四平昊华氯碱扩产新装置计划2006年7月开车

吉林四平昊华新老装置的管线对接工作已经完成，老装置结束检修恢复开车，5万t／a烧碱新装置预计7月开车。     

浅谈二氯乙烷裂解的开车

对８万ｔ／ａＶＣＭ装置中二氯乙烷裂解系统生产原理及工艺流程进行简单介绍,同时对开车过程中出现的问题进行了详细分析,找出解决问题的办法。     

渭化大机组开车方式的比较

详细叙述了渭化大机组的3种开车方式：自动开车方式,半自动开车方式和手动开车方式;并对3种开车方式进行了比较。     

论化工总承包模式下的开车管理

开车服务管理是工程总承包项目管理的重要内容之一,是集设计、采购、施工和生产准备工作成果之大成。本文阐述了化工工程总承包开车管理的意义、工作内容、与总承包各阶段的衔接,提出开车管理的过程条件和实施管理的注意事项。     

裂解装置开车过程减少火炬排放的探讨与实践

随着裂解装置的大型化,其开车的成本也不断增大,同时火炬排放对环境的影响也越来越大,如何降低开车成本和火炬排放对环境的影响,成为企业关注的问题。通过对镇海炼化1000kt／a裂解装置两次开车过程的对比,探讨裂解装置减少火炬排放降低开车成本的措施。     

生产指挥系统在开车过程中的作用

针对开车过程中的指挥、协调等工作,合理安排人员工作分工,明确责任,使开车程序标准化、流程化。     

硫酸车间无污染开车的生产实践

介绍60 kt／a硫铁矿制酸装置无污染开车的生产实践。沸腾炉采用木柴点火升温,杜绝了用柴油升温时的放空污染;净化工段减少了排酸量;转化和干吸工段注意工艺参数的控制。装置最终实现开车期间烟囱不冒大烟,无黑酸产生,并且节约了费用。     

庆安年产15万吨DOP项目开车

浙江庆安化工有限公司5万吨／年苯酐，15万吨／年增塑剂（DOP）项目近日建成并开车成功，进入商业运行阶段。     

2万t/a离子膜烧碱装置开车总结

介绍2万t／a离子膜烧碱装置的开车情况及运行考核结果，并介绍了开车过程中应注意的问题。     

离子膜烧碱一期工程开车及运行总结

介绍了3t／a子膜烧碱装置开车情况及运行中出现的问题和处理方法。     

湖南金迪聚酯投料试车及试生产

介绍该装置的试车过程和 2年来的运行状况。吸纳了专利公司的许多改进之处 ,形成本装置的工艺条件、设备特点。一次投料试车成功 ,目前装置在 12 5 %负荷下平稳运行 ,各项指标优于合同值。在 12 0 %负荷下 ,PTA、EG、电的单耗分别为85 8、334、81。经过论证 ,在 5釜不做大的改动的情况下 ,可扩容至 2 80t d     

Start up of biological sequencing batch reactor (SBR) and short‐term biomass acclimation for polyhydroxyalkanoates production

BACKGROUND: The adaptation/selection of mixed microbial cultures under feast/famine conditions is an essential step for polyhydroxyalkanoates (PHA) production. This study investigated the short‐term adaptation of a mixed microbial culture (activated sludge) during the start up of a sequencing batch reactor (SBR). RESULTS: Four different SBR runs were performed starting from different inocula and operated at the same organic load rate (8.5 gCOD L^?1 d^?1) and hydraulic retention time (1 day). At 3–7 days from SBR start up, the selected biomass was able to store PHA at comparable rate and yield with those obtained after long‐term acclimation. Independently from the time passed, a short feast phase was the key parameter to obtain PHA storage at high rate and yield in the following accumulation stage (244 mgCOD g^?1CODnonPolym h^?1 for specific storage rate and 48% COD COD^?1 as PHA content in the biomass). The DGGE profiles showed that the good storage performance and the structure of the microbial community were not fully correlated. CONCLUSIONS: The results suggest a new strategy for operating the PHA accumulation stage directly in the SBR, after very short biomass adaptation, instead of using two separate reactors for biomass enrichment and PHA accumulation, respectively. © 2012 Society of Chemical Industry     

Start‐up of slot die coating

A flow visualization technique was employed to observe the start‐up of slot die coating. The effects of five variables, i.e., prewetting on the die surface, fluid viscosity, slot gap, coating gap, and die lip length on the start‐up time were investigated. Prewetting on the die surface can effectively reduce the start‐up time. Any variable that enlarges the steady‐state coating bead would increase the start‐up time. Therefore, increasing the fluid viscosity, coating gap, slot gap and decreasing the die lip length can be helpful in reducing the start‐up time. It was found that there exist four distinct modes for the establishment of steady‐state coating bead. The four distinct modes can be distinguished by a Reynolds number, which is defined as the ratio of the inertial force of the coating solution impinging on the moving web to the viscous force needed to pull the coating solution on the web. Comparison of the experimental observation with the theoretical prediction based on the commercial package Flow3D was also performed; the four modes can be found in the numerical simulations, the start‐up time computed to reach steady state is shorter. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

Analysis of the Start‐up Process for Reactive Distillation

The start‐up procedure of a distillation column is a time‐ and energy‐consuming process. Further, the products during the start‐up time are off specification and cannot easily be recycled as for conventional distillation but must costly be disposed of. In this paper, a process model to simulate the barely analyzed start‐up procedure for a reactive distillation from the cold and empty state to steady state is presented. The start‐up of a reactive distillation column has been modeled with gPROMS. The advantage of a cold and empty start‐up is the consistent and reproducible initialization. Commercial simulators do not give the opportunity to start form a cold and empty state, e.g., a column modeled with Hysys must be shut down from a steady state to be able to model the complete start‐up process, which is not possible, for example, for a batch process. Also, a change in the describing equations and discontinuities in process variables is difficult to handle within the simulation. In this paper, the start‐up strategies normally used for distillation without reaction are examined and applied to reactive distillation. It will be shown that the widely used strategy of total reflux is not suitable for reactive distillation. A simplified model to derive a time constant which describes the influence of parameter setting changes, like heating power, reflux ratio and feed composition on the start‐up time, is introduced and validated.     

减少烯烃分离装置开工损失的措施

介绍了目前国内煤制烯烃项目投产情况,叙述了烯烃分离装置典型工艺流程和技术特点;分析了烯烃分离装置在开工过程中的物料损失原因;提出了减少烯烃分离装置开工损失的措施;分析了压缩机组在开工过程中非计划停车的常见原因及相应对策。     

软起动的介绍及应用

从软起动的定义着手,指出了电机直接起动的要求及危害,介绍了软起动的工作原理、控制方式及技术特点,结合软起动的应用条件,通过计算验证了起动过程电压下降满足设计规范的要求,阐述了软起动的调试及同步电机软起的起动过程。总结列出了常见故障现象及处理方法,最后从运行的角度分析了应用效果及注意事项。     

An Extensive Analysis on the Start‐up of a Simple Distillation Column with Multiple Steady States

The impact of start‐up procedures on the behaviour of simple distillation columns with multiple steady states is analyzed. A well‐known system with hysteresis is studied in this paper and transient responses for a binary distillation column yielding different steady states during the start‐up operation are shown. Several dynamic simulation results showing an interesting behaviour are presented. Through the examination of the profile evolutions corresponding to given start‐up policies, it can be seen how the column arrives to different steady states. It is shown that it is possible to identify a set of critical values for the start‐up supervision. Also, guidelines of general validity are achieved with the aim of finding the appropriate start‐up policy to obtain the desired solution.     

Dissolution and Migration of Platinum in PEMFCs Investigated for Start/Stop Cycling and High Potential Degradation

Dissolution and migration of platinum due to start/stop degradation and increased cathode potentials were studied for commercial membrane electrode assemblies (MEA). The chosen conditions closely mimic real situations in automotive operation. In start/stop tests, we observed a strongly enhanced platinum dissolution due to the dynamic interplay of repeated cell start‐up and consecutive normal fuel cell operation, which is related to platinum oxidation (start‐up) and reduction (normal operation) cycles. Consequently, the performed test protocols distinguish between dynamic and static load profiles. Electrochemical investigations before and after degradation monitor the loss in cell performance. Since electron microscopy offers the unique possibility to unravel and distinguish degradation due to carbon corrosion and agglomeration or platinum dissolution, a focus was set on this method. For the start/stop MEA pronounced platinum dissolution accompanied by the formation of large platinum precipitations in the membrane was found. Carbon corrosion was also observed, but did not lead to a significantly reduced porosity and loss in platinum dispersion. In contrast, the MEA which was exposed to high constant potentials exhibited severe damage to the 3D cathode structure due to carbon corrosion. However, no pronounced platinum dissolution was observed and only few Pt precipitations were found in the membrane itself.     

磁控软起动在煤气鼓风机中的应用

介绍电动机直接全压起动的原理及缺点,电机当前主要起动方式的优缺点,RQD—D7软起动装置的原理、特点及改造效果等。     

Experimental Studies on the Influence of Operational Parameters on the Cold Start of a 2 kW Fuel Cell

In this paper, experimental investigations on the influence of operational parameters on PEM fuel cell cold start are presented. The effect of current density, stack impedance at 1 kHz prior to start, as well as gas flow rate, gas pressure, coolant flow rate and surrounding subfreezing temperature are studied. The experimental apparatus is briefly described. It includes a main unit at room temperature and a smaller separate unit in a climatic chamber. Low current density, high impedance prior to start, moderate subfreezing temperature (–5 °C), high gas flow rate, low gas pressure and low coolant flow rate are found to have a positive impact on the cold start performance. Combining these parameters, self start‐up of the fuel cell without additional energy is achieved at –5 °C in 30 min. The whole set of observations leads to the following hypotheses on freeze mechanism: in the first phase, dry membranes and low current lead to a transient phase of membrane humidification. Then, in the second phase, ice clogging of the active layers occurs. In the third phase, a variable quantity of the produced water reaches the gas diffusion layers and channels.