流化床干燥聚碳酸酯小试实验研究

使用流化床小试装置对聚碳酸酯粉料进行干燥,绘制聚碳酸酯干燥速率曲线,初步证明了卧式流化床干燥聚碳酸酯具有一定的可行性。     

双桨叶干燥器在聚碳酸酯干燥中的应用

介绍了双桨叶式干燥器的流程及结构特点,使用双桨叶干燥器对聚碳酸酯树脂粉料进行干燥处理,通过绘制干燥曲线,初步验证了双桨叶干燥器在聚碳酸酯干燥过程中应用的可行性。     

热敏性物料干燥实验研究

根据聚碳酸酯产品的热敏性要求,对干燥工艺进行了分析研究,设计流化床干燥系统。实际应用表明,流化床系统具有产品质量符合要求、干燥效果好、操作使用方便等优点。     

组合干燥的应用及进展

组合干燥可以干燥某些单一干燥方法难以干燥的物料。组合干燥的应用不仅可以节约能源,而且可以较好地控制整个干燥过程,有助于获得高质量的产品。文章介绍了组合干燥的现状及其进展,并结合实例对组合干燥的应用特点进行了讨论。     

聚碳酸酯气流干燥系统影响因素研究

介绍了气流干燥基本原理及其特点,并结合中试装置气流干燥系统干燥聚碳酸酯实际应用效果,分析加热介质种类、流量、水蒸汽品位、伴热水蒸汽气量、伴热面积等因素对干燥效果的影响。     

喷动干燥床技术研究及应用

阐述了喷动干燥床技术研究的进展,介绍了喷动干燥床的工作原理和系统设计要求.并对喷动床干燥聚碳酸酯粉料效果进行研究。     

酞菁蓝组合干燥经济分析

介绍了旋转闪蒸干燥技术在酞菁蓝干燥中的应用 ,在分析其经济性的基础上 ,提出了组合干燥法用于酞菁蓝干燥     

组合干燥系统在浆料干燥中的应用

介绍了应用于浆料干燥的两种桨叶组合干燥系统,重点阐述了工艺流程及关键设备,分析了两种组合形式的特点及经济性,并列出了两种具有代表性浆料的工业应用参数。     

组合干燥系统在浆料干燥中的应用

介绍了应用于浆料干燥的两种桨叶组合干燥系统，重点阐述了工艺流程及关键设备，分析了两种组合形式的特点及经济性，并列出了两种具有代表性浆料的工业应用参数。     

浅析热风干燥技术中的节能途径

阐述了我国碳排放现状及节能减排的紧迫感。以传统的热风炉粮食干燥的和传统的木材蒸汽干燥为例,分析了传统干燥热效率不高的主要因素,指出排气余热回收是传统干燥作业节能减排的主要途径之一,采用普通换热器、热泵及热管换热器回收排气余热,均有明显的节能效果。采用普通换热器平均节能12.4%,采用热泵平均节能40%左右,采用热管换热器居二者之间。介绍了太阳能干燥、太阳能与热泵组合干燥、热风与真空微波组合干燥、超声波与热风干燥组合等各种低碳干燥技术。建议逐渐推广用生物质能源作为干燥的热源,有利于实现低碳干燥。     

Corn,Rice, and Wheat Seed Drying by Two-Stage Concept

Corn, rice, and wheat seeds with an initial moisture content (IMC) of 20–25% wb were dried to moisture content below 18% wb at 40–80°C in a fluidized bed dryer (FBD) and spouted bed dryer (SBD) and the seeds with IMC 18% wb were dried to below 14% wb at air temperatures 18–30°C and relative humidity 60–70% by an in-store dryer (ISD). As a result, it appears that a two-stage drying concept is feasible in drying high-moisture-content seeds due to the high germination rate of dried seeds. Nonetheless, the drying temperature must be carefully selected. A drying temperature of 40°C was clearly safe for all samples, whereas more than 90% of wheat seeds still germinated after drying at 60°C in FBD. Furthermore, drying seeds with IMC 18% wb by ISD was safe under specified drying conditions.     

PAPER DRYING: A STRATEGY FOR HIGHER MACHINE SPEED. II. IMPINGEMENT AIR DRYING FOR HYBRID DRYER SECTIONS

For printing and heavier grades, combining cylinder and impingement air drying into a multiple technique dryer section can enable higher productivity through higher machine speed. The large differences in local moisture content and temperature across the sheet which develop quickly under high intensity impingement drying provide the potential for reducing drying time by sheet reversal between impingement drying cylinders. This advantage was determined experimentally under low intensity impingement drying conditions. Use of the micro-scale based McGill dryer simulator for determining the advantage from sheet reversal between impingement drying cylinders was demonstrated for both laboratory and industrial impingement drying intensities. For completing the drying of 205 g/m² linerboard from 0.3 to 0.5 kg/kg dry under 400°C air jets of Re 20000, drying time is about 30% less with sheet reversal between two impingement drying cylinders than for a single, larger diameter cylinder. This extensively validated dryer simulator enables determining advantageous design specifications and operating conditions for hybrid dryer sections involving combinations of cylinder and impingement air drying, a concept with potential to become common industrial practice.     

新型组合干燥器在镍精矿干燥中的应用

传统的回转窑等干燥设备在镍精矿的干燥上存在污染环境、能耗高及效率低等弊端,急切需要一种节能、环保、高效的干燥设备应用于镍精矿的干燥上。采用双桨叶干燥器和盘式连续干燥器组合干燥器对硫精矿进行干燥,通过25 d的半工业化试验,取得了成功,证明了此新型组合干燥设备在镍精矿干燥上的优越性,特别适合现在节能环保的要求,具有较大的社会推广意义。     

用于污泥干化的新型桨叶式干燥机的设计

针对污泥的特性及其干燥机理,对现有桨叶式干燥机的结构进行改进设计,使现有的桨叶式干燥机成为一种比较理想的污泥干化设备。     

新型干燥工艺在间苯二甲酸生产中的应用

介绍了新型组合干燥工艺在间苯二甲酸生产中的应用,重点阐述了桨叶干燥机-蒸汽管回转干燥机的工艺流程及干燥设备,分析了组合干燥工艺的特点。新系统投用后的一年内,没有物料堵塞和黏壁现象发生,未因干燥机碱洗造成COD超标,装置负荷率由80%提高到100%。     

MODELING AND SIMULATION OF CROSSFLOW MOVING BED GRAIN DRYERS

ABSTRACT

The drying of grain in dryers of a crossflow moving bed type was theoretically and experimentally studied. Two different dryer configurations were analyzed, a dryer with central air distribution and another with multiple air duels. Experimental information was obtained in pilot-size dryers. A mathematical model to simulate the process was developed. Hindered drying was accounted for by using the concept of relative drying rate. An adjustable factor, specific to the dryers, was used to account for the uncertainties of the contact area and the transfer coefficients encountered in the literature. Agreement between experimental results and simulations was fairly good. Simulations showed that distance between inlet air and outlet devices, air to solid flow ratio and dryer height to cross section ratio have great influence on the process. The mathematical model may be a useful tool for process exploration and optimization of this type of dryers.     

Comparison Between Drying of Timber in a Solar Dryer and in an Electrically-Heated Kiln

ABSTRACT

Solar dryers have been considered for timber drying in a number of countries because of the expected savings in drying costs. From a review of past works on solar, natural, and conventional drying it was observed that while solar dryers were able to dry timber faster compared to natural drying, the difference was only marginal in some instances. The drying rates are expected to be dependent upon ambient conditions in which the dryera are operated. Solar dryers would operate more efficiently in countries with low humidity than in tropical regions. Thus the thermal performance and also the economics of solar dryer is country dependent. In the present paper, a comparison of the drying rates obtained with a solar dryer is made with that obtained with an electrically operated drying kiln.     

颗粒离心干燥机工作原理及在聚合物干燥中的应用

概述了颗粒离心干燥机工作原理及其在聚合物水下造粒后干燥中的广泛应用.以Gala和CarterDay公司相关产品为例,综述了其进展及国内外现状.这种脱水-干燥一体化的机型具有设备结构紧凑、产量高、干燥时间短、能耗低及操作连续、简单等特点.表明了国内外在其基本原理和设计准则方面缺乏定量的理论依据,为此需要开展相关基础研究,如分析产量和干燥程度这两个相互制约的指标与各结构和工艺参数的关系,这对于正确选型和设计更高效率设备非常重要.     

旋转闪蒸干燥器在碳酸钡干燥中的应用

介绍了河北诺达化工设备有限公司开发生产的旋转闪蒸干燥器代替回转圆筒干燥器在碳酸钡干燥过程中的应用.通过对投资、能耗、产品质量、环保效益的详细分析得出结论:用旋转闪蒸干燥器代替回转圆筒干燥器,具有节省投资,节约能耗,提高产品质量,减小环境污染等优势,为碳酸钡的干燥提供了一种新方法.该设备也适用于碳酸锶、硫酸钡、碳酸钙等滤饼类物料的干燥,同样对于冶金、化工、医药、食品等行业的滤饼类物料的干燥也具有极高的应用价值.     

ON THE STUDY OF TIME-VARYING TEMPERATURE DRYING—EFFECT ON DRYING KINETICS AND PRODUCT QUALITY

ABSTRACT

The ability of heat pump dryer to produce controlled transient drying conditions, in terms of temperature, humidity and air velocity, has given it an edge over other drying systems. Exploiting this characteristic, we studied and compared the effect of different temperature-time profiles on the quality of agricultural products in a tunnel heat pump dryer capable of providing up to 14.6 kW of cooling capacity. The product quality refers to the color change of the products. Samples of banana and guava were dried in batches in a two-stage heat pump dryer. The effects of the starting temperature of a selected profile and the cycle time on both drying kinetics and product quality were studied. It was observed that by employing a step change in drying air temperature with the appropriate starting temperature and cycle time, it was possible to reduce significantly the drying time to reach the desired moisture content with improved product color.