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由于地理、用户使用条件和峰段要求的限制，LNG槽车在输送天然气方面有着巨大的市场需求，是管道输配的重要补充手段。LNG槽车往往需要在没有机械动力的情况下，依靠配套的增压汽化器提供压力源，采用顶部气相空间加压方式卸载液体。槽车常配用的汽化器有空温式汽化器和水浴式汽化器两种形式，空温式汽化器使用空气作为热源，节约能源，操作费用低廉。对于长江三角洲地区，常年气候温和湿润，最低气温在零度以下的天数屈指可数，使用空湿式气化器完全满足生产要求。文章介绍LNG槽车自增压空温式汽化器的设计计算，其中包括天然气气相和液相物性的计算方法，以及空温式汽化器的热力计算。然后给出空温式汽化器的换热面积和结构尺寸等设计参数。     

红外加热蒸发器浓缩放射性废液研究

本文叙述了红外加热器蒸发液体的机理和浓缩废水蒸残液(不含放射性)的实验结果,讨论了红外加热蒸发器系统处理放射性废液的优点和前景。     

用于乙酸乙酯蒸发的单效降膜式蒸发器的设计及应用

乙酸乙酯用于茶多酚浸渍提取,完成浸渍提取后需要将其蒸发、冷凝、回收返回至储罐内储存以备再利用。而用于乙酸乙酯蒸发的单效降膜式蒸发器不同于其它水溶性物料的蒸发,随其物理及化学性质的不同而发生了根本性的变化,不能按常规的降膜式蒸发器设计,尤其冷凝器的设计更为关键。以YZJM01-3500型单效降膜式蒸发器在乙酸乙酯的蒸发、冷凝、回收上的应用为例,阐述了其设计过程及应用中的注意事项。     

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）。     

Sludge properties and their effects on membrane fouling in submerged anaerobic membrane bioreactors (SAnMBRs)

Two submerged anaerobic membrane bioreactors (SAnMBRs) (thermophilic vs. mesophilic) were operated for a period of 3.5 months with kraft evaporator condensate at a feed chemical oxygen demand of 10,000 mg/L. The results show that the filtration behavior of the two systems was significantly different. The filtration resistance in the thermophilic SAnMBR was about 5–10 times higher than that of the mesophilic system when operated under similar hydrodynamic conditions. Comparison of sludge properties and cake layer structure from the two systems was made to elucidate major factors governing the different filtration characteristics. There were more soluble microbial products (SMP) and biopolymer clusters (BPC) produced and a larger portion of fine flocs (<15 μm) in the thermophilic SAnMBR. Analysis of bound extracellular polymeric substances (EPS) showed that the thermophilic sludge had a higher protein/polysaccharide ratio in EPS, as compared to that in the mesophilic sludge. A series of analyses, including Fourier transform infrared (FTIR) spectroscopy, energy dispersive X-ray spectroscopy (EDX), confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), atomic force microscopy (AFM) and particle size analyzer showed that the cake layer formed in the thermophilic SAnMBR contained higher levels of both organic and inorganic foulants, smaller particle sizes, and especially, a denser and more compact sludge cake structure. These results indicate that floc size, SMP, BPC, bound EPS as well as cake layer structure are the major factors governing membrane fouling in SAnMBR systems.     

尿素溶液升膜式蒸发器的模拟计算

本文采用升膜式蒸发器的计算方法对尿素一段、二段蒸发器进行模拟计算。建立了尿素一段、二段蒸发过程物质体系的物性数据估算模型,选择合适的升膜式对流传热膜系数计算方法,用微元段积分法对尿素溶液蒸发器进行模拟计算,计算结果与实际装置数据吻合。模拟计算可以为现有尿素设备的能力考核、扩容改造、以及新设备的设计提供理论数据。     

SolidWorks软件的薄膜蒸发器虚拟装配

以三维参数化造型软件SolidWorks2005为绘图支撑软件,结合Visual Basic6.0对SolidWorks2005进行二次开发,实现薄膜蒸发器的虚拟装配设计.通过建立薄膜蒸发器的装配模型、装配顺序及装配路径,配合约束关系并对过程装配进行干涉检查,确保薄膜蒸发器虚拟装配过程的高效性和可靠性.薄膜蒸发器虚拟装配设计的开发对缩短产品开发周期、提高产品设计质量、优化产品结构设计具有显著意义.     

不同参数对含盐污水在蒸发管中流动特性影响的数值模拟分析

蒸发处理是炼化企业产生的含盐污水处理的方法之一,但是蒸发过程存在着因流动条件差异而导致传热效果不佳的问题。以降膜蒸发含盐污水为研究对象,通过数值模拟的方法分析不同参数对蒸发管传热传质效果的影响。结果表明,液体入口速度不同对蒸发管加热效果的影响是复杂的,入口速度适当增大导致轴向速度增大,虽然液体加热时间会变短,但加热效果更好;增大布膜间隙对近壁面处温度分布有积极作用,但在距管中心13.5～18.0mm范围内气相湍流强度略低,布膜间隙为1.25 mm时的温降相较于1.0 mm和1.5 mm间隙时的温降大;含盐污水盐度增大对蒸发管传热传质效果不利,特别是在近壁面处温降增大,内部湍流强度在沿径向方向距管中心0～19 mm范围内增大,近壁面处距管壁4 mm范围内速度增大。     

Optimization of the Liquid Distributor in a Falling Film Evaporator by Means of Air‐Water Experiments

Air‐water experiments (cold‐flow experiments) were performed for the liquid distributor of an industrial falling film evaporator (FFE). The feed to the FFE is superheated and a flash evaporation occurs in the head of the FFE. The aim of the experiments was to investigate the vapor‐liquid flow in the head and the resulting liquid distribution to the evaporator tubes. Several different designs of the distributor were investigated and explanations for the performance losses of the real evaporator over time were found. Several measures were finally concluded and also implemented for the real FFE.     

Droplet Entrainment Analysis in a Flash Evaporator with an Image-Based Measurement Technique

Local droplet sizes and volumes of entrained liquid are captured with an image-based measurement technique for comparison with a conventional, integral method for entrainment analysis. Experiments in a forced circulation flash evaporation were performed for different operating conditions and with two different chemical systems. Droplet size and frequency rise with an increase in thermal energy input. The local readings confirm the trends found by the integral measurement method. The modification of the image-based probe enables the detection of small (≈ 10 µm) and at the same time fast droplets under challenging operating conditions, such as vacuum and superheated feed similar to industrial process conditions.