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双轴式和面机设计

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无锡太湖学院信 机系 机械工程及自动化 专业毕 业 设 计论 文 任 务 书一、题目及专题:1、题目双轴式和面机设计 2、专题 二、课题来源及选题依据和面机又称调粉机,是面食加工的主要设备,它主要用于将小麦粉与水按1:0.380.45的比例,根据用户加工工艺要求,混合制成面团,广泛适用于食堂、饭店及面食加工单位的面食加工。 随着市场份额的发展,手工和面的产量已跟不上人们的日常需求,和面机也应运而生。和面机操作方便,自动化程度高,不仅节省了人力,还省事省力,真正的做到了化劳力为动力的要求。和面机的产生使得面粉事业得到了更一步的发展。 和面机模拟手工和面的原理,使面筋网络快速形成,使得蛋白组织结构均衡,使面的的产量大大高于手工和面,且生产出来的面品,口感光滑,透明度高,弹性好。 三、本设计(论文或其他)应达到的要求:熟练掌握双轴式和面机的工作原理与结构; 熟悉双轴式和面机中和面过程的运动搅拌器结构设计与受力分析; 熟练掌握双轴式和面机的各参数的设计和各传动的结构的设计; 设计方案思路明确,具备熟练使用CAD制图的能力,绘制装配图及零件图; 查阅资料整理资料和提取资料的能力; 对整个设计过程作出总结,撰写设计说明书。 四、接受任务学生: 机械95 班 姓名 孙勇 五、开始及完成日期:自2012年11月12日 至2013年5月25日六、设计(论文)指导(或顾问):指导教师签名 签名 签名教研室主任学科组组长研究所所长签名 系主任 签名2012年11月12日编号无锡太湖学院毕业设计(论文)相关资料题目: 双轴式和面机设计 信机 系 机械工程及自动化专业学 号: 0923210学生姓名: 孙 勇 指导教师: 戴宁 (职称:副教授 ) (职称: )2013年5月25日目 录一、毕业设计(论文)开题报告二、毕业设计(论文)外文资料翻译及原文三、学生“毕业论文(论文)计划、进度、检查及落实表”四、实习鉴定表无锡太湖学院毕业设计(论文)开题报告题目: 双轴式和面机设计 信机 系 机械工程及自动化 专业学 号: 0923210 学生姓名: 孙勇 指导教师: 戴宁 (职称:副教授) (职称: )2012年11月25日 课题来源自拟课题科学依据(包括课题的科学意义;国内外研究概况、水平和发展趋势;应用前景等)(1)课题科学意义和面机又称调粉机,是面食加工的主要设备,它主要用于将小麦粉与水按1:0.380.45的比例,根据用户加工工艺要求(有时加食油、食堂、及其他食物和食物添加剂)混合制成面团,广泛适用于食堂、饭店及面食加工单位的面食加工。随着市场份额的发展,手工和面的产量已跟不上人们的日常需求,和面机也应运而生。和面机操作方便,自动化程度高,不仅节省了人力,还省事省力,真正的做到了化劳力为动力的要求。和面机的产生使得面粉事业得到了更一步的发展。和面机模拟手工和面的原理,使面筋网络快速形成,使得蛋白组织结构均衡,使面的的产量大大高于手工和面,且生产出来的面品,口感光滑,透明度高,弹性好。双轴和面机的特点:双轴和面机是在单轴和面机的基础上加以改进而成,其性能较单轴和面机优越。1该机有两根旋转轴,每根轴上垂直安装数个叶片,构成平行,以相同方向转动的搅拌器。2传动方式可以由主电机通过变速箱分别带动两轴做同向旋转,也可以将一根作为主动轴,通过齿轮传动实现同向转动。(2)和面机的研究状况及其发展前景随着食品行业的日益发展壮大,生产设备产能变大的要求变得日益强烈。和面机是大多数食品行业必备的生产设备,且一般处在生产流程的上游,和面机的产能,稳定性,对整个生产线来说就显得非常重要。如果单纯靠增加设备的数量,产能虽然可以上去,但是不但设备的费用回大大增加,人力成本和故障率也会增加。为了很好的解决以上问题,于是大型和面机诞生了。大型和面机自动化程度高,机器故障率低,一个人可以轻松看护两台大型和面机,其产量可以满足大中型食品企业的需求。研究内容1熟练掌握双轴式和面机的工作原理与结构;2熟悉双轴式和面机中和面过程的运动搅拌器结构设计与受力分析;3熟练掌握双轴式和面机的各参数的设计和各传动的结构的设计;拟采取的研究方法、技术路线、实验方案及可行性分析研究方法:根据课题所确定的和面机种类,用途及生产能力确定和面机的主要构件(例如桨叶,容器)机构形式和尺寸参数,运动参数及动力参数(电机功率)。根据双轴式和面机主要构件的形式,性质及运动参数,拟定整机的机械传动链和传动系统图。计算并确定各级传动的传动比,皮带转动,齿轮转动等传动构件的结构参数及尺寸,拟定机器的结构方案图。根据结构方案图,在正式图纸上拟定传动构件及执行构件的位置,然后依次进行执行构件及传动系统设计机体,操纵机构设计,密封及润滑的结构设计。研究计划及预期成果研究计划:2012年10月12日-2012年12月31日:按照任务书要求查阅论文相关参考资料,完成毕业设计开题报告书。2013年1月1日-2013年1月27日:学习并翻译一篇与毕业设计相关的英文材料。2013年1月28日-2013年3月3日:毕业实习。2013年3月4日-2013年3月17日:双轴式和面机的主要参数计算与确定。2013年3月18日-2013年4月14日:双轴式和面机总体结构设计。2013年4月15日-2013年4月28日:零件图及三维画图设计。2013年4月29日-2013年5月21日:毕业论文撰写和修改工作。 预期成果:根据提供的主要构件参数而计算出的传动构件的参数,尺寸及机体等是合理的,可以进行正常的生产组装,最终达到双轴式和面机的工作要求。特色或创新之处 造型优美,占地面积小,机器操作噪音小。故障率低,使用寿命长。双轴式和面机可以均匀的进行搅拌,使得面团得到良好的拉伸和揉捏,适于调制韧性面团。已具备的条件和尚需解决的问题1、设计方案思路已经非常明确,已经具备使用CAD制图的能力和了解和面机原理结构等知识。2、使用CAD制图能力尚需加强,结构设计能力尚需加强。指导教师意见 指导教师签名:年 月 日教研室(学科组、研究所)意见 教研室主任签名: 年 月 日系意见 主管领导签名: 年 月 日英文原文New energy-saving mechanical mixer and Overview of adaptable die design for extrusionAbstractIn the work there are described the results from the laboratory researches of the basic characteristics (performance) of one new type of energy-saving mechanical mixer, conditionally named Eleron. These characteristics (performance) are compared with respective results of the other known in the literature and successfully used in practice mixers. The mixer is designed for mixing and aerating liquid systems and it will be effective for mixing in the ferment reactors for biochemical industries, where the processes are energy absorbing. Keywords: Mixer; Air-saturation; Power-number; Heat and mass-transfer during mixing; Aeration-number1. Introduction In implementing a long-term, energy-saving program for industry 1, the department of Heat and Mass-Transfer Technics in TU-Sofia, under the guidance of the author, has conditionally created for patent an original construction of energy-saving mixer. It has a universal function for mixing liquid systems in chemical, food, wine, tobacco, and biochemical industries. We expect our mixer to take its place with dignity in fermentation technics, because of its easy manufacture, good results in air-saturation and low energy consumption. Till now it was the investigated laboratory version of Eleron-1 mixer, which is a small type, with D=(0.25/0.35)T. Universal appearance of mixer is shown in Fig. 1. It consists of a central round disk (1), which is carrying pap (2) and four wings (3). The wings are cut through in the middle (aa) and in the beginning, near the round disk (cc), and the receiving pieces are bend arch-shaped up and downward, making four blades with radius R=(0.05/0.07)D. Their length is L=0.8pR, as (considered) from line of bend. The blades on each following wing are in different order in bend direction, and because of this in working conditions there are circumstances for vortexes. This is very important when there is more than one mixer on a shaft (Figs. 1 and 2). When mounting, we observe the axial flows, created by curved blades, to meet each other (if we aim air saturation) or to pass each other, when we aim mixing without aeration. In this way we create multitude of symmetrical current lines (vortexes), which spread symmetrically vessel.2. ExperimentalFor researching characteristics (performances) of mixer Eleron-1 there are used two identical laboratory reactors with plane bottom and releasers, respectively with volumes 6.5 and 24 dm3. Reactors diameters are, respectively 190 and 300 mm, and mixers are make up with D_0.35T. As pattern substances there are used water and die thylene glycol, which under 20C have dynamical viscosity and Pa s. Reactors configuration is on Fig. 2 and the experiment tal installation, which is used, is on Fig. 3. With this installations configuration we are researching the power consumption, working with and without aeration , heat-transfer during mixing with Eleron-1, that is why reactors have heat-transfer bogies-worm-pipes (serpentines) with respective tube diameter d1 and wind up diameter dS, which are on Fig. 2. For measuring DO2 (dissolved oxygen) in liquid phase during aeration, installation also has a bottle with nitrogen, air-compressor, sensor for DO2and a writing instrument, which register on the tape the oxygen absorption (Fig. 3).Fig. 1. Scheme of mechanical mixer Eleron-1 in appearance from above.2.1. Power coefficient determination For this mixers characteristic are usedtwo reactors and two pattern substances, and the rotation frequency of mixers shaft is changing from 100 to 1200 min_1. Rotation frequency is chosen and fixed and after that is controlled with electronic cyclometer. Eu-number is determined under equation and it is read net power consumption P, for respective rotation frequency . The dependency is in Fig. 4 and is compared with the dependency of Rush ton-turbine.2.2. Aeration-number determination This exponent is defined under known methods, which is adopted for mixing technics. In our reactor with volume 6.5 dm3, with the help of air-distributed mechanism, the air is entranced with flow of qG_0.1 to1.5 V . The researching results are on Fig. 5 and are compared and heat-transfer surface (serpentine). Fig. 2. Configuration of laboratory reactors with mechanical mixerFig. 3. Scheme of experimental installations: 1, thermostat; 2, reactor; 3, pressure vessel; 4, heat-transfer surface (serpentine)2.3. Mass-transfer coefficient determination during mixing with Eleron-1 There are used two reactors with different volumes, which have air-distributed mechanisms and sensor form easuring and registering of CO2 in water. We work under 20C, and the liquid phase, before each attempt, is scavenged with nitrogen until initial oxygen concentrationC0, which is changing progressively and is writing on the tape till establishing an equilibrium (saturation concentration) .3 Traditional Mixer3.1 Different ways to classify the mixers.3.1.1 According to the number of mixing spindles .There are single-spindle mixers and double-spindle or even triple-spindle mixers.3.1.2 According to their mixing speed .There are slow-speed mixers(less than 30rev/min), high speed mixers (above 35rev/min), and variable speed mixers.3.1.3 According to their operation mode. They can be classified into batch mixers and continuous mixers.3.1.4 According to the axis position of the mixing spindle from which the mixing arms receive torque and motion .They can be classified into vertical mixers and horizontal mixers .In this chapter, he machines will be discussed in terms of this classification.Investigations show that horizontal mixers are still the dominant mixing equipment in todays modern bakery and snack industry, for they are of simple construction, simple in operation, and cheaper to run. They also have varied capacities and can be used for a wide variety of mixtures from a thin batter for cookie depositing to extremely tough dough for Chinese snack casing.3.2 HORIZONTAL MIXERSHorizontal mixers are characterized by having a horizontally located mixing spindle on which the mixing arms are fixed into the mixing bowl .Fig.2.1 is a typical front view of this kind of mixer.3.2.1 Construction A typical horizontal mixer consists of a mixing bowl,one or two mixing spindles by which the mixing arm(s) is or are driven through transmission mechanisms,and a main frame made of either cast iron or unitary construction of heavy steel plate,One or two motors are mounted below for mixing and bowl tilting functions together with a facia control and an electric interlock system to prevent access when the machine is running. There are two types of weighing systems: one is separate from the mixer; the other calculates the weight change of the complete mixer before and after the addition of an ingredient, the mixer being located on a suitable weighing scale or platform. In this case the mixer is often referred to as a weigh-mixer.3.2.2 Mixing bowlThe bowl of the horizontal mixers is of trough-like design with a curved bottom (U-shaped in cross section) and flat ends. The bowl surfaces in contact with the dough are commonly of stainless steel or stainless clad steel. This is the usual construction for the bowl ends, where the bearings are fixed to support the mixing spindles. The bowls of large modern mixers are generally double-skinnedin the form of a jacket through which chilled water or refrigerant can be circulated to prevent the dough warming up to too high a temperature as a result of mixing friction. To avoid flour and other ingredients splashing, especially at the beginning of mixing, and for safety as well as food hygiene, the bowl is always equipped with a lid which is either removable or hinged for dough discharge and cleaning. For large mixers, he lid usually has provision for assisted ingredients feed.There are two methods of dough discharging: by tilting the bowl(110。to 180。),or by mechanically sliding down the door in front of the stationary bowl to allow the dough to fall into an underlying hopper. For a ground-floor installation, the dough is often discharged into a dough tub which is usually fabricated in heavy gauge stainless steel and is supplied separately by the manufacturer. The bowl-tilting operation is generally carried out by a worm-gear mechanism in which the worm-gear is fixed on the bowl sidewall. Feeding of the bowl is carried out either manually for small mixers, or automatically through the corresponding pipes above the mixer and by means of a weighing system for large horizontal mixers. Bowls are manufactured in a wide range of volumes which allow from a few kilograms up to 1500 kg of food materials to be mixed in them. The larger the bowl size, the greater the required power of the mixing motor, so that bigger batches of dough can be mixed, resulting in a higher rated capacity for the mixer. For most large mixers, the bowl is tilted by a separate reversible motor ranging from 0.75 to 2.26Kw.3.2.3 Mixing arms Mixing speed The mixing operation is directly performed by the mixing arms, while its power is transmitted by its driving spindle (shaft or axle).That is, the speed of the mixing arm is dependent on the speed of its spindle. Horizontal mixers are designed in either a single or dual mixing speed mode. For the dual mode, its lower speed is half the rated maximum speed. As dough mixing is often carried out in two stages-blending of the ingredients, and developing the gluten-it is essential that the first stage should be accomplished at a lower speed(for example 36 rev/min) and the second stage at the rated speed (which will be 72 rev/min).Generally speaking, the machine with a mixing speed below 30rev/min is referred to as a slow-speed mixer, and that with a speed above 35rev/min as a high-speed mixer.Modern mixers commonly cover a wide range of speed variation from 20 to 145 rev/min or even up to more than 200 rev/min, which high speed allows a quick development of gluten elastic dough by means of suitable mixing arms. The slow-speed mixers are generally used in short and soft dough mixing since a much longer time would be needed for hard and bread dough。For of the mixing arms The mixing arms are designed in various configurations and cross-sections for different mixing functions such as blending, dispersing, beating, shearing, scraping, stretching, or kneading to form either a uniform mass or a dispersion or a solution, or aeration (that is, either a soft dough or hard dough, a sponge dough or batter or topping with other food material). Some mixing tools have a floral-hoop type, oval-type, or twisting-plate type and comprised only one or two loop-like arms without a centre shaft; they are referred to asshaftlessa agitators or mixing arms. The corresponding machines are referred to as shaftless mixers. In the group, there are some other types of arm such as Z-type and S-type. Their cross-section is large to ensure strength . Their relatively complex configurations are commonly cast in one piece or are welded after forging .Attention should be paid to the coaxiality of the two sides of the arm during manufacturing to avoid severe trouble in the later mixing operation.This type of mixer can be used for a wide range of dough with different consistencies, from thin batter to extremely tough dough., as the shaftless arms are especially efficient in dealing with extensible dough, since in their rotation orbit there is always a limited clearance from the bowl inner walls, which is beneficial in showing the dough to be stretched and kneaded repeatedly to form an oriented gluten network.Some other mixing tools (agitators) comprise simple shaped arms and a centre shaft. This kind of segmented construction is easy to manufacture and assemble, and its maintenance is lower than that of those described earlier. However, to deal with sticky dough, this group of agitators are at a disadvantage since the tendency of sticky dough is to adhere to the shaft, and the circular velocity at the centre shaft area is very low, resulting in a dead space and therefore improper mixing. Sometimes the centre shaft is covered by dough, layer upon layer.The term “adaptable die design” is used for the methodology in which the tooling shape is determined or modified to produce some optimal property in either product or process. The adaptable die design method, used in conjunction with an upper bound model, allows the rapid evaluation of a large number of die shapes and the discovery of the one that produces the desired outcome. In order for the adaptable die design method to be successful, it is necessary to have a realistic velocity field for the deformation process through extrusion dies of any shape and the velocity field must allow flexibility in material movement to achieve the required material flow description. A variety of criteria can be used in the adaptable die design method. For example, dies which produce minimal distortion in the product. A double optimization process is used to determine the values for the flexible variables in the velocity field and secondly to determine the die shape that best meets the given criteria. The method has been extended to the design of dies for non-axisymmetric product shapes. 2006 Elsevier B.V. All rights reserved.Keywords: Extrusion; Die design; Upper bound approach; Minimum distortion criterion1. IntroductionNew metal alloys and composites are being developed to meet demanding applications. Many of these new materials as well as traditional materials have limited workability. Extrusion is a metalworking process that can be used to deform these difficult materials into the shapes needed for specific applications. For a successful extrusion process, metalworking engineers and designers need to know how the extrusion die shape can affect the final product. The present work focuses on the design of appropriate extrusion die shapes. A methodology is presented to determine die shapes that meet specific criteria: either shapes which pro-duce product with optimal set of specified properties, such as minimum distortion in the extrudate, or shapes which produce product by an optimized process, such as minimum extrusion pressure. The term “adaptable die design” is used for the method nology in which the die shape is determined or modified to produce some optimal property in either product or process. This adaptable die design method, used in conjunction with anupper bound model, allows the rapid evaluation of a large number of die shapes and the discovery of the one that can optimize the desired outcome. There are several conditions that need to be met for the adaptable die design method to be viable. First, a generalized but realistic velocity field is needed for use in an upper bound model to mathematically describe the flow of the material during extrusion through dies of any shape. Second, a robust crite-rion needs to be established for the optimization of the die shape. The criterion must be useable within an upper bound model. The full details of the method are presented elsewhere 16. In the present paper, following a review of previous models for extrusion, the flexible velocity field for the deformation region in a direct extrusion will be briefly presented. This velocity field is able to characterize the flow through a die of almost any configuration. The adaptable equation, which describes the die shape, is also presented. The constants in this die shape equation are optimized with respect to a criterion. The criterion, which can be used to minimize distortion, is presented. Finally, the shape of an adaptable die, which produces of an extruded product with minimal distortion, is presented. The objective of the present paper is to provide a brief overview of the adaptable die design method.2. Background2.1. Axisymmetric extrusionNumerous studies have analyzed the axisymmetric extrusion of a cylindrical product from a cylindrical billet. Avitzur710 proposed upper bound models for axisymmetric extrusion through conical dies. Zimerman and Avitzur 11 modeled extrusion using the upper bound method, but with generalized shear boundaries. Finite element methods were used by Chen et al. 12 and Liu and Chung 13 to model axisymmetric extrusion through conical dies. Chen and Ling 14 and Nagpal 15 analyzed other die shapes. They developed velocity fields for axisymmetric extrusion through arbitrarily shaped dies. Richmond16 was the first to propose the concept of a streamlined die shape as a die profile optimized for minimal distortion. Yang et al. 17 as well as Yang and Han 18 developed upper bound models for streamlined dies. Srinivasan et al.19 proposed a controlled strain rate die as a streamlined shape, which improved the extrusion process for materials with limited workability. Lu and Lo 20 proposed a die shape with an improved strain rate control.2.2. Distortion and die shape analysisNumerous analytical and experimental axisymmetric extrusion investigations have examined the die shape and resulting distortion. Avitzur 9 showed that distortion increases with increasing reduction and die angle for axisymmetric extrusion through conical dies. Zimerman and Avitzur 11 and Pan et al. 21 proposed further upper bound models, including ones with flexibility in the velocity field to allow the distorted grid to change with friction. They found that increasing friction causes more distortion in the extruded product. Chen et al.12 con-firmed that distortion increases with increasing reduction, die angle, and friction. Other research work has focused on non-conical die shapes. Nagpal 15 refined the upper bound approach to study alter-native axisymmetric die shapes. Chen and Ling 14 used the upper bound approach to study the flow through cosine, elliptic, and hyperbolic dies in an attempt to find a die shape, which minimized force and redundant strain. Richmond and Devenpeck 16,22,23, instead of assuming a particular type of die shape, decided to design a die based upon some feature of the extruded product. Using slip line analysis and assuming ideal and frictionless conditions, Richmond 16 proposed a stream-lined sigmoidal die, which has smooth transitions at the die entrance and exit. The streamlined die shape is the basis for many efforts in axisymmetric extrusion die design. Yang et al. 17 , Yang and Han 18 , and Ghulman et al. 24 developed upper bound models using streamlined dies. Certain materials, such as metal matrix composites, can be successfully extruded only in a narrow effective strain rate range, leading to the development of controlled strain rate dies. The control of the strain rate in the deformation zone came from studies that showed fiber breakage during the extrusion of whisker reinforced composites decreases when peak strain rate was minimized 25 . Initially developed by Srinivasan et al. 19 , the streamlined die shape attempts to produce a constant strain rate throughout a large region of the deformation zone. Lu and Lo 20 used a refined slab method to account for friction and material property changes in the deformation zone. Kim et al. 26 used FEM to design an axisymmetric controlled strain rate die. They used Bezier curves to describe the die shape and minimized the volumetric effective strain rate deviation in the deformation zone.2.3. Three-dimensional non-axisymmetric extrusion analysisBoth the upper bound and finite element techniques have been used to analyze three-dimensional non-axisymmetric extrusions. Nagpal 27 proposed one of the earliest upper bound analyses for non-axisymmetric extrusion. Upper bound and finite element models were developed Basily and Sansome28 , Boer et al.29 , and Boer and Webster 30 . Kiuchi 31 studied non-axisymmetric extrusions through straight converging dies. Gunasekera and Hoshino 3234 used an upper bound model to study the extrusion of polygonal shapes through converging dies as well as through streamlined dies. Wu and Hsu 35 proposed a flexible velocity field to extrude polygonal shapes through straight converging dies. Han et al. 36 created a velocity field from their previous axisymmetric upper bound model 37 in order to study extrusion through streamlined dies that produced clover-shaped sections. Yang et al. 37 applied a general upper bound model to study extrusion of elliptic and rectangular sections. Han and Yang 38 modeled the extrusion of trocoidal gears. Yang et al. 39 also used finite element analysis to con-firm the experimental and upper bound analysis of the clover sections. Non-axisymmetric three-dimensional extrusions have been studied further by using upper bound elemental technique 40 and spatial elementary rigid zones 41,42 . Streamlined dies have been the proposed die shape for most three-dimensional extrusion. The shape of the die between the entrance and exit has been selected by experience and feel rather than rigorous engineering principles. Nagpal et al. 43 assumed that the final position of a point that was initially on the billet is determined by ensuring that area reduction of local segments was the same as the overall area reduction. Once the final position of a material point was assumed, a third order polynomial was fit between the die entrance and exit points. Gunasekera et al.44 refined this method to allow for re-entrant geometries. Ponalagusamy et al. 45 proposed using Bezier curves for designing streamlined extrusion dies. Kang and Yang46 used finite element models to predict the optimal bearing length for an“L” shape extrusion. Studies on the design of three-dimensional extrusion dies have been limited. The controlled strain rate concept has only been applied to axisymmetric extrusions and not to three-dimensional extrusions 19,20,26.3. The adaptable die design methodThe adaptable die design method has been developed and is described in detail in a series of papers 15. The method has been extended to non-axisymmetric three-dimensional extrusion of a round bar to a rectangular shape 6. The major criterion used in developing the method was to minimize the distortion in the product. The present paper provides a brief overview of the method and results from these previous studies. Fig. 1. Schematic diagram of axisymmetric extrusion using spherical coordinate system through a die of arbitrary shape4. Conclusions It has created a new original construction of mechanical mixer, which first version Eleron-1 is researched in laboratory conditions with two reactors with different volumes and presented good results. This gives us area son to continue researching in half-industrial and industrial conditions with real technological processes, where is proved the complex power efficiency. We are going to produce and investigate Eleron-1in the future.新型节能机械搅拌器和挤压模具设计概述摘要从实验对这种新型节约型机械搅拌器的实验基本参数表中表明,我们可以有条件的把它命名为Eleron。这些特征也与其它文献中的参数特征进行了比较,那些参数已经被成功用于一些搅拌器中。这种搅拌器通常用于液体的搅拌,对于一些生化反应类的发酵行业也比较有效,这种过程是吸收能量的。关键字:搅拌器 饱和空气 电源数量 传热传质 通风1 介绍在进行一项长期的节能工业工程中,在作者的指导下,索菲亚的传热与传质部门设计了一种带有专利的建筑行业的节能搅拌器。在食品,酒类,烟草和生化行业,这种搅拌器对液体的混合起到一种很好的效果。我们希望我们的搅拌器在发酵工艺方面可以取代原有的机械,原因是它制造简单,在饱和空气方面有良好的效果,最重要的是它节约能源。到目前为之,Eleron搅拌器仍然是在实验阶段,这种实验搅拌器是一种很小的样本,只有0.25-0.35吨。它的基本外形在Fig1图中,它有一个中心盘和四个搅拌桨,搅拌桨在中间和端部的地方圆形磁盘和接收件呈拱形向下弯曲,弯曲半径为0.05-0.07D。考虑到弯曲线,其长度为L = 0.8pR。每个机翼下面的叶片呈不同方向的弯曲,这是因为工作时可能会产生漩涡。当搅拌机是多轴的时候,这种设计是很重要的。安装时,我们观察轴向流动,产生弯曲叶片,以满足对方(如果我们的目标是饱和空气),或通过对方,当我们的目标没有气体搅拌。用这种方法我们可以制造大量的匀称气体。2 实验研究Eleron搅拌机的特点得知,在飞机底部有两个完全相同的实验室反应器,反应器的直径分别是190和300毫米,搅拌机有0.35吨。由于物质是由水和乙二醇构成,而它们的温度在20度以下。有了这个装置的配置,我们对功耗,有无曝气,与搅拌机工作时的传热等进行了研究。这就是为什么反应堆传热转向架,蠕虫管与各自管直径d1和结束直径,这于图中表现出了。测量DO2的(溶解于液相氧)曝气过程中,还安装氮瓶,空气压缩机,这些为DO2和传感器的书写工具,它在磁带上记录氧气的吸收过程。图1 Eleron搅拌机搅拌桨的外观图2.1 功率系数的测定为此搅拌机的特点是使用两个反应堆和两种物质,以及搅拌机的轴旋转频率是从100到1200 min/1。旋转频率的选择和固定之后是电子环米的控制。欧盟数目取决于根据方程,它是读取各自旋转频率净功率消耗率。依赖关系如图。2.2 曝气量的确定这指数是指根据已知的方法确定的,这些方法采用混合工艺。在我们与反应器体积6.5 cm3的空气与分布式机制的帮助下,空气流空隙率最大宽度为1.5米。该研究结果在图 5进行了比较和换热面(蛇纹石)。图2实验室配置与机械搅拌反应器图3 计划实验装置:1,温控器; 2,反应器; 3,压力2.3与Eleron搅拌机混合时传质系数的测定有不同的使用量,具有空气分布机制和传感器形式和CO2的记录在水中两个反应堆。我们的工作在20液相,在每次尝试,直到与氮氧初步清理,这是逐步改变,直至建立一个平衡(饱和浓度)。3 传统的搅拌机3.1搅拌器有不同的分类方法:3.1.1考虑搅拌轴的数量.可以分为单轴搅拌器、双轴搅拌器和三轴搅拌器.3.1.2考虑搅拌的速度.可以分为低速搅拌器(低于30转/分钟),高速搅拌器(高于35转/分钟)以及可调速搅拌器.3.1.3考虑操作方式.可以分为间歇式搅拌器和连续式搅拌器.3.1.4考虑轴的位置.可以分为立式搅拌器和卧式搅拌器.在这篇文章中,所有的搅拌器都是这种分类方法下讨论的. 调查显示在今天的方便食品和面包食品工业中,卧式搅拌器在混合设备中还是占有主导地位的,因为它们结构简单,操作方便,运行成本低.而且他们可以有不同的容量用在不同的混合场合,不管是混合稀薄的制作曲奇饼用的面团,还是混合做中国快餐用的极其坚韧的生面团. 3.2 卧式搅拌器 卧式搅拌器的特征是有一根水平放置的搅拌轴.搅拌桨是通过搅拌轴固定在搅拌容器内的. 一台典型的卧式搅拌器包括一个搅拌容器,一根或两根通过传动装置驱动搅拌桨的搅拌轴,一个用生铁或或整块钢板做成的搅拌罐,一到两个装在下面的用来驱动搅拌和搅拌器转动的动力装置,装置上附加一个控制仪表和一个电保险装置防止机器运行时出现故障。 有两种计量称重系统:一种是跟搅拌器分离的;另一种是计量搅拌器加物料前后的重量差,搅拌器被放置在一个合适的计量平台。在这种情况下搅拌器通常被称做称重搅拌器。3.2.1 搅拌容器 卧式搅拌器的搅拌容器被设计成槽状,有一个弯曲的底部(U型的横剖面)和平面的末端。搅拌容器表面与面团接触的地方是普通的不锈钢或覆盖着一层不锈钢。这是搅拌容器端部最普通的结构,用来安放支撑搅拌轴的轴承。现在大型搅拌器的容器都是双层带夹套的,使冷却水或冷冻剂可以在夹套中循环,防止面粉在搅拌过程中因为摩擦温度过高。 为了防止面粉和其它成分飞溅,特别是在开始搅拌时,也为了食品卫生安全,搅拌容器通常配有一个可移动或带铰链的盖子用来卸出面团和清洁用。对于大型搅拌器,容器盖通常还可以提供辅助成分的喂料。 有两种方法可以卸出面团:倾斜搅拌容器(110。到180。),或者打开固定容器前面的门,让面团掉进下面的一个倾料器。为了地面安装设施的方便,面团常常被卸进一个用不锈钢制作的标准规格的盆里,卸面的过程是由操作者间歇的进行的。 倾斜容器的操作是由一组安装在容器侧壁的齿轮机构执行的。 对于小型搅拌器,容器的喂料是由手工执行的;对于大型卧式搅拌器,喂料是由容器上方对应的管子通过计量系统称量的方法自动进行的。容器制作在允许从几公斤到1500公斤在里面搅拌的容积范围内。容器的尺寸越大,动力装置要求的功率就越大,所以一次性搅拌的面团越大,要求的搅拌器容量等级要求就越大。对于多数大型搅拌器,容器的倾斜是由一个功率在0.75到2.26Kw之间的独立可逆发动机带动的。3.2.2 搅拌桨搅拌速度搅拌的操作是由搅拌桨直接进行的,搅拌桨的动力上从搅拌轴传递过来的。也就是说,搅拌桨的速度是由搅拌轴决定的。卧式搅拌器被设计成能运行一种或两种速度的样式。对于能运行两种速度的样式,它运行的低速是高速的一半。因为面团的执行需要两个阶段,并且显现出面筋是第一个必要的阶段,这决定了第一个阶段必需在低速下进行(比如36转/分),第二阶段必需在高速下进行(对应的72转/分)。一般来说,搅拌速度在30转/分以下的搅拌起被称作低速搅拌器,35转/分以上的称作高速搅拌器)。现在的搅拌器可以在大范围内变速,从20转/分到145转/分,甚至可以达到200转/分,使得面团在合适的搅拌桨作用下快速变成有弹性的面筋。搅拌桨被设计成各种各样的构造和横断面为不同的操作使用,比如混和, 分散, 摔打, 剪切, 刮, 舒展, 或揉捏成均匀的质体或分解或通分(不管是柔和的面团,坚硬的面团,海绵面团,鸡蛋牛奶面团还是加了其它材料的面团)。有些混合工具是花卉箍形状的,还有椭圆形的或者扭曲的盘状的,包括一到两个环状的搅拌桨,没有中间轴,它们被称作无轴搅拌器或搅拌桨,对应的机器被称作无轴搅拌器。在这种类型中,有的搅拌桨是Z型的,有的是S型的。为了保证足够的强度,它们的横断面很大。它们相对复杂的构造一般铸造成一体或者制造后焊在一起。在制造过程中必需注意搅拌桨两面的同轴性,避免在搅拌过程中出现大的意外。这种类型的搅拌器可以用来搅拌各种不同类型不同成分的面团,从稀薄的面团到极其坚韧的面团,因为无轴的搅拌桨在处理延伸性面团面团方面非常有效,因为在它们的自转过程中,会
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本文标题:双轴式和面机设计
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