薄膜蒸发器过程参数的信息系统

介绍了薄膜蒸发器及其过程监测系统,阐述了粗糙集理论适用的信息系统以及时间序列数据的概念。通过对薄膜蒸发器连续生产过程的特点及信息系统的特征分析,提出了针对薄膜蒸发器过程参数如温度、压力、流量等时间序列数据的不同处理方法,建立了粗糙集理论适用的薄膜蒸发器过程参数预测预警研究的信息系统。     

基于Rough集理论的薄膜蒸发器产量预测

由于薄膜蒸发器生产过程高度复杂,导致产量的预测比较困难且准确率低。采用基于Rough集理论的数据分析工具包Rosetta,实现了薄膜蒸发器的产量预测研究。该研究完成了知识发现的全过程包括数据准备、数据分析以及结果的解释评估。研究结果表明:对条件属性的约简找出了对产量影响较大的因素,如试验时间、流量、蒸发强度、导热油温度以及刮板转速等;对产量的预测基本符合实际,总体正确率达73.7%。     

基于粗糙集的薄膜蒸发器工况预警

运用粗糙集理论为薄膜蒸发器工况分析提供了一种新的途径.针对薄膜蒸发器工况预警判断条件的冗余、不完全性和不确定性的不利影响,运用粗糙集理论中不可分辨关系、可辨识矩阵和最大正域3种方法对薄膜蒸发器工况预警分析.结果表明导热油温度、进料温度、真空度是影响薄膜蒸发器工况的重要特征参数,从而得到更为简明的最优工况预警规则.     

旋转薄膜蒸发器的应用

介绍了一种新型高效蒸发装置———旋转薄膜蒸发器的结构原理、性能特点、技术参数以及在浓碱蒸发中的应用，并对该蒸发器的应用前景作了预测。     

刮板薄膜蒸发器的设计与应用

刮板薄膜蒸发器是一种工作效率非常高的蒸发器,目前,在物理工程、医药工程、食品工程领域有着非常广泛的应用。基于此,首先介绍了刮板薄膜蒸发器的作用原理。其次,对刮板薄膜蒸发器的整体设计框架进行探讨。最后,在此基础上分析刮板薄膜蒸发器的具体应用。     

旋转薄膜蒸发器的应用

天津化工修配厂与天津轻化工研究所合作研制成功了旋转薄膜蒸发器,并作了大量应用试验工作,而且已经系列化生产。现简介如下: 一、旋转薄膜蒸发器的结构简述旋转薄膜蒸发器(见图1)由顶部的驱动部份和下部的蒸发、浓缩部份组成。驱动部份由电动机和减速机或皮带轮减速器组     

苯乙烯装置焦油产量的影响因素研究

焦油产量是影响苯乙烯装置物耗的主要因素,分析焦油组成得出,降低焦油产量应从降低焦油中苯乙烯含量及降低装置聚合物生成量着手。薄膜蒸发器控制温度、T4003塔釜温度、焦油循环比与系统阻聚剂含量是影响装置焦油产量的主要影响因素。薄膜蒸发器控制温度、T4003塔釜温度,主要影响焦油中苯乙烯含量,通过建立物料组成与温度的拟合关系式,结合生产的实际情况,摸索出薄膜蒸发器控制温度的适宜范围为116~122℃,薄膜蒸发器进料中苯乙烯含量控制的适宜范围为33%~39%,T4003塔釜温度控制的适宜范围为85.5~89℃,此时焦油苯乙烯含量能降低至8%左右,焦油仍保持较好的流动性。焦油循环比与系统阻聚剂含量主要影响系统聚合物含量。根据装置实际运行情况,确定了焦油循环比与系统阻聚剂含量的工艺调整思路,达到了降低装置物耗的目的,提高了装置精细化操作水平。     

18m^2高效旋转薄膜蒸发器的研制

随着２ｍ＾２、４ｍ＾、６ｍ＾２、８ｍ＾２薄膜蒸发器在医药、食品、油脂、化工及石化等行业的应用日趋成熟，现已开发了换热面积达１８ｍ＾２的高效旋转膜蒸发器。本文阐述了该薄膜蒸发器的部分计算与分析。     

新型实用旋膜蒸发器与流程

旋转薄膜蒸发器又名刮抹薄膜蒸发器或搅拌薄膜蒸发器。文内择要讨论了原有设备及流程的特点与不足，以及为解决这些不足而开发出的新型设备与流程。     

薄膜蒸发器的设计

综述了机械搅拌式薄膜蒸发器的基本结构、原理,并以1 m2机械搅拌式薄膜蒸发器为例论述了薄膜蒸发器的结构设计过程。机械搅拌式薄膜蒸发器是利用旋转的刮板将料液分散成均匀的薄膜,以进行物料浓缩的一种新型高效蒸发设备。     

Horizontal-tube film desalination plants. Research data of principal processes and of production prototypes design

The paper presents experimental data on the dynamics of a liquid film on the outher surface of a horizontal pipe as well as on heat transfer from vapour to the inner surface and from outher surface to a film of draining off liquid for smooth and diversely shaped horizontal pipes, on moisture separation and the design of a tube bundle and a feed distributor. The data were obtained from the tests of laboratory, rig and experimental-commercial horizontally arranged tube climbing film evaporators (HTFE). The data permitted the methods of HTFE calculation and four types of desalination units of the output from 10 to 700 t/h equipped with the above evaporators to be developed.     

Anwendungsmöglichkeiten und Grenzen des Einsatzes von Dünnschichtverdampfern

Application and Operating Limits of Thin Film Evaporators For separation of mixtures, which are thermally unstable, the use of film evaporators is quite common, as a bottom reboiler of a rectification column as far as an alternative separation device for partial distillation in single or multistage distillation plant often by applying vacuum. It is shown which separation results can be achieved on certain operation conditions with regard to energy input. The model equations describing the separation process by partial distillation of a thin liquid film are dealt with and it will be indicated by numerical examples the application of these relations to determine the separation range and the limits of the practical use of thin film vaporizors regarding the separation effect.     

蒸发器的保温与降噪

国内绝大多数的降膜式蒸发器未进行保温绝热处理,蒸发器在工作运行中未经保温绝热处理的热量损失约为5％～6％,其噪声约高出作保温处理的8～10dB（A）。     

降膜蒸发器在维C工业中的应用

用多效降膜蒸发器代替单效石墨列管升膜蒸发器对维Ｃ原料进行浓缩，解决了耐腐蚀的性能要求，不仅产品质量好，而且降低了操作费用和维护费用。对促进维Ｃ工业的发展与技术进步是很有意义的     

One-Piece Stainless-Steel 3D Printed Minichannel Evaporators using Flow Boiling Carbon Dioxide

New concepts are required for high-performance minichannel evaporators with low mass and reduced size involved in the cooling of cylindrical or conical surfaces. The development of one-piece stainless-steel evaporators using flow boiling CO₂ for the cooling of conical copper test specimens heated by a foil heater element is presented. The specimens mimic a mobile cooling device used in high-energy and particle physics. The stainless-steel evaporators were manufactured with a state-of-the-art 3D stainless-steel printer via selective laser melting. The computer-aided design and the construction of this new type of evaporators are described. A dedicated two-phase accumulator controlled loop filled with liquid CO₂ was developed, it allowed for operating four parallel connected evaporators. Cooling efficiency and manufacture reproducibility were experimentally investigated by applying different thermal loads and refrigerant mass flows.     

蜂窝夹套薄膜蒸发器的失效隐患及其防护

对蜂窝夹套薄膜蒸发器冲压、焊接及使用过程中出现的失效问题进行了分析,提出了改进和防护措施。运用大型统计分析软件STATISTICA对蜂窝夹套强度的影响因素进行了分析,为工程设计提供了参考依据。     

Simulation of a forward feed multiple effect desalination plant with vertical tube evaporators

In recent years, vertical tube falling film evaporators have been widely used in desalination industries. In this paper mathematical modeling of a multiple effect evaporators (MEE) system has been carried out for brackish water desalination. The system includes a set of forward feed vertical tube evaporators with thermal vapor compression (TVC) and a condenser. Modeling has led to calculation of several parameters such as overall heat transfer coefficients, entrainment ratio and recovery of the process which is restricted by scale formation. A scaling prediction chemical model has been employed to calculate the allowable rate of recovery for prevention of scale formation. Physical properties of streams have been assumed as functions of temperature and salinity. A code has been developed for simulation of the process based on mass and energy balance equations. Results showed maximum allowable recovery of 74% for the treated brackish water sample with total dissolved solid (TDS) of 14,761 ppm is achievable. Dealing with mentioned sample under specified set of conditions, it was concluded that changing the number of effects from 3 to 8, enhances gained output ratio (GOR) value from 3.8 to 7.5. However, specific heat transfer surface is increased from 215 to 1052.     

Trennleistung von Dünnschichtverdampfern

The evaporation process has recently gained new momentum through special applications in chemical engineering and especially in environmental engineering, e.g. in the recovery of materials of value from liquid production residues. Thin‐layer evaporators with rotating wipers are particularly suitable for such tasks if the products of interest are thermally unstable or are prone to crusting. If these applications involve distillation‐type separation then a knowledge of the expected separation effect is important for calculations. This article aims to make a contribution to this topic. It is based on experimental studies performed on a laboratory‐scale thin‐layer evaporator and on earlier treatments of the theory of distillation in thin‐layer evaporators with a mechanically generated liquid film.     

Chaotic forecasting of time series of heat-transfer coefficient for an evaporator with a two-phase flow

The time series of heat-transfer film coefficient for an evaporator with a vapor-liquid two-phase boiling flow were forecasted by the chaotic prediction or the local nonlinear short-term prediction. The forecasting method was based on the phase space reconstruction theory and a mathematic model in the form of datum driving had been developed to carry out the prediction. The signals of heat-transfer film coefficients predicted by this method were compared with those obtained from the experimental measurements. Different from the previous work, the comparisons in this work were done both from the point of view of the time trajectory and from the point of view of macroscopic or general characters. Besides the time-averaged statistics characteristics, such as the average value, average deviation and standard deviation, the power spectrum, phase plane map and chaotic invariants including the correlation dimension and Kolmogorov entropy had been calculated and been compared for the time series obtained both from the experimental measurement and from the forecast. The comparison for each parameter between the value calculated from the time series measured and that estimated from the time series forecasted by the chaotic forecast method shows satisfactory agreement. The limited length in time with an accuracy prediction indicates that the system is chaotic. The agreement of the comparison of the general parameter indicates that the chaotic prediction is effective for the estimations of the heat transfer characteristics of the two-phase flow boiling system and that the chaotic prediction method may be a potential tool for the effective thermo-fluid control for such evaporators.