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聚乙烯缠绕结构壁管的环刚度是其抵抗径向变形的重要性能参数,影响着其外压承载能力。以PR1型截面的埋地聚乙烯缠绕结构壁管为例,对管道轴向截面进行截面单元划分,同时,综合考虑截面发生变形、局部材料迁移等情况,建立截面单元的简化计算模型,并对截面单元关键尺寸参数进行修正。在此基础上,研究PR1型聚乙烯缠绕结构壁管环刚度的计算方法;通过实例验证了PR1型聚乙烯缠绕结构壁管的截面单元的形心、惯性矩以及环刚度计算方法的准确性,相关研究方法与结果将对聚乙烯缠绕结构壁管的设计、生产与使用以及其他复杂截面管道的环刚度计算提供一定的参考作用。 相似文献
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高密度聚乙烯缠绕增强管的应用 总被引:3,自引:2,他引:1
介绍了高密度聚乙烯(HDPE)缠绕增强管的种类,性能,生产工艺及特点等。因HDPE缠绕增强管具有输水量大,铺设简便等优点,可适用于远距离低压输水,城市给排水,海水输送,以及农田灌溉等输送工程。举例阐述了使用HDPE缠绕增强管的优化,并展望了HDPE缠绕增强管的发展前景。 相似文献
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日前,扬子石油化工股份有限公司(简称扬子石化)高密度聚乙烯(HDPE)管材在江苏省盐城市盐城沿海化工园污水处理管道项目招标中,一 相似文献
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设计了一种复杂截面缠绕结构壁管的优化设计方法,以实现管径环刚度、截面结构尺寸和管道质量的最优化配置。以工程设计中的性能要求、最佳经济效益为优化目标,以可制造性要求、结构尺寸合理性要求等为约束条件,实现基于精英策略非支配排序遗传算法-Ⅱ(NSGA-Ⅱ)的埋地缠绕结构壁管截面优化设计,即在管道公称直径、材料模量、环刚度取值范围等条件已定的情况下,获得缠绕结构壁管的最优截面类型和截面尺寸。结果表明,该方法满足复杂截面的缠绕结构壁管在工程设计中的选型和优化设计,同时为其他管道优化设计提供一定的参考作用。 相似文献
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The morphology of unimodal and bimodal high-density polyethylene (HDPE) pipes during a hydrostatic pressure test was studied in detail using 1H solid-state NMR. Characterizing the changes of the molecular network during such a test is of key importance for understanding the long-term properties of different HDPE pipe grades. The changes in amount, thickness, and molecular mobility of the crystalline phase, the interface, and the amorphous phase of the two pipe grades with the storage time have been quantified for the first time. The most sensitive microscopic parameter to storage is the molecular mobility of the amorphous phase, with the strongest changes shown by the unimodal HDPE. The density of the tie-molecules is not the main factor controlling the very different behavior of the two pipe grades, but rather it is the density of the entanglements. The NMR results offer unprecedented insights into the changes in the molecular network and support existing deformation models. 相似文献
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从工艺、设备等方面对生产高密度聚乙烯产品7000F的难点进行了统计分析,主要存在质量不稳定、低聚物量大、易堵塞工艺管线、离心机故障率高、己烷汽提塔系统易堵塞、造粒困难等问题,并对此提出了相应对策。通过技术改造、优化工艺参数等手段,使7000F生产周期在1个月以上,基本达到了长周期稳定生产的目的。 相似文献
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Crosslinkable high-density polyethylene (XHDPE) is used to manufacture large and rigid products such as fuel tanks using rotomolding. Currently, defective and postconsumer parts are not recycled and sent to landfills. Hence, recycling of this material through compression molding is the objective of this study. Thermal analysis revealed that the extent of crosslinking varied across the thickness of the rotomolded part due to the role played by oxygen in air. Despite the crosslinking, the recycled XHDPE (RXHDPE) could be remelted with higher viscosity than the virgin XHDPE (VXHDPE). Consolidation studies indicated that both the RXHDPE and the VXHDPE could be compression molded to a density of 0.952 g cm−3. However, higher consolidation stress is required for the RXHDPE when compared to the VXHDPE to realize the same density. The RXHDPE, compression molded at 1.6 MPa and 230 °C, had properties similar to those of the VXHDPE molded at 0.32 MPa. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48145. 相似文献
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低压高密度聚乙烯装置动态模拟模型开发策略浅谈 总被引:2,自引:0,他引:2
讨论了应用通用流程模拟软件AspenPlus、聚合物模拟软件PolymersPlus及动态模拟软件AspenDynamics开发低压高密度聚乙烯装置反应系统动态模型的策略和方法。 相似文献
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氯化聚乙烯工艺技术的比较 总被引:1,自引:0,他引:1
介绍了氯化聚乙烯的几种生产工艺,比较了釜式气固相氯化工艺、溶液法工艺、盐酸相悬浮工艺、水相悬浮法工艺,认为国外开发的水相悬浮法工艺优点显著。 相似文献
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Wettability and interfacial phenomena investigations on high-density polyethylene and petroleum coke
An in-depth wettability and interfacial phenomena investigation was carried out to study interactions between high density polyethylene (HDPE) and petroleum coke. The aim is to investigate the effect of temperature and contact times on possible interactions and adhesion characteristics for partially substituting coal-tar pitch binder with waste polymers. Using a sessile drop arrangement, experimental assemblies consisting of ground HDPE and a petroleum coke substrate were heat treated in the temperature range of 150–350°C for 15–60 min. Contact angles between molten HDPE and petroleum coke surface and depth of penetration of HDPE into petroleum coke substrate were measured. The highest contact angle (131.5°) was observed at 250°C after 15 min. and lowest contact angle (30.9°) was observed at 350°C after 60 min. Highest penetration depth (75 μm) was observed at 350°C after 60 min and lowest penetration (13 μm) at 200°C after 15 min. Analysis of results showed that increasing time and temperature of heat treatment had a significant impact on the interactions of molten HDPE with petroleum coke. Longer residence time and higher temperatures increased the extent of melting of HDPE, which in turn resulted in improved wettability and deeper penetration into petroleum coke substrate. HDPE was found to bind and adhere strongly with petroleum coke. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
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Atomic force microscopy (AFM) was used to study the structure of extruded polyethylene (PE) pipe. During extrusion, the outer surface of the pipe was cooled with water. Two cross sections, parallel and transverse to the extrusion direction, were examined in order to spatially follow the structural development during extrusion. The morphology revealed was spherulitic, and the spherulites had a mostly banded appearance when viewed under the AFM. We were not able to distinguish an oriented skin layer at the surface of the pipe, either by AFM or polarizing microscopy. The changes in the pipe's structure resulting from the cooling conditions were found to be rather gradual, and no clearly defined zones were observed. A slight orientation towards the extrusion direction was detected only in the area of the pipe crystallized under the lowest degree of undercooling. Measured spherulitic size, band period, and lamellae thickness showed a gradual increase in their values from the cooled to the noncooled surface of the pipe. Transmission electron microscopy (TEM) was used to verify the band period and lamellae thickness measurements done by AFM. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 515–523, 1997 相似文献
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以聚酯装置中PET料仓刚性环耳座的设计为实例,运用NB/T 47003.1-2009《钢制焊接常压容器》的计算方法进行强度计算,介绍了刚性环耳座的计算方法。 相似文献