真空干燥技术在香皂行业中的应用

本文报道了香皂生产中,根据皂胶温度、喷漆、喷出方式、喷嘴轴转数等诸影响皂基干燥因素,自行设计一条真空干燥生产线,与老式烘房干燥工艺相比成本可下降21.3元/t,蒸汽消耗指标下降5．8倍,     

厌氧胶在真空技术中的应用

目前胶粘剂已广泛应用于国民经济各个部门,近几年来发展起来的厌氧胶在三防(防水、防气、防油)方面的堵漏密封已为人们所熟知。笔者认为厌氧胶在真空领域中同样有着广泛的实用价值。一、问题的提出许多真空容器在其生产过程中,由于多数是由几个零件,乃至更多零件用焊接方法制造而成,所以在生产实践中常常遇到因毛坯材料零件的焊接结构、施工工艺、操作人员的技术素质等各种原因而产生     

大型粮食真空干燥设备的研究开发及应用

介绍了真空低温连续干燥新技术的发展背景，通过技术性分析，探索出了一条解决粮食干燥问题的新途径。加强新一代真空低温连续干燥新技术的推广和应用具有重要的现实意义，必将提高能源利用效率，起到节能减排的作用，为我国绿色干燥技术的发展指明了方向。     

真空混合烘干技术在塑料加工行业中的应用

利用真空干燥原理,以双螺杆挤出机产生的废热为热源,采用单螺旋混合干燥机在真空状态下混合烘干物料.实践表明,该真空混合烘干技术节能效果明显,可满足物料的干燥技术要求,尤其适用于热敏性塑料的干燥.     

自动真空履带干燥机在制药行业中的应用

介绍了自动真空覆带干燥机的结构、工作原理、特点及控制系统的总体设计,将其应用于中药浸膏干燥,实现了干燥温度、真空压力、干燥速度和干燥物料含水率稳定的目标.     

浓缩干燥一体机及其在氯化钙行业中的应用

干燥浓缩一体机可极大地缩短常规工艺的流程、提高产品质量、减少占地面积、提高设备利用率、改善工人劳动条件和操作环境、解决多种常规工艺的设备严重腐蚀问题,是一套以浓缩干燥为主体功能兼顾多项其它功能的多功能集约化设备。干燥浓缩一体机将化工工艺过程中的浓缩、结晶、分离、干燥、煅烧与除尘集为一体的集约装置,文中列举了其在无水氯化钙生产中的应用实例,并与常规工艺进行了对比。结果表明这一装置环保、高效、可行。     

除尘设备在煤泥干燥中的应用

结合中国现阶段普遍应用的煤泥干燥系统,详细分析了系统中重力除尘器、旋风除尘器以及湿式除尘器等除尘设备的除尘原理,通过对设备除尘原理的分析,并结合煤泥干燥系统的实际情况,列举了重力除尘器、旋风除尘器以及湿式除尘器等设备在煤泥干燥系统中的作用及优缺点。结果表明:3种除尘设备的串联使用,能够完全达到国家环保标准中所允许的排放浓度,且3种除尘设备的应用完全适合选煤厂的实际生产情况。通过对设备除尘原理的分析,并结合实际经验给出了系统中重力除尘器、旋风除尘器以及湿式除尘器等除尘设备的选型计算公式。     

真空干燥冷却工艺的发展

本论证通过洗衣皂真空干燥冷却设备的改进，可使之成为既能生产洗衣皂，也可生产半透明皂的多功能生产设备。     

管道真空干燥技术简介

从理论上对真空干燥技术进行了简介,包括干燥的原理、过程、影响因素、验收方法、适用范围,并对真空干燥的优缺点进行了简单地分析。     

Pulsed vacuum drying (PVD) technology improves drying efficiency and quality of Poria cubes

The objective of this research was to examine the drying characteristics of pulsed vacuum drying (PVD) system as an alternative drying technology for a functional food—Poria cocos. Poria cubes in thin layer were dried at different temperatures (55, 65, and 75°C), vacuum duration (5, 15, and 25?min), and atmospheric pressure duration (4, 8, and 12?min) to evaluate the operating conditions on the drying kinetics and quality attributes of P. cocos. The quality attributes included volume shrinkage ratio, firmness, water-soluble polysaccharide content. Volume shrinkage ratio was determined by image processing technology and analyzed by Bigot’s curves. The material internal temperature was also recorded during the whole drying process. Considering the drying rate and quality attributes, drying temperature of 65°C, vacuum pressure duration of 15?min, and atmospheric pressure duration of 4?min were proposed as the most favorable drying conditions for drying Poria cubes. The current work indicates PVD is a promising technology for P. cocos drying as it not only enhances the drying process but also improves the quality attributes of it.     

污泥低温真空脱水干化成套技术的设计探讨

随着我国经济技术不断发展,污泥处置将从传统的卫生填埋向污泥干化焚烧或资源化利用方向发展。低温真空脱水干化成套设备采用低温真空干化原理,可以一次性将污泥的含水率从98%左右脱水干化至30%~40%,为后续的焚烧或资源化利用创造了条件。池州市前江工业园污水处理厂通过引进该项技术,实现了在一套设备内干化污泥的目的,出泥含水率小于40%。     

Dehydration of asparagus cookies by combined vacuum infrared radiation and pulse-spouted microwave vacuum drying

ABSTRACT

The restructured cookies were made from old stalks of asparagus (Asparagus officinalis). Combination of vacuum infrared radiation drying and pulse-spouted microwave vacuum drying (VIRD–PSMVD) was studied as a potential mean for dehydration of restructured cookies. The samples were first dried by VIRD and then by PSMVD to final moisture content less than 6%. Expansion ratio, texture, color, flavor, and other attributes of samples dried by this method were evaluated and compared with those dried by PSMVD and VIRD. Results showed that the samples dried by VIRD–PSMVD showed higher overall acceptability, crisper texture, and higher expansion ratio.     

真空干燥脱水制备高纯度无水硫化钠条件控制

高纯度的无水硫化钠是合成高性能特种工程塑料聚苯硫醚（PPS树脂）的优质原料。以新研制的高纯度白色结晶硫化钠（Na2S质量分数约为45％）为原料，通过真空干燥脱水得到无水硫化钠。实验确定的真空干燥条件为：真空度≥0．096MPa，同时采用两段温度进行干燥：一段低温85℃，二段高温115℃，干燥完成后出料口温度要保证小于40℃。控制原料晶体中Na2S2O3，与Na2SO3质量分数之和不超过0．5％，且不加抗氧剂。解决了以往含水硫化钠在真空干燥脱水过程中的熔化粘壁和氧化等问题，同时缩短了干燥时间。所得无水硫化钠中Na2S2O3，和Na2SO3质量分数一般都小于1．0％，能满足PPS合成对无水硫化钠的质量要求。     

Design and performance evaluation of a pilot-scale pulsed vacuum infrared drying (PVID) system for drying of berries

Abstract

The objective of current work was to develop a new pilot-scale pulsed vacuum infrared drying (PVID) system for the drying of berries. The system design and drying performance evaluation for grape and goji berries are reported here. The PVID system consisted of three major sections, including infrared heating section, vacuum section, and a controlling section. Electrical infrared (IR) emitter was made with carbon fiber sheet at the thickness of 2–4?mm, which emitted IR wavelength of 1–30?μm. The control system was used to achieve paused pressure by switching the drying chamber pressure between atmospheric pressure (101?kPa) and vacuum (3–10?kPa) successively and maintaining the pressure for different time periods. Grapes and goji berries were dried in a single layer at three different temperatures (55, 65, and 75?°C) with an atmospheric duration ranging from 1 to 12?min and vacuum duration from 10?min to constant vacuum. The drying characteristic and quality of PVID dried berries were investigated and compared with that of hot air (HA) dried berries. Results showed that the IR heating temperature, atmospheric duration, and vacuum duration had significant effects (p?<?.05) on the drying time. The optimum drying conditions for grapes and goji berries were IR heating at 65?°C, vacuum duration of 15?min, and atmospheric duration of 4 and 2?min, respectively. The corresponding drying time is nearly 720?min for grapes, and 450?min for goji berries. The PVID dried grapes and goji berries had more attractive color than that of HA dried ones. These findings demonstrated that PVID should be a promising method to produce high-quality dried berries. This study laid a good foundation for scaling up the technology in the future.     

Controlling the drying process in vacuum foam drying under low vacuum conditions by inducing foaming by needle stimulation of the solution

Abstract

Vacuum foam drying is a promising drying technique but an extremely high vacuum is needed to achieve “foaming.” The findings reported herein show that, when a solution is partially vacuum-dried to 0.05–2?g-solvent/g-dry matter (initial drying) and the solution is then punctured with a steel needle (needle stimulation), vacuum drying resumes as a result of the solution foaming, even under conditions of an insufficient vacuum (ca. 1,000?Pa) where foaming is minimal. Methanol, ethanol, and isopropanol were used as solvents, and sugar and different molecular weight polyvinylpyrrolidone were employed as solutes. The results indicate that needle puncturing introduces minute bubbles, which then triggers foaming.     

Effect of three drying methods on the drying characteristics and quality of okra

The objective of this study was to compare the drying characteristics and quality of dried okra obtained by vacuum freeze drying (VFD), microwave vacuum drying (MVD), and pulse-spouted microwave vacuum drying (PSMVD). The quality parameters include color (L*, a*, and b*), texture (hardness and fracturability), shrinkage ratio (SR), nutrient retention (chlorophyll, flavonoids, and vitamin C), and sensory score was investigated. Vacuum freeze drying maximally preserved the original properties of samples. And the samples dried by PSMVD showed higher quality and more uniformity compared to MVD. Considering of all aspects comprehensively, such as cost-effectiveness, practicability, and scale-up, PSMVD was a promising technique which would match results obtained by vacuum freeze drying.     

Multiphase transport modeling for vacuum drying of pharmaceutical products

Vacuum drying of active pharmaceutical ingredients (API) is an energy‐intensive process that is often a manufacturing bottleneck. A multiphase transport model to predict drying performance under the assumption that boiling is the dominant mechanism is developed. Laboratory scale drying experiments were performed over a range of temperatures and pressures using acetone as the solvent and glass beads of three different particle sizes to mimic APIs. A two‐phase transport model with the vapor and solid considered as one phase and the liquid treated as the second phase was capable of qualitatively reproducing the drying dynamics is found. Adjustable model parameters estimated from experimental data collected over a range of operating conditions exhibited trends that provided further insight into drying behavior. Boiling is the dominant mechanism in vacuum drying and our transport model captured the key physics of the process. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3639–3655, 2015     

ODS替代技术--碳氢真空清洗技术

对碳氢清洗剂和真空清洗技术进行了详细论述,列举了它们在中国的应用现状,指出碳氢技术与真空清洗技术结合的良好前景,碳氢真空清洗技术将是中国替代ODS技术的最主要的清洗技术,并对其经济效益进行了分析。