Yu Bao, Chen Tongbin, Zheng Guodi, Yang Junxing, Huang Xue, Fu Lili, Cai Lu
Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
Waste Manag. 2022 Mar 15;141:220-230. doi: 10.1016/j.wasman.2022.01.041. Epub 2022 Feb 8.
Sewage sludge bio-drying technology has attracted considerable attention in recent years. In this study, we explored the water-heat balance under two ventilation strategies for the first time in bio-drying plants with circulated air, and examined the influence of air circulation on water removal and heat recovery. We want to obtain the relationships of pile temperature, ventilation, and water removal. Then, it provides support for optimizing the bio-drying process conditions and improving the efficiency through analysis of the water-heat relationship. In the low-ventilation and high-ventilation trials, water removed was mainly on Days 9-12 and 1-4, respectively. Ventilation and pile temperature jointly determine the water removed during the bio-drying process. Water balance indicated that more than 30% of the water was removed under the nonventilated process. More organic matter was degraded to maintain a higher pile temperature under low-ventilation than under high-ventilation, which also led to more radiation heat being lost. High-ventilation trial input less energy (3.36 MJ/kg water removed) but obtained a higher bio-drying index I (7.04) and heat utilization efficiency Q (94.1%). Heat balance showed that lower energy consumption by dry air (Q) was obtained due to circulation air with high temperature. Circulation air also has a higher carried capacity of water vapor but carries more water into the pile due to higher humidity.
污水污泥生物干燥技术近年来备受关注。在本研究中，我们首次在循环空气生物干燥装置中探索了两种通风策略下的水热平衡，并研究了空气循环对水分去除和热量回收的影响。我们想获得堆体温度、通风和水分去除之间的关系。然后，通过分析水热关系，为优化生物干燥工艺条件和提高效率提供支持。在低通风和高通风试验中，水分去除主要分别发生在第9 - 12天和第1 - 4天。通风和堆体温度共同决定了生物干燥过程中的水分去除量。水平衡表明，在无通风过程中，超过30%的水分被去除。与高通风相比，低通风条件下更多的有机物被降解以维持更高的堆体温度，这也导致更多的辐射热损失。高通风试验输入的能量较少（每去除1千克水3.36兆焦），但获得了更高的生物干燥指数I（7.04）和热利用效率Q（94.1%）。热平衡表明，由于高温循环空气，干燥空气的能耗较低（Q）。循环空气的水汽携带能力也较高，但由于湿度较高，会将更多的水带入堆体。
