生物过滤填料层的温湿度场分布

为了优化生物过滤(BF)废气处理系统的结构设计和参数控制,实验研究了BF系统净化H2S模拟废气过程中填料层的温湿度场分布规律,考察了填料层湿度与废气温度的耦合关系及H2S浓度沿填料层的轴向分布.实验结果表明,BF系统底部通人模拟废气后,填料温度开始上升,且下层温升幅度明显大于上层,温升现象自下而上逐步推移,运行12d后形成上高下低的轴向温度梯度;由于壁面热传导效应,填料层内形成由轴心向两侧降低的径向温度梯度.下层填料的湿份迁移速率明显大于上层填料,最终形成上高下低的湿度梯度;填料层湿度随废气进气温度升高,以指数方式减小.H2S浓度沿轴向自下而上逐渐降低,并随系统运行时间延长,轴向各点H2S浓度逐渐增大.

Temperature and moisture distribution in biofilter packings

To optimize the structural design and control parameters of biofilters (BF), experiments were conducted to study the temperature and moisture distribution in the packings for H2S removal in the biofilter. The coupling relationship between the moisture in the packings and the inlet gas temperature as well as the axial distribution of the H2S concentration was investigated. The experimental results showed that, after the simulated waste gas with H2S is pumped into the BF, the temperature in the packings starts to increase, and the increase is greater at the lower parts than at the upper parts. The increase in temperature propagates from the bottom to the top and an axial temperature gradient forms after 12 operation days. Due to the heat conduction of the wall, a radial temperature gradient is also established. The transfer rate of moisture at the lower parts is much larger than that at the upper parts and finally an axial moisture gradient forms. As the inlet gas temperature increases, the moisture in the packings decreases exponentially. The H2S concentration gradually decreases along the axis from the bottom to the top. As the operation time increases, the H2S concentration at any point of the axis gradually increases.