高含硫气田延长贫液泵机械密封寿命研究

在高含硫天然气田开发砜胺脱硫脱碳工艺中,砜胺液泵机械密封失效频繁、清洗置换隔离繁琐、备件费用高、检修周期和备件采购周期长,这也是转动设备专业日常维护的重点和难点。从机泵的工艺工况、机械密封设计制造、设备运行、密封管理、冲洗方案及密封维护等多方面探寻制约砜胺液泵机械密封长周期运行的关键点,发现了贫液泵机封轴套与泵轴不同步是机械密封失效的根本原因,通过在主轴上钻取沉孔固定机械密封轴套能够可靠且稳定地延长机械密封运行周期。     

高危介质泵机械密封及密封冲洗方案的改造

针对炼油厂催化裂化装置分馏塔底循环油浆泵的机械密封寿命短、泄漏频繁、检修率高的问题。文章分析了导致油浆泵机械密封泄漏的原因,分别对油浆泵机械密封的选型、机械密封冲洗方案进行了改造,改造后延长了机械密封的使用寿命,达到了长周期运行。     

工艺废热锅炉泵机械密封的改造与设计

基于工艺废热锅炉泵的运行实际,分析比较工艺废热锅炉泵机械密封与填料密封的优缺点,针对设备存在的问题,根据现场情况实施改造,结合设计的填料套、填料压盖的尺寸选定填料,改造后实现了设备长周期运行无漏液的目标。     

浅议磷酸料浆泵的选型及轴封改造

以磷肥厂磷酸、磷铵装置中磷酸料浆泵为例,在结合其工况特点及现场使用情况的基础上,从泵的结构形式、过流部件材质、叶轮型式、泵转速等几方面作了简要阐述;另外,对于磷酸料浆泵长期以来比较难解决的轴封问题,介绍了目前在磷酸轴流泵上成功改造的一种集装式双端面机械密封,并提供了该机械密封的设计参数及材质要求;对轴封改进前后,使用填料密封和机械密封的优缺点进行了对比;该机械密封的成功改造,满足了设备长周期运行的要求,大大降低了设备维修资金,具有良好的参考价值,对磷酸料浆泵的选型工作也有很大帮助。     

立式高速泵的密封系统改造

介绍了立式高速泵的原机械密封的使用情况,从机械密封追随性和辅助密封圈两个方面分析了原机械密封泄漏的原因,结合干气密封的工作原理和性能特点,提出了由干气密封替代原机械密封的具体改造措施,详细阐述了机封的结构选型和控制系统改造方案,总结了干气密封使用维护注意事项,成功解决了机械泄漏问题,为高速泵的长周期运行提供了参考。     

泵用机械密封长周期运行的关键点

通过泵类机械密封的应用,提出了机械密封长周期的关键在于正确选型,安装、消除振动、优化操作和维护,从而提高机械密封稳定性、长期性。     

催化油浆泵密封失效分析及对策

油浆泵在运行过程中,多次因机械密封失效而停泵紧急检修。分析运行工况对密封件寿命的影响,采取对策,对机械密封的结构和运行环境作了改进,降低了故障检修率,使该泵能长周期稳定运行。     

冷凝液泵机械密封选型探索及安装

根据冷凝液泵的轴承箱及机封冷却水等外在条件,探索适合于变换冷凝液泵的机械密封,从而保障泵的长周期运行。     

串联式干气密封在高压氨泵上的开发应用

分析了合成氨装置核心设备高压氨泵原有双端面机械密封存在的主要问题,提出了采用串联式干气密封装置,并在实际生产中得到了成功的应用。现场考核结果表明:在高压氨泵上采用改造后的串联式干气密封,实现了氨介质的零泄漏,彻底解决了原密封使用寿命短、泄漏严重的问题,确保了装置长周期、安全运行,减少了维修维护成本,创造了良好的经济效益。     

延炼40万吨催化裂化装置液化气泵密封改造

通过对延炼40万吨装置液化气泵的机械密封进行改造,防止该泵密封的突然失效造成液化气泄漏,提高可靠性和设备的安全、长周期运行。     

焦油一次汽化温度计算方法的探讨

利用相平衡原理得出的焦油蒸馏时一次汽化温度的计算方法,其结果与按经验公式的计算结果进行了比较,同时讨论了一次汽化温度与焦油馏分产率及二段蒸发器过热蒸汽用量的关系。     

Techniques for screening adhesives for structural applications

—Due to its chemistry, no structural adhesive system (epoxies, acrylics, etc.) is likely to offer an ideal combination of toughness, strength, moisture resistance, and ambient-temperature curing. Therefore, for effective use of adhesives in primary structures, an engineer must be able to identify adhesives that represent an optimum compromise among the different properties. In this paper, we present techniques for screening high-strength, ambient-temperature-curing adhesives for (1) moisture resistance under sustained loading and (2) fracture resistance in a way that is directly related to joint performance.     

Efficacy for Whitlockite for Augmenting Spinal Fusion

Whitlockite (WH) is the second most abundant inorganic component of human bone, accounting for approximately 25% of bone tissue. This study investigated the role of WH in bone remodeling and formation in a mouse spinal fusion model. Specifically, morphology and composition analysis, tests of porosity and surface area, thermogravimetric analysis, an ion-release test, and a cell viability test were conducted to analyze the properties of bone substitutes. The MagOss group received WH, Group A received 100% beta-tricalcium phosphate (β-TCP), Group B received 100% hydroxyapatite (HAp), Group C received 30% HAp/70% β-TCP, and Group D received 60% HAp/40% β-TCP (n = 10 each). All mice were sacrificed 6 weeks after implantation, and micro-CT, hematoxylin and eosin (HE) staining, and Masson trichome (MT) staining and immunohistochemistry were performed. The MagOss group showed more homogeneous and smaller grains, and nanopores (<500 nm) were found in only the MagOss group. On micro-CT, the MagOss group showed larger fusion mass and better graft incorporation into the decorticate mouse spine than other groups. In the in vivo experiment with HE staining, the MagOss group showed the highest new bone area (mean: decortication group, 9.50%; A, 15.08%; B, 15.70%; C, 14.76%; D, 14.70%; MagOss, 22.69%; p < 0.0001). In MT staining, the MagOss group demonstrated the highest new bone area (mean: decortication group, 15.62%; A, 21.41%; B, 22.86%; C, 23.07%; D, 22.47%; MagOss, 26.29%; p < 0.0001). In an immunohistochemical analysis for osteocalcin, osteopontin, and CD31, the MagOss group showed a higher positive area than other groups. WH showed comparable bone conductivity to HAp and β-TCP and increased new bone formation. WH is likely to be used as an improved bone substitute with better bone conductivity than HAp and β-TCP.     

Demand Increases for New Fungicides for Rice

<正> After June this year China's regions growingmiddle and late rice had widespread blastand sheath/culm blight.Such diseasesplagued 19.2 million hectares.Starting fromJuly the market for new fungicides that cancontrol blast and sheath/culm blight for ricewas more and more active.Makers of traditional pesticides for thecontrol of blast have to contend with fiercecompetition from new pesticides in marketthis year.Kitazine,iprobenfos,isoprothiolane and tricyclazole,oftenused by farmers in the past,are graduallybeing replaced by new varieties with high