids within PS Ⅱ protein-pigment complex, and accelerate energy transport from tyrosine residue to chlorophyll a. In summary, the photochemical activity of PS Ⅱ （fluorescence quantum yield） and its oxygen evolving rate were enhanced by Ce^3＋.     

Effects of 4f Electron Characteristics and Alternation Valence of Rare Earths on Photosynthesis： Regulating Distribution of Energy and Activities of Spinach Chloroplast

Chloroplasts were isolated from spinach treated with taCl3, CeCl3, and NdCl3. Because of owning 4f electron characteristics and alternation valence, Ce treatment presented the highest enhancement in light absorption, energy transfer from LHC Ⅱ to PS Ⅱ, excitation energy distribution from PS Ⅰ to PS Ⅱ, and fluorescence quantum yield around 680 nm. Compared with Ce treatment, Nd treatment resulted in relatively lower enhancement in these physiological indices, as Nd did not have alternation valence. La treatment presented the lowest enhancement, as La did not have either 4f electron or alternation valence. The increase in activities of whole chain electron transport, PS ⅡDCPIP photoreduction, and oxygen evolution of chloroplasts was of the following order： Ce〉Nd 〉La〉 control. However, the photoreduction activities of spinach PS I almost did not change with La, Ce, or Nd treatments. The results suggested that 4f electron characteristics and alternation valence of rare earths had a close relationship with photosynthesis improvement.     

Mathematical Modeling of Fluid Flow in Bath during Combined Side and Top Blowing AOD Refining Process of Stainless Steel: Mathematical Model of the Fluid Flow

Considering that the liquid flow field under the conditions of the combined side and top blowing would be a combined result from the common action of the side blowing gas streams and a gas top blowing jet, as the first attempt, the three‐dimensional mathematical models for the flows of molten steel in an AOD converter bath during the simple side and top blowing processes have been proposed and developed, respectively. And the mathematical model of the flow in the bath during the combined blowing AOD refining process of stainless steel has been given by the composition and superposition of the two models. In the composed model, the gas‐liquid two‐phase flow is described and treated in terms of the two‐fluid (Eulerian‐Eulerian) model. The especially modified two‐equation k?ε model for the turbulence in the liquid phase is employed. And, the surface of the sunken pit formed by impact of the gas jet blown from a top lance at the central location of the bath liquid surface is regarded as a revolution paraboloid. The related details of the composed model are shown.     

济钢焦化厂节能减排、清洁生产的探索与实践

以提出的“蒸汽是劣质的、低效的传热介质”等焦化清洁生产理念为指导,对传统焦化厂生产工艺过程中的水、尘、渣、气、汽及余热余能等通过技术创新进行了资源化、高效化治理和应用,主要开发了干熄焦国产化应用、无蒸汽蒸氨、煤的气流分级分离调湿、煤气半负压净化、除尘式装煤车、脱硫废液提盐、化产废渣配型煤等一系列清洁生产工艺技术,使焦化工序能耗降至92．5kgee／t,吨焦耗水、耗汽分别为1．04m^3和26kg,逐步实现了焦化清洁生产的目标。     

Energy and Exergy Analysis of the Primary Aluminum Production Processes: A Review on Current and Future Sustainability

The common industrial practice for primary aluminum production consists of the Bayer process for the production of alumina followed by the Hall–Héroult process for the production of aluminum. Both processes were developed at the end of the 19th century and despite continuous optimization, their basic thermodynamic inefficiencies and environmental issues remain till today unchanged. As a result, primary aluminum production industry is the world's larger industrial consumer of energy, is ranked among the most CO₂ intensive industries, and is associated with the generation of enormous quantities of solid wastes. In this paper a detail energy and exergy analysis of the primary production of aluminum is presented and alternative sustainable processes are reviewed.     

Displacement activity and motivational theory: A case study in the history of ethology.

Behaviors occurring out of their characteristic motivational context and in the midst of conflict and thwarting situations have been called "displacement activities." Such behaviors were originally explained by reference to energy models of motivation. It is now known that the nature and intensity of such activities are primarily a function of 3 sets of variables: type and intensity of peripheral stimulation, the existence of behaviors incompatible with the activity in question, and the existence and duration of states of motivational equilibrium with respect to such incompatible behaviors. The implications of these findings for motivational theory are discussed and it is suggested that drive and energy concepts no longer serve any useful function in the study of species-specific behavior. (80 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Clinical utility: A prerequisite for the adoption of a dimensional approach in DSM.

A potential obstacle to implementing dimensional representations in the Diagnostic and Statistical Manual of Mental Disorders (DSM) is lack of data about clinical utility and user acceptability. Adopting a dimensional approach would likely complicate medical record keeping, create administrative and clinical barriers between mental disorders and medical conditions, require a massive retreating effort, disrupt research efforts (e.g., meta-analyses), and complicate clinicians' efforts to integrate prior clinical research using DSM categories into clinical practice. Efforts to empirically demonstrate the clinical utility of dimensional alternatives should be a prerequisite for their future implementation in order to establish that their advantages outweigh the disadvantages. Approaches to promote user acceptability and the development of an empirical database include dimensionalizing existing DSM categories and including research dimensions in the DSM appendix. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reach and posture hand preferences during arboreal feeding in sifakas (Propithecus sp.): A test of the postural origins theory of behavioral lateralization.

Sixteen sifakas (11 Propithecus verreauxi coquereli, 2 Propithecus verreauxi verreauxi form majori, and 3 Propithecus tattersalli) were videotaped as they fed on leaves in an arboreal context. The hand used to feed and the hand used to maintain postural stability was coded. For each subject, the lateral bias of the hand used to feed was opposite the hand used in postural support. Seven sifakas displayed no bias for feeding or posture-related hand use, 7 sifakas displayed significant feeding-related reach preferences for pulling branches to the mouth (5 left- and 2 right-hand preferences), and 9 sifakas exhibited significant hand preferences for postural support (2 left-, 7 right-hand preferent). Although these data do not strongly support the postural origins theory of behavioral lateralization, the modal preference pattern for sifakas that displayed significant hand preferences for posture and feeding involve a left bias for feeding and a right bias for postural support. (PsycINFO Database Record (c) 2010 APA, all rights reserved)