物料下落过程中随机性粉尘的产生特性及其数学模型

EMISSION CHARACTERISTICS OF FUGITIVE DUST GENERATION OF FALLING MATERIAL AND ITS MODEL

为了研究物料下落过程中随机性粉尘的产生特性,在实验室开发并设计了一套自由下落装置。通过实验主要测定空气湿度和质量流量对粉尘产生率的影响。结果表明,空气湿度对粉尘排放有影响,且对粗细粒子的影响程度不同;当空气湿度达到一定数值时,粉尘产生率已很小,此后再增加空气湿度,粉尘产生率基本不变。随着质量流量的增加,粉尘产生率逐渐减小,但粉尘浓度会增加,对工作场所工人的身体健康及环境带来严重危害。根据实验数据建立了空气湿度和质量流量与粉尘产生率之间的数学模型,经验证,相关性很好,实测值与理论计算值基本一致,可以定量评价不同质量流量下不同空气湿度的粉尘产生率。

In order to investigate emission characteristics of fugitive dust generation of falling material, a free falling apparatus was developed in the lab. The influence of air Relative Humidity and mass flow on dust generation rate was determined. The results showed that, Relative Humidity affects dust generation rate, which is larger for coarse particles and smaller for fine particles; when Relative Humidity is up to a certain value, dust generation rate remained constant; dust generation rate was decreased with the increase of mass flow, mainly because the falling center materials has no chance to contact with air, but the dust concentration is increased with the increase of mass flow, which was harmful to workers＇ health and environment. Model of above mentioned factors was set up, which is remarkable and the relationship between experimental and theoretical data was good, so it can be used to evaluate dust emission characteristics quantitatively for different Relative Humidity.