The metal silo: An effective grain storage technology for reducing post-harvest insect and pathogen losses in maize while improving smallholder farmers’ food security in developing countries

Traditional storage practices in developing countries cannot guarantee protection against major storage pests of staple food crops like maize, leading to 20-30% grain losses, particularly due to post-harvest insect pests and grain pathogens. As a result, smallholder farmers end up selling their grain soon after harvest, only to buy it back at an expensive price just a few months after harvest, falling in a poverty trap. The potential impact on poverty reduction and greater livelihood security will not be realized, however, if farmers are unable to store grains and sell surplus production at attractive prices. Apart from causing quantitative losses, pests in stored grain are also linked to aflatoxin contamination and poisoning. To address this problem, a metal silo was developed as a valid option and proven effective in protecting stored grains from attack by storage insect pests. A metal silo is a cylindrical structure, constructed from a galvanized iron sheet and hermetically sealed, killing any insect pests that may be present. The impact of metal silo technology in Africa, Asia and Latin America includes, improving food security, empowering smallholder farmers, enhancing income opportunities and job creation, and safeguarding the agro-ecosystems. The metal silo can be fabricated in different sizes, 100 kg-3000 kg holding capacity by trained local artisans, with the corresponding prices of $35 to $375. The use of metal silo, therefore, should be encouraged in order to prevent storage losses and enhance food security in developing countries.     

钢板仓聚氨酯保温效果浅析

采用聚氨酯发泡喷涂技术对钢板仓外表面进行保温隔热处理,之后再喷涂白色乳胶漆作为聚氨酯硬泡体的保护反光层,这种保温技术有效地控制了外温变化对钢板仓的仓温、粮温的影响,延缓仓内粮食品质劣变,保温隔热效果显著,有利于钢板仓储粮保管和储粮安全,促进低温储粮发展。     

浅圆仓环流熏蒸磷化氢气体在粮堆内分布规律的研究

通过对较大型浅圆仓环流熏蒸后,粮堆内不同深度的磷化氢气体浓度的跟踪监测,了解磷化氢气体在粮堆内不同部位的浓度分布及变化特征,分析造成磷化氢气体在粮堆内的不同部位浓度不均的原因,从而为浅圆仓环流熏蒸提供依据。     

筒仓储粮多功能减压管的设计与应用试验

通过筒仓会粮多功能减压管的小型、中型和大型生产性试验研究,参照国内外有关资料,设计出技术先进、结构合理、储粮安全可行经济衫且投资少、收效快、能耗低的减压、熏蒸、能负多功能减压管装置。     

浅圆仓侧压力非线性分布分析

采用总体平衡方法给出了浅圆仓散体静态非线性分布侧压力计算公式。该公式计算简单,可用于浅圆仓的储料顶部为平顶和锥顶两种情况。将用本文公式计算的结果、用国家规范得出的结果和库仑公式的计算结果,与实仓测试结果进行对比分析,表明用本文公式计算得出的侧压力曲线与实仓测试得出的侧压力曲线吻合良好。     

不同改流体对稻种颗粒在料仓卸料流动的影响

为探明不同改流体对稻种颗粒在料仓卸料流动的影响机理，实现种群流动从中心流到整体流转变，改善种群流动环境，该研究利用离散元法（discrete element method，DEM）建立传统料仓、垂直扰动和水平扰动料仓模型与稻种颗粒仿真模型，进行卸料数值模拟，并与料仓实际卸料试验作流型对比，验证离散元模型与数值模拟结果准确性。整体流指数（mass flow index，MFI）与z轴颗粒速度表明传统和垂直扰动料仓中部区域颗粒速度均随颗粒堆积高度增加而减小，边壁区域颗粒速度均随颗粒堆积高度增加而增大；而水平扰动料仓边壁区域颗粒速度随料仓颗粒堆积高度增加而减小，中部区域颗粒速度随颗粒堆积高度增加而增大；传统料仓，垂直和水平扰动料仓的流型转化高度分别为130、118以及130 mm。料仓不同区域种群垂直速度、水平速度和角速度表明，种群垂直速度在垂直与水平改流体作用下，相较传统料仓流动区域分别降低34.82%和83.46%；随料仓颗粒堆积高度降低，种群水平速度波动增大，传统料仓、垂直及水平扰动料仓颗粒水平速度标准差分别为0.0273、0.0187以及0.0103 m/s。传统和垂直扰动料仓中心和边壁区域颗粒角速度变化相似，垂直扰动料仓中心区域角速度峰值小于传统料仓；水平扰动与传统料仓流动区域颗粒角速度变化相似，但水平扰动料仓颗粒角速度变化小。研究结果可为工程提出改流体设计标准、结构与位置参数及提高料仓使用面积提供参考。