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香菇双螺杆挤压膨化机的设计与试验 总被引：1，自引：0，他引：1
针对现有双螺杆挤压膨化设备生产香菇膨化产品时存在物料堵塞、预熟度低、作业参数缺失等问题而导致生产的产品膨化率低、吸水性差、硬度高等缺陷,该研究设计了一种香菇双螺杆挤压膨化设备,并对设备中的关键部件喂料搅拌防堵装置、预熟调质装置与双螺杆结构参数进行了设计与确定。同时,为探究设备中的作业参数对产品膨化性能的影响,研究了设备的螺杆转速、膨化温度、物料含水率对产品的膨化率、硬度、脆度、吸水性的影响。结果表明:影响膨化率的显著性顺序依次为螺杆转速、物料含水率、膨化温度;影响硬度的显著性顺序依次为螺杆转速、膨化温度、物料含水率;影响脆度的显著性顺序依次为膨化温度、物料含水率、螺杆转速;影响吸水性的显著性顺序依次为膨化温度、物料含水率、螺杆转速。其次,结合各因素交互作用的影响规律与目标优化结果,得出设备的最佳作业参数为:螺杆转速167.23r/min,膨化温度151.68℃,物料含水率16.83%,此时,产品的膨化率、硬度、脆度、吸水性分别为4.04%、18.61N、-8.46mm/cm^2、313.86%。将优化后的参数值在设备中进行了生产性应用,得到生产值与优化值的误差均小于4%,最大生产率为165 kg/h。与扬州大学机械工程学院实验室内的现有设备相比,在提高物料送料的连续性与调质熟化度的基础上,膨化率提高了25.00%,硬度降低了48.21%、脆度提升了40.55%、吸水性提高了62.35%。因此,该机的设计可为香菇膨化产品的开发提供了一种较为成熟的技术装备。 相似文献
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螺杆挤压膨化机加工农作物秸秆的试验研究 总被引：13，自引：3，他引：13
利用小型自热式单螺杆挤压膨化机对农作物秸秆进行膨化加工试验。将螺杆螺距、喷嘴出口间隙、秸秆物料含水率、秸秆物料粒度作为试验因素，经单因素试验和二次通用旋转组合试验找出其对秸秆膨化加工性能(膨化压力、生产率、度电产量等)的影响规律，并经优化设计得出最佳参数组合。利用电子显微扫描观察和分析膨化及未膨化玉米秸、豆秸的微观结构的变化，对农作物秸秆膨化机理进行了初步探讨，并通过膨化和未膨化玉米秸、豆秸的营养成分对照测试分析，证实了秸秆膨化能够改善秸秆的理化性状和营养成分，为提高秸秆的利用率和可消化率创造了条件。 相似文献
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合理的原料预处理工艺可以提高玉米淀粉出酒率,该文用单螺杆挤压膨化机对脱胚玉米进行挤压膨化,以模孔直径、套筒温度、物料含水率、螺杆转速和酵母添加量作为因素,以挤压膨化脱胚玉米淀粉出酒率为考察指标,采用5因素5水平(1/2实施)进行二次正交旋转组合试验设计,探讨了挤压膨化工艺参数和酵母添加量对挤压膨化脱胚玉米淀粉出酒率的影响规律,得到了优化的工艺参数:模孔直径为12mm,套筒温度140℃,物料含水率19%,螺杆转速200r?min-1,在酵母添加量为0.4%时,玉米淀粉出酒率可以达到55.81%。 相似文献
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水产沉性颗粒饲料挤压蒸煮工艺对其理化特性的影响 总被引：3，自引：2，他引：1
为了规模化生产出低污染、高转化率的环保型水产沉性颗粒饲料,选用双螺杆挤压机对水产全价配合原料进行挤压熟化研究。以沉性水产硬颗粒饲料理化特性(膨化度、近似密度、糊化度、耐久性和水中稳定性)为重要指标,采用表面响应分析法研究了物料含水率（22%～38%）、套筒温度（70～170℃）和螺杆转速（73～107?r/min）对其挤压工艺和饲料理化特性的影响规律,SEM分析其微观结构。结果表明：物料含水率、套筒温度和螺杆转速均显著影响饲料的理化特性。中高物料含水率和套筒温度及低螺杆转速时,才能获得理想的沉性高熟化水产颗粒饲料,其理化特性具有低膨化度（1.14）,高近似密度（757.6?g/L）、糊化度（879.5?g/kg）、耐久性（96.6%）和水中稳定性（88.7%）。SEM分析显示优化条件（物料含水率31%,套筒温度126℃,螺杆转速78?r/min）下生产的颗粒饲料结构光滑质密。该研究可为发展高效、低耗、低碳高品质沉性水产饲料研究和生产提供参考。 相似文献
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该文通过4因素5水平二次正交旋转组合试验，研究了用于浸油的玉米胚挤压膨化预处理过程中的挤压系统参数(套筒温度、模孔孔径、物料含水率、螺杆转速)对考察指标(残油率、剪切强度、密度)的影响规律。得到最佳挤压工艺参数：模孔直径9 mm，物料出口温度93℃，喂入物料含水率13.3%，螺杆转速238 r/min，在此条件下得出残油率最优值为0.40%。和传统工艺相比，浸提时间缩短一半，膨化物的密度与轧坯和预轧样相比分别增加29.3%和13.8%。只要参数选择合适，可使原设备的浸出能力提高60%～120%。 相似文献
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亚麻籽挤压膨化脱毒的工艺优化 总被引：2，自引：1，他引：2
采用SLG67-18.5双螺杆挤压机优化亚麻籽脱毒工艺。通过二次正交旋转组合设计试验，研究了温度、含水率、螺杆转速、喂料速度对亚麻籽中氰华氢(HCN)去除率的影响。单因素分析表明，亚麻籽中HCN去除率随温度升高、含水率增加、螺杆转速提高而升高；随喂料速度增加呈抛物线，中等喂料速度脱毒效果更好。利用频数分析法进行优化，得到亚麻籽中HCN去除率有95%的可能高于90%的参数范围，即膨化温度为147～153℃，亚麻籽含水率为13.8％～17.6%，螺杆转速为186～211 r/min，喂料速度为61.7～74.0 kg/h，从而为亚麻籽脱毒和开发利用及现有挤压膨化机的操作和调整提供了理论依据。 相似文献
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挤压膨化大米做啤酒辅料的试验研究 总被引：12，自引：4，他引：12
该文通过实验室试验,研究了做啤酒辅料的大米挤压膨化系统诸参数(模孔孔径、套筒温度、物料含水率、螺杆转速),对醪液的主要考察指标(麦汁醪液的总还原糖、过滤速度)的影响规律,指出挤压膨化大米做啤酒辅料的可行性。 相似文献
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菜籽挤压膨化系统参数对出油率影响的试验研究 总被引：7，自引：1，他引：7
该文研究了用于浸油的一种菜籽挤压膨化预处理工艺(油菜籽清理—带壳粉碎—膨化—浸油)的可行性，油菜籽挤压膨化系统参数(模孔孔径、套筒温度、物料含水率、螺杆转速)对各考察指标(粕的残油率、膨化物含油率及榨笼出油率)的影响规律，挤压膨化系统优化参数的范围为模孔孔径8～12 mm、套筒温度105～125℃、物料含水率6.6%、螺杆转速35～55 r/min。研究表明：只要参数选择合适，带壳油菜籽清理、粉碎、挤压膨化、浸出的菜籽浸油预处理工艺是可行的，且残油率较低。该菜籽挤压膨化浸油预处理工艺可供生产参考。 相似文献
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挤压加工参数对重组米生产过程及产品膨胀度的影响 总被引：3，自引：1，他引：2
为了考察重组米生产过程中挤压加工变量对几种系统参数与产品膨胀度的影响,试验以杂交籼米（9?718品种）为原料,利用响应面模型,以螺杆转速、进料速度、进料含水率以及末端机筒温度为输入变量,以挤压系统参数（物料温度、模头压强、扭矩、比机械能和产品含水率）和重组米膨胀度为响应变量,探索在重组米生产过程中加工变量与系统参数及产品膨胀度的关系。结果表明,压强、比机械能和产品膨胀度都受到4个挤压变量的显著影响,但是物料温度受进料速度影响不显著,马达扭矩受末端机筒温度影响不显著,产品含水率仅受进料含水率的显著影响。比机械能与螺杆转速正相关,与进料速度、进料含水率和末端机筒温度负相关。所得二次回归模型均拟合良好,建立的挤压数学模型可应用于重组米生产,为重组米工业化生产的过程预测和产品性质预测提供参考。 相似文献
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The oil absorption characteristics of a multigrain extruded and fried snack product were studied as a function of extruder screw speed and cooking temperature using a central composite response surface methodology (RSM). The extruded product was produced using a corotating twin screw extruder, dehydrated to a uniform moisture content, and subsequently deep‐fat‐fried at 192 ± 1°C for 10–40 sec to complete expansion. Significant RSM models were developed for oil absorption and extrudate water absorption index (WAI). According to the lowest oil model, absorption (19.9%) was obtained with an extruder screw speed of 218.6 rpm and a cooking temperature of 117.8°C. WAI reached a maximum at a screw speed of 221.9 rpm and a cooking temperature of 109°C. Oil absorption characteristics and extrudate WAI were significantly correlated (r= ‐0.84, P = 0.0002). The data suggest that extrusion conditions can be optimized to influence the physicochemical structures in the extrudate matrix so that oil absorption can be minimized. 相似文献
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Parisa Fallahi Kurt A. Rosentrater Kasiviswanathan Muthukumarappan Mehmet Tulbek 《Cereal Chemistry》2013,90(3):186-197
A fractional factorial design with a replicated central composite point was used to investigate the effects of extrusion processing on physical properties of distillers dried grains with solubles (DDGS) based aquafeeds using a twin‐screw extruder. Extrusion cooking trials were performed with a nutritionally balanced ingredient blend for Nile tilapia, with two levels of screw speed (350 and 450 rpm), two levels of extruder water (0.236 and 0.302 kg/min), and two levels of conditioner steam (0.1 and 0.15 kg/min). The central point was 400 rpm screw speed, 0.271 kg/min extruder water, and 0.12 kg/min conditioner steam. Effects of these processing conditions on extrudate characteristics were extensively analyzed and included moisture content, water activity, thermal properties, expansion ratio, unit density, bulk density, color, water stability, sinking velocity, water absorption and solubility indices, and pellet durability index. Increasing the extruder water and conditioner steam resulted in a 5.3% decrease and nearly 8.6% rise in mass flow rate, respectively. As screw speed increased from 350 to 400 rpm, water stability and water activity increased by 13 and 58%, respectively. Increasing extruder water from 0.236 to 0.302 kg/min led to a significant increase in water stability by 12.5% and decreases in water absorption index, water activity, and expansion ratio by 13, 21, and 5.5%, respectively. As conditioner steam increased from 0.1 to 0.15 kg/min, sinking velocity and water absorption index decreased by 25 and 15%, respectively. Increasing conditioner steam from 0.1 to 0.12 kg/min resulted in 20, 5.5, 10, and 3% decreases in moisture content of the extrudates, brightness (L*), water stability, and expansion ratio, respectively. It also increased bulk density by 5.8% and unit density by 4.2%. Overall, all trials produced viable extrudates with properties appropriate for Nile tilapia feeding. 相似文献
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Expansion during extrusion of starches is a unique phenomenon used extensively in the food industry. Sectional expansion index is usually determined as the ratio of the square of the diameter of the final extrudate to the square of diameter of the die through which the product is expelled. Longitudinal expansion index is calculated indirectly by doing a mass balance across the extruder and making an assumption for density of the dough melt in the die. The objective of this research was to determine the longitudinal expansion index experimentally using a die designed to measure the velocity of the melt dough inside the die. A tracer was induced to change the conductivity of the melt dough. The velocity inside the die was then determined by measuring the time of travel of a tracer with the help of electrical probes. Corn starch (25% amylose and 30% moisture content) was extruded in a twin-screw extruder at a barrel temperature of 140°C, screw speeds of 80, 120, and 160 rpm, and feed rates corresponding to the screw speeds varying from 7.35 to 13. 35 kg/hr. An inverse relationship was observed between the longitudinal expansion and the sectional expansion indices. 相似文献
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We have modeled a rice extrusion process focusing specifically on the starch gelatinization and water solubility index (WSI) as a function of extrusion system and process parameters. Using a twin‐screw extruder, we examined in detail the effect of screw speed (350–580 rpm), barrel temperature, different screw configurations, and moisture content of rice flour on both extrusion system parameters (product temperature, specific mechanical energy [SME], and residence time distribution [RTD]) and extrudate characteristics (expansion, density, WSI, and water absorption index [WAI]). Changes in WSI were monitored to reveal a relationship between the reaction kinetics during extrusion and WSI. Reaction kinetics models were developed to predict WSI during extrusion. WSI followed a pseudo first‐order reaction kinetics model. It became apparent that the rate constant is a function of both temperature and SME. We have developed an adaptation of the kinetic model based on the Arrhenius equation that shows better correlations with SME and distinguishes data from different screw configurations. This adaptation of the model improved predictability of WSI, thereby linking the extrusion conditions with the extruded product properties. 相似文献
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Nehru Chevanan Kurt A. Rosentrater Kasiviswanathan Muthukumarappan 《Cereal Chemistry》2007,84(5):428-436
Extrusion trials were conducted with varying levels of distillers dried grains with solubles (DDGS) along with soy flour, corn flour, fish meal, vitamin mix, mineral mix, and net protein content adjusted to 28% using a Wenger TX-52 twin-screw extruder. The properties of extrudates were studied in experiments conducted using a full-factorial design with three levels of DDGS content, two levels of moisture content, and two levels of screw speed. Increasing the DDGS content from 20 to 60% resulted in a 36.7% decrease in the radial expansion, leading to a 159 and 61.4% increase in the unit density and bulk density of the extrudates, respectively. Increasing the DDGS content resulted in a significant increase in the water absorption index (WAI) but a significant decrease in the water solubility index (WSI) of the extrudates. Changing the screw speed and moisture content had no significant effect on the radial expansion ratio but resulted in a significant difference in the bulk density of the extrudates, which may be due to the occurrence of longitudinal expansion. Even though changing the moisture content and screw speed had no significant effect on the WSI of the extrudates, significant differences in the WAI of the extrudates were observed. The ingredient components in the blend and moisture content had an influence on the color changes of the extrudates, as did the biochemical changes occurring inside the barrel during processing. Overall, it was determined that DDGS could be included at a rate of up to 60% using twin-screw extrusion, and that viable pelleted floating feeds can be produced. 相似文献
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This study was conducted to develop a ready‐to‐eat extruded food using a single‐screw laboratory extruder. Blends of Indian barley and rice were used as the ingredients for extrusion. The effect of extrusion variables and barley‐to‐rice ratio on properties like expansion ratio, bulk density, water absorption index, hardness, β‐glucan, L*, a*, b* values, and pasting characteristics of extruded products were studied. A central composite rotatable design was used to evaluate the effects of operating variables: die temperature (150–200°C), initial feed moisture content (20–40%), screw speed (90–110 rpm), and barley flour (10–30%) on properties like expansion ratio, bulk density, water absorption index (WAI), hardness, β‐glucan, L*, a*, b* values, and sensory and pasting characteristics of extruded products. Die temperature >175°C and feed moisture <30% resulted in a steep increase in expansion ratio and a decrease in bulk density. Barley flour content of 10% and feed moisture content of <20% resulted in an increased hardness value. When barley flour content was 30–40% and feed moisture content was <20%, a steep increase in the WAI was noticed. Viscosity values of extruded products were far less than those of corresponding unprocessed counterparts as evaluated. Rapid visco analysis indicated that the extruded blend starches were partially pregelatinized as a result of the extrusion process. Sensory scores indicated that barley flour content at 20%, feed moisture content at 30%, and die temperature at 175°C resulted in an acceptable product. The prepared product was roasted in oil using a particular spice mix and its sensory and nutritional properties were studied. 相似文献
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The influence of added fatty acids on extrusion cooking of corn grits and extrudate properties was studied. Samples with three average corn grits particle sizes were processed in a twin-screw extruder; fatty acids content (0.2–0.8%, wb) varied, and experimental conditions were kept constant (moisture content 18.4% wb, barrel temperature 150°C, screw speed 165 rpm). The effect of adding fatty acids was studied by analyzing water solubility and absorption indices, expansion indices, and mechanical (puncture test) and structural (computerized image analysis) extrudate properties. When fatty acids were added, water solubility and absorption indices decreased, radial expansion index decreased, longitudinal expansion index increased, number of cells increased, and mechanical resistance of extrudates decreased. The influence of added fatty acids was attributed to the formation of fatty acids-amylose complexes. 相似文献
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Grains of two regular and two waxy barley cultivars were milled into break and reduction stream flours using a wheat milling mill, granulated to facilitate feeding and flow through the barrel, and extruded to form expanded products using a modified laboratory single‐screw extruder. As moisture content of barley granules decreased from 21 to 17%, the expansion index of extrudates increased from 1.81 to 2.68, while apparent modulus of compression work (AMCW) decreased from 17.1 × 104 to 7.8 × 104 N/m2. Break stream flours of both regular and waxy barley produced extrudates with higher expansion index (2.72–3.02), higher water absorption index (WAI), and lower AMCW than extrudates from reduction stream flours. Extrudates produced from regular barley had generally higher expansion and lower density than those produced from waxy barley. The specific mechanical energy (SME) was greater during extrusion of regular than of waxy barley. Barrel temperatures of 130, 150, and 170°C for the feeding, compression, and metering sections, respectively, resulted in higher SME, higher expansion index, lower water absorption index and lower AMCW of extrudates compared with a constant extruder barrel temperature of 160°C. Increased screw speed generally resulted in larger expansion index and increased WAI of extrudates. With increased feed rate from 89 to 96 g/min, the expansion index of extrudates decreased from 3.20 to 2.78 in regular barley and 3.23 to 2.72 in waxy barley, and harder extrudates were produced. 相似文献