中文摘要：

厌氧发酵过程中,物料分层及各层料液黏度、密度等参数是搅拌装置设计的重要依据。该文采用接力试验研究了牛粪中温厌氧发酵过程中各层料液基础物性的变化情况。结果表明：牛粪厌氧发酵过程中,反应器中料液密度自上而下逐渐变大,且各层密度随总固体含量增加而升高,反应过程中各层密度均在发酵第4天达到最大值,料液总固体质量分数为4%、6%、8%时对应的上中下层溶液的密度最大值分别为1.02、1和1.02,1.02、1.03和1.07,1.03、1.03和1.07 g/cm3。受料液分层的影响,反应器中上层和中层料液黏度呈先增大后减小并逐步趋于稳定,下层料液黏度以初始黏度为最大,且不同初始料液总固体含量对黏度变化过程具有显著影响,TS=4%时,上、中层料液黏度分别在第7天、第4天达到最大值11.5和14.7 m Pa·s,下层初始最大黏度为107 m Pa·s;TS=6%、8%时,上、中层料液黏度均在第4天达到最大值,上层料液黏度最大值分别为25.5和63.5 m Pa·s,中层料液黏度最大值分别为15.5和95.5 m Pa·s,下层初始最大黏度分别为135.5和185.5 m Pa·s。随着初始物料总固体含量的增加日产气量也相应增高,产气高峰出现时间相应提前;TS=8%时的累积产气量分别比6%和4%提高了21.4%和8.71%,但产气中甲烷含量增加速率基本相同,并在第10天左右基本趋于稳定。该结果可为厌氧发酵反应器的搅拌装置设计提供参考。

英文摘要：

In the process of anaerobic fermentation, the material stratification and the parameters of the stratified fermentation fluid, such as viscosity and density, are the key foundation of the stirring device design. In this paper, the relay methods were adopted to investigate the variation of the basic properties of stratified anaerobic fermentation fluid in the process of cow dung anaerobic fermentation at mesophilic temperature. The results demonstrated that the densities of the fermentation fluid increased from top to bottom in the reactor, and increased along with the increase of substrate concentration. In the process, the maximum density of each stratified fluid appeared on the 4th day; when Total solid were 4%, 6% and 8%, the maximum densities were 1.02, 1.02 and 1.03 g/cm3 in the top layer, 1, 1.03 and 1.03 g/cm3 in the middle layer, and 1.02, 1.07 and 1.07 g/cm3 in the bottom layer, respectively. The viscosities of fermentation fluid in the top and middle layer of the reactor increased in primary stage, then got decreasing and tended to be stable at last under the influence of the liquid stratification. The maximum viscosity of the liquid in the bottom layer was the initial viscosity, and the initial substrate concentration affected the viscosity change significantly. When TS was 4%, the viscosities of the fluid in the top and middle layer reached the maximum on the 7th and 4th day, respectively, and the maximum viscosities were 11.5 and 14.7 mP a·s, respectively; the maximum viscosity of bottom layer was 107 mP a·s. When TS was 6%, the viscosities of the fluid in the top and middle layer reached the maximum on the 4th day, and the maximum viscosities were 25.5 and 15.5 mP a·s, respectively; the maximum viscosity of bottom layer was 135.5 mP a·s. When TS was 8%, the viscosities of the fluid in top and middle layer reached the maximum on the 4th day, and the maximum viscosities were 63.5 and 95.5 mP a·s, respectively; the maximum viscosity of bottom layer was 185.5 mP a·s. Daily gas yield increased and