• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Separation and Purification Technology >Skin effect in the heat and mass transfer model for sewage sludge drying
【24h】

Skin effect in the heat and mass transfer model for sewage sludge drying

机译：污泥干燥传热传质模型中的集肤效应

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The thermal drying of sewage sludge was studied in the 30-65 °C temperature range with two types of sewage sludge, showing different behaviour in the formation of a skin during the drying process. Twenty-one runs were carried out at different temperatures and air flows in an apparatus that provided a continuous flow of air. Small sewage sludge spheres and cylindrical tablets were produced to study the kinetics. During each run, the variation of moisture content vs. operation time was monitored, and during some tests, the temperature inside the sample as well. A kinetic model was developed to correlate the experimental data, both moisture content and temperature, vs. time. The resulting kinetic parameters (mass transfer coefficient, heat transfer coefficient, skin effect parameter, diffusion coefficient and activation energy) are discussed with reference to correlations and kinetic parameters presented in the literature. In general, the model seemed to suitably reproduce the experimental moisture and temperature data. For some runs there were significant deviations between the experimental and calculated temperatures, which could be explained by an evaporation effect taking place at the surface of the thermocouple wire placed inside the sludge spheres. The kinetic parameters have been used for simulation of continuous dryers. Finally, an analysis of the influence of the different parameters on the drying process has been carried out in order to obtain a general model valid for different types of sewage sludges.
机译：在30-65°C的温度范围内，对两种类型的污水污泥进行了热干燥研究，结果表明在干燥过程中皮肤形成过程中存在不同的行为。在提供连续空气流的设备中，在不同的温度和气流下进行了21次运行。生产了小的污水污泥球和圆柱形药片以研究动力学。在每次运行过程中，都要监测水分含量随运行时间的变化，在某些测试中还要监测样品内部的温度。建立了动力学模型以关联实验数据，水分含量和温度与时间的关系。参照文献中给出的相关性和动力学参数讨论了所得的动力学参数（质量传递系数，热传递系数，集肤效应参数，扩散系数和活化能）。通常，该模型似乎可以适当地再现实验湿度和温度数据。在某些运行中，实验温度与计算温度之间存在明显偏差，这可以通过放置在污泥球内部的热电偶丝表面发生蒸发效应来解释。动力学参数已用于模拟连续干燥机。最后，对不同参数对干燥过程的影响进行了分析，以获得适用于不同类型污泥的通用模型。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号