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采用溶胶-凝胶法,制备了有序多孔羟基磷灰石(hydroxyapatite with highly ordered three-dimensional pores,HA-HODP)。在37℃,将HA-HODP在CaCl2和Ca(H2PO4)2溶液中浸泡几天,通过X射线衍射、场发射扫描电子显微镜、Fourier变换红外光谱以及pH值等的测试手段分析、研究了Cl-和H2PO4-对HA-HODP组成和形貌的影响。结果显示:HA-HODP浸入到CaCl2溶液中,生成Ca5(PO4)3Cl和CaCO3相。Ca5(PO4)3Cl相的生成系Cl-取代了OH-;CaCO3相的生成系Ca2+在碱性环境下,与溶解在溶液中的CO2发生了反应。在Ca(H2PO4)2溶液中,由于存在过量H2PO4-,在HA-HODP的表面生成了Ca9HPO4(PO4)5OH相。 相似文献
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本文根据化学平衡原理,并考虑到循环冷却水的实际情况,用离子积时间曲线来判断水中是否析出磷酸钙垢,并将所得结果和从磷酸钙饱和指数法所得结果进行了比较。 相似文献
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不同络合剂对电沉积磷酸钙涂层作用的比较 总被引:1,自引:1,他引:0
研究了在电沉积磷酸钙陶瓷涂层溶液中三种络合剂丙酸、柠檬酸及磷酸对磷酸钙涂层质量电量比、组成、结构及形貌的影响,通过SEM、XRD观测、分析,结果显示:在含有丙酸、柠檬酸及磷酸不同的络合剂溶液中,电沉积得到涂层组成分别为CaHPO4·nH2O;CaHPO4·nH2O,Ca3(PO4)2·nH2O;Ca3(PO4)2·nH2O,Ca10(PO4)6(OH)2。而且涂层质量电量比、结构、形貌也存在较大的差别。 相似文献
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为保证饲料级磷酸氢钙产品合格 ,必须控制预中和液的 p H值。目前 p H值的控制依赖试纸 ,其精度最高为 0 .4p H,凭经验判定稍不注意 ,就会给正常生产带来不必要的麻烦。对此 ,我们通过快速测定预中和澄清液中的 P2 O5,计算其 m( P2 O5)m( F) ,并及时返馈给操作工 ,从而保证了产品中氟含量在规定值( 0 .1 5 %~ 0 .1 7% )。1 原理预中和澄清液中存在着如下几种物质 :Ca( H2 PO4 ) 2 、H3 PO4 、Mg2 + 、Fe3 + 、Al3 + 、Si O2 ·n H2 O、Al F63 -等。且有 :Ca(H2 PO4) 2 + 2 H2 O 2 H3PO4+ Ca(OH) 2Na OH标准溶液中和澄清液… 相似文献
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三元复合驱中由于碱剂的引入,地层中的岩石矿物有很大程度地被溶蚀,进而释放出大量的成垢离子,例如Ca2+、Mg2+和Si4+等离子,这些成垢离子在一定的的温度压力下会结合成垢并沉积在近井地带、井筒及举升设备表面,影响了油井正常的生产,且作业成本大大增加.研究温度、压力对成垢的影响,可了解垢的形成规律,从而帮助解决垢给油田生产带来的影响. 相似文献
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介绍了尿素装置难溶垢的形成过程、垢样分析结果、HuaRong-958尿素装置不锈钢设备难溶垢专用清洗剂的功能及清洗难溶垢的反应原理。采用HuaRong-958清洗剂清洗中、低压分解加热器(E102和E103)和真空预浓缩器(E113)后,效果显著。 相似文献
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以磷酸氢二氨[(NH4)2HPO4]、四水硝酸钙[Ca(No32·4H2O]和四水硝酸铅[Pb0N03)2·4H20]为原料,在200℃水热处理12h制得Ca10-xPbx-HA[x=0~10,Ca-Pb-Ca10(PO4)6(OH)2,Ca-Pb-bydroxyapatite,Ca-Pb-HA]固溶体.通过X射线衍射、化学分析方法以及电子显微镜对Ca-Pb-HA固溶体的晶相、化学组成和形貌进行了分析.利用Rietvdd方法对Ca-Pb-HA固溶体进行了结构精修,结果表明:晶体结构随铅离子固溶量的增大发生了较大的变化,晶胞参数a和c不随铅离子含量的变化而呈线形变化.在Ca-Pb-HA固溶体中铅离子优先占据M(2)位置.Rietveld分析结果很好地解释了Ca-Pb-HA固溶体结构随铅离子含量的变化规律. 相似文献
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Nicole Brueggemann Tim Puehmeier Ralf Fiekens Franz-Josef Richardt Manfred Salvermoser 《臭氧:科学与工程》2017,39(3):196-201
The efficiency of ozone generators is determined by many factors. Operating conditions such as feed gas quality and especially cooling conditions are of utmost importance. Cooling of ozone generators is absolutely necessary, since ozone destruction reactions increase exponentially with temperature. The most common way to cool an ozone generator is water flowing in close contact to the electrodes. The heat removal out of the discharge gap depends on different parameters. Electrical input power, cooling water flow conditions, electrode geometry and material properties are some of them. Simultaneously lowering cooling water temperature, applied power density and gap width, leads to a lower gas temperature in the discharge gap and thus to increased ozone production efficiency. Minimizing the temperature difference between the cooling water inlet and outlet improves the ozone production efficiency as well. This measure, however, results in high cooling water flows and requires additional cooling water chilling, resulting in higher operational costs and capital expenses. Cooling associated costs rise disproportionally with increasing cooling water flow. Simultaneously, energy consumption of ozone generators decreases as the average cooling water temperature goes down. As a result, there exists an optimum between the operational and capital expenses for the combination of ozone generator and cooling water system related expenses, offering significant cost savings for the customer. 相似文献
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敞开式循环冷却水的pH值、碱度及加酸量估算 总被引:1,自引:0,他引:1
从分析水中pH与碳酸盐碱度的关系入手,在总结大量实践经验的基础上,提出了三种类型补充水的循环冷却水的总碱度与pH值之间的关系式。在分析了循环冷却水的自然pH变化规律后,归纳出了四种不同类型补充水的循环冷却水的自然pH值的计算公式,提出了循环冷却水中加酸量的估算公式 相似文献
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This paper presents a technique for simultaneous targeting and design in cooling water systems comprising of at least two cooling towers and several cooling water using operations. The presented technique is based on a superstructure from which a mathematical formulation is derived using system specific variables and parameters. It is demonstrated that in a system like this, true optimality can only be realized by a holistic consideration of the entire cooling water system. Consideration of individual subsets of cooling towers with their dedicated cooling water operations yields suboptimal results. Four operational cases are considered and structural considerations of corresponding mathematical formulations presented. The first case results in a linear programming (LP) formulation, the second case yields a mixed integer linear programming (MILP) formulation whilst the other two cases yield mixed integer nonlinear programming (MINLP) formulations which cannot be exactly linearized. However, in all cases significant improvements in excess of 40% were realized in targeting, without compromising the heat duty of the cooling water using operations. The main objective of this investigation is to debottleneck the overall cooling water supply for the cooling water network. 相似文献
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蒸汽喷射真空泵的影响因素及测试罩的应用 总被引:2,自引:0,他引:2
实际生产中的影响因素很多 ,诸如蒸汽压力、蒸汽干燥度、冷却水量、冷却水温、冷却水喷嘴堵塞、真空泵泄漏、拉瓦尔蒸汽喷嘴堵塞、泵前工艺设备冷却效果不好等等。但主要的是冷却量、拉瓦尔蒸汽喷嘴和泵前工艺设备的冷却。测试罩安装在真空泵的吸入真空管道上 ,在测试罩上选择不同直径的空气流量喷嘴 ,可以测得真空泵的空气流量喷嘴、抽气量、真空度之间的关系 ,从而可指导正确操作。 相似文献
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提高冷却塔配水均匀性的探讨 总被引:1,自引:0,他引:1
在冷却塔的设计中,配水管及喷头的布置是影响冷却效果的重要因素之一。通过水力计算,分析了水压分布规律,指出冷却塔的喷头布置,配管形式对布水均匀度的影响因素,探讨了提高布水均匀度的对策,认为采用全对称树枝状配管及六角形喷头布置方式可有效提高冷却塔配水的均匀度。 相似文献
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总结了蒸发冷却冷水机组结构类型和工作原理,理论和实测验证了间接蒸发冷却的湿通道侧发生的并非绝热等焓直接蒸发冷却。根据对间接预冷式蒸发冷却冷水机组的性能测试分析,间接蒸发冷却器的湿球效率在41%~92%之间,立管、板管、露点间接蒸发冷却器比卧管间接蒸发冷却器效率高,间接预冷式蒸发冷却冷水机组制备冷水可达到亚湿球温度,制备冷水温度受间接蒸发冷却器效率、填料塔内气水比、外热源影响。以间接预冷式蒸发冷却冷水机组、机械制冷冷水机组、乙二醇自然冷却为冷源的数据中心空调系统,水侧蒸发冷却与乙二醇自然冷却应用在乌鲁木齐市、北京市、上海市的时间分别为8736、6261、4708 h,相比机械制冷的全年节电率分别为62%、53%、46%。 相似文献
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Thomas Frech 《化学,工程师,技术》1988,60(5):359-364
Monitoring of liquid effluents as preventative protection of natural bodies of water. One possibility to improve the safety of river water cooling systems is to control the river water side of the cooling system continuously by process analyzers. In this way, leakages in cooling systems can be recognized earlier and the amount of products which contaminate the river water can be minimized. The aim of this article is to inform the user of water cooling systems about the process analyzers which are available. A second aim is to help him to decide which of these analyzers is the best for his measuring problem. 相似文献