混流谷物干燥机沿通气盒纵向粮层气流分布均匀性的研究

在混流干燥机中,因穿过粮层的气流沿通气盒纵向分布不均匀常导致干燥不均匀。为了改善气流分布的均匀性,出现了多种变截面通气盒,但对其作用一直存有争议。该文通过实验研究了混流干燥机内粮层气流沿通气盒纵向分布的特点及影响因素,证实变截面通气盒对改善粮层气流分布均匀性的作用不明显。提出了变开孔率通气盒的型式和设计计算方法,它以增加3～4mm水柱气流阻力为代价,可使粮层气流分布达到均匀一致。

Study on Air Distribution Uniformity in Grain Bed Along Longitudinal Direction of Air Duct in Mixed Flow Grain Dryer

In mixed-flow grain dryer, there is uneven drying because the air distribution is not uniform a-long the longitudinal direction of air ducts. In this paper, the characteristic of the air distribution is investigated by experiments. It is also found that conical air duct is not as effective as expected in improving air distribution uniformity. A new type of air duct with changed perforation rate plate is designed, which can eliminate the unevenness of air flow at the expense of 3- 4 mm water column increase in air resistance.