打叶复烤成品片烟在线降温系统的设计与应用

为解决复压打包环节中因成品片烟与环境温度存在差异而造成局部片烟含水率超标等问题，采用真空降温技术设计了一种打叶复烤成品片烟在线降温系统。将原平板式打包压头改为安装有真空吸口的空腔压头，在空腔压头下行复压打包时将烟箱中的湿热空气从真空吸口抽出，从而降低烟箱内部温度，减少高温高湿气体蓄积，避免在塑料内膜袋内侧形成冷凝水；增加反吹扫装置，避免片烟或烟末进入真空管道。以咸阳烟叶复烤有限责任公司生产的成品烟箱为对象进行测试，结果表明：使用降温系统后，成品烟箱局部片烟含水率超标比例降低1.995百分点，烟箱平均温度下降3.12℃；节约人工费用约1.5万元/万箱，节约采暖蒸汽费用约24万元/年。该技术可为提高打叶复烤生产质量和降低生产成本提供支持。

Online cooling system for tobacco strips after threshing and redrying

In the process of tobacco strips prepressing and packing, the temperature difference between tobacco strips and ambient environment might result in some wet strips. Therefore, an online vacuum cooling system was designed. The pressing head on the bale presser is replaced by a hollow pressing head with a vacuum suction mouth. The pressing head draws the humid and hot air out of the case through the suction mouth during downward pressing process, thereby reduces the temperature and prevents the formation of condensation inside the plastic bag. An opposite-blow cleaning device is used to prevent strips or tobacco dust from entering the vacuum pipe. The designed system was tested in Xianyang Tobacco Redrying Corporation Limited. The results showed that the proportion of wet strips in cases decreased by 1.995 percentage points, the average temperature inside cases reduced by 3.12 ℃. About 1.5 RMB yuan per case were saved in labor cost and about 240 thousand RMB yuan of steam cost for heating were saved per year. This technology provides supports for improving tobacco quality and reducing production costs in green leaf threshing.