大型5HFS-10负压自控粮食干燥机的设计与试验

为了降低一次能源的消耗和提高玉米等粮食干燥产能,结合寒区高水分玉米干燥特性,以负压干燥原理为基础,设计了一种负压自控粮食干燥机.该机采用负压多级顺流缓苏结合的干燥方式,将并联式扩张口型风机和变径角状管相结合,协调冷风配额调控机构,应用多传感器实时采集在线工作参数,配合自适应调控系统,实现大宗粮食的智能保质干燥生产.该文详细进行了干燥参数和技术经济指标的计算,可为负压干燥机的设计和综合评价提供.生产试验表明,该机工作性能优良,节能显著,烘干品质好,单位质量成本低,自动化程度高.有效控制干燥机出粮水分偏差小于等于±0.5％w.b,与传统正压送风式干燥机相比,节省能耗20％以上,降低生产成本12％以上.该干燥机各项作业性能指标完全符合农场集约化和规模化干燥作业要求,可为开发节能粮食智能化干燥机型提供参考.

Design and experiment of large-scale 5HFS-10 type automatic control negative pressure grain dryer

Abstract: Large-scale grain drying technology has a nearly 50 years of development history in China. There are concurrent flow dryer, countercurrent dryer, cross flow dryer and mixed flow dryer, which meet the actual needs in various fields. But compared with the similar foreign products, there are many defects on our grain dryer, such as low manufacturing technology, low level of automation and high energy consumption. The co-current flow dryer has the characteristics of dry uniformity, low unit heat consumption and high productivity. But there are some defects, such as poor control of drying quality, high cost of drying and environmental pollution. These shortcomings are not conducive to the sustainable development of agricultural production and ecological environment. Therefore, from the perspectives of the structure and the process of the high temperature grain dryer, combining energy saving with conservation of grain quality is the key to the development of modern grain drying technology. Generally, the form of air supply in large-scale grain dryer is positive pressure, with easy maintenance and adjustment. The negative pressure air supply technology is only used for small cycle dryers. In this paper, the negative pressure technology in the large-scale grain drying system was applied for the first time. Negative pressure drying can effectively solve the internal control problems of the drying process based on the theory of micro pressure. Negative pressure is beneficial to collect the grain dust, create excellent production environment and realize safe production. The losses of static pressure and dynamic pressure are relatively small in the process of negative pressure drying, and this technology can reduce power consumption, and is easier to realize intelligent control of air volume and air medium parameters. In order to reduce primary energy consumption and improve corn drying process capacity, combined with grain drying characteristics in cold region, 5HFS-10 type negative pressure grain dryer was designed based on the principle of negative pressure drying. This drying technology combined the multi-stage concurrent flow and countercurrent flow, and a set of advanced structure and control system were applied in this drier. The parallel dilated fan was combined with variable diameter cornute duct, the cold air quota regulation agencies were coordinated, online work parameters were real-time collected with multi sensors, the adaptive control system was adopted, and all of these completed the intelligent quality-guaranteeing drying production of the staple food crop. In this paper the calculation of drying parameters and structure parameters was carried out providing the theory basis for the comprehensive evaluation and the design of negative pressure dryer. Production test shows that the machine''s work performance is good, its energy saving is significant, and it has good drying quality, unit mass of low cost, high degree of automation, and so on. The deviation of the moisture of discharged grain is less than ±0.5% w.b. Compared with the traditional positive pressure air supply dryer, this dryer saves the power by more than 20%, and reduces the production cost by more than 12%. The operating performance can perfectly meet the requirements of farm drying and large-scale drying technique. It provides the theoretical basis for the development of energy-saving intelligent grain dryer.