共查询到19条相似文献,搜索用时 78 毫秒
1.
2.
为研究洋葱在真空干燥条件下的干燥特性,选用不同干燥条件对洋葱进行脱水处理,测定不同工艺条件下洋葱的干燥曲线和干燥速率曲线。结果表明,温度和真空度对洋葱真空干燥过程都有明显的影响,且洋葱真空干燥的动力学模型符合Page方程,并得到本试验条件下的动力学模型。 相似文献
3.
对离子交换树脂的两种流化床干燥工艺作了简单介绍,重点介绍了一种利用流化床连续干燥系统对离子交换树脂进行干燥冷却的工艺。此工艺针对离子交换树脂的特点进行设计。试验证明该工艺具有投资少和节能高效的特点,有很好的推广前景。 相似文献
4.
6.
本文对用于造粒和包涂过程的顶喷流化床内的干燥过程进行了较为详细的实验和理论研究。从传质传热过程中分析可知,床层可分为三段。影响生产能力的最大允许喷淋速度受流化空气流量和入口温度影响最大。 相似文献
7.
在流化状态下种子(大豆)与硅胶能够很好的混合,通过湿含量梯度进行传质,干燥后种子质量显著提高;种子与硅胶粒径不同,便于分离。通过实验比较了在不同混合比和不同流化条件下种子的干燥特性。随着吸附剂的加入,干燥速率明显增大,并且随着风速的提高、硅胶与种子混合比的增大,干燥速率也随之提高。通过试验还表明,采取流化床与固定床动静结合的吸附干燥方式,在节能和产品质量方面有一定的优势。 相似文献
8.
9.
10.
11.
Chaiwat Rattanamechaiskul Nittaya Junka Chalermchai Wongs-Aree Somkiat Prachayawarakorn Somchart Soponronnarit 《Drying Technology》2016,34(12):1462-1470
The influence of drying using a fluidization technique on the quality of purple rice was investigated in this study. The results demonstrated that the initial moisture of rice was 28.3% dry basis (db). Compared to the sun-dried or reference purple rice samples, the influence of drying at temperatures ranging from 100 to 150°C did not affect the quality of color, anthocyanin content, total phenolic content, or antioxidant activity. At this initial moisture level, samples should be dried at 150°C air because such temperatures yield the highest drying rate. Drying at this temperature also causes an increase in the head purple rice yield because of the gelatinization of starch. In the case of an initial moisture content of 33.3% (db), the drying temperature should not exceed 130°C. 相似文献
12.
Theerasak Srimitrungroj Somchart Soponronarit Adisak Nathakaranakule 《Drying Technology》2019,37(8):1044-1052
This study aims to experimentally investigate the drying characteristics and quality of a paddy dried by hot air (HA) and humidified hot air (HHA) fluidization technique. Qualities such as head rice yield (HRY), white belly, degree of gelatinization (DSG), and color of dried paddy were evaluated. A paddy with an initial moisture content of 14% d.b. was soaked in hot water at a temperature of 70?°C for 5?h then dried at a temperature of 130,150, and 170?°C, relative humidity in the range of 0.3–12%, an air velocity of 3.9 m/s, and a bed height of 10?cm. The results showed that the drying time of the paddy in the HHA condition took longer than the HA drying condition. Because HHA provided a higher grain temperature and a slow rate of drying, the degree of starch gelatinization was significantly higher when compared to HA. The subsequent HRY was relatively higher than using HA drying. However, the color of the sample obtained from the HHA condition was relatively browner, but the parboiled rice product still had a light brown color for the drying temperature range used in this study. To produce parboiled rice, HHA could be operated up to the temperature of 170?°C, relative humidity of 6%, and DOM of 10%. 相似文献
13.
从水资源短缺的现状入手,结合科学技术的发展现状,重新探讨了空气重介流化床干法选煤技术的定位问题,并对空气重介流化床干法选煤的工艺设计进行了剖析,阐明了该工艺的发展潜力,旨在推动空气重介流化床干法选煤技术的推广与应用。 相似文献
14.
Particle-to-emulsion and interparticle heat transfer rates were estimated in the range 1.5 ? u/umf ?3.5, 0.69 ? dp ? 2.15 mm by drying wet refractory particles in fluidized beds of similar dry particles of the same sizes. Overall particle-to-emulsion heat transfer coefficients decrease roughly as the inverse of the particle diameter. Particle-to-particle heat transfer coefficients vary with the power-2 of the particle diameter and decrease as the fluidization velocity increases. 相似文献
15.
16.
从干法选煤领域中空气流态化技术应用的背景及实现环境出发,综述了实现该技术的必要性和正确性。回顾了空气重介流化床选煤中的一些重要历程,展望流态化技术在选煤中发挥更大效用,促进选煤事业的发展,实践建设环境资源友好型社会。 相似文献
17.
流化床氛围下多孔物料干燥传热传质的数值模拟 总被引:4,自引:1,他引:4
用有限差分法数值求解一个热、质传递耦合模型,理论研究多孔物料流化床干燥过程。方程离散采用全隐格式的控制容积方法,三对角矩阵法(TDMA)用来求解线性方程组。选用球形的苹果丁作为多孔物料。在典型操作条件下,通过分析温度、饱和度和压力的分布侧形,讨论了物料内部的热、质传递机理。在对比条件下,考察了气体入口温度、气速和床面积因子对干燥过程的影响。结果表明:干燥过程受气、固相间的耦合传热传质的影响十分明显,干燥时间随气体入口温度和气速的提高而减少;随床面积因子的增大而增加。 相似文献
18.