共查询到18条相似文献，搜索用时 218 毫秒
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该文以研究光皮树果实冷榨制油过程中的流变特性为目标,利用自制直筒式压榨试验装置进行不同压榨应变水平的应力松弛试验,基于岩石流变基本模型分段模拟应力应变关系,建立其流变模型并进行验证。结果表明:光皮树果实加载过程中应力应变关系呈现线性和非线性两部分,屈服应变为0.4,应力松弛量随着压榨应变的增大而增大。采用分段模拟建模分析,并确定相应的模型参数。首先利用弹性元件和阻尼器模组合而成的广义Maxwell模型模拟线性段松弛过程,再利用线性与川北公夫模型叠加共同模拟非线性段松弛过程,构建了直筒式冷态压榨的流变模型,并进行了参数求解。误差分析表明:应变为0.5时,相对误差较大;而实际压榨过程中光皮树果实压榨应变均大于0.55,在此段应变范围内的模型平均相对误差均在7%之内,因此该模型为研究光皮树果实直筒式冷态压榨设备时应力应变参数的选取提供基础数据。 相似文献
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基于EDEM的家用榨油机压榨腔工作性能仿真研究 总被引：3，自引：2，他引：1
为改善榨油机出油率,利用CATIA建立压榨腔三维模型,在EDEM中构建家用榨油机压榨腔的破碎仿真模型,采用多指标三水平三因素的正交试验探究家用榨油机压榨腔压榨花生工作性能与榨杆转速、物料投放量、榨杆螺距三者的关系,利用极差法分析影响因素对各指标的主次顺序,通过矩阵分析得到物料颗粒黏结键断裂比例、理论出油率与三因素的各层结构矩阵以及2个指标值的权矩阵,并计算得到各因素各水平的权重。根据权重大小确定各因素对压榨腔总体工作能力影响主次顺序以及最优工作方案。结果表明:物料黏结键断裂比例的影响因素主次顺序为:榨杆转速物料投放量榨杆螺距。随着榨杆转速的增大黏结键断裂比例不断增大;随螺距的增大先减小后增大;随物料投放量的增加不断减小。理论出油率的影响因素主次顺序为:榨杆转速物料投放量榨杆螺距,随着转速的增加理论出油率大小逐渐增加,随着投放量的增加不断减小;随着榨杆螺距的增加而逐渐增加。通过矩阵分析,各个因素对正交试验的指标值影响的主次顺序为:A(榨杆转速)B(物料投放量)C(榨杆螺距),因素A3、B1、C3的权重最大,故压榨腔最佳方案为A3B1C3,即榨油机压榨腔压榨花生最佳工作参数为:榨杆转速80 r/min,单次投放量100粒,榨杆螺距6.3 mm。经验证试验验证,矩阵分析所得最佳工作参数条件下的花生出油率为45.20%,高于其余9组方案,故仿真所得结果具有合理性,为小型家用榨油机改良,油脂工业生产、榨油机械制造业升级奠定理论基础。 相似文献
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双低油菜籽脱皮冷榨的关键技术研究 总被引：1，自引：4，他引：1
针对双低油菜籽脱皮籽仁在冷榨过程中存在的一些关键技术问题，提出了双阶多级压榨的冷榨结构模型，对现有的螺旋榨油机的榨膛结构进行了改进，设计并制造了一种小型实验型冷榨机。在该机上，对操作工艺参数对脱皮籽仁的冷榨性能的影响进行了实验研究，结果表明，榨油机设定在较低转速(11 r/min) 有利于油料的冷榨，对入榨油料进行适度的调质(水分在6.4%)处理能改善油脂的提取效率，5%以下的仁中含皮率的要求是适宜的。冷榨脱皮菜籽仁的最大料筒温度始终低于70℃，确保了冷榨的需要。所研究的成果将为大型商用冷榨机的开发铺平道路。 相似文献
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提高病死畜禽胴体中的油脂提取率是实现病死畜禽进一步资源化的关键,为此该研究设计了一种动物油脂热压联合提取装置。首先基于静力学和热传递分析,结合动物油料特性,对关键部件压力机构和油脂提取机构进行了设计,并对加热、加压和可编程控制系统分别进行了关键参数设计和设备选型,最后选取板油进行了装置性能试验,并对提取的油脂进行了黏度测试。结果表明：在70～150℃范围内,单独温度和热压联合两种油脂提取方法的最佳温度均为130℃,在此温度下油脂提取率最高分别可达到59.15%和81.35%。相同温度下,热压联合油脂提取率较单独温度作用最高可提升31.21个百分点。减小油料规格对单独温度作用可明显提高油脂提取率,而对热压联合油脂提取率无明显影响。在高于130℃试验温度下进行热压联合油脂提取,能够达到油脂完全提取效果,所提取油脂在70～150℃温度范围内测得黏度为0.004～0.091 Pa·s,符合工业用润滑油黏度标准。 相似文献
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可加工脱皮菜籽仁的YPHG100型高油分油料挤压膨化机研制 总被引：5，自引：1，他引：4
介绍了解决脱皮菜籽仁制油难题的关键设备——YPHG100型高油分油料挤压膨化机的研究及应用情况,在入榨水分3.7%～5.0%、温度90～95℃,机膛温度108℃,饱和蒸汽压力0.75～0.80 MPa的工艺条件下,该机可挤压榨出菜籽仁中的部分油脂,并将物料膨化成直径6.5 mm、容重480～495 kg/mm的多微孔状膨化粒料,膨化系数1∶1.69,膨化粒料残油率27%～28%(干基）,出油效率39.0%。 相似文献
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低温萃取法提取杏仁油的研究 总被引：4，自引：2，他引：4
杏仁是油脂和蛋白质含量均高的原料，该研究旨在采用低温法萃取杏仁油，达到既萃取油又减少蛋白质变性程度的目的。首先经过一系列水酶法萃取试验后发现，不同萃取条件对于出油率的影响很大，从中筛选出水酶法萃取的最佳条件为：选取进口（日本Yakult公司）纤维素酶与木瓜蛋白酶的复合酶（1∶1），加酶量3%，作用时间3 h，料液比1∶2，反应温度40℃。初步油质检验表明, 水酶法比浸出法制得的毛油更清亮，酸价略低，磷脂少，油质稳定。然后进行CO2为溶媒的超临界流体萃取试验，通过7因素2水平正交试验并对其结果进行单指标直观分析发现：浸泡时间短的仁用杏出油率较高；粒度越小，出油率越高；以1∶1搀和二氧化硅粉与仁用杏的出油率较1.5∶1的为高；20 MPa压力的出油率较8 MPa的略高等，在此基础上筛选出了最适工艺路线。对上述结果进行了6因素无交互作用方差分析，结果表明仅有浸泡时间对出油率的影响是显著的，浸泡的时间越短出油率越高，其余条件对出油率的影响并不显著，按其影响程度从大到小依次为粒度、二氧化硅与杏仁比例、压力、杏仁种类、流速，这与直观分析极差所示结果一致。最后液相色谱法测定显示萃取出的仁用杏油中90%以上的脂肪酸为不饱和脂肪酸。 相似文献
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柴油机活塞的二阶运动不仅影响活塞侧击力、摩擦磨损、机油耗和漏气量,而且还对活塞内冷油腔内机油的振荡流动与传热性能产生影响。在活塞动力学与运动学分析的基础上,结合活塞内冷油腔内的振荡传热性能模拟试验结果,采用计算流体力学仿真方法,建立了包含往复运动与二阶运动的计算流体力学仿真模型,研究了活塞二阶运动对内冷油腔内机油的振荡流动与传热性能的影响规律。研究结果发现,二阶运动的径向运动主要影响内冷油腔中机油的振荡流动,偏摆运动主要影响内冷油腔的瞬时换热性能。二阶运动使内冷油腔的瞬时充油率降低,循环平均降低4.6%。对油腔壁面的瞬时换热性能影响很大,最大的变化幅值为24.9%。对于整个换热过程,虽然充油率降低,但平均换热系数变化不大。因此,二阶运动对内冷油腔综合换热性能的影响可以忽略不计。该研究可为耐高温高强度铝合金活塞的设计提供理论和技术参考。 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(11):1480-1498
Oilseed productivity in Himachal Pradesh, India, in northwestern (NW) Himalayas is far less than national averages because of poor crop management. Frontline demonstration (FLD) program is an effective technology transfer tool for better technology adoption that bridges the yield gaps. The technological and extension yield gaps in oilseed crops were studied for 3 years during Kharif 2008 to Rabi 2010–2011 under an FLD program in the Mandi District in Himachal Pradesh, India, revealing that there was a wide yield gap between potential and demonstration yields due to technology and extension yield gaps. Extension yield gaps varied to the extent of 577–905 kg ha?1 in soybean (Glycine max), 108–195 kg ha?1 in sesame (Sesamum indicum), 237–350 kg ha?1 in linseed (Linum usitatissimum), 340–355 kg ha?1 in toria (Brassica campestris subsp. oleifera var. toria), 448–557 kg ha?1 in gobhi sarson (Brassica napus var. napus), and 438 kg ha?1 in brown sarson (Brassica campestris var. brown sarson) during the study period. Improved technology package has also enhanced the profitability of oilseeds in terms of gross and net returns besides additional returns in the range 2445–12838 ha?1, enhancing incremental benefit–cost ratio (0.96–4.65). Technology indexes in soybean (29.6–52.2%), sesame (52.8–64.7%), linseed (42.3%), toria (45.2–46.4%), gobhi sarson (47.8–51.4%), and brown sarson (29.3%) has implied that demonstrated farm technology in oilseeds is quite feasible under prevailing farming situations in Himachal Pradesh, but it needs to be popularized in an intensive manner to educate hill farmers in NW Himalayas to adopt this technologically sound and economically viable method to enhance oilseed productivity and farm profitability. Improved farm technology, especially improved cultivars and nutrient management technology under these adaptive research trials, has also raised water-use efficiency (WUE) in Kharif (0.28–2.87 kg ha?1 mm) and Rabi oilseeds (1.79–9.43 kg ha?1 mm). Overall, it is concluded that demonstrated farm technology has great potential to improve oilseed productivity, profitability, and WUE, thus enabling resource-poor hill farmers to earn better livelihoods in Himachal Pradesh, India, and collateral farming situations in the developing world. 相似文献
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为研究不同破碎和均细化处理对胡萝卜汁中类胡萝卜素释放途径的影响,采用打浆﹑胶体磨和高压均质3种破碎和均细化方式处理胡萝卜汁。应用分光光度法对处理后不同植物组织(大细胞聚集体﹑小细胞聚集体和有色体)中类胡萝卜素含量,游离类胡萝卜素含量,总类胡萝卜素含量,油脂可萃取类胡萝卜素含量进行测定。应用激光共聚焦扫描显微镜观察不同处理后类胡萝卜素的分布情况。利用高效液相色谱法对油脂可萃取类胡萝卜素单体含量进行测定。通过显著性分析确定不同均细化处理对以上3种植物组织中类胡萝卜素含量﹑游离类胡萝卜素含量﹑总类胡萝卜素释放率和油脂可萃取总类胡萝卜素含量及单体含量的影响。结果表明破碎和均细化处理后,大细胞聚集体中类胡萝卜素所占比例减小(从36.18%减小至15.28%),小细胞聚集体(从11.11%增加至15.73%)和有色体部分(8.36%增加至30.56%)中类胡萝卜素所占比例增大,类胡萝卜素释放在对其释放阻碍程度低的组织部分中。经过均细化处理后,激光共聚焦显微镜下可见的类胡萝卜素颗粒减少,处理越均细,可见的类胡萝卜素颗粒越少。对胡萝卜汁处理越均细,胡萝卜汁中类胡萝卜素释放率越高,其中胶体磨和高压均质联合处理胡萝卜汁后类胡萝卜素的释放率为50.91%。对胡萝卜汁处理越均细,胡萝卜汁中油脂可萃取总类胡萝卜素﹑β-胡萝卜素和α-胡萝卜素含量越少。研究结果对后续分析如何提高胡萝卜汁中类胡萝卜素生物利用率提供依据。 相似文献
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Re‐establishment of vegetation on landfill sites, as required in UK planning consents, frequently means establishing viable arable agriculture rather than grassland. However, there is currently little information on crop suitability or yield, especially where the land has been restored with clay subsoils. Results are presented from three years growing oilseed rape and two years growing field beans, on a landfill site in south Essex, England, which was restored with London Clay. The site was restored in two ways. One area had a 900 mm depth of London Clay applied on top of the capped landfill. The second area had a 700 mm depth of London Clay topped with 200 mm of imported sieved material (known as screened material or ‘screenings’) which looked suitable for use as a soil forming substrate. The amendments tested were indigenous topsoil, screened material, mineral fertilizer, greenwaste compost or sewage sludge cake. Results show that oilseed rape is not suitable. It performed poorly regardless of amendment (greatest yield = 1.1 t ha−1 or 50 per cent of average agricultural yield). Mineral fertilizer produced some small improvement with oilseed rape when grown on London Clay or with a topsoil‐forming layer of screenings. Beans performed well (greatest yield 3.9 t ha−1, comparable to average agricultural yields). Sludge cake had little effect on bean growth performance and both crops performed poorly on land amended with green waste compost. Screenings improved yield if sludge or no amendment was used, but had no effect when mineral fertilizer was applied. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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Cruciferous oilseeds are important sources of oil, proteins, and glucosinolates (GLs), potentially available when biorefinery processes are used. The proposed extraction technology is based on the use of reverse micelles (RMs) made with cetyltrimethylammonium bromide (CTAB) dispersed in organic solvent. The physicochemical properties of this extraction system and the good water solubility of many high value compounds, such as GLs and some proteins, permit the simultaneous extraction of oil, and these products from cruciferous oilseed meals. This procedure is based on three main steps: (i) seed conditioning; (ii) solid-liquid extraction by RM solution; and (iii) back-transfer of the RM solution for recovery of the extracted compounds. The method makes it possible to simultaneously extract almost the same amount of oil as with pure organic solvents used in the current extraction plants and more than 90% of soluble proteins and GLs. It is a promising biorefinery technology alternative to traditional oil extraction processes. 相似文献
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Hydrophobic cyclic peptides, termed cyclolinopeptides, found in flaxseed are known for their immunosuppressive activity. This study is the first report of the occurrence of cyclolinopeptides in flaxseed fractions and products produced by aqueous processing and cold pressing. The distribution of cyclolinopeptides in flaxseed was determined after processing of flaxseed by various industrial and laboratory processes. Extracts of the water-soluble mucilage did not contain cyclolinopeptides. The cotyledon had the highest concentration of cyclolinopeptides, whereas seed coat had lower levels. An oil body fraction separated from seed after homogenization in water, followed by centrifugation, had the highest concentration of cyclolinopeptides of the fractions produced by this method. Further washing of the oil body fraction led to a loss of cyclolinopeptides. When oilseed was extruded using an expeller press, cyclolinopeptides were found in greater concentrations in crude oil and the solid sediment present in the oil fraction than in meal or the unprocessed seed. The concentration of cyclolinopeptides in crude flaxseed oil immediately after pressing was much higher than that observed in flaxseed oils purchased from a retail outlet. The effect of oil refining treatments on the removal of cyclolinopeptides was also tested. Acid degumming using aqueous H(3)PO(4) removed cyclolinopeptides from crude flaxseed oil. Alkali refining was less effective as this treatment failed to remove all peptides equally. This work illustrates ways that cyclolinopeptides may be extracted from flaxseed oil that could be developed for large-scale industrial extraction. The ability to extract cyclolinopeptides on a larger scale would allow faster exploitation of commercial applications of these molecules and provide the flaxseed industry with value-added coproducts. 相似文献