畜牧机械设备系列讲座 混合设备的选型

混合是保证饲料产品质量的主要因素,近年来混合机发展较快,已达到了比较完善的阶段.主要混合机型有单、双桨叶式高效混合机,螺带式、卧式混合机及悬臂式双螺旋锥形立式混合机等.要求饲料混合均匀度CV<1%,预混合饲料为CV<5%.混合机选择的基本条件主要有:混合均匀度、混合时间、残留量等几项因素.     

立式饲料预混机混合性能测定试验

通过盐法原理,以CV(混合均匀度变异系数)作为混合均匀度评定指标,确定饲料预混机最佳混合时间和最小适宜混合时间。制作特性曲线(CV-t曲线图),反映出饲料的混合均匀度与混合时间呈近似倒抛物线形关系。以试验确定的DSH-0.5型立式行星双螺旋混合机的最小适宜混合时间为24min左右。8～16min时段CV基本趋于稳定,但25min后CV有增大趋势,即混合时间过长,可能出现分级现象。     

不同装载系数和混合时间对添加剂预混料混合均匀度的影响

混合是配合饲料生产的重要工序,为了研究不同装载系数和混合时间对配合饲料混合均匀度的影响,探求悬臂非对称双螺锥形混合机在添加剂预混料生产中合理的装载系数和最佳的混合时间。采用甲基紫示踪法、以添加剂预混料为物料对象,采用两因素交叉设计就2个装载系数(500kg和250kg料位)和4个不同混合时间(16、18、20、22min)对饲料混合均匀度的影响进行研究。结果表明:混合机的料位为250kg(装载系数为0.3)时的混合均匀度显著低于500kg料位(装载系数0.6)的(P<0.05),但在低料位时通过选择合适的混合时间也能取得较满意的混合效果(CV为3.21%);4个不同的混合时间中以20min为最佳,混合时间过短或过长均降低饲料产品的混合均匀度。     

不同混合机最佳混合时间测定的试验研究

研究旨在探讨腰鼓型混合机和V型混合机混合时间对混合均匀度的影响,以确定满足生产实际的最佳混合时间。以扬州大学饲料厂生产的复合预混料为试验材料,采用单因子分组试验,按混合时间分7个处理组,每个处理做3个重复,每个重复取10个样品。采用邻菲罗啉比色法测定其变异系数。结果表明:在装载系数为0.42工况下,腰鼓型混合机的最佳混合时间为4 min,对应的变异系数(CV)为4.68%,混合时间对变异系数有显著影响(P<0.05)。V型混合机的最佳混合时间为11 min,变异系数(CV)为4.19%,混合时间对变异系数影响极显著(P<0.01)。实际生产中应根据不同机型选择适宜的混合时间。     

卧式混合机的混合机理、结构性能特点及发展前景分析

在饲料生产过程中,混合工序是决定饲料产品质量及生产效率的关键环节。因此,作为混合工序主导设备的混合机,其性能的好坏与作业效果如何,将直接影响饲料厂的产品质量和生产效率。目前国内所生产和使用的卧式混合机基本上以常规的螺旋环带式混合机和双轴桨叶式混合机为主。本文将分别对其混合机理、性能特点及发展前景作一探讨。1双螺旋环带式混合机1.1结构特点及混合机理双螺旋环带式混合机的转子是由内、外两条螺旋环带所组成。内外螺旋环带为等螺距、单头双层,结构比较简单、制造较容易,混合原理主要以对流混合为主。由于内外螺旋环带旋向…     

双轴桨叶式混合机

饲料工业的迅猛发展，人们对提高饲料的质量十分重视，混合设备是直接影响产品质量、生产效率和能耗等方面的关键设备之一，目前我国饲料厂使用的混合设备有许多类型，有V型、立式螺旋、双锥型、圆筒型、腰鼓式和卧式叶带、卧式螺旋及立式锥形等混合机，不仅效率不高，而且配料精度低。混合机主要机型性能见表1。轴桨叶式混合机结构见附图，主要机型技术参数见表2。如何提高饲料的配料精度、混合均匀度和缩短混合时间是人们要解决的问题，双轴桨叶式混合机在这些方面已取得了突破性的进展。1结构与工作原理生产饲料的混合过程是指物料间的…     

饲料加工混合设备的选用

现代的饲料生产中 ,饲料质量问题已普遍引起了养殖业的重视。饲料产品的混合均匀度是反映饲料加工质量的一项重要指标 ,也是评价混合机混合性能的一个主要参数。所以 ,饲料混合工段是饲料加工厂的重要工段 ,其中混合机的性能与使用效果如何 ,直接决定着该饲料厂的生产效率和产品质量。影响混合效果的因素是多方面的 ,但从选用的设备来讲 ,主要是受混合机机型和混合时间的影响。本文仅就不同混合机类型分述其生产性能和对饲料生产的影响 ,以供不同饲料加工厂参考。1、带式螺旋锥型混合机带式螺旋锥型混合机 (图 1 )在研制中以双螺旋锥型混合…     

饲料加工中的混合、制粒与膨化设备简介

1 混合设备 混合是将计量配料后的各种物料组分搅拌混合使之互相掺和均匀分布的一道工序.在饲料厂,主混合机的生产率决定该生产线的生产率.在现代饲料加工工艺中,配料混合系统,对饲料厂的生产率和饲料产品的的质量起着决定性作用,被称为饲料厂的心脏.混合机按主轴位置形式分为立轴式混合机和卧式混合机.卧式混合机有混合周期短、混合均匀度高以及残留量少等优点,所以使用较多.     

饲用混合机工艺性能的研究

本文测定分析了目前主要饲用混合机的混合性能,重点考察了预混合饲料生产中混合时间与均匀度、相对承载能力的关系.结果显示:双轴桨叶混合机速度最快,目前可作为配合饲料和预混合饲料生产的首选机型;卧式双螺带混合机、立式双螺带混合机、立式悬臂非对称双螺旋混合机也适于预混合饲料的生产,而卧式犁刀混合机的残留率过大,易引起各批次间的交叉污染.     

油脂添加及圆锥形混合机工艺特性

近年来,全价配合饲料中添加油脂来提高饲料能量已得到广泛应用。在预混合饲料生产中,油脂添加具有改善预混合料产品质量和降低作业场所有毒有害粉尘浓度的作用。圆锥形混合机是预混合饲料生产中常用的混合机之一。本文通过考察混合均匀度、残留量和“死角”现象,研究了矿物油添加顺序、添加量对圆锥形混合机工艺性能的影响。结果表明,“先加油后混匀”有利于提高预混合饲料的混合均匀度,为减少残留量,添加1% 矿物油较适宜。     

Effects of Marker Selection and Mix Time on the Coefficient of Variation (Mix Uniformity) of Broiler Feed

An experiment was conducted evaluating several markers to determine mix uniformity. Treatment diet was a corn-soybean meal-based diet formulated for broiler chicks fed from 0 to 17 d posthatch. Dietary nutrients or tracers evaluated included the following: 1) dl-Met (99%), 2) l-Lys-HCl (78%), 3) CP, 4) mixing salt (chloride ion), 5) P, 6) Mn, 7) Fe particles (#40 Red, count), 8) Fe particles (#40 Red, absorbance), 9) Fe particles (RF-Blue Lake), 10) roxarsone, and 11) semduramicin. All minor and microingredients were individually hand-weighed and added to the mixer to insure accuracy and were added at the same location for all treatments. Diets were mixed using a double ribbon mixer for 3 different mix times (0.5, 2.5, and 5.0 min). Overall, from 0.5 to 5.0 min, all markers evaluated showed a numerical reduction in percentage of CV. Crude protein and P should not be considered as markers, because many different components in the batch of feed contribute some level of CP or P, and results can be confounding. dl-Methionine (99%) and l-Lys-HCl (78%) were the only markers that statistically reduced over time and had a CV < 10% (23.86 to 9.47% and 19.75 to 8.70%, respectively). These data suggest that mixer uniformity results can be influenced by the particular marker that is chosen for mixer uniformity analysis.     

基于FX_(2N)的饲料配料混合系统设计与研究

文章采用PLC对淮安天参农牧水产有限公司饲料生产线的配料混合工序进行改造,以基于PLC的集散控制系统作为总体控制方案。通过对几种常见配料混合工艺比较分析,确定选用多料双秤同时配料工艺以缩短饲料配混时间,设计了PLC配料混合控制系统,介绍了系统硬件设计和软件控制流程。实践表明,以PLC为核心的该配料混合系统的配料精度和生产效率大幅提高,工人劳动强度明显降低。     

Diet mixing time affects nursery pig performance

The objective of this study was to determine the effects of mixing time (mixer efficiency) of diets containing several low-inclusion ingredients (crystalline AA, ZnO, a medication, and vitamin and trace mineral premixes) on growth performance of nursery pigs. In a pilot study, mixing efficiency of a 1,360-kg capacity, horizontal ribbon mixer was evaluated with salt of different particle sizes (440, 730, 2,000, and 3,000 microm). Sample preparation was evaluated by analyzing diet samples as collected (unground) or by grinding the entire sample to approximately 400 microm in particle size (ground). Diets (907 kg) were mixed, and samples were collected after 0, 30, 60, 120, 210, 330, 480, and 630 s of mixing. The coefficient of variation among 10 samples for each mixing time was used to measure mixer efficiency as determined by Cl concentration. A salt particle size x sample preparation x mixing time interaction was observed (P = 0.04). Samples with 2,000- or 3,000-microm salt particle size (unground or ground) never reached the desired mixing efficiency of a 10% CV. Using 440-microm salt (unground or ground) or 730-microm salt particle sizes (ground) was necessary to accurately achieve a mixing efficiency of a <10% CV within 330 and 630 s, respectively. Next, 180 weanling pigs (PIC, 6.31 +/- 0.84 kg of BW, 21 +/- 3 d of age) were fed diets in 2 phases (d 0 to 14 and d 14 to 28). Treatments consisted of mixing diets for 0, 30, 60, 120, or 330 s (440-microm salt particle size). Samples were collected in the mixer, and then each bag of feed (22.5 kg) was labeled (first to last as-manufactured) and sampled to determine the mixing efficiency. An individual bag of feed was fed to a single pen of pigs, and when finished, the next sequential bag was used. As mixing time increased, mixer CV were 178, 38, 26, 21, and 5% for phase 1 and 172, 79, 60, 48, and 26% for phase 2. As mixing time increased, bag CV values were 26, 20, 16, 11, and 7% for phase 1 and 56, 45, 40, 33, and 12% for phase 2. From d 0 to 14, increasing mixing time increased ADG (linear, P < 0.01) and G:F (quadratic, P = 0.03). From d 0 to 28, increasing mixing time increased ADG (quadratic, P < 0.01) and G:F (linear, P = 0.04). These data demonstrate that inadequate diet mixing (CV > 12%) reduces nursery pig performance.     

小型饲料搅拌机和平模颗粒机组合使用制备颗粒饲料的工艺研究

[目的] 研究JB-300型精饲料搅拌机和300型平模颗粒机组合使用制备牛羊精补料颗粒饲料的最佳工艺参数。[方法] 测定不同搅拌时间、装载系数对饲料混合均匀度的影响;确定搅拌混合工艺参数的基础上,测定不同玉米粉碎粒度、水分含量对颗粒饲料成型率的影响。以模孔直径、玉米粉碎粒度和水分含量为测定因素,以成型率和硬度的综合加权评分值为指标,确定制备颗粒饲料的最优组合参数。[结果] 搅拌时间为10 min、20 min的变异系数均显著（P<0.05）低于搅拌5 min和15 min。装载系数为80%时,变异系数显著（P<0.05）低于装载系数为70%和60%。玉米粉碎粒度为2 mm和4 mm时,颗粒饲料成型率显著（P<0.05）高于玉米粉碎粒度为6 mm和8 mm。水分含量为10%和13%时,颗粒饲料成型率显著（P<0.05）高于水分含量为16%和19%。影响正交试验综合加权平均分值的模孔直径、玉米粉碎粒度、水分含量的极差分别为18.76、1.64和3.47。[结论] JB—300型精饲料搅拌机混合饲料最佳参数：装载系数为80%、搅拌时间为10 min;300型平模颗粒机制作精补料颗粒饲料最佳参数：模孔直径为4 mm（压缩比为6）、玉米粉碎粒度为4 mm、水分含量为13%。     

日粮混合时间对饲料理化特性及肉牛育肥早期生长性能的影响

本研究旨在评估日粮混合时间对饲料理化特性及不同阶段肉牛生长性能、反刍活动的影响.将全混合日粮的混合时间分为15 min和30 min.将120头平均体重为(475±30)kg的肉牛随机分为2组,每组60头,每个重复10头.试验持续60 d,分为两个阶段,每个阶段30 d.在第1阶段结束后采用交叉设计,2组肉牛分别采食不...     

The Standardization of an Apparatus for the Mixing of Soil Samples for Nematode Extractions

Quantitative determination of nematode populations in soils frequently necessitates the mixing of representative soil samples to form a homogeneous, compound sample from which the nematodes are extracted. A mixing apparatus was developed and standardized with the aid of a spectrophotometric technique by which the dispersion of a dye through the soil during mixing could be determined. It was found that the mixer is most suitable for use on sandy loam soils. Optimal mixing is obtained at a speed of 15 rpm for 2 minutes. Under these conditions mechanical damage to nematodes during mixing is minimal.     

畜禽体外培养细胞生长规律研究

本研究利用组织块贴壁培养法对鲁西黄牛、蒙古马、北京鸭和狼山鸡等4个品种体外培养细胞的生长、分化规律进行了研究。通过绘制其生长曲线和在激光共聚焦显微镜下拍摄细胞生长过程,初步分析成纤维细胞的生长、分化规律。试验结果表明,4个品种的细胞生长曲线均呈明显的“S”形,家畜和家禽的细胞潜伏期和停滞期的长短以及细胞群体倍增时间均有明显差异,蒙古马和狼山鸡体外培养细胞的单个细胞分裂期也有显著差异,蒙古马为97 min,而狼山鸡为85 min。本试验构建的4个品种成纤维细胞系不仅使畜禽遗传资源在细胞水平永久保存下来,而且为分子生物学研究提供宝贵材料。     

土大黄对云南省滇西北高山草地生物多样性的影响

2009年9月,用点样（Point Quatfats）法调查了云南省滇西北贡山县迪麻村色娃龙巴高山牧场的4种不同土大黄覆盖率群落的空间垂直分布,并采用Shannon’s多样性指数（H）和均匀性指数（EH）对物种和群落多样性进行了分析。结果表明,云南省滇西北高山牧场有比较丰富的牧草资源,共25种;中等和中上等的土大黄覆盖率群落里具有最多的物种丰富度和最高的物种多样性指数,同时也具有高的物种均衡性;其次是高等的土大黄覆盖率群落;低等的土大黄覆盖率群落里则具有最低的物种丰富度和物种多样性指数。这些结果表明,土大黄对高山草地的生物多样性的影响并不明显,造成高山草地生物多样性变化的主要原因是家畜的放牧强度和频率。     

云雾山本氏针茅草地群落恢复演替过程中的物种多样性变化动态

采用样方法对云雾山干草原区本氏针茅草地群落进行长期定位监测,对未封育样地和封育5,10,15,20和25年样地群落的平均高度、盖度、多度和地上生物量以及植物多样性进行实地调查分析,以研究围栏封育对草地植物群落特征动态变化的影响.结果表明,围封10年样地群落的高度、多度以及地上生物量最大,而群落的盖度则随封育年限的增加呈显著增加趋势,在封育25年达到最大;围栏封育的不同年限也显著影响了群落的物种多样性,在围封10年样地群落具有最高的多样性指数,围封15年样地具有最高的丰富度指数,而均匀度指数则是在未封育群落中表现为最高值,最低值是在物种丰富度最高时出现.由此可见,围栏封育在一定时间范围内可以显著改善群落的特征,增加群落的生产力,对于本研究地本氏针茅群落的最佳封育期限为10～15年,但围封时间过长在草地退化方面有一定程度的影响.     

Vortex mixing of feline blood to disaggregate platelet clumps

Abstract: Platelet clumping is a common cause of erroneous platelet counts in cats. Mixing of blood with a vortex mixer was evaluated as a method to disaggregate platelet clumps in feline blood and thus obtain accurate platelet counts. Whole blood samples from 42 cats with platelet clumping and 10 control cats without platelet clumping were mixed for 1 minute at the maximal setting using a standard vortex mixer. Blood smears (for subjective assessment of the type and amount of platelet clumping), platelet counts, and total leukocyte counts were evaluated before and after mixing. Vortex treatment of blood samples with platelet clumps caused an increased platelet count in all but 1 sample. Although most samples had strong increases in platelet counts after mixing, only a minority of samples (5 of 42) appeared to have all platelet clumps dispersed. Of 39 feline blood samples with platelet counts initially <200×10⁹ cells/L, 23 counts increased to >200×10⁹ cells/L and 34 counts increased to >100×10⁹ cells/L. Overall, mixing gave inconsistent and partial improvement in platelet counts. Total leukocyte counts were not significantly affected by vortex mixing. Vortex mixing of 10 feline blood samples without platelet clumping had no consistent effect on platelet or WBC counts. In conclusion, vortex mixing of feline blood does not appear to be a consistent means of correcting the problem of feline platelet clumping.