摘要：For obtaining the drying curve of powder under fluidized drying, a normal fluidized-bed dryer is designed to study the drying kinetics of PVC （polyvinyl chloride） powder in the experiment. A new measure system is derived for drying dynamics testing. In the small fluidized-bed dryer, fluidization parameter of PVC powder is tested, and the operating air velocity can be chosen in the range of 0. 41 to 0. 55 m/s. Accordingly, the fluidized number Ua/Umf is from 1.24 to 1.67. A promising drying model is used to describe the drying process, and then the characteristic drying curve of PVC powder derived from a suspension method can be expressed as f = [-0. 622 6 ＋ 1. 254 6exp（2. 561 5Φ -0. 707 2） /[1 ＋ exp（2. 561 5Φ -0. 707 2）] Based on the experiments, the critical moisture content xc and the mass transfer coefficient K are determined to be 0. 02 kg/kg and 6. 0 × 10^-4 kg/（ m2 · s）, respectively. The experimental results in the small fluidized-bed dryer are similar to those of the real fluidized drying process, so the descried method can also be used in determining drying kinetics of powder materials such as PVC powder.

摘要：针对陕西省乔化改造果园低矮狭窄的作业环境,设计了一种轻简型果园作业平台。为缩小整机长度,将动力装置及变速箱设置于升降平台下方,同时采用可折叠护栏,使其能根据转场输运、果物周转、高空作业等不同作业需求,灵活调节作业平台整机高度,整机高度最小可降低至900mm。为增强作业平台行驶安全性和操作便捷性,平台集成了遥控技术以实现远程操作,平台上集成有可为电动剪枝等电动机具提供动力源的电源接口,能将操作人员从背负电池的繁重劳动中解放出来。测试结果表明:果园作业平台举升负载量200.06kg,高速档行走作业速度1.58m/s,低速档行走作业速度0.18m/s,平台最大起升高度2080mm,最大沉降量18mm,符合设计要求。

摘要：针对现有果园管理机在乔化密植果园作业时,存在机型过高、无法进入树冠下作业、配套农机单元后整机过长地头转弯困难,以及因地势起伏、动力不足、开沟深度、施肥均匀性难以保持稳定和人机无法分离等问题,设计了一种超短低矮型果园管理机,集成遥控技术,可实现远程操作。通过对其传动方式和履带行走系统张紧装置的优化,可实现整机轻量化和小型化。田间试验表明,研制的超短低矮型果园管理机整机高度680mm,长度1950mm,开沟深度稳定性97.8%,排肥一致性变异系数1.9%,达到设计参数值,可满足乔化密植果园作业要求。