The performance of the 12,000 m3/day seawater ro plant at Jeddah,Saudi Arabia

This paper outlines the performance of the 12,000 m³/day seawater RO plant at Jeddah, Saudi Arabia. The plant started operation in February 1979 and has been operating since then. The feedwater to the plant has a TDS of 42,000 ppm and the maximum seawater temperature is 32°C. The plant is made up of a first and a second stage. The first stage includes nine units, eight operating and one stand-by, and the second stage containes three units. The nine first stage and the three second stage RO units are each composed of 56 Fiberglass pressure tubes (Model 66 FRP-6) 150 mm diameter by 6.5 m long, each containing six spiral wound elements manufactured by UOP Fluid Systems Division. The plant uses Fluid System's polyamide thin film composite membrane element, Model 1501 TFC. The pretreatment is composed of dual media filtration, acid injection, sodium hexametaphosphate injection and cartridge filtration.The performance from the start of operation till the present time is shown both for the overall plant and for each unit. The product rate of each unit and its water quality throughout its operating period is indicated showing the times when the unit was shut-down and the reason for it. Deterioration in unit performance is analyzed and explained. Actual plant consumption of fuel and chemicals is given and estimates of the plant operating costs are made.     

Operational experience of 2 × 11,500m3d MSF seawater desalination plant

This paper outlines the operational experience with 2 × 11,500 m³ p.d. Multi Stage Flash desalination plants which were introduced to Bahrain in 1976. It attempts to place in perspective the problems which this technology presented, as it was new to Bahrain. The particular difficulties which resulted from use of bare carbon steel are identified. The corrective measures which were taken to minimise the rate of corrosion are stated. The paper concludes that careful specifications of materials for such plants is essential, and that the necessary expertise must be available at start up to achieve stable operation and to minimise down time.     

Ship-mounted seawater 2500 m3/d flash evaporation plant for Abu Dhabi. economical drinking water for arid regions

Buckau-Walther AG (Krupp Group) handed over a ship-mounted seawater desalination plant to the Water and Electricity Department of the Government of Abu Dhabi on February 16, 1982, in Bremen. This followed a 12-month construction period and two weeks of trials. Named the “Rumaith”, this is the first self-propelled floating seawater desalination plant built for commercial use. The plant, consisting of a self-propelled pontoon-like hull carrying two centrally positioned desalination units of 1250 m³ each, will supply islands, coastal towns and major construction sites in the United Arab Emirates with drinking water and will also be deployed in the event of break-down of stationary desalination plant, to provide an emergency water supply and to alleviate plantation water shortages. After handover, the vessel, accepted by German Lloyd for class + 100 A4K, was pulled by tug to Abu Dhabi in the Arabian Gulf in 40 days. As general contractor, Buckau-Walther AG had the vessel built by a shipyard in Bremen.     

2000m^3液化石油气球罐选材评述

对16MnR,16MnR(H)和15MnNbR钢的力学性能,焊接性能和抗H2S应力腐蚀性能进行了评述,并就这些材料用于2000m^3液化石油气球罐的综合性能和经济性进行了对比,认为15MnNb是2000m^3液化石油气球罐的理想钢种。     

20万m^3粉煤灰混凝土砌块生产线工艺设计

概述目前国内综合利用粉煤灰生产墙体用建材的途径,介绍某热电厂20m^3/a粉煤灰混凝土砌块生产线的工艺设计方案。     

DCS系统在30m3聚合釜上的应用

在30m     

缩短PVC糊树脂聚合周期新工艺在48m3聚合釜中的应用

简要介绍了缩短PVC糊树脂聚合周期的小、中试及48m     

108 m3聚合釜引发剂用量及加入技术对树脂质量的影响

引发剂是调节氯乙烯悬浮聚合反应速率,并影响聚合放热、聚合周期和聚合釜生产能力的重要助剂。引发剂对氯乙烯悬浮聚合动力学的影响主要与引发剂的活性、用量有关。引发剂用量、加入方式和前后期使用比例等对树脂质量也有明显的影响。     

防粘釜喷涂技术在127m^3聚合釜上的应用

介绍了不同防粘釜剂在聚合釜上的应用。结果表明：NOXOLWSW（1）对釜壁有特殊部位防粘釜效果良好;（2）对反应体系及PVC树脂质量无不良影响;（3）用量少且无毒,有利于环保;（4）粘釜减轻,有利于釜温、釜奔流控制,保证安全。除了对防粘釜剂进行对比选择之外,防粘釜剂雾化喷涂技术的进一步完善对防粘釜效果也起到了推进作用。经过对8台聚合釜全线改造后,目前各牌号聚氯乙烯树脂的月优级品率可达到93％,为公司改造了可观的质量效益。     

羧基丁腈胶乳在20m^3釜的工业放大研究

主要考察了羧基丁腈胶乳在工业放大中引发剂的用量及其加入方式、反应前期温度、搅拌转速等因素对聚合过程及胶乳稳定性的影响.结果表明在20m3釜上引发剂的使用量仅为小试的50%～60%,且引发剂量减少及加入时间延长,使聚合稳定性增加,设备操作周期延长;反应初期温度以15±2℃为宜;反应转化率＜70%,搅拌器采用100r/min转速,转化率≥70%,搅拌器采用75r/min转速,可有效减少胶乳的凝胶量,提高胶乳质量.     

Spectral pure RGB up-conversion emissions in self-assembled Gd2O3: Yb3+, Er3+/Ho3+/Tm3+ 3D hierarchical architectures

Self-assembled three-dimensional Yb³⁺(Ln = Er, Ho, Tm) co-doped Gd₂O₃ up-converted (UC) phosphors were synthesized by a facile co-precipitation method, and their morphologies and microstructures were investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis. Under the excitation at 980 nm, spectral pure three primary colors red, green and blue (RGB) emissions were respectively achieved in Yb³⁺/Er³⁺, Yb³⁺/Ho³⁺ and Yb³⁺/Tm³⁺ co-doped Gd₂O₃ phosphors, in which spectral color purities were tuned by adjusting the doping concentration, annealing temperature, excitation power density and the pulse-width of 980 nm laser. These results provide deeper insights into modulating spectral color purities of up-converted emission, and the potential applications of spectrally pure RGB up-converted materials in fingerprint recognition and multi-color printing were also investigated.     

127 m3聚合釜热水进料及优化水油比的实践与研究

介绍了上海氯碱化工股份有限公司采用127 m3聚合釜生产悬浮法PVC的情况,该公司的7万t/a PVC装置扩产后采用热水进料,省去了聚合反应升温的步骤,同时对聚合体系进行优化,调整水油比,使聚合过程平缓且放热均匀,缩短了聚合时间(聚合釜的生产周期缩短至7 h以内),提高了单釜产量,使PVC的生产能力达到了35万t/a,同时PVC树脂的质量也能得到可靠保证.     

30m^3 PVC聚合釜面临的挑战和机遇

主要讲述30m^3聚合釜生产PVC如何进行调整、改造及今后工作方向、生产中应注意的事项。介绍利用30m^3聚合釜生产特殊牌号树脂（如用低温法生产高聚合度树脂,用添加交联剂生产高聚合度树脂以及消光树脂和共聚树脂）应注意的问题。     

Spectroscopic Properties and Energy Transfer Mechanism of Er^3＋/Yb^3＋/Ce^3＋ Codoped Tellurite-based Glasses

为进一步揭示多稀土离子共掺低声子能量玻璃中Er3＋的光谱特性及其发光机理,采用高温熔融法制备了Er3＋/Yb3＋/Ce3＋共掺组分为（72.5–x）TeO2–20ZnO–5La2O3–0.5Er2O3–2Yb2O3–xCe2O3（x=0,0.4,0.7,1.0,摩尔分数x%）的碲酸盐玻璃,通过测量吸收光谱、荧光光谱和无掺杂样品的Raman光谱,以及计算相应能级间的吸收截面和受激发射截面,研究并分析了Yb3＋和Ce3＋离子掺杂对于Er3＋的1.55μm波段荧光特性的影响。结果显示：Yb3＋和Ce3＋的引入能显著增强975nm泵浦下Er3＋的1.55μm波段荧光强度。分析表明：Er3＋在1.55μm波段荧光强度的增强主要归结于Yb3＋/Yb3＋、Yb3＋/Er3＋离子间的共振能量传递过程以及基于单声子和双声子辅助的Er3＋/Ce3＋离子间的能量传递过程,并通过计算得到了相应稀土离子间的能量传递微观参数和声子所作的贡献比。     

Polymorphism of BaTiO3 Acceptor Doped with Mn3+, Fe3+, and Ti3+

The effect of Mn doping on the cubic to hexagonal phase transition temperature in BaTiO₃ has been determined by quenching samples with different Mn contents from a range of temperatures. Under conditions of equilibrating samples in air over the range 1000°–1400°C, cubic solid solutions BaTi_{1− x} Mn _x O_3−δ form over the range 0≤ x ≤0.015(5), whereas hexagonal solid solutions form for x ≥0.02, depending on the temperature. The results are compared with those on doping BaTiO₃ with Fe³⁺ and observations made concerning acceptor doping with Ti³⁺.     

Das redox-standardpotential von Co3+/Co2+

The standard potenial of the process Co³⁺+e=Co²⁺ has been calculated on the basis of the calorimetric determination of the thermal effect of the reaction Fe²⁺+Co³⁺=Fe³⁺+Co²⁺. The standard potential has also been estimated by extrapolating the cathode and anode tafel curves to intersection. The data available concerning the value of E^o_{Co³⁺/Co²⁺} have been thoroughly analysed, and the average value E^o from all independent methods of estimating the standard potential an acidic medium has been shown to be + 1·45. It has been found from the data on potentials of cobalt oxides in an alkali medium that the standard potential Co³⁺/Co²⁺ must be within the range 1·40–1·53 V. This value agrees with the value 1·45 V obtained in acidic media.     

Largely enhanced mechanoluminescence properties in Pr3+/Gd3+ co-doped LiNbO3 phosphors

Pr³⁺/Gd³⁺ co-doped LiNbO₃ phosphors were prepared by a traditional solid-state reaction method and their structure, photoluminescence, mechanoluminescence and thermoluminescence were investigated. The results showed that the LiNbO₃ phase with a rhombohedral structure and an R3c space group was successfully prepared. Mechanoluminescence intensity in nonstoichiometric LiNbO₃:Pr³⁺ was largely increased by introducing Gd³⁺ ions. The optimal co-doped concentration of Gd³⁺ was 1?mol% and the enhanced ML intensity of LiNbO₃:0.01Pr³⁺, 0.01Gd³⁺ was about 177% times compared with that of LiNbO₃:0.01Pr³⁺. The effect of Gd³⁺ co-dopants on trap levels were explored through thermoluminescence curves. The enhancement of mechanoluminescence intensity was suggested to be ascribed to the regulated trap quantities caused by co-doped Gd³⁺ ions. Appropriate co-dopants are proved to be effective sensitizers for mechanoluminescence materials.     

Photochemical Reaction in a Reduced Soda-Lime-Silica Glass Containing Ce3+ and As3

The photochemical reaction between Ce³⁺ and As³⁺ in a reduced 16Na₂O. ¹1CaO.73SiO₂ glass (mol%) was examined by exposing it to an Xe or Hg arc. In addition to Ce⁴⁺, a paramagnetic As(II)OS center having C_2v symmetry and a trapped electron center were identified by ESR. The As(II)O defect is the origin of the unidentified ESR signal which correlates with the discoloration of a borosilicate glass developed for solar energy application .