葡萄糖气流干燥管道上喷嘴的计算确定

本文介绍了气流干燥管道上喷嘴计算的一种新方法，此法适应范围广，不仅适用于高风压、小流量的情况，而且适用于低风压，大流量的情况，是一种行之有效的计算方法。     

Heberlein公司的空气喷嘴

瑞士Heberlein纤维技术公司在ITMA’99上将展示各类空气喷嘴。这些喷嘴主要用于加工密实度高的长丝纱或用空气交缠方法把不同种类的纱混合在一起。适用于纺丝、纺丝－牵伸－变形、牵伸－加捻、牵伸－络丝、假捻－变形工艺以及共交缠和空气包纱等复合工艺。1、用于纺丝、纺丝－牵伸和纺丝－牵伸－变形工艺的喷嘴PolyJet系列喷嘴适用于各种纺长丝工艺,其中：·PolyJet－SP系列喷嘴用于FDY和SDY丝的高密度均匀交缠;·PolyJet－SPECO系列喷嘴用于POY丝较低密度、有规则的交缠。·PolyJet。－TG系列喷嘴用于纺丝及工业丝纺一牵工…     

假捻变形的交络技术

德国Ｅｎｋａｔｅｃｎｉｃａ公司制造的ＴＤ喷嘴系列适用于假捻变形工艺的新进展,本文介绍了该喷嘴的结构,以及变形纱的质量测定方法。     

美国新型天然气辅助注塑成型技术

美国塑料加工设备制造商宝华压缩机Bauer Compressors）公司是一家专门从事天然气辅助注塑成型（GAIM）设备的生产商，最近推出了适用于异型挤塑工艺的气体辅助技术。这项新技术可以不使用发泡剂，在混合区的挤出机料筒安装上专门设计的气体喷嘴。事实上该气体喷嘴也是采用气辅注塑成型的，但它需要不断通入氮气。典型的应用为车窗，车门和盖板。     

ZJS型扇形自清洗喷嘴的特性与经济效益

ZJS型扇形自清洗喷嘴是近代世界上先进的喷水装置之一,是轻工业部杭州轻工机械设计研究所和绍兴县齐贤轻工机械厂进行技术协作的科技成果。喷嘴结构参考联邦德国制造的自清洗喷嘴样品。使用本装置后,预计经济效益较高,是造纸机械清洗装置上的一项改进。该产品于1987年11月由绍兴县科学技术委员会组织鉴定。一、用途ZJS型扇形自清洗喷嘴,主要适用于造纸机中清洗铜网、毛毯,也可用于化工、食品工业。二、主要技术参数1.喷嘴开口规格可根据用户需要选定,目前确定开口角度有α=30°,α=60°,     

织物数码喷墨印花技术的动向

介绍织物数码喷墨印花技术的发展过程、原理特性、现状及其动向。数码喷墨印花是集电感、网络、数字和信息技术以及精密机械加工和精细化工于一体的新技术群体，是改造染整工业传统加工技术的冲击波。适用于织物数码喷墨印花技术，按其喷墨方式有应用微压电技术和热气泡技术两种。数码喷墨印花技术的工作原理是墨水施加外力，使其通过喷嘴喷射到织物上形成一个个色点。它是数字化图像的喷射技术，由数字技术控制喷嘴，保证在织物表面上形成所要求的图像和颜色。织物数码喷墨印花采用染料型墨水为多，目前有CMYK墨水技术和预配色墨水技术两种，后成本低，似是发展方向。     

扇贝剥离设备喷嘴内部流场的仿真分析与参数优化

本课题依托国家海洋公益性行业科技专项。由于采用水射流技术进行扇贝剥离加工有加工质量好;闭壳肌剥离完整;清洁卫生;加工原料易获得等诸多优点,故利用水射流技术对海湾扇贝闭壳肌剥离进行研究分析,以期得出一种新型的扇贝闭壳肌加工模式。由于喷嘴为该剥离设备的关键部件,而喷嘴参数变化会对流场速度分布产生影响。因此本文利用扇贝剥离加工的窄角扇形喷嘴内部流场的二维数学模型,将加工用窄角扇形喷嘴网格模型用quad-dominated（四边形占优）形式进行划分。并通过FLUENT流体计算软件,采用标准κ-ε湍流模型对窄角扇形喷嘴内部流场进行了仿真,通过分析喷嘴锥角、出口直径、出口长度等变化对出口处流场速度分布影响,得出适用于水射流加工扇贝的喷嘴的最优参数组合。     

扇贝剥离设备喷嘴内部流场的仿真分析与参数优化

本课题依托国家海洋公益性行业科技专项。由于采用水射流技术进行扇贝剥离加工有加工质量好;闭壳肌剥离完整;清洁卫生加工原料易获得等诸多优点,故利用水射流技术对海湾扇贝闭壳肌剥离进行研究分析,以期得出一种新型的扇模式。由于喷嘴为该剥离设备的关键部件,而喷嘴参数变化会对流场速度分布产生影响。因此本文利用扇贝剥离加工的窄角扇形喷嘴内部流场的二维数学模型,将窄角扇形喷嘴网格模型用quad—dominated（四边形占优）形式进行划分。并通过FLUENT流体计算软件,采用标准湍流模型对窄角扇形喷嘴内部流场进行了仿真,通过分析喷嘴锥角、出口直径、出口长度等变化对出口处流场速度分布影响,得出适用于水射流加工扇贝的喷嘴的最优参数组合。     

功能型系列辅助喷嘴通过科技成果鉴定

由陕西省科技厅组织、陕西省教育厅主持，西安工程科技学院完成的“喷气织机功能型辅助喷嘴”项目于2004年11月26日在西安进行了科技成果鉴定。功能型辅助喷嘴的研制目的在于替代现有的各种辅助喷嘴，为高效、节能、低成本用好喷气织机提供技术支持。其中，减磨型辅助喷嘴将喷射角上移至头端、节能型辅助喷嘴采用异孔径多孔式结构、提速型辅助喷嘴采用变径的气流通道，     

合成鞋底材料的加工设备与技术

橡胶的注射加工技术注射加工成型是这个领域的最新进展。其所应用的注射机，虽然它的操作机理与塑料相似，但在机器尺寸和加热系统两方面有所不同。它除了包括热塑性材料所需的耐热系统外，还要通过流体循环的温度自动控制来加减热量，这是橡胶加工机器所不可缺少的。下边我们针对这一最新的模具注射机理作一简单的解释，它适用于单密度和双密度的直接注射以及多色鞋底注射。①直接注射模具系统１．注射喷嘴直接进入模腔。２．注射的同时，喷嘴从模具上后退，射出的橡胶量与鞋底的设计量相对应。３．当注射接近完成时，活塞提升，压缩橡胶。…     

新型连杆式喷头应用于烟草的喷雾效果评价

  目的  探索新型连杆式喷头在烟草上的适宜喷雾技术,为精准施药提供依据。  方法  采取室内和田间试验法,利用连杆式喷头设计不同组合喷雾方式,分别测定其基本参数、作业效率、药液附着率及防治效果。  结果  （1）优化设计了分别适用于烟草苗床期、团棵期和旺长至成熟期喷雾的钉耙式连杆8喷头、人字式连杆5喷头和鱼骨式连杆8喷头3种组合方式。在不同喷雾方式下,叶片药液附着率均随喷液量的增加而提高,但在各生育期的3个中高喷液量处理间无显著差异,在叶位间的分布特点均为上部叶 > 中部叶 > 下部叶;（2）在相同药剂浓度和喷液量条件下,3种组合方式喷雾的药液附着率较常规喷头分别提高20.11%~34.54%、28.41%~66.67%和30.60%~70.87%。鱼骨式连杆8喷头组合喷雾防治赤星病的防效是常规喷头的1.9倍;（3）在相同药液附着率条件下,3种组合方式喷施药液量较常规喷头分别减少34.21%、49.15%和57.45%,作业效率分别是常规喷头的1.8、1.9和2.7倍。  结论  该新型喷头具有节药、省工、增效及灵活组装等优点,适用于各类背负式喷雾器的喷头更新,具有良好的推广应用前景。      

Effect of Spray Nozzle Design on Fish Oil–Whey Protein Microcapsule Properties

Abstract: Microencapsulation improves oxidative stability and shelf life of fish oil. Spray and freeze drying are widely used to produce microcapsules. Newer spray-nozzles utilize multiple fluid channels allowing for mixing of wall and core materials at the point of atomization. Sonic energy has also been employed as a means of atomization. The objective of this study was to examine the effect of nozzle type and design on fish oil encapsulation efficiency and microcapsule properties. A total of 3 nozzle types, a pressure nozzle with 1 liquid channel, a pressure nozzle with 2 liquid channels, and a sonic atomizer with 2 liquid channels were examined for their suitability to encapsulate fish oil in whey protein isolate. Physical and chemical properties of freeze dried microcapsules were compared to those of microcapsules produced by spray drying. The 2-fluid pressure and ultrasonic nozzles had the highest (91.6%) and the lowest microencapsulation efficiencies (76%), respectively. There was no significant difference in bulk density of microcapsules produced by ultrasonic and 3-fluid pressure nozzles. The ultrasonic nozzle showed a significantly narrower particle size distribution than the other nozzles. This study demonstrated that new nozzle designs that eliminate emulsion preparation prior to spray drying can be beneficial for microencapsulation applications. However, there is still a need for research to improve microencapsulation efficiency of multiple channel spray nozzles. Practical Application: Since this research evaluates new spray nozzle designs for oil microencapsulation, the information presented in this article could be an interest to fish oil producers and food industry.     

Physico-chemical studies on agricultural sprays VIII.—Viscosity and spray drop size of water-in-oil emulsions

The effect of the viscosity of the spray fluid on the size of drops produced from fan-jet nozzles is complex; an increase in viscosity can lead to either an increase or a decrease in the drop size. With water-in-oil emulsions the value of the viscosity governing spray behaviour is the limiting value measured under conditions of very high shear. The factors which influence the limiting value of the viscosity include the disperse phase ratio, the method of mixing and the degree to which the two phases are mixed, the nature and concentration of the emulsifying agents used and the type of toxicant incorporated in the emulsion. Within certain limits, it is shown that the disperse phase ratio provides a convenient means of varying the viscosity of the emulsions and that the viscosity may also be varied by variations in the emulsifying agents and toxicants. Although the method of mixing has a considerable effect on the viscosity of the emulsion, the further mixing that takes place in the spray nozzle governs the effective viscosity of the spray fluid that is emitted from the nozzle. The practical application of the theoretical expressions which describe the formation of drops from fanjet nozzles has been discussed and the relationship between disperse phase ratio, viscosity, nozzle size and operating pressures has been illustrated for several typical water-in-oil emulsions.     

Heat transfer in a tunnel pasteuriser. Part I. Factors affecting the rate of heating of liquid in a bottle

The purpose of this work was to investigate heat transfer conditions in tunnel pasteurisers used to pasteurise beer and fruit juices in glass containers. A module of a pasteuriser was built and the following process variables were investigated: bottle shape, hot water spray intensity, location of bottle in relation to the spray nozzle axis, and the spray nozzle pattern and the deflection angle of nozzles with respect to the vertical. It was found that all these variables affect the rate of heating of liquid in bottles. However, the shape of the bottle has little effect, while spray intensity and location of the bottle in relation to the nozzle axis are important factors in the heating process. The effect of the angle of the nozzle to the horizontal is rather ambiguous, since it improves heating at one location but worsens it at another.     

Characteristics of intersecting airflows in the narrow flow channel

Air-jet loom is a kind of shuttleless loom, which is widely used in textile industries. The weft insertion system is composed of main nozzle, auxiliary nozzles, and profiled dent groove. The jets from the main and auxiliary nozzles intersect in the profiled dent groove. The velocity and stability of the intersecting airflows have a direct impact on the yarn’s motion. In this paper, the commercial software is adopted to simulate the intersecting airflows in the profiled dent groove. The result shows it is reasonable that the distance from the main nozzle to the first dent is 15 mm. The optimal distance from the main nozzle to the first auxiliary nozzle is between 45 and 50 mm based on the criteria of the utilization efficiency of the airflow. According to the standard of airflow stability, when the spray angle of auxiliary nozzle is about 7°, the standard deviation of the radical airflow velocity is the smallest in different cross sections. Therefore, the intersecting airflows are the most stable when the spray angle of auxiliary nozzle is about 7°. The velocity distribution of intersecting airflows in the profiled dent groove is measured using Particle Image Velocimetry (PIV) technique. The research results can provide some useful references for the optimization of the weft insertion system of the air-jet loom.     

辅助喷嘴结构对喷气织机异形筘内合成流场特征的影响

为提高喷气织机引纬系统的引纬速度和稳定性,采用雷诺时均方程中的k-ε双方程湍流模型分别对单圆孔、正三角形孔和星形孔3种不同的典型喷嘴与异形筘的合成流场进行模拟仿真,得到在0.2~0.4 MPa供气压力下不同辅助喷嘴间距合成流场中心轴线气流速度和流场速度云图。结果表明:当压力相同时,正三角形孔辅助喷嘴合成流场中心轴线气流速度最高,对纱线牵引力最大;星形孔辅助喷嘴合成流场中心轴线气流速度变化幅度最小,引纬稳定性最好;单圆孔辅助喷嘴中心轴线气流速度波动最大,间距超过70 mm,不适合引纬;在全幅织物接力引纬时,各组喷嘴射流的喷射时间互相衔接,喷嘴间距不宜太长。     

纸机上常用喷嘴的选用

纸机上所用喷嘴的形式日趋多样化。本文介绍了造纸业常用喷嘴及喷淋管的类型、结构、特性以及在纸机上的应用位置和使用情况等,以便根据具体使用位置和工艺条件进行选择和满足设计需要,并进行有效控制。     

Process engineering variables in the spray washing of meat and produce.

Recently, much attention has been focused on the safety of fruits and vegetables. Washing is a fundamental operation in the processing of produce. Aqueous spray energy can be, and often is, used to remove mineral, chemical, or biological contaminants from produce. A few advantages of spray washing over washing by dipping, soaking, or gravity rinse are increased energy directed to contaminants, reduced volume of water use and wastewater generation, and reduced water uptake by produce. The kinetic energy of the spray droplets produces the cleaning action. Increased spray pressure increases energy. If the energy is too great, produce may be physically damaged. If the energy is too little, the surface may not be cleaned. Indeed, studies on meat have shown that water pressures ranging from 1,379 to 2,070 kPa (200 to 300 psi) are effective in reducing microbial contamination, and a water flow rate of 7.5 liters/min is recommended. Water temperature >70 degrees C has been found to reduce bacterial counts in carcass tissue by 2 to 3 log CFU/cm2. These levels are likely too high for the fragile produce; hence, the main function of spray washing in produce applications will probably shift to being a delivery system for antimicrobial agents. Several other equipment, process, and product variables are relevant to the optimization of such a system. Qualities of the spray, such as droplet spectrum, droplet velocity, angle of droplet impingement, number and orientation of nozzles, spray rate, and resident time of the produce in the sprayer, also can be manipulated to adjust the amount of energy directed to the surface. There is a need to scientifically investigate the effects of these processes and equipment parameters on the removal of microbiological contaminants on meats and produce. Such empirical investigations guided by the results from fundamental studies about produce surface characteristics and the mechanism of bacterial attachment to plant tissue surfaces would allow for the efficient development of spray washers that effectively decontaminate produce.     

喷气织机引纬筘槽内气流状态的测试分析

 为了解辅助喷嘴的喷射区间长度、辅助喷嘴的喷向角、辅助喷嘴的供气压力等因素与引纬筘槽内气流流速的关系,采用毕托管,通过自行设计的测量装置对引纬筘槽内的气流速度进行测量,同时研究了不同供气条件下气流速度的变化情况。研究结果表明：引纬槽内的气流速度变化剧烈,并按辅助喷嘴间距周期性波动;供气压力过小时筘槽内气流速度无法达到引纬要求;在引纬槽的同一截面上,不同的测量点具有不同的速度,纬纱在不同测量点受到的作用力也不一样。     

Spray cooling effects on milk production, milk, and rectal temperatures of cows during a moderate temperate summer season

During summer 1982, responses of lactating Holstein and Guernsey cows were measured by milk temperature recorded by a Digital Dataloger with thermocouples attached to Boumatic flow meters. Maximum air temperature and temperature-humidity index averaged 30.8 degrees C and 75.6 for July. Breed did not affect milk temperature, but within-breed milk temperature increased with production. In a second study, benefits of spray cooling were evaluated with 24 Holsteins in midlactation assigned randomly to two groups of 12 and maintained under loose-housing conditions. Spray nozzles were installed in the walkways and under the manger shade for the spray treatment group. Maximum temperature and temperature-humidity index during the spray study were 27 degrees C and 73.9. Rectal temperature taken following milking averaged less for treatment than control (38.8 versus 39.1 degrees C). Milk temperature was similar (37.8 versus 38.1 degrees C). Daily milk yield was .70 kg higher than controls. Milk temperature may provide reliable indication of climate stress similar to rectal temperature, and spray cooling improves cow comfort and lessens summer decline of milk production.