在线分析仪表在水煤浆气化装置中的应用

结合实际工程,通过对水煤浆气化装置中在线分析仪表的类型及分析系统,包括取样装置、样品传输、样品预处理装置、分析仪表原理的介绍,论述在线分析仪表在水煤浆气化装置中的应用。     

A device for measuring solids flowrate in a circulating fluidized bed

The on-line measurement of solids flowrate is important to numerous industrial processes. This paper considers a variation of impact-type solids flow meters suitable for use in numerous applications, including circulating fluidized beds (CFBs). The solids flowrate meter introduced herein is on-line, capable of operation in high temperature environments, and useful for a broad range of flowrates with good linearity, accuracy and fast response time. The flow meter works by measuring the torque that results on a hinged plate when falling solids impact the plate. A theoretical model of the device is developed and its results are compared to experimental data for the operation with various solids.     

On-line monitoring of polymer quality in a batch polymerization reactor

A novel experimental reactor system has been designed to study a variety of problems related to on-line measurements and computer control of batch polymerization reactors. A number of measuring devices such as densitometer, viscometer, size exclusion chromatograph, and torquemeter have been put on-line to a batch reactor and interfaced to a real time computer to monitor monomer conversion and molecular weight during polymerization. A new feature of the experimental setup is its microprocessor-based sampling system which automatically collects samples from the reactor and injects them into the SEC analyzer. Computer software has been developed for on-line acquisition and processing of SEC data. This work demonstrates the feasibility of on-line measurement of monomer conversion and molecular weight. Furthermore, it presents a comparative study of some common techniques employed for off-and on-line measurement of polymer quality.     

Numerical analysis of the temperature profile in the melt conveying section of a single screw extruder: Comparison with experimental data

The prediction and measurement off the developing radial temperature profile in a single-screw extruder is essential since excessive extrudate temperature and poor temperature uniformity at the die affect the quality of coextrusion and film/sheet extrusion processes. A finite-difference scheme is used to predict the development of the radial temperature profile in the metering section of a single-screw extruder for power-law fluids. A finite-element analysis of the flow around the screw-tip transposes this temperature profile onto an on-line temperature measuring device consisting of 10 thermocouples for a comparison of numerical results with experimental data on polycarbonates.     

水系胶体Zeta电位的电声法测量

基于电声法原理研制了一种能同时用于胶体声阻抗和Zeta电位测量的电声探头,建立了一套测量胶体Zeta电位的实验装置,多次实验证明设备稳定性良好. 通过多次回波测量声阻抗计算Zeta电位,测得纳米黄土及TiO2胶体的Zeta电位分别为-52.69和-16.09 mV,分析了5%~30%(j) SiO2胶体的Zeta电位变化趋势,表明该方法可用于高浓度胶体测量,与马尔文公司光脉动Zeta电位测量仪测量结果偏差较小. 本方法有望实现在线测量Zeta电位.     

基于被控变量在线建模的化工过程实时优化方法

选择合适的被控变量可对过程进行实时优化(RTO),但现有方法在设计阶段确定被控变量后,不允许对其进行在线调整,导致了RTO效果的局限性。针对这一问题,提出了一种基于被控变量在线建模的方法,使用局部建模技术在线寻找相似样本并建立一阶最优性必要条件(NCO)的估计模型,将其作为被控变量更新控制回路,在反馈控制作用下达到更好的RTO效果。对一个蒸发过程的研究表明,此方法能够通过对NCO的在线准确建模,增加生产过程的经济效益。     

Improvement of copper recovery in electrochemical reactors using turbulence promoters

This paper compares the concentration-time relationship and faradaic yield for copper removal in an electrochemical reactor system operating with continuous recirculation of the electrolyte through a channel including or not eddy promoters.It is shown that the promoted device presents higher performance for copper depletion and an approximate model taking into account a plug flow inside the reactor associated with a well mixed tank is shown to describe experimental data very satisfactorily.From an energetic aspect, the presence of promoters in the cell increases the mechanical energy consumption, but this disadvantage is counterbalanced by a lower overall energy consumption for a given depletion in copper concentration.     

A New Device for the Measurement of Ozone in the Gas Phase

This paper presents a new device for the dosage of ozone in the gas phase. This device measures the concentration of ozone according to the isothermal differential pressure procedure. In principle, this procedure achieves a totally physical ozone measurement without requiring calibration using a chemical method. A comparison is made between the physical results and chemical results obtained by the iodometric standard method (IOA, 1987). There is satisfactory agreement between the two series of measurements in the range of ozone concentration where the chemical method is applicable (with a standard error of estimate of 4.4%).The method and the device are perfectly reliable based upon the strict measurements of temperature and pressure and a convenient choice of constitutive materials.     

基于Fast-RVM的在线软测量预测模型

生化需氧量(biochemical oxygen demand,BOD)是评价水质好坏和污水处理效果的关键指标之一。由于污水生化处理过程复杂,在线仪表维护困难,生化需氧量无法得到快速精确地测量。针对这一问题,提出了一种基于Fast-RVM的在线软测量回归模型来实时在线预测出水指标BOD。该模型采用基于贝叶斯框架的相关向量机来在线预测输出指标,并且引入快速边际似然算法来加快模型的更新速度。通过污水数据的仿真实验,结果表明该在线模型的预测精度高于离线模型,泛化能力强,模型在线更新的快速性尤为突出,能较好地实现污水处理中出水水质的实时在线预测。     

ON-LINE OPTIMAL FEED OF SUBSTRATE DURING FED-BATCH CULTURE OF CELL MASS

In the cultivation of cell mass, a mathematical model for the specific growth rate of the cells can be used to design a strategy for the optimal feed of substrate to the culture. In this paper, a model of specific growth rate valid at both low and high cell concentration is developed for Candida utilis and Candida brassicae. An on-line control algorithm is then proposed to determine the optimal substrate concentration for the production of cell mass in fed-batch culture. An on-line estimation scheme using the sensitivity method is also included for cases in which the cell mass can not be measured. Simulation results demonstrate that the proposed method can minimize the production time of fed-batch culture.     

Development of High-Efficiency PERC Solar Cells Using Atlas Silvaco

Silicon - This paper presents the results of an investigation of Passivated Emitter Rear Cell (PERC) solar cell technology and the current understanding of the fundamental device physics. The...     

在线总汞含量测定方法研究

研究了水中总汞离子含量的在线测定方法,通过在线富集、消解,并在水溶液中显色的方式建立了总汞含量在线分析装置。利用该装置测得汞含量的相对误差为6.7%,相对标准偏差为8.4%,可以满足在线分析精度要求。汞的线性范围为5～60μg/L,最低检测下限为1μg/L,由于采用了富集-消解-双硫腙/乙醇溶液显色的方式,能够实现对水中总汞含量的在线监测。     

A laser interferometric method for electron concentration measurements in stabilized plasmas

This work presents an interferometric means for measuring electron concentrations between 10¹² and 10¹⁶ electrons per cm³ in a stabilized ionized medium and an Argon plasma is used to illustrate the method. The interferometer is a 100 mW He-Ne laser emitting at 6,328 Å and 3.39 microns and a movable mirror is used to obtain the interferometric fringes required for calculation of the electron concenrations in the plasma The method uses the interesting feature of the He-Ne laser that both emissions at 6,328 Å and 3.39 microns originate at the same upper level so that variations in the 3.39 microns emission modulate the visible light (6,328 Å) output. This property has been used by a number of authors for measurements on plasmas in transient conditions; this paper presents an application of the method for stabilized plasmas, thus broadening the field of application     

ON-LINE OPTIMIZATION OF DISTILLATION COLUMNS IN SERIES

This paper presents an on-line optimization algorithm for distillation columns which consists of a steepest descent technique based on a simple model of product recovery with on-line estimation of the critical model parameter. The algorithm is developed for a single column and then for a two-column train. A dynamic programming approach is used to reduce the optimization problem to a single parameter search for each column in the train. The resulting algorithm is simple and computer resource requirements are small. The algorithm has been successfully used in two industrial applications, one consisting of two columns in series and the other of three columns in series.     

聚乙烯熔融接枝硅烷动力学及在线测量技术的应用

为了获得更广泛和更实际的商业化应用，定量了解聚烯烃熔融接技不饱和单体的动力学规律是十分重要的．本篇综述了用ＤＳＣ（差热分析）确定聚乙烯熔融接枝有机硅的动力学的方法及实验验证，并描述了在线流变测量和在线富里叶红外光谱测量技术在其中的应用．     

差动传感测量釉层热应力

本文介绍一种以差动传感原理测量冷却过程中釉层热应力的方法及装置，并对该装置的测量误差进行了分析。     

基于奇异值识别的模式切换过程递归PCA监控

常规的PCA方法难于对发生模式变化的过程参数进行监控,为此,本文提出了一种基于奇异值识别递归PCA技术,用于解决多模式切换过程的监控问题。首先建立了在线奇异值识别算法,通过识别奇异值的变化可以准确判断过程发生模式切换的时间,然后采用递归PCA对过程的模式切换过渡阶段进行监控。将TE过程用于实例研究,验证了所提出方法的有效性。     

辉铜矿氨法制铜盐工艺研究

本文研究了用含有活性剂的碳氨液从辉铜矿中浸取铜。经反复对比试验，筛选出含活性剂的碳氨液能有效地浸出辉铜矿中的铜，可望替代目前严重污染环境的干法取铜工艺。     

Predicting conversion using temperature as the measured variable in the RIM process. Part I: Simulation and measurement structure

In general the monitoring and control of many industrial processes is so complicated by problems associated with the on-line measurement of the desired objectives that they must be inferred from available measurements. This leads to a state estimation problem in which the selection and adaptation of the structure of the measurements plays an important role. In particular, in the reaction injection molding (RIM) process, an accurate on-line estimate of the conversion field is highly desirable. Since conversions cannot be determined readily by direct measurements, and a thermocouple can provide reliable dynamic temperature data, we can predict the conversion field from the solution of a state estimation problem using temperature as the measured variable. In this article, we describe an algorithm for designing the optimal arrangement of measuring sensors and analyze the RIM process dynamics which influence the structure depending on the operating conditions. The search for the optimal measurement structure for the purpose of state estimation makes up the bulk of the results. No particular estimation-control strategy is investigated in this paper. Work is underway to develop the on-line corrective system, which will use the temperature measurements to correct model predictions. The results of that work will appear in part II of this series.     

改进的卡尔费休法滴定装置测定葡萄糖酸镁水含量

用带橡皮塞的导管将滴定管的上口与锥形瓶连接构成一个密闭的滴定装置,将此装置应用于卡尔费休容量法测定水含量,在滴定过程中所有试剂与外界完全隔开,防止了空气中的水蒸气干扰,滴定终点明显,且能长时间稳定（8h以上）。该装置结构简单,操作方便。利用此方法成功测定了葡萄糖酸镁中的水含量,其平均回收率为102．0％。