变频器在双“D”石灰竖窑卷扬提升机上的应用

介绍了ABBAACS800变频器在双“D”石灰竖窑自动控制系统中的应用。双“D”石灰竖窑上料系统利用现代计算机技术将PLC系统与变频器系统紧密结合在一起，实现PLC与变频器控制的统一，解决了因卷扬控制系统不稳定而造成的停产问题，提高了卷扬上料系统的稳定性。降低了上料系统的故障率。高效变频器的灵活应用，成为双“D”石灰竖窑实现稳产、高产的基础。     

机械化石灰立窑上料控制系统的改进

对机械化石灰立窑上料系统限位形状进行改进,增加可靠的超程保护,改进布料器控制,利用PLC实现软件设计,替代传统的继电器控制系统,实现自动控制,使系统控制更完善。     

PLC在脱盐水处理自动控制系统中的应用探究

PLC作为可编程逻辑控制器因其具有高稳定性和高可靠性可大大提高整个运行系统的质量和效率,对于脱盐水处理自动控制系统起到十分重要的促进作用。本文旨在研究PLC在脱盐水处理自动控制系统中的应用,详细分析拖延水处理工艺的特点以及PLC在具体工艺中的应用优势,为我国脱盐水工程的发展提供参考和依据。     

铁水脱硫处理设施自动控制系统

介绍唐钢一钢轧厂铁水脱硫处理设施自动控制系统的工艺特点及其自动控制系统的硬件配置,以及PLC控制功能特点和系统网络通信情况。     

氯化反应釜自动联锁控制技术

1系统说明 由PLC系统根据反应釜内的温度及出口压力,自动调节氯气控制阀门的开度,同时自动调节反应釜夹套冷却水回流阀门的开度,在设备及反应过程异常时,能有效的自动控制各阀门按照系统设计方案执行。通过PLC编程,组成一个智能化的多参数的自动控制系统,实现化学反应过程自动控制,优化工艺的目的。     

示踪剂自动上料和注入技术浅析

为了提高注入示踪剂的效率,减少人工操作的次数和错误,增加示踪剂注入浓度的精确性,结合海上示踪剂注入的实际情况,开发出一种可移动撬装式示踪剂上料注入装置。采用示踪剂自动上料和注入撬,可以大大减轻海上作业人员的作业强度,增加示踪剂注入的精确性,减少作业人工费用,提高作业时效。分析认为,示踪剂自动上料和注入技术取得了较大成功,为我国油田合作开发及技术引进起到了借鉴作用。今后随着智能化橇块的研究,进一步加强自动控制的要求和精度,从而做到无人化智能化的示踪剂自动注入装置。     

浅谈变频器和主令开关在石灰窑上料系统中的应用

安全可靠的设备运行是现代化工业发展的必要途径,可靠稳定的设备运行可有效保证石灰窑产量以及提高质量。本文根据石灰窑生产的要求以及卷扬机主驱动系统,在石灰窑上料系统中采用PLC与编码器及变频器相结合实现了单料车的稳定控制,解决了因卷扬控制系统不稳定而造成的停窑问题。提高了卷扬上料系统的稳定性,降低了上料系统的故障率和设备运行的基本故障判断及停机保护时间。上位系统可有效的记录故障数据。     

智能集中润滑系统在TRP辊压机的应用

<正>随着工业自动化程度的不断提高,对设备运行条件的要求也更加严格,机械的、人为的润滑操作已不能满足科技进步的要求,因此润滑自动控制系统得到广泛的应用。ZDRH-2000型智能集中润滑系统即是改变传统润滑思路,采用PLC智能     

基于iFIX2.6的液化气罐区监控系统

随着科学技术的不断进步，现代化工行业的生产技术、工艺过程日趋复杂，生产自动化的要求越来越高。在这种形势下，对于一个自动控制系统而言，不但要求其现场控制器具有高可靠、高精度和全分散的特点，而且也要求其上位机监控软件具有强大的功能和友好的人机交互界面。我厂“液化气罐区监控管理系统”选用了西门子PLC作为下位机，选用了成熟的监控软件iFIX2．6作为上位机软件。本文以该系统为例介绍了iFIX2．6     

S7—300PLC在城市污水处理中的应用

本文以某城市污水处理厂为背景,介绍了西门子S7—300PLC在城市污水处理自动控制系统中的应用,主要包括污水处理厂的控制要求及功能、PLC的主要特点、PLC的硬件配置、系统构成及其布局、系统软件和实际运行效果等内容。     

氢气纯度分析方法准确性的探讨

ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l／3为氧气,2／3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中：A一混…     

COMPARISON OF METHODS OF ANALYSIS OF GYPSUM1

The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO₃ and determination of CaO by KMnO₄ titration, the SO₃ by Andrews method of titration of BaCrO₄ has been found to give very reliable results with the least consumption of time.     

SEDIMENTATION OF BINARY MIXTURES OF PARTICLES OF UNEQUAL DENSITIES AND OF DIFFERENT SIZES

A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases.     

HEASUREHENT OF INSTANTANEOUS RATES OF LOSS OF VOIATILE COMPOUNDS DURING DRYING OF DROPS

A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.

Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology.     

茶多酚提取方法进展

本文综述了国内外现有茶多酚提取方法的现状以及近期的研究进展，并对其优缺点进行了评价。这将有助于中低档茶的综合利用和茶多酚的进一步开发应用。     

ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES

Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log₁₀ viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log₁₀ viscosity as a function of soda content are smooth up to 50% Na₂O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO₂, 2Na₂O) due to Molecular Substitution of CaO, MgO and Al₂O₃ for Na₂O The effect is clearly brought out by plotting (from the results of English) the change of log₁₀η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature T_a. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log₁₀η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A1₂O₃) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al₂O₃) per 100°. At the aggregation temperature the change of log₁₀η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al₂O₃. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log₁₀η due to substitution of an oxide for Na₂O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na₂O-CaO-SiO₂. Change of Viscosity of Glass (4SiO₂, 2Na₂O) due to of Substitution of B₂O₃ for SiO₂ The change of log₁₀η (from the results of English) is plotted as a function of temperature, and also the change of log₁₀η per per cent B₂O₃. The curves are more complex than for the substitution for Na₂O.     

环氧树脂羟基值测定方法的研究

利用乙酸酐、吡啶和浓硫酸混合的乙酰化试剂测定环氧树脂中羟基值含量的方法具有操作简便、滴定终点明显和分析结果误差小等优点。     

骑式摩托车油箱喷涂工艺的改进

面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。     

几种针状焦性能对比

针状焦分石油系和煤系两大类,这主要取决于针状焦的原料来源。在同一系列中由于原料不同和工艺条件不同 ,针状焦的各自性能也不相同。针状焦是生产超高功率石墨电极和高功率石墨电极的主要原料 ,针状焦的性能对石墨电极的质量有至关重要的影响。所以对针状焦性能以及其对石墨电极质量影响的研究十分必要的。以下是常用的几种进口针状焦和国产针状焦的性能对比。１原料性能分析对比原料试样包括４种针状焦 ,其中两种为进口针状焦：三菱针状焦和新日化针状焦;另两种为国产针状焦：鞍山针状焦和锦州针状焦。其中除锦州针状焦是石油系针状焦外…     

聚酰亚胺的合成法

本文评述了缩聚型聚酰亚胺的主要合成方法和近年来国际上在合成中所做的探索。