杉木木束热风循环干燥参数对干燥效率与能耗的影响

利用热风循环干燥的方法，对铺装方式、转筒速度、装载量、初含水率、气流温度、气流速度等影响木束干燥效率和能耗的因素进行实验研究，探讨木束热风循环干燥参数对干燥时间和能量消耗的影响。实验结果表明，各参数对干燥结果的影响程度不一，按显著程度排序为：气流速度、初含水率、气流温度、装载量、铺装方式、转筒转速。     

振动流化床在季戊四醇干燥中的应用

对比了气流干燥床、振动流化床用于季戊四醇干燥的优缺点，经生产实践证明，振动流化床具有热效率高、干燥成本低、操作简单稳定、操作弹性大、尾粉量少、对风量及热风温度要求不高等优点。     

氯化橡胶干燥技术与设备

介绍国内氯化橡胶常用的沸腾干燥、气流干燥技术和设备流程、新式的脉冲式气流和薄膜蒸发干燥技术及国外红外干燥和组合干燥的新进展，指出干燥技术的发展趋势主要为有效利用能源、提高产品质量和产量、减少环境污染、操作安全、易于控制和一机多用等。     

关于硬脂酸盐气流干燥装置若干技术问题的讨论

硬脂酸盐溶点低,堆积密度大,湿态含水量高,其成品干燥与破碎具有一定难度,目前国内普遍采用气流干燥工艺。但在具体装置上各生产厂差异较大,因而实际使用效果也不尽相同。本文根据实践,重点讨论硬脂酸盐气流干燥的加料方法、热风温度选用以及含尘尾气处理等问题,并就如何提高干燥速率,如何确保系统运行条件稳定以及改善劳动保护、环境保护方面提供了成功的经验。     

微波干燥和热风干燥对金萱茶叶品质影响

将微波干燥和热风干燥应用于新鲜金萱茶叶的干燥,在3个不同的微波功率（350 W,470 W,800 W）和4个不同的空气温度（70 ℃,80 ℃,90 ℃,100 ℃）下,研究了干燥参数即微波功率或温度对干燥时间、失水量的影响,同时还考察了茶叶中茶多酚总量和儿茶素含量的变化、干茶叶的复水性。实验得出,与热风干燥相比,微波干燥的时间缩短了76%～95%,而且干燥后的茶叶有很好的复水性,但干燥后茶多酚总量少于热风干燥;同时随着功率增加,微波干燥时间由11 min降为6 min,随着温度升高,热风干燥时间由127 min缩短为45 min。这两种方法的茶叶干燥动力学模型均满足Page’s半经验公式。     

耐火浇注料对流与微波干燥的实验研究

进行了耐火浇注料热重分析,热风和微波干燥实验研究,得到了浇注料热风和微波干燥特性曲线。实验结果表明,与热风干燥比较,微波加热极大地降低了耐火浇注料干燥时间、提高了干燥效率和能源效率高,在耐火浇注料干燥过程中有着广阔的应用前景。     

天然胶乳厚胶膜热风干燥与红外干燥对比研究

采用失重法研究了天然胶乳厚胶膜在热风与红外线两种干燥方式下的干燥过程。研究结果表明,在相同条件下,红外干燥的干燥速率常数远大于热风干燥,采用红外干燥可大大缩短干燥时间,干燥温度和厚度均显著影响干燥过程,红外干燥对温度更敏感。通过动力学拟合结果,得到了干燥动力学方程,可以预测干燥时间。     

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。     

粘胶短纤维的干燥特性及其动力学模型研究

分析了热风温度、纤维层厚度、热风速度、纤维层含水率等工艺参数对粘胶短纤维干燥过程的影响,在此基础上,建立了粘胶短纤维的干燥动力学模型,应用单指数干燥模型和Logaritmic干燥模型对比研究了纤维的干燥特性。结果表明:单指数干燥模型和Logaritmic干燥模型都能很好地描述热风温度、纤维层厚度、纤维层含水率对其干燥速率的影响;在计算热风温度以及热风速度对纤维干燥的影响时,两个干燥模型计算结果与实验结果略有偏差;相比单指数模型,Logaritmic干燥模型的计算结果和实验结果吻合较好,能更好地分析粘胶短纤维的干燥规律,对粘胶短纤维干燥特性的工程应用提供理论依据。     

杉木木束热风循环干燥的正交实验分析

利用正交实验设计方法安排实验，并用综合分析法和方差分析法分析实验结果，比较在不同的初含水率下，木束热风循环干燥影响因素中气流温度、气流速度和带载率对干燥时间和能量消耗影响的差异。实验结果表明：随着初含水率的不同，各个因素对干燥时间和能量消耗的影响程度有变化，同一因素对干燥时间或能量消耗的影响程度也有变化。     

催化裂化催化剂喷雾干燥热风再循环技术

分析了催化裂化催化剂喷雾干燥尾气热风的相对湿度;在催化裂化催化剂喷雾干燥生产过程中,采用热风再循环技术;比较不同循环比下的热效率和节能效果,优化操作参数;喷雾干燥热风再循环技术提高了装置的热效率,节能效果明显。     

生物质型煤热风干燥特性及模型研究

为降低生物质型煤干燥成本,提高干燥效率,研究热风干燥风速和温度对热风干燥特性的影响,拟合了生物质型煤在不同热风干燥条件下水分随时间变化的模拟曲线。结果表明:生物质型煤与多数多孔介质类似,干燥过程可分为加速干燥、恒速干燥、降速干燥3个阶段,其中恒速干燥阶段的干燥时间约25 min;热风温度越高,风速越大,生物质型煤的干燥速率越大,干燥时间越短,干燥时的裂纹率也越高。当干燥温度180℃,风速1.2 m/s时,生物质型煤热风干燥效果较好,干燥热效率最高为48.34%。通过对不同温度、风速条件下的生物质型煤干燥试验数据与常用干燥模型进行拟合分析,发现Sabbet干燥模型拟合度最好,当干燥温度180℃,风速1.2 m/s时相关性系数为0.997,二者相关性显著,因此Sabbet干燥模型可较好地反映生物质型煤在不同温度、风速下的干燥特性。     

环己酮生产中碳酸钠回收干燥装置的设计与分析

针对环己酮生产过程中废碱碳酸钠回收利用的工艺特点,设计了一种新型干燥装置,对干燥器的干燥流程、干燥器的结构和工作原理进行了分析及计算。结果表明:循环自动干燥碳酸钠设备主要由干燥箱、供热风系统、抽湿系统、扩散系统和包装系统组成;通过温控由电烘箱进行碳酸钠干燥实验,得到了碳酸钠干燥设备的干燥曲线,该系统干燥能力达1～2 t/h,干燥后碳酸钠含水率小于2%;该系统利用工厂废烟气作热源,节省干燥成本,且无环境污染。该设备干燥能力大,热效率高,能耗低,调控性能好,很好的解决了环己酮工业中废碱处理的难题。     

振动床混流干燥系统热效率研究

振动床混流干燥系统由热风系统、干燥系统和除尘系统三部分组成,旨在降低褐煤水分,提高单位褐煤的发热量,以提高褐煤质量。由于振动床混流干燥是一种新型干燥系统,因此需要对干燥系统进行测试,并研究振动床混流干燥系统的热效率。通过现场测试,针对不同煤流量分别测得干燥系统进出口的温度、湿度、风量及测定干燥前后煤样的水分及发热量。采用了熵焓值计算方法,得出干燥不同煤量所需的理论风量。通过对比理论风量与测试风量,分析研究干燥系统的热效率,找出干燥效果不佳的直接原因和干燥系统改进的方法,为振动床混流干燥系统的改进提供理论支持。     

温度、时间和尺寸对市政污泥热风干燥的综合影响

通过单因素实验和正交实验讨论了热风温度、干燥时间和试样尺寸对市政污泥热风干燥的综合影响。实验结果表明：热风温度为140—180℃时,干燥时间为20—40min,热风温度和试样尺寸对污泥热风干燥都有显著的影响,干燥时间的影响不明显。     

Hot air drying of purple-fleshed sweet potato with contact ultrasound assistance

A drying technique using a combination of a contact ultrasound apparatus and a hot air dryer is developed to investigate the strengthening effect of contact ultrasound on hot air drying. The effects of drying parameters such as ultrasound power and drying temperature on drying characteristics, effective moisture diffusivity (D_eff), microstructure, glass transition temperature (T_g), rehydration ratio, and color difference are discussed. The results show that the application of contact ultrasound causes a significant acceleration of internal mass transfer, and higher ultrasound power applied leads to faster drying rate. The effect of ultrasound power on drying rate decreases along with the reduction of moisture content during drying process. The increase in drying temperature significantly reduces drying time but has a little negative influence on the strengthening effect of ultrasound. D_eff values range from 1.0578?×?10^?10 to 5.4713?×?10^?10?m²/s in contact ultrasound-assisted hot air drying of purple-fleshed sweet potato and increase significantly with an increase in drying temperature as well as ultrasound power. The microstructure of purple-fleshed sweet potato is greatly different at different ultrasound powers during contact ultrasound-assisted hot air drying and shows more microchannels and dilated intercellular spaces in the cross-section of purple-fleshed sweet potato micrographs at higher ultrasound power. Contact ultrasound application during hot air drying could improve the mobility of water and consequently reduce glass transition temperature. Lower color difference and higher rehydration ratio could be achieved as drying temperature decreases and ultrasound power increases. The increase in contact ultrasound power could reduce energy consumption of drying process up to 34.60%. Therefore, contact ultrasound assistance is a promising method to enhance hot air drying process.     

Effect of infrared pretreatment on low-humidity air drying of apple slices

The dried apple is used in the preparation of weaning foods and bakery products. The current drying processes, especially hot air (HA) drying, still face the problem of longer processing time and product quality degradation. The low-humidity air (LHA) drying can be an option to retain product quality in heat-sensitive food such as apple. The present work focuses on the effect of pretreatment of apple slices with potassium metabisulfite and infrared (IR) waves on drying characteristics when subjected to LHA drying and comparing the product quality with conventional hot air and freeze drying (FD). Pretreatment with IR waves reduced the drying time by nearly 23 and 17% in LHA and HA drying, respectively. The results indicated that IR-treated and LHA-dried slices retained nearly 82–90 and 72–74% of ascorbic acid and total phenolic content, respectively and was comparable to FD slices. The drying time for LHA was nearly 37% lesser than that for HA drying. LHA-dried apple slices had better color and rehydration ratio compared to FD- and HA-dried slices.     

Evaluation of the energy efficiency of combined drying and heat treatment by superheated steam

This study compares energy efficiency of a combined drying and heat treatment with that of conventional hot air heat treatment, the theoretical heat consumptions required for each treatment were determined, and the actual heat consumptions for each treatment were measured at a pilot scale. Conventional heat treatment method separately performs kiln-drying and heat treatment for wood with hot air in different equipment. On the contrary, in the combined treatment, the wood is simultaneously dried and heat-treated in the same enclosed space. Because of the time and energy savings, the economic feasibility of combined treatment is much higher than that of conventional heat treatment. Although the theoretical required energy of the combined treatment was similar to that of the two-stage method, the actual energy consumption of combined treatment was less than that of the two-stage method. And, the energy efficiency of the combined treatment was calculated to be two times higher than that of the two-stage method. From the results of this study, decreases in the processing time and energy consumption and increases in the energy efficiency of the combined treatment by superheated steam were quantitatively shown when compared to two-stage method.     

微波加热在纱线烘干中的应用

介绍了微波加热的基本原理、特点以及影响微波加热的因素,与蒸汽烘干、射频烘干相比,微波加热比蒸汽烘干节能40％,比射频烘干节能20％,仅每年运营维护费用比射频烘干节省4．5万元。提出应重点加强微波与物料间相互作用理论、微波场中物料的传热、传质机制,微波加热工艺与设备、微波加热技术与其它技术的有机结合等方面的研究。