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通过分析南方稻谷的干燥特性、传统燃料谷物干燥机的特点和应用状况,指出了传统谷物干燥机难以满足南方稻谷干燥的共性问题,阐述了热泵干燥技术在高温高湿条件下的应用优势。对自主研发的5HRD-30型稻谷热泵干燥机进行了应用试验测试,在设定干燥温度为55~60℃时,将稻谷水分由29.28%干燥至14%,耗时18.56 h,较传统谷物干燥机(设定干燥温度70℃以上)的烘干时间24.5 h缩短了24.2%,平均干燥速率为0.835%/h,每吨湿谷烘干能耗为59.87 kW·h,稻谷爆腰率增值为0.66%,实现了南方稻谷低能耗高品质高效烘干。 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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刚收获的谷物含水率较高,必须将含水率降低至安全标准,才能进行贮藏;否则,会产生霉变甚至发芽,从而带来经济损失。文章介绍了谷物烘干办法及谷物机械化干燥技术原理,并对低温循环干燥机械进行了研究分析。 相似文献
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针对当前广泛应用的各类谷物干燥机普遍存在高温快速干燥爆腰率高、低温干燥脱水速率低、循环干燥破损率高、热能利用率低和烘干成本高等问题,介绍了一种混流静态房式谷物干燥机,其采用“保温控湿、热风循环利用、混流通风、薄层大风量静态持续干燥”的谷物机械干燥新方法,可解决谷物干燥爆腰率高、损伤率高和脱水效率低等系列问题,实现热风循环利用,提高烘干热效率。2017—2019年,在同等干燥条件下应用该机与其他类型烘干机、人工晾晒等谷物干燥方式开展了多批次干燥稻谷及杂交水稻种子的对比试验及性能验证工作。结果表明,该机在烘干效果、效率及烘干成本等各方面明显优于其他类型烘干机,在水稻种子干燥方面也有突出表现。经第三方检验检测机构检测,该型干燥机干燥谷物的籽粒脱水速率1.3%/h,爆腰率≤0.01%,籽粒破损率≤0.02%;干燥水稻种子的脱水速率0.9%/h,干燥种子的发芽率和破损率与自然晾晒级相当。 相似文献
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谷物的机械化烘干技术在我国正处于推广普及阶段,利用机械干燥谷物及农产品具有许多优点,如干燥时间短、干燥能力强、干燥成本低、抗自然灾害等。特别是近年来实现干燥设备的电气控制后,操作使用更简便,保证了农产品干燥后的品质。因此,我国农产品的干燥趋势,正由机械干燥逐步替代传统的自然方式。现将谷物烘干机的选购原则与安全使用叙述如下: 相似文献
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粮食烘干机械化发展对策与建议 总被引:2,自引:0,他引:2
当前,我国粮食烘干机械化正面临着难得的发展机遇:一是各级领导十分重视,各地相继提出了农业现代化和粮食生产全程机械化的目标,形成了良好的外部氛围;二是联合收割机的快速推广和跨区作业模式的建立,使大量谷物需要及时、快速干燥,且相当数量的种粮大户,对烘干机有使用的愿望和要求;三是目前烘干机械的种类较多,有可供选型推广的适用 相似文献
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正随着环保意识的不断增强,对谷物干燥的整体环境有一定的要求。谷物干燥不仅要考虑烘干效果,还要考虑后续的粉尘污染问题。目前,需要烘干的谷物的收割方式多以机械收获为主,相应的石子等杂质和稻麦表面的灰尘含量会减少很多。在谷物循环干燥过程中,谷物表面的大部分颗粒(统称为粉尘)会脱离谷物,在干燥设备有缝隙的地方冲冒出来,给烘干的现场环境及周围环境造成不同程度的影响。谷物表面携带的粉尘一般有两种,粒径大于10μm 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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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
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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