共查询到17条相似文献,搜索用时 109 毫秒
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将微波辐射用于干燥城市脱水污泥,考察了污泥含水率和温度变化,并作了经济可行性分析。结果表明,微波干燥比常规加热干燥具有更快的速度,微波干燥过程后期温度过高,伴随着污泥热解。微波干燥脱水污泥时,污泥吸收的能量有约70.7%被有效利用,损失的能量基本上可通过干化污泥的燃烧放热得以补偿。 相似文献
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简述了一种新型的城市污泥清洁化处理技术,该技术采用干化污泥等固体废弃物掺杂煤粉进行发电,产生的蒸汽通过圆盘干燥机对污泥进行间接干燥。文章研究了干燥的主要操作参数(进料湿含量、产品湿含量和蒸汽压力)分别对蒸发水量、蒸汽耗量和有效干燥面积的影响。结果表明,利用自身热值污泥干化过程中无需额外添加燃料。城市污泥进料湿含量增加,水分蒸发量、蒸汽耗量和有效干燥面积线性增大。产品湿含量增加,水分蒸发量、蒸汽耗量和有效干燥面积逐渐减少,且前者影响明显大于后者。实验表明,选择合适的蒸汽压力可以获得更大的经济效益。 相似文献
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利用太阳能和高温热泵的城市污泥热干化系统技术研究 总被引:2,自引:0,他引:2
太阳能是取之不尽的能源,高温双热源热泵也是节能型产品,节能率比普通热泵高70%。所以将太阳能与热泵组合作为热源对城市污泥进行热干化,热干化的污泥可以作为燃料进行焚烧,具有极大的应用潜力。介绍了利用太阳能和热泵作为热源,利用干燥机对城市污泥进行热干化的系统结构、工作原理和实验研究。该系统也可应用于干燥其它物料,如食品、药材等。 相似文献
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随着城市的发展,污水量的增加,市政污泥产量越来越大,污泥的处理已经成为影响到城市发展的重要环境问题之一。某污水厂采用离心脱水+低温干化工艺,实现了污泥含水率从97%~98.5%降到含水率30%~40%(含水率可调)。处理后的污泥运至发电厂进行掺烧。实现污泥的减量化、稳定化,无害化、资源化。污泥低温干化工艺主要由污泥脱水系统、污泥低温干化系统、污泥储运系统、冷却循环系统、除臭系统组成。本文主要介绍整个系统工艺设计及其运行情况总结。 相似文献
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采用污泥薄片模拟分散态污泥干化过程,研究了干化风速、温度对污泥干燥速率的影响,并分析了污泥干燥过程中的形貌变化,采用热红联用分析污泥在(35~700℃)干化过程中气体的释放情况.结果表明:污泥干燥过程中的自由水、空隙水和吸附水干燥速率不同,提高干燥温度和热风风速,污泥干燥速率增大;污泥体积的收缩主要由于自由水的蒸发,粘滞区的存在是由于自由水蒸发完毕而引起干燥速率发生突变;污泥升温过程中释放的气体主要有C02、H2O、NH3、VFA及庚烷,273.75~333.76℃的温度区间为失重速率最大区域;VFA在273.75℃释放量最大,庚烷在333.76℃释放量最大. 相似文献
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The drying mechanism is important to the drying technology of sewage sludge. Using dynamic electronic balance and image acquisition technique, the paper studies the change of surface configuration and characteristics of moisture transference for three kinds of sewage sludge during drying. In the meantime, the paper also analyses the influence of sludge shape on moisture transference and the change of sludge apparent volume and porosity in the course of drying. 相似文献
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Shaoqing Chen Mathieu Milhé Patricia Arlabosse Fenglin Liang Yong Chi 《Drying Technology》2016,34(16):1979-1990
Sludge drying is an important intermediate process for sewage sludge treatment, usage, and disposal. A series of drying experiments were conducted in a continuous paddle dryer in order to have a better understanding of the sludge drying mechanism. The couple model of penetration model and Markov chain was used to simulate the drying kinetics in a continuous paddle dryer. The drying process has been compared in experimental and theoretical results, which show good agreement. The sewage sludge drying process in a continuous paddle dryer can be divided into three stages: the pasty phase, the sticky phase, and the complete-granular phase. The influences of the drying parameters on the sludge drying kinetics in a continuous paddle dryer were investigated. The sludge flow rate, dryer wall temperature, and dryer slope have remarkable influence on sludge drying in the examined range, but the stirrer speed and steam temperature have little influence on the drying kinetics. 相似文献
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VOLUME REDUCTION AND BIOLOGICAL STABILIZATION OF SLUDGE IN SMALL SEWAGE PLANTS BY SOLAR DRYING 总被引:2,自引:0,他引:2
High investments, high dumping costs and high electrical energy consumption turn waste water treatment in small sewage plants an expensive process. Therefore, the University of Hohenheim and the company Thermo-System have developed a fully automatic low temperature solar drying plant allowing further stabilization and volume reduction of sewage sludge by continuous mixing and aerating. To test the potential of the technology, the drying process was investigated in a commercially operated municipal sewage treatment plant with aerobic sludge digestion. During experiments, the changes of the dry solids concentration and the volatile solids, the climatic conditions and the energy consumption were constantly measured and documented. It was found, that the sludge could be dried from a dry solids concentration of 3 to 93% w/w in 64 (flocculated) or 83 days (non-flocculated). At the same time, the volatile solids content was reduced from 65 to 34% w/w, respectively. The electrical energy consumption was only 22 to 28 kWh per ton of evaporated water, compared to 70 to 110 kWh required for conventional drying processes. The thermal energy for evaporation was fully covered by solar energy. 相似文献
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Measurement and simulation of the contact drying of sewage sludge in a Nara-type paddle dryer 总被引:3,自引:0,他引:3
Wen-Yi Deng Xiao-Dong Li Fei Wang Sheng-Yong Lu Yong Chi Ke-Fa Cen 《Chemical engineering science》2009,64(24):5117-4924
Contact drying experiments were carried out in a Nara-type paddle dryer to study the drying kinetics of sewage sludge in the presence of air. In order to have a better understanding of the sewage sludge drying mechanism, a penetration model developed by Tsotsas and Schlünder is used to simulate the drying kinetics of the pasty, lumpy and granular phase which the sludge experiences during the drying process. The pasty phase is assumed to be a saturated particulate phase, and the granular phase is considered as a mono-dispersed particulate phase whose diameter was experimentally determined. In the lumpy phase, a sludge wall sticking still to the paddle-shaft surface was formed, and the heat transfer resistance from the sludge wall is considered during the model calculation. The influence of the drying parameters (temperature, stirrer speed and air flowrate) on the drying process is investigated experimentally and theoretically. The result indicates that the penetration theory is able to describe the sludge drying kinetics of the three distinct phases. Experimental and calculated drying kinetics are in satisfactory agreement for different drying parameters. 相似文献
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An incineration process is routinely used in Japan to treat nearly all the generated sewage sludge. The drying process now is recognized to play an important role as a pretreatment process of a incineration process.
This paper provides a brief introduction to the conventionally utilized drying methods/equipment (i.e, hot gas drying, fluidized bed drying, pneumatic conveyor drying, and steam drying( for treating dewatered sludge cakes. 相似文献
This paper provides a brief introduction to the conventionally utilized drying methods/equipment (i.e, hot gas drying, fluidized bed drying, pneumatic conveyor drying, and steam drying( for treating dewatered sludge cakes. 相似文献
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《Drying Technology》2013,31(4-5):829-837
ABSTRACT High investments, high dumping costs and high electrical energy consumption turn waste water treatment in small sewage plants an expensive process. Therefore, the University of Hohenheim and the company Thermo-System have developed a fully automatic low temperature solar drying plant allowing further stabilization and volume reduction of sewage sludge by continuous mixing and aerating. To test the potential of the technology, the drying process was investigated in a commercially operated municipal sewage treatment plant with aerobic sludge digestion. During experiments, the changes of the dry solids concentration and the volatile solids, the climatic conditions and the energy consumption were constantly measured and documented. It was found, that the sludge could be dried from a dry solids concentration of 3 to 93% w/w in 64 (flocculated) or 83 days (non-flocculated). At the same time, the volatile solids content was reduced from 65 to 34% w/w, respectively. The electrical energy consumption was only 22 to 28 kWh per ton of evaporated water, compared to 70 to 110 kWh required for conventional drying processes. The thermal energy for evaporation was fully covered by solar energy. 相似文献
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针对大伙房水库上游污水处理厂污泥处理过程中存在的问题,提出采用流化床污泥干化法对污水厂脱水后的污泥进一步处理,实现减量和无害化。文中给出了详细的工艺过程和参数,对污泥干化工程的实施有一定的参考价值。 相似文献