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关键词： closed water system   kraft pulp   bleaching   evaporation   precipitation   nanofiltration  

摘要： A summary of an EU project concentrating on separation processes for the closed-loop manufacture of bleached kraft pulp is presented. The project includes four separate tasks in which the need and function of specific "kidneys" are studied. In the first task, the reuse of condensates from black liquor evaporation in pulp bleaching has been studied, including a detailed characterization of the condensates. The discharge of accumulating non-process elements (NPEs) from acidic or neutral bleach filtrates was the focus of the second task of the project. Precipitation of NPEs occurs during a separate pre-evaporation of the filtrates to about 20% DS content. Further precipitation may be obtained by pH adjustment to a level where the precipitation and separation properties can be optimized to favour the discharge of some specific NPEs (e.g., silicon). The third task concentrates on the discharge of accumulating compounds from alkaline bleach filtrates by the use of ceramic nanofiltration membranes developed within the project. In the fourth task an overall system analysis of the closed cycle pulp mill is made.

关键词： Computer simulation  

摘要： Although the inherent interrelationships between business processes and the underlying Information Technology (IT) applications imply that the design of these two organisational facets should be performed in parallel, this doesn't appear to be the case in practice. For example, simulation is being extensively used in both the business and the IT domains, albeit in a disjoint fashion. In this paper, we investigate the potential of integrating business and network simulation models to facilitate concurrent engineering of business processes and Information Technology. (C) 1999 Elsevier Science Ltd. All rights reserved.

关键词： Separation science   Solution chemistry   Diffusion   Mass transfer   Chromatography  

摘要： A variety of economic and social pressures require lowering the costs of equipment and process development, and particular emphasis must be placed on speeding what is basically a heuristic activity. The early stages of conceptualization and screening of alternatives are the most critical, and it is precisely these which have largely been ignored in the public literature and academic curricula. Such early decisions must be made without detailed understanding, and they are essentially evolutionary activities (Lightfoot, E. N. Chem. Eng. Frog. 1998, Jan, 67-74). Evolution dynamics are notoriously unpredictable, and yet observation of biological evolution shows that they can be both surprisingly fast and efficient. Here methods are suggested for achieving high efficiency for equipment-and process development. A critical feature of evolutionary dynamics is the need to identify system anomalies, and these can only be discussed effectively through use of specific examples. Here examples will be taken from the general area of separations processes, with particular emphasis on biological separations.

关键词： 计价模式   量价分离   工程造价  

摘要： 通过对工程造价计价模式探讨,提出新的改革计价模式———“量价分离”的设想。

关键词： 整体识别   宏观特征   节点区域   工程图纸  

摘要： 在工程图纸矢量化处理中着眼于图形的宏观特征，提出了一种整体识别方法。该方法中，引入节点区域的概念，通过节点区域与图段的连接关系确定图形的拓扑结构，并由节点区域分离分割图段，图段的跟踪识别以图段轮廓的方向码序列为引导实现。整体识别算法矢量化速度快。

关键词： 有机高分子膜   酵母废水   工业废水   废水处理   发酵工业  

摘要： 该文对有机高分子膜在食品和发酵工业中的研究现状及进展作了简要的综述和分析.在食品和发酵工业领域中,与水处理行业相比,不仅各种料液的性质千差万别,而且生产工艺各不相同,很难建立一套标准的膜应用工艺,需要针对不同情况,进行不同的实验研究以选择不同的膜法处理工艺.用MF、UF、RO膜对发酵工业主要产品和酵母生产工艺废水进行处理.进行了实验室实验、现场小试和中试,优化了操作条件,分析了膜污染阻力的构成,进行了膜污染清洗方式的正交实验研究,确定了较好的膜污染清洗方法.用UF和RO对酵母废水进行了现场周期试验,膜通量符合工业生产要求.采用德国SIMENS公司的Logo型230RCL可编程控制器自行建立的自动反冲洗错流MF装置处理酱油和醋,分别进行了自动反冲洗周期试验,考察了膜通量的稳定性和膜寿命,取得了较好效果.

关键词： 中药   提取   分离   SCFE   酶工程   超滤  

摘要： 伴随着现代工业工程技术的迅猛发展,中药工程技术也取得了长足的进步,一些现代高新工程技术正在不断地被借鉴到中药生产中来,一方面使中药生产更加符合传统的中医药理论,确保用药的质量要求;另一方面也提高了现有中草药资源的利用率,使传统而神秘的中医药工业更加生机盎然。

关键词： 乙烯   裂解分离   扩建工程   改建工程  

摘要： 对乙烯改扩建的情况进行分析,指出了改造的工艺技术特点,探讨了原始开工的基本思路。

关键词： 变压吸附气体分离技术   推广者   催化剂研制   应用领域   我国化肥工业   推广应用   技术难题   吸附剂   分离工程   天然气换热转化  

摘要： 根据我国化肥工业节能降耗的实际需要，我院从７０年代初开始进行ＰＳＡ法从氨厂释放气中提氢技术的研究，于１９８１年建成两套１０００Ｎｍ３／ｈＰＳＡ制氢工业装置。这标志着我国ＰＳＡ提氢技术进入工业应用阶段。１９８３年４月，冯孝庭同志任副院长，主管全院科研生...

关键词： 膜分离   生物工程   膜过滤流速   膜过滤阻力  

摘要： 较为全面地分析了膜分离在生物工程应用中存在的问题和解决这些问题的方法与思路。