应用KMM可编程调节器改造聚合釜的温度控制系统

一、概述 PVC聚合釜的温度控制系统,是PVC生产过程中的关键环节,该系统控制质量的好坏,直接影响VCM聚合的质量、产量和安全生产,原控制方案是以手动程序升温及釜温为主参数,夹套温度为副参数的串级调节系统组成。其操作步骤繁琐,操作工人必须凭经验按T—A、T—B过程操作和投自控,由于我厂使用的是30m~3大型聚合釜,时间常数大,温度滞后时间长,加上测温热电阻的时间滞后,原控制系统经     

史密斯预估算法在聚合釜温度控制中的应用研究

工业过程中的时滞现象非常普遍,大时滞的存在严重影响了系统的控制效果和稳定性,导致系统的超调变大,调节时间变长,甚至出现振荡和发散。史密斯预估控制是一种有效的时滞补偿方法,它能有效的解决控制系统中控制通道的纯滞后问题,减少超调量并加速调节过程。聚合釜温度被控对象的迟延的特点,本文介绍了一种采用施密斯预估补偿的聚合釜温度控制系统的应用研究,预计结果采用施密斯预估补偿的控制要优于传统的PID控制,能够很好地满足工业聚合釜的控制性能要求。     

锦纶聚合釜温度模糊自适应PID控制系统研究与仿真

锦纶聚合釜温度具有非线性、大滞后等特点,使用传统PID控制器的控制效果不够理想。在建立聚合釜温度数学模型的基础上,采用模糊算法与PID控制相结合的模糊自适应PID控制算法,实现PID参数自整定,提高控制精度。基于MATLAB平台构建釜温控制系统模型,仿真结果表明所提模糊自适应PID控制算法效果优于传统PID控制。     

模糊-PID在聚合釜温控中的应用

针对被控对象惯性延迟大、被调节信号反馈慢的特点,笔者采用恒流量温度控制方案对原聚合釜温度控制系统的单回路控制方案进行了改造,应用模糊-PID控制使聚合釜夹套水温与聚合反应温度保持较小的温差,将调节温度的过程变得更加平缓,经过实际应用取得了令人满意的效果.     

F46聚合反应釜温度智能控制设计及应用

聚合反应釜是聚合反应工程中的重要装置,其运行质量将直接影响到聚合产品的质量和整个生产过程的安全与稳定。根据聚合釜间歇操作的工艺条件不确定性问题提出了采用分段切换控制的方法。该方案在DCS中通过SCX编程语言实现,实际运行结果表明,聚合温度的智能控制系统其稳定情况和温度超调都符合工艺要求。     

糊树脂种子釜温度控制系统的国产化开发研制

在我们引进的法国阿托公司１万吨／年的糊树脂生产线中,种子釜温度控制系统,是用来控制其聚合反应过程的一套最重要、最复杂仪表控制系统。它以一台法方配套引进的四通道智能调节器为主要控制设备,用四个通道的输出量来调节控制种子釜的反应温度。由于引进的该系统是单...     

异戊橡胶中试装置聚合系统的温度调节方法

结合吉林石化公司研究院异戊橡胶中试装置,探讨了异戊橡胶聚合工艺升温机理和控温方法,通过长周期开车表明,选用合适的聚合釜个数、聚合釜搅拌形式,通过夹套冷却水温度调节、进料己烷温度调节、侧线冷己烷和催化剂用量调节可以使异戊橡胶中试装置聚合工序温度平稳可控。     

PVC生产中聚合温度异常原因探讨

在ＰＶＣ聚合期间根据生产牌号的需要，投用回流冷凝器，提高釜的传热能力，能较好地保证釜内反应物料温度的稳定。在生产末期，粘釜成为聚合反应后期温度高的主要因素。冷冻水的温度和流量直接影响着聚合釜的传热速率，要加强工艺操作技术管理和设备维护。     

含氟单体聚合温度的控制策略

本文在讨论含氟单体的聚合工艺和聚合速率、聚合釜传热能力、聚合温度和冷却水温选择的基础上，提出了聚合温度自控方案。     

提高PVC装置夏季生产能力的措施

分析了聚合循环水温度对聚合生产的影响，提出了优化引发剂配方，采用复合引发剂，做好聚合釜的涂釜工作避免粘釜和使用低温盐水等措施。通过改进，提高了聚合釜的传热能力，使聚合装置生产能力得到提高。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

三种煤样燃烧热的测定

本文通过三个厂家提供的三种煤样燃烧热的测定,由测定结果综合得出3号煤样燃烧最完全、燃烧热也最大,是三个煤样中最好的一种。     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

小议汽车涂装工艺设计对涂装成本的影响

论述了涂装工艺设计对涂装设备投资、涂装生产成本的影响。     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

Measurement of the gradient of viscosity with composition of mixtures of non-ideal gases

A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%.     

塔设备改造选型的分析

就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后，着重介绍一种新型塔板（导向梯形浮阀塔板）和一种新型填料（波环填料——乾隆帕克）。     

Effect of degree of deacetylation of chitin on the properties of chitin crystallites

In the present article, chitin from crab shell was systematically deacetylated using a NaOH treatment with control of the reaction time. The degree of deacetylation, monitored using solid-state NMR, revealed that the reaction was pseudo-first order. Based on this, swollen and NaOH-saturated particles are proposed as the reaction system. The weight loss of the partially saponified and neutralized samples after HCl hydrolysis increased linearly with the degree of deacetylation. The crystallinity of the samples was found to increase after acid hydrolysis. According to conductimetric titration, the surface charge density of the crystallites, after acid hydrolysis, was found to increase with base treatment time. The effect of surface charge on the formation of a chiral nematic phase, due to the rodlike nature of the crystallites, was explored. These results show that because the contribution of charged particles to the ionic strength was significant the double layer compression was affected, especially since the surface charge density was close to the Manning limit. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:373–380, 1997