Continuous flow characterization of solid biomass in a reciprocating/rotating scraper tube: An experimental study

The performance of reciprocating/rotating scrapers has been assessed in a visualization study of the continuous flow hydrodynamics of air‐fluidized solid biomass under varying conditions of air flow rate and scraping velocities. A combination of low air flow rates and high scraping velocities results in more uniform flow of both types of biomass investigated. Power consumed by the reciprocating action of the scrapers increases with the scraping velocity but typically represents no more than 20% of the overall power consumption at the highest air flow rate applied. We also demonstrate that rotation of the scrapers superimposed on their reciprocating action gives higher flow rate of biomass and better mixing within the bulk solid compared to reciprocating action alone. The application of the reciprocating/rotating scraper technology described in this study represents a viable step forward in developing a continuous, large‐scale process for the microwave‐assisted decomposition of solid biomass to produce bio‐oils. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3732–3738, 2014     

平宝公司首山一矿通风系统技改工程设计方案研究

根据首山一矿通风能力不足现状,结合矿井长远发展,分别从进风和回风系统两个方面提出了改造方案。综合分析了每个方案的优缺点,确定了总体设计、分期施工的实施原则,减少了初期投资,既保证了矿井近期安全生产的需要,又确定了矿井达产的目标、任务,为矿井的安全可持续发展奠定了基础。     

煤炭企业运输成本优化研究

针对企业运输过程中存在的运货数量不合理、市场运输价格掌握滞后、车辆管理不到位、路线设计不合理等因素,导致运输成本增加的问题,以煤炭企业为例,通过了解运输成本的构成,研究、分析影响运输费用的各项因素,提出相应优化方案,及时解决运输过程中存在的各种问题,实现了对运输成本的有效控制。     

大中型往复式压缩机采购过程中的质量控制

大中型往复式压缩机是化工建设项目中的关键采购设备之一,笔者提出了技术数据表审查、制造商及用户考察、技术方案论证、技术协议签订、图纸方案审查和制造质量检验验收等采购流程中各环节技术要求和质量控制要点,为化工工程建设同类设备的采购提供参考。     

用AspenPlus模拟分析和优化多晶硅合成工段洗涤塔

利用AspenPlus模拟分析了三氯氢硅合成洗涤塔,利用灵敏度工具分析了摩尔回流比对洗涤塔操作的影响,还利用优化分析工具对进料温度进行了分析。经对洗涤塔的模拟分析,建议实际运行采用适宜的较小回流比操作,可提高氯硅烷的回收率,还可降低再沸器的供热,甚至可取消它,有效避免硅粉和金属氯化物对其的严重磨蚀和腐蚀,同时还可减少冷凝器所需的冷量,降低多晶硅生产中的操作成本。     

氧气对低温甲醇洗系统的影响及解决措施

分析了低温甲醇洗系统中氧气的来源;简述了氧气对低温甲醇洗系统的影响;提出了降低低温甲醇洗系统中氧气含量的控制措施以及相应的设计方案。     

可降解镁锌合金支架材料加工改性方法的研究进展

药物洗脱支架是冠心病支架治疗中的首选材料,但其永久存留在体内易损害内皮细胞,还有可能发生支架内血栓形成、支架内再狭窄等严重问题,而且现在冠心病发展越来越年轻化,导致药物洗脱支架在临床工作中的应用越来越受到限制。近年来,生物可降解材料逐渐被开发和探索,作为心脏支架材料的新生力量,被国内外多个研究机构看好。主要介绍了可降解镁锌合金材料。首先介绍了镁、锌元素的良好的生物相容性,它们是人体内含量丰富的元素,在体内多种生命活动中都发挥重要作用,缺乏镁、锌元素会增加人体患心血管等疾病的风险,镁锌元素组合还有助于改善各自不适宜的性能,使其更接近临床对可降解材料的需求。然而,镁锌合金支架降解产物局部浓度过高、支架的力学性能和降解速率可控机制等仍需要进一步提高。针对这些问题,重点讨论了近些年来常用于改善合金材料性能的加工改性方法,常用于改进镁锌合金材料的技术包括添加元素、表面改性、热处理、塑性加工、快速凝固、多种技术相结合等方法。介绍了这些方法的原理、效果、优点以及作为可降解血管支架改性方法的局限性,最后对生物可降解镁锌合金支架进行了展望。     

适用于地铁线路的嵌入式轨道结构方案研究

嵌入式轨道结构在缓解钢轨磨耗和减振降噪等方面表现优异,目前主要用于有轨电车线路。研究提出适用于地铁线路的连续支承无扣件嵌入式轨道结构系统,为地铁轨道结构的减振方案提供一种新选择。在总结分析嵌入式轨道结构型式基础上,结合地铁线路的特点,确定了地铁用嵌入式轨道结构的选型原则和具体要求,提出并比较分析了4种新式嵌入式轨道结构型式。类I型、类III型板式嵌入式轨道适宜于直线线路,钢槽扣结式嵌入式轨道因换轨方便更适用于曲线线路,附加槽式可用于因提高减振降噪要求而进行的既有线改造。嵌入式轨道结构应用于地铁线路具有安全可靠,平顺性高、稳定性强和修复性好等显著优点。     

Design criteria for impact factors based on dynamic on-site data in railway bridges

To evaluate the dynamic behaviours of bridges, many researchers have analysed interactions between vehicles and bridges with numerical methods instead of field loading tests. However, conventional numerical methods take too much time and cost to evaluate the impact factor of bridges in design and maintenance practice. The objective of this study was to propose improved design criteria by using impact factors based on natural frequency rather than span length of railway bridges using dynamic field load-carrying capacity test database. The improved design criteria use a different methodology than that outlined in the International Union of Railway specifications Code. Statistical regressions are applied to more easily estimate the natural frequency of a bridge with a span length of 20?m or longer with steel plate girder or truss superstructures. Calculated impact factors were compared to impact factors obtained from field measurements. Results indicated that the improved method could provide a very reliable estimation for actual impact factors. Since the suggested impact factor criteria are conservative, the proposed method can be used in design and management stages to consider dynamic effects of railway bridges in a more intuitive manner.     

供热管道沉管工程施工方案设计

分析了供热管道沉管施工中沟槽开挖、垫层铺设、管道埋设及回填与驳岸修复的施工方案,探讨了施工过程的技术、质量保证措施。