PTA球阀加热夹套热媒垢化学清洗

采用复合表面活性剂对ＰＴＡ装置球阀加热夹套热媒垢成功地进行了化学清洗。     

导生放空冷凝器技术改造及工艺流程优化

气相热媒-导生被广泛应用于聚酯装置中设备夹套的供热和设备保温系统,一般采用自然循环方式加热。该文通过对设计缺陷导致的设备运行温度低、导生放空回收系统设备故障率高等问题进行研究分析,找出主要原因,实施针对性的设备技术改造和工艺流程优化,有效解决了上述问题。研究表明始终保持导生加热系统循环回路总推动力大于回路总摩擦压力降,避免压降过大,产生闪蒸形成汽液混流,是气相导生冷凝放空回收系统设计的关键。     

PTA球阀加热夹套热媒垢化学清洗

采用复合表面活性剂对ＰＴＡ装置球阀加热夹套热媒垢成功地进行了化学清洗。     

聚酯装置中热媒循环系统的设计

热媒系统是聚酯装置的重要组成部分,国产化聚酯装置设计初期的全液相热媒加热系统能耗相对较大,总体效率较低。随着聚酯装置中气相热媒系统替代液相热媒系统和一次热媒直接加热第一酯化反应器盘管技术的使用,减少热媒循环泵,降低了运行电耗。详细介绍了二次液相热媒系统和气相热媒系统的工作流程,并分析了各自的设计要点;指出聚酯装置中热媒循环系统的设计应当从流程、控制、布置等方面来完善,严格控制聚酯熔体温度,以保证聚酯装置及纺丝装置的正常运行。     

PET工厂液相热媒系统的操控调整

对PET厂液相热媒系统作了讨论。针对一个热媒站供2套PET装置的情况进行重点分析,提出2套PET装置相互影响下调整液相热媒系统以稳定生产的注意要点及调整方向。     

气相热媒系统与液相热媒系统热媒循环泵选择

阐述气相热媒站系统与液相热媒站系统热媒循环泵的选型的差异。主要讨论热媒循环泵的流量、扬程、气蚀余量的计算异同,对热媒循环泵的选型提供指导。     

热媒炉油改气前后运行状况对比分析

热媒炉是聚酯、长丝、短丝三套装置的主要供热设备,是聚酯装置的关键设备。由于运行时间较长、设备老化,热媒炉在实际运行中出现许多故障。这些故障严重影响了热媒炉的平稳运行。为了解决这些问题,对热媒炉进行了油改气改造。油改气后,热媒炉的抗风险能力得到很大的提高,效率也由之前的89%提高到了90.5%以上。油改气改造解决了影响热媒炉平稳运行的隐患,为三套装置的平稳运行打下了坚实的基础。     

聚酯装置中气相热媒系统的设计与应用

介绍了气相热媒介质联苯-联苯醚共沸混合物的物理性质和使用要求;分析了在聚酯装置中气相热媒系统的设计与控制方案。提出在气相热媒系统设计中,应减少热媒泄漏,采取程序化升温,先快速升温到216℃,然后缓慢升温至270～295℃;在其配管设计中,要考虑每段管道的特殊性,减少凝液直接回流至热媒蒸发器,一次热媒的流向为蒸发器的下部进、上部出的方式;在聚酯装置开车时,气相热媒的加热应采取液相温度和气相压力共同控制的方法,保证热媒蒸发器的稳定性。     

利用聚合液相热媒加热纺丝联苯技术的工程实现

论述了熔体直纺纺丝过程循环加热系统和实现方法。研究利用直纺聚合一次热媒较高温度液相热媒,通过新型热媒蒸发器加热用于纺丝箱体循环及熔体管道输送的气相热媒,从而达到纺丝工艺要求温度的技术,并对该技术的计算方法和工程实现方式以及控制工艺进行了探讨。     

使用EXCEL进行PET装置热媒蒸发器的设计计算

通过对热媒蒸发器的特点进行分析,选取了合适的计算模型和公式,使用EXCEL电子表格的单变量求解和宏工具,方便地实现了热媒蒸发器的设计型计算。为实现程序自动迭代运算,文中还列出了通过EXCEL电子表格的数据处理功能对气相热媒和液相热媒参数在所使用的温度区间内进行连续化归纳的计算公式。     

Heating/Drying Using Particulate Medium : A Review Part I. General and Heat transfer parameters

This paper presents an Overview of particulate medium drying and heat treating of cereal grains. While the conventional air drying of grains is well documented, studies on the drying of grains using heated granular medium do not appear to exist. The scientific study of the different aspects of drying with a heated granular medium began in the early 1970's. Progress on the utilization of particle-to-particle heat transfer was slow as evidenced by the fact that there is no commercial dryer using the method as of today.

The first section of this paper deals with conduction heating and how it led to the use of granular medium in heating the grain. Starting with the earliest work on conduction heating reported by Kelly ( 1939), the developments in the heating of grain using granular media is discussed. For decades since Kelly's report, work in the subject area dealt mostly with the theoretical aspects of solid-to-solid heat transfer. Thus, in the succeeding section of the paper, heat transfer parameters and mechanisms involved in the process are thoroughly investigated.     

Heating/Drying Using Particulate Medium : A Review Part I. General and Heat transfer parameters

ABSTRACT

This paper presents an Overview of particulate medium drying and heat treating of cereal grains. While the conventional air drying of grains is well documented, studies on the drying of grains using heated granular medium do not appear to exist. The scientific study of the different aspects of drying with a heated granular medium began in the early 1970's. Progress on the utilization of particle-to-particle heat transfer was slow as evidenced by the fact that there is no commercial dryer using the method as of today.

The first section of this paper deals with conduction heating and how it led to the use of granular medium in heating the grain. Starting with the earliest work on conduction heating reported by Kelly ( 1939), the developments in the heating of grain using granular media is discussed. For decades since Kelly's report, work in the subject area dealt mostly with the theoretical aspects of solid-to-solid heat transfer. Thus, in the succeeding section of the paper, heat transfer parameters and mechanisms involved in the process are thoroughly investigated.     

热媒锅炉的改造

分析了涤纶纺丝用热媒锅炉运行中热媒排放温度逐渐下降的原因是热媒锅炉用加热棒附近的局部温度过高。通过降低单根加热棒的加热功率,增加加热棒的数量,加热棒表面温度降低,保证了正常生产,且可节省热媒。     

Microwave combination heating: Coupled electromagnetics‐ multiphase porous media modeling and MRI experimentation

The work includes development of a multiphase porous media model and magnetic resonance imaging (MRI) experiments to study microwave combination heating. Combination of electromagnetic, convective and radiant heating was considered. The material being heated was modeled as a hygroscopic porous medium with different phases: solid matrix, water and gas, and included pressure driven flow, binary diffusion and phase change. The three‐dimensional transport model was fully coupled with electromagnetics to include the effect of variable properties. MRI was used to obtain spatial temperature and moisture distributions to validate the model. The model demonstrated that high and low moisture materials behave differently under different combinations of heating and general guidelines for combining heating modes were obtained. Low moisture materials can be heated effectively using higher microwave power which is not possible in high moisture material. Cycling of microwave was found to be useful in distribution of excessive volumetric heat generated by microwaves. © 2011 American Institute of Chemical Engineers AIChE J, 2012     

12.5m~3搪瓷氯化釜传热系数的测定

在12.5m3搪瓷氯化釜上,以热水通入反应釜夹套加热釜内物料,测得反应釜内物料温度、反应釜夹套进出口温度以及加热时间等数据,然后,依据牛顿插值法处理水的物性数据,再根据传热速率方程计算得到传热系数为333.7W/(m2·℃)。     

高效、节能、环保型聚四氟乙烯加热器(反应釜内专用)

多年来,国内外广大化工企业生产中使用的反应釜,都是用钢壳外壁上的夹套来加热釜内介质,由于其热传递过程长,热阻大,而导致介质加热速度慢,时间长,高温上不去,热效率又低等结果,从而抑制了工业生产的发展。作者针对上述问题,发明了一种高效、节能与环保型的聚四氟乙烯加热器,直接置于反应釜内加热介质,改变了原有的生产面貌,从而达到了显著的节能、减排与增产的效果。     

带浸没管的惰性粒子振动流化床传热特性

采用带浸没加热管的惰性粒子振动流化床对膏状物料干燥进行了实验研究。考察了加料速率、进气温度、进气速度、加热管功率、振动强度等参数对床温和体积传热系数的影响,得出了计算体积传热系数的关联式。结果表明,在流化床中增设振动和浸没加热管装置,能大大强化传热传质,体积传热系数随加料量、振动强度、加热管功率、进风速度的增加而增大,随进气温度的增加而减小。其结果对惰性粒子流化床干燥器的设计和改进具有重要的指导意义。     

天然气换热式转化工艺常见事故原因及处理

介绍了TANDEM天然气换热式转化工艺中一段转化炉触媒层阻力大，出一段炉转化气温度高，一段炉出口气甲烷含量高和二段炉阻力大，二段炉壳体水夹套内水沸腾或过热及触媒层温度分布畸形的原因及处理方法。