蒸发设备再利用技术改造

介绍了将闲置钾碱蒸发装置用于烧碱蒸发工艺的技术改造方案,对改造后蒸发装置在运行中出现的问题提出了解决方法,达到了预期效果.     

制约蒸发装置生产能力的因素

介绍了提高隔膜法烧碱蒸发系统生产能力的技术改造措施,分析了技术改造后仍存在的制约蒸发装置发挥最佳效能的因素,并提出了进一步改进方案。     

轴流式强制循环泵的国产化改造

针对烧碱蒸发装置中强制循环泵存在的问题进行了技术改造,包括优化机械密封结构、优化主轴结构、改进轴承润滑方式。改造达到了预期效果。     

加强蒸发综合管理 降低蒸汽消耗

分析烧碱蒸发系统存在蒸汽消耗高的原因及对其技术改造的情况。投运后效果明显,汽耗降低,且蒸发装置运行平稳。     

加强蒸发综合管理 降低蒸汽消耗

分析烧碱蒸发系统存在蒸汽消耗高的原因及对其技术改造的情况。投运后效果明显，汽耗降低，且蒸发装置运行平稳。     

加强蒸发综合管理 低蒸汽消耗

分析烧碱蒸发系统存在蒸汽消耗高的原因及对其技术改造的情况。投运后效果明显，汽耗降低，且蒸发装置运行平稳。     

提高采盐及分离装置能力的作用与方法

论述了在隔膜烧碱蒸发系统中,提高采盐能力,盐碱分离能力对蒸发装置能力的影响及对产品成本的影响,列汾了现有生产条件下通过技术改造提高采盐能力及碱盐分离能力的几种方法。     

关于我国烧碱蒸发的改造

我国烧碱产量逐年增长,预计今年可达200方吨,隔膜碱约占总产量的90％。烧碱蒸发工艺落后,设备陈旧,产品质量差,能耗高,平均汽耗较国外先进水平高一倍。为了缩短国内外差距,赶上国际先进水平,应进行蒸发技术改造。一、逆流给料国内烧碱蒸发除在沈阳化工厂建立一套能力3万吨/年三效逆流装置外,其余都是顺流装置。而国外除西欧部分隔膜碱蒸发装置采用三效错流外,美、日等国都采用逆流流程。对于我国蒸发改造应选用哪种给料方式,应该认真研究。     

烧碱蒸发装置扩建及效果

介绍了原烧碱蒸发装置扩建，技术改造的情况及其经济效益分析，生产实践证明，技改后各种消耗指标都明显下降，厂里获得较好的经济效益。     

隔膜法烧碱蒸发工艺的优化

分析了隔膜法烧碱蒸发装置存在的问题,并进行了技术改造,改造后生产强度平均提高了加．4％,生产1t NaOH平均降低蒸汽消耗0．44t。     

The evaporation and condensation coefficient of water,ice and carbon tetrachloride

The evaporation and condensation coefficients of water, ice and carbon tetrachloride were determined in the same experimental apparatus. Both low and high values were obtained for all three materials. An unsteady-state experimental method was used and the high values resulted when the evaporating or condensing times were very short. Surface temperature errors of two different types are shown to be the major factor in contributing to low values. The condensation coefficient of water is at least 0·7 and could easily be 1·0. Condensation coefficients of 0·55 were measured for ice and 0·94 for carbon tetrachloride.     

引进三效降膜真空蒸发装置及国产化研制

引进三效降膜真空蒸发装置蒸汽耗量低 ,1kg蒸汽可以蒸发 4kg水 ,有较大的浓缩比 ,而且适用范围大 ,粘度大的溶液由于流动蒸发而不会结焦。但由于造价大 ,一般企业难以承受。经过改造后的蒸发装置 ,达到了预期要求 ,生产能力达到引进装置的 95 % ,而价格仅为引进装置的 6 5 %。     

Control of particle size distribution of ultrafine iron particles in the gas phase reaction

Experiments on the synthesis of ultrafine iron particles have been made for the control of particle size distribution using the gas phase reduction of ferrous chloride with hydrogen. The previous studies were focused on the control of particle size of ultrafine particles with the variation of the partial pressure of reactants, residence time of feed, and reaction temperature. However, it is also very important to control the size distribution of ultrafine particles. In this study, the control of particle size distribution was investigated from the standpoint of nucleation. The variation of evaporating condition at the same evaporation rate of ferrous chloride, and of the temperature gradient of reactants between preheating zone and reaction zone were adopted as experimental variables. Ultrafine iron particles having uniform size distribution could be produced under the control of evaporating condition such as the change of the surface area at constant evaporating temperature. As the temperature gradient decreased, particle size distribution became uniform and average particle sizes were also decreased.     

Fest-Flüssig-Trennung auf der ACHEMA 2022

A large number of applications and apparatuses for solid-liquid separation were presented at ACHEMA 2022. The innovations presented by the various companies not only relate to apparatus design or mechanical engineering, but also to the topics of materials (especially filter media) and the major challenge of digitization of filtration processes.     

蒸发压力对卡琳娜循环不同目标参数的影响

研究了蒸发压力对卡琳娜循环系统性能的影响。以基液氨浓度分别为65%、75%和85%的氨水工质为研究对象,建立一个数学模型进行模拟分析。在其他变量一定的情况下,通过改变蒸发压力,从热力学第一定律、第二定律和经济性3个角度,分析其对卡琳娜循环系统热力学过程的影响。结果表明:在基液氨浓度和热源一定的条件下,蒸发压力越高,基液氨和富氨蒸气质量流量越小,蒸发器和冷凝器换热量越小,系统热效率和(火用)效率越高;存在一个最佳的蒸发压力使系统净输出功达到最大,且最佳的蒸发压力会随基液氨浓度升高而增大;蒸发器和冷凝器所占系统总(火用)损比例随蒸发压力增大而增大,而汽轮机和回热器则正好相反;从经济性角度分析还得出:当蒸发压力大于2.5MPa时,换热器的投资相对有利,对汽轮机尺寸参数的优化设计则要综合考虑其成本和发电量。     

A COMPARTMENTAL MODEL OF THIN-LAYER DRYING KINETICS OF ROUGH RICE

Rough rice at about 21% (wet basis) was dried at various conditions of temperatures and evaporating capacities of air. The influence of both parameters on drying rate has been studied. At high temperatures, high drying rates can be achieved with low evaporating capacities. In addition, desorption isotherms of rough rice were measured at 35, 60 and 85°C and the experimental isotherms data were fitted using a modified Pfost equation.

A compartmental model was developed to simulate the grain moisture content. Heat and mass transfer coefficients were optimized using a Nelder & Mead method. Internal mass transfer coefficient was written as an exponential function of the average moisture content and temperature of the grain and the external mass transfer coefficient as a function of air temperature. The compartmental approach predicts very well the average moisture content with a mean error of about 5% in static and dynamic conditions.     

离心式分子蒸馏设备在发酵L-乳酸精制工艺中的应用

以发酵液中的乳酸为原料,采用离心式分子蒸馏设备进行精制。研究了离心式分子蒸馏设备的蒸发面温度、蒸发面转速、冷热面间距、冷热面温差对L-乳酸纯度和收率的影响,试验结果表明利用离心式分子蒸馏设备精制发酵L-乳酸的最适工艺条件为：压力0.1Pa,进料温度50～70℃,蒸发面温度60～75℃,蒸发面转速700～900 r/min,冷热面间距20～30 mm,冷热面温差40～45℃,在此条件下操作L-乳酸的纯度由80%提高到95%,收率为70%。     

可溶性硫酸盐测定中预处理工具的改进

用可调电炉、瓷蒸发皿分别代替马弗炉和铂蒸发皿，进行可溶性硫酸盐的预处理，获得了满意的结果，并对瓷蒸发皿 可调电炉消解法的精密度和准确度进行了验证。     

A COMPARTMENTAL MODEL OF THIN-LAYER DRYING KINETICS OF ROUGH RICE

ABSTRACT

Rough rice at about 21% (wet basis) was dried at various conditions of temperatures and evaporating capacities of air. The influence of both parameters on drying rate has been studied. At high temperatures, high drying rates can be achieved with low evaporating capacities. In addition, desorption isotherms of rough rice were measured at 35, 60 and 85°C and the experimental isotherms data were fitted using a modified Pfost equation.

A compartmental model was developed to simulate the grain moisture content. Heat and mass transfer coefficients were optimized using a Nelder & Mead method. Internal mass transfer coefficient was written as an exponential function of the average moisture content and temperature of the grain and the external mass transfer coefficient as a function of air temperature. The compartmental approach predicts very well the average moisture content with a mean error of about 5% in static and dynamic conditions.     

Influence of Drying Conditions on the Processing Quality of Rough Rice

ABSTRACT

The purpose of this study is to examine the influence of drying conditions on paddy mechanical behavior, evaluated by the evolution of the percentage of broken kernels during drying. Results show that air temperature alone cannot explain the observed quality degradation of rice during drying. The drying rate and the drying time are mainly influenced by the air temperature, and to a lesser extent, by the evaporating capacity of air at low temperatures. The percentage of broken kernels increases very rapidly with the evaporating capacity of drying air.