山羊粪污颗粒床层的空气压降特性

Investigation on Air Pressure Drop Through Bed Packed by Goat Dung Particles

好氧堆肥过程中氧气的有效供给是成功堆肥的必要条件,如何选择适当的风机取决于所需要的风量与堆体的压降.然而,在堆肥过程中堆体的物性总是随时间发生变化,因此研究堆肥过程中的气相压降对于其变化情况的了解、堆肥参数的调控和风机选型很有必要.对新鲜、腐熟风干山羊粪污颗粒堆体床层进行了空气压降研究.结果表明：随着山羊粪污颗粒堆肥的进行,堆肥床层的空气压降逐渐减小;与新鲜羊粪相比,熟化后自然晾干的羊粪颗粒床层压降值平均下降了30％～50％;山羊粪污颗粒堆体的空气压降与堆体高度和床层孔隙率之间的关系符合方程式△p=Lru02ρ（1-ε）/fdsε3;空气流过新鲜、腐熟风干山羊粪便颗粒床层的摩擦因数公式分别为f=Re/3960.54＋3.31（190 ＜Re ＜1 560）、f=Re/3890.03＋3.33（210 ＜Re ＜1 700）.

The effective air supply is the prerequisite for successful aerobic composting of organic mat- ters, and how to select a proper blower depends on the air flow rate and air pressure drop required by a composting body. So it is very necessary to investigate the pressure drop and its change during corn- posting for process adjustment. As an example, the pressure drop through the bed packed by goat dung particles was investigated in this work. The results indicate that the air pressure drop through the packed bed decreases with the progress of composting and decreases by 30% - 50% when the corn- posting process finishes. The correlation between the air pressure drop and the height, voidage fits △p=Lru02ρ（1-ε）/fdsε3 , and the friction coefficients of air flowing through the beds packed by fresh and 3 960.54 composted goat dung particles are f=Re/3960.54＋3.31（190 〈Re 〈1 560）and f=Re/3890.03＋3.33（210 〈Re 〈1 700）,respectively.