污水流量计量仪表的选型

介绍了污水流量测量的特点和污水流量计量仪表的选型要点,结合各种流量仪表的特点阐述其选型原则,并给出了结论。     

采用新技术 提高计量水平

1 前言 我厂进出厂的物料、能源计量仪表,大部分是早期随装置引进的,主要采用孔板和电磁等作为计量手段。在实际使用中存在着精度低、抗干扰能力差、计量不准等问题。投产初期,在厂际物料计量方面经常出现和外厂计量误差太大而又无法科学合理解决的难题。特别是我厂的主要产品50％隔膜碱的总量和外供量,由于原仪表存在较多问题,时常     

计量仪表的测量误差及防范措施

本文就计量仪表在测量中出现的误差,着重讨论了影响计量仪表误差较大的附加误差(流量系数、流束膨胀系数、节流件开孔直径、管道内径、被测流体密度和压差的误差等),同时提出了减小附加误差、提高测量精度的措施。     

中国石化普光天然气净化厂仪表选型

以普光天然气净化厂第一联合装置为工程背景,详细介绍了仪表选型原则及规范。     

合成氨厂液氨计量方法介绍

介绍氨厂涡轮流量计在使用过程中出现的几个问题，针对这些问题从流量计的原理出发，进行逐一分析并提出合理的解决方法。值得同行们在使用氨流量计时借鉴和参考。     

天然气计量管理计量仪表与输差控制

本文主要分析了天然气计量管理中计量仪表和输差控制设置的现状,重点介绍了输差相关概念以及存在的原因,它不仅会影响到人们的生活品质,还会有利于相关部门通过对用户使用天然气的量进行了解,进而对天然气进行合理收费.通过对天然气计量管理的计量仪表进行分析,也能对天然气的输送情况进行控制,这对提高天然气的输送效率具有重要的意义,并...     

中色建设公司将在伊朗合资建造中型氧化铝厂

中色建设公司2007年10月11日发布公告称，该公司将在伊朗合资建造一座20万t／a的中型氧化铝厂。     

能源三气的计量及仪表

煤气、天然气和水蒸汽(以下简称三气)的计量。是存在了多年的棘手计量课题。随着环保事业的发展和人民生活水平的提高。工业城镇居民用气的数量正在与日俱增，由此，科学地解决煤气、天然气和供热蒸汽的计量问题，越发显得重要起来。     

建立计量与自控仪表网上管理系统

计算机网络技术正在逐步改变我们的工作方式,许多原来通过文件、传真或电话解决的问题正在逐渐由计算机网络来完成,它不但能节省开支,更重要的是极大地提高了工作效率。本文主要阐述如何通过计算机技术实现计量与自控仪表的网上管理。     

聚氨酯计量装置工作原理

介绍了丝框螺母机构、摆杆式计量装置、计量泵装置等计量装置的工作原理。这些装置满足双组分聚氨酯原料按一定比例、按一定速度输出的要求,宜于控制,具有良好的精度,有利于实现自动化。     

水厂废水处理投加PAM的分析选择

水厂废水需要寻求高效、无毒、经济的絮凝剂改善污泥水质 ,本文通过实验 ,对多种型号聚丙烯酰胺 (PAM )絮凝剂进行测试 ,对比分析 ,选择了合适型号的絮凝剂     

火电厂循环冷却水处理方案的选择

火电厂循环冷却水量较大,节水效果明显。对采用高硬度、高碱度,高硫酸根含量的水作循环冷却水的补充水时,采用部分软化方法具有投资省、运行费用低,废水排放量小、管理方便的特点。     

铝阳极氧化膜热水封闭粉霜抑制剂的研究

0 前言 铝具有质轻、光泽性佳、导热性高及价廉等优点,使其在日常生活及工业生产中被广泛应用.上世纪80年代起,由于建筑方面使用铝合金门窗越来越普遍,对铝型材的耐蚀性和装饰性提出了越来越高的要求.由于铝的活性大,易在表面生成一层极薄的氧化膜,但该氧化膜并不足以抵抗外界的腐蚀.所以工业上对铝和铝合金进行阳极氧化处理,得到一层无色透明、致密多孔、硬度较高、耐蚀能力强的氧化膜,以达到保护和装饰铝型材基体的目的.     

Dispersion-Strengthened Aluminum Oxide

Finely divided molybdenum particles were dispersed in aluminum oxide to serve as inclusions for the inhibition of grain growth and secondary recrystallization during sintering. Conventional powder metallurgy techniques were used to fabricate compacts of aluminum oxide containing up to 16 vol% molybdenum. Three methods for developing a uniform dispersion of molybdenum particles in aluminum oxide are compared on the basis of the resulting microstructures. Specimens sintered in vacuum had densities approaching 98% of theoretical density with an average grain size of 2μ or less with no evidence of secondary recrystallization. The grain refinement is reflected in transverse rupture strength data with average strengths exceeding 80 kpsi and maximum strengths exceeding 100 kpsi.     

Water Content and Water Evolution from Reaction-Bonded Aluminum Oxide (RBAO) Powder Precursors

Water evolution behavior from reaction-bonded aluminum oxide (RBAO) powder precursor was studied by the Carl-Fischer titration method. RBAO mixtures were milled for 4 and 8 h in absolute ethanol and water–ethanol mixtures containing 5 and 10 vol% water. The water content was then determined under dynamic heating conditions from 20°C to 250°C and static heating at 250°C. When the aluminum content is increased from 30 to 60 vol%, the water content of the milled powder precursor mixtures also increased. The higher water contents observed in powders milled in absolute ethanol are discussed in terms of the possible interaction of the ethanol with the surface of the aluminum particles.     

用于珠光颜料的片状氧化铝制备

采用熔融盐法制备片状α-Al2O3,研究了硫酸盐、煅烧温度、添加剂(磷酸盐、二氧化钛)对片状α-Al2O3晶体形貌的影响。当氢氧化铝凝胶煅烧温度为900℃时,没加硫酸盐分解所得的氧化铝晶相为κ-Al2O3晶相,而加入硫酸盐的氧化铝晶相为α-Al2O3晶相,熔融盐降低了片状α-Al2O3的形成温度,促进κ-Al2O3向α-Al2O3晶型转变。煅烧温度由900℃上升到1200℃时,片状α-Al2O3的团聚程度降低,颗粒尺寸分布更加均匀。当煅烧温度在1200℃下、磷酸盐添加量为3%、二氧化钛添加量为2%时,所制得片状氧化铝分散均匀,径厚比较大,片状氧化铝平均粒径为5.225μm、厚度约400-500 nm。     

Synthesis of Aluminum Oxide Platelets

Aqueous solutions of boehmite and hydrofluoric acid (HF) were used to prepare homogeneous mixtures of alumina and aluminum fluoride. Calcination at temperatures as low as 1000°C resulted in the formation of well-defined hexagonal-shaped α-alumina platelets. Containment of the aluminum fluoride by covering the calcination crucible promoted crystal growth presumably by a reaction of continuous evaporation–condensation of aluminum fluoride. Hexagonal-shaped platelet α-alumina was observed with average diameters ranging from 7 to 33 μm. Large platelets with a narrow size distribution and average diameter of over 25 μm were prepared by controlling the initial concentration of HF and the calcination time, temperature, and atmosphere.     

Hot Pressing of Aluminum Oxide

The hot-pressing characteristics of two aluminum oxides were studied in order to acquire a better understanding of the densification process and to develop a method of predicting the effects of experimental conditions other than those actually tested. A rapid hot-pressing technique was developed which greatly reduced the time element. The rate equation proposed by Murray, Livey, and Williams for hot-pressing ceramics was found to hold for the two aluminas, thus making it possible to predict the effects of changes in hotpressing conditions. The equation used was     . Viscosity, η, was calculated as a function of temperature using this equation and the experimental hot-pressing results. Values varied from 1.2 × 10¹² poises at 1300°C. to 4.6 × 10¹⁰ at 1600°C.     

石化装置中变压器的选择

从节约电力的角度对石化装置中电力变压器的型号、容量的合理选择提出建议。