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梳齿式采棉机籽棉清理装置的研制 总被引:1,自引:0,他引:1
为缓解在棉花采收时节农村劳动力匮乏的局面,通过对中国棉花生产机械化现状和收获方式进行调查,设计了一种与梳齿式棉花采收机配套使用的籽棉清理装置,对清理装置的结构和工作原理进行了分析。工作时,刺钉滚筒将籽棉打松并输送到除杂筛网表面,通过与网面的摩擦,使粒径小的杂质与籽棉脱离。随后,籽棉被抛掷到锯齿滚筒上,根据籽棉与杂质在锯齿滚筒上的反弹性能和附着力的不同,使铃壳、僵瓣在惯性离心力的作用下与籽棉分离。田间试验表明:该清理装置工作顺畅,生产率为2t/h;籽棉含杂率为16%,将籽棉送美国原装机采籽棉生产线进行试轧,综合等级达到3级,纤维长度29mm,12mm以下的短绒含量8.3%;性能达到设计规范要求。 相似文献
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本文对籽粒穿过凹板筛孔的过程进行了理论分析,导出了籽粒从栅格凹板孔中分离的概率模型,并通过计算机模拟试验,从理论上建立了滚筒的结构参数、运动参数和滚筒分离性能之间的联系;本文还通过实测,给出了凹板分离分布规律,并通过室内台架试验,分析了滚筒的结构参数和运动参数对滚筒分离性能的影响规律,给出了减少滚筒分离损失的较优组合。 相似文献
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针对现有采棉机结构复杂、维护成本高以及采收后棉花含杂率高等问题,设计了梳齿式采棉机,首次将清杂装置与采摘台同机使用,降低了籽棉的含杂率.工作时,刺钉滚筒将籽棉打松,并输送到除杂筛网表面,通过与网面的摩擦,使粒径小的杂质与籽棉脱离.随后,籽棉被抛掷到锯齿滚筒上,根据籽棉与杂质在锯齿滚筒上的反弹性能和附着力的不同,使铃壳、僵瓣在惯性离心力的作用下与籽棉分离.田间试验表明:该清理装置工作顺畅,纯小时生产率为2t/h,籽棉含杂率为16%,将籽棉送美国原装机采籽棉生产线进行试轧,综合等级达到3级,纤维长度29mm,12mm以下的短绒含量为8.3%,性能达到设计规范要求. 相似文献
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梳齿式采棉机籽棉清杂系统参数优化 总被引:1,自引:0,他引:1
采用二次回归通用旋转组合设计,对籽棉清杂系统的参数进行优化.试验结果和分析表明:影响籽棉含杂率的主要因素是刺钉滚筒转速、锯齿滚筒转速和刷棉滚筒转速,按重要性排序为锯齿滚筒转速、刷棉滚筒转速和刺钉滚筒转速.确定的最优组合为锯齿滚筒转速291 r/min、刷棉滚筒转速695 r/min和刺钉滚筒转速367 r/min,此时含杂率为15.10%. 相似文献
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本文在叶片式立置分离滚筒内质点运动的力学-数学模型的基础上,利用可描述质点在滚筒内运动全过程的计算机数值模拟模型上机进行了模拟试验,研究了质点在滚筒内的运动规律,讨论了滚筒的结构参数和运动参数对质点运动规律的影响。在此基础上,对籽粒从栅格凹板孔中分离的过程进行了理论分析,导出了籽粒从栅格凹板孔中分离的概率计算式,并上机进行了滚筒分离性能的计算机模拟试验。最后对计算机计算和模拟试验的部分结果进行了高速摄影观察验证。 相似文献
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横轴流双滚筒脱粒分离装置设计与试验 总被引:7,自引:2,他引:5
详细论述了一种横轴流双滚筒脱粒分离装置的总体结构、脱粒滚筒与凹板的设计方案,脱粒滚筒采用短纹杆-板齿结构,分离滚筒采用带螺旋叶片钉齿滚筒结构.室内台架试验表明,该装置可适合较大喂入量、难脱水稻脱粒分离,具有脱净率高、夹带损失率小、脱出物中含杂率小且分布均匀等特点.田间性能测试表明:当收获单产11 625 kg/hm~2的梗稻,喂入量为4.32 kg/s时,该机总损失率为1.94%、脱粒损失率0.89%、破碎率0.84%、含杂率0.20%.各项技术指标均达到了设计要求. 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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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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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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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