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粮食干燥是粮食产后的重要环节,关系国家粮食安全问题。远红外烘干设备烘干速率快、耗能低且能有效保障粮食干燥品质,正慢慢取代传统热风烘干机械,成为市场的新宠儿。综述近15年来国内外远红外干燥技术研究现状,并从原理出发阐述干燥机理、工艺参数影响及联合干燥技术优缺点。归纳可知,当前远红外烘干设备多采用高温热源,存在粮食辐照时间短、瞬时强度大的问题,难以满足热敏性物料的烘干需求,同时单一远红外干燥技术烘干效果不理想。分析指出联合干燥技术及清洁能源将会是远红外烘干设备的发展趋势,最后探讨了以石墨烯红外辐射板为新热源的栅栏型红外烘干设备的优点,为发展新材料新热源提供新思路,旨在对远红外粮食烘干设备的研发提供参考 相似文献
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“及时烘干,安全入仓”是粮食生产全程机械化解决耕、种、收后的最后一个关键环节,对于国家粮食安全、农业生产效益、农产品质量以及农民增收具有非常重要的意义。然而,粮食烘干设备仍然是我国粮食安全生产的短板,目前我国粮食烘干机的发展还远远不能适应粮食生产发展的需要。一、漯河市玉米机械化烘干基本情况玉米是漯河市的主要粮食作物,种植面积常年稳定在120万亩左右,年产玉米65万吨左右,种收机械化水平90%以上,其中机收水平85%以上。玉米生产实现机械化的过程途径存在不同,部分直接采用籽粒收获,而后经烘干入库;部分采用先收果穗、剥皮,经晾晒干燥后,对果穗进行机械化脱粒入库。 相似文献
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由于我国粮食干燥水平较低，粮食烘干机械水平良莠不齐，因此如何提高谷物烘干水平是保证我国农业可持续发展的主要问题。基于国内外谷物机械化干燥技术的种类及发展特点，系统阐述了谷物干燥条件、干燥设备、设计依据及影响因素，着重介绍了谷物机械化干燥技术自动控制部分及辅助系统，研究结果为谷物干燥技术发展提供理论参考与技术支撑。 相似文献
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粮食烘干机械化技术是保障国家粮食安全的重要手段。介绍粮食烘干的技术原理及设备,阐述粮食烘干机械化技术及设备在国内外的研究情况,以期为促进我国粮食烘干机械化的进一步发展提供参考。 相似文献
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我国是一个农业大国 ,随着现代先进的农业生产技术的广泛应用 ,粮食单产不断提高。每到收获季节 ,公路晾晒现象仍然存在。据多年相关统计资料显示 ,由于不能进行有效的烘干 ,我国每年约有 2 5 0～ 10 0 0万吨粮食收获时发生霉变。如今随着机械化程度的不断提高和规模经济的发展 ,国家农业、经贸等部门领导近年多次作出重要指示 ,要加快、加大对谷物烘干设备研制的投入和开发力度。发展适应我国国情的粮食烘干设备已成为我国农业机械化必须突破的重点环节。干燥加工后稻谷的爆腰率 ,是评定稻谷干燥品质的一个重要指标。我国稻谷的质量标准是… 相似文献
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《Journal of Agricultural Engineering Research》1998,69(3):249-254
A model to represent the discolouration of dried powder of carrots as a function of temperature was developed. Two types of carrots, Asian and European, containing large amount of lycopene and β-carotene, respectively, were tested. The dried powder was stored under an atmosphere with O2and at three different temperatures, 5,20 and 35°C. The surface colour of the powder was monitored during storage by a Hunter colour ratioa/b. In the proposed model, the rate of oxidation was assumed to be represented by the product of the fraction of concentration of oxidized pigment at arbitrary time and a specific rate of oxidation of pigment. The rate parameters in the proposed model were calculated by fitting the experimental data with smooth curves by trial and error at the end of the induction period but before discolouration took place. The frequency constant and activation energy, expressing the temperature dependence of the rate parameters, were expressed by the Arrhenius relation. The simulation results of a Hunter colour ratioa/bof dried powder at 25°C showed good agreement with the experimental data, suggesting that the proposed model was effective for the prediction of discolouration of dried powder of both types of carrot. The use of the induction period in the manner described may enable the shelf life of dried powder to be predicted. 相似文献
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The fractional outflow rate of water from the rumen, measured as the rate of disappearance of the chromium complex of ethylenediamine tetra-acetic acid, was related to a number of dietary factors. A multiple regression equation was derived which expressed fractional outflow rate as a function of the intakes of dry matter, ash, acid-detergent fibre and crude protein.The data analysed consisted of 243 observations for sheep on 59 diets, including forage, concentrate and mixed diets. The ranges covered by the data were: fractional outflow rate 0.7–3.6 day?1; dry matter intake 560–1400g/day; ash 4–30%, acid-detergent fibre 7–41%, crude protein 5–26 % of dry matter; there were no observations for sheep of less than 34 kg liveweight.The equation accounted for 56·3 % of the total variance. Between-sheep variance could not be calculated for the whole of the data but was undoubtedly substantial since, for a sixth of the data, it was known to account for 38 % of the total variance. 相似文献
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感官检验棉花的品级,这是农村常见的一种检测手段.它的一个主要特点就是存在不确定性.这是由于检验员的品级检验水平存在一定的差异,其中有很多因素制约着检验的结果.文章对影响感官检验结果的因素进行了系统的分析. 相似文献
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从灾害经济学的角度探讨了城镇供水优化调度的必要性和可能性，认为在缺水不可避免的情况下，对供水进行优化调度可以减小缺水带来的损失，产生较好的减灾效益，特别是可以大大减小严重干旱的灾害效应。并根据水资源的特性，提出了缺水损失的计算模式以及优化调度的原则和方法。 相似文献