一种新型的齿形零件滚轧机

这种两轮对滚式齿形零件冷滚轧机是由中国兵器工业第五九研究所一室特种轧制组利用旧设备的基础研制的。主要用于中小模数蜗杆、齿轮及花键的冷滚轧加工、机床主轴电机功率7.5kW;主轴压下缸最大压力250GPa,并带有轴向推力送料系统,可以实现轴向推进滚轧工艺过程。可加工工件的大致范围为:最大工件直径100mm:最大工件长度400mm;最大蜗杆类零件模数4M;齿轮、花键模数一般可达1.5M 左右,精滚轧齿轮模数可达2.5～3M。机床主轴传动采用电子复频调速,两主轴同步精度高,周向相位调整方便。     

减震器油封金属骨架的冲裁模设计

该公司的奥迪轿车减震器配套油封的金属骨架产量很大，材料０８Ｆ，厚度２．８ｍｍ。金属骨架在油封当中的作用是增大油封的刚度，防止橡胶部分塑性变形，以满足油封的装配和使用要求。因作为嵌件的金属骨架对橡胶的收缩量有较大的影响，故对骨架的同轴度和平行度要求较高。１模具结构及工作过程 为适应大批量生产，模具应设计成自动冲裁模，采用气动夹持装置自动送料。 经过对工件进行分析，决定采用四导柱复合模（如图１），图中压力机滑块正处于下死点位置。 此模具的结构有如下特点： （１）采用了通用模架，结构简单，对生产同类型工件…     

电子枪钉子高效自动复合精密冲压成形及模具设计

设计了一种高效自动复合精密冲压成形模,利用普通压力机在同一冲压行程内从三维方向自动完成电子枪G_2钉子冲压的下料(切断)、压扁、弯曲、成形等四道工序的精密成形,并自动完成卸料动作。这种成形方法完全可以替代目前普遍采用的进口的电子枪钉子制造专用机器成形方法,且其生产效率高于后者。本成形方法采用的模具结构设计精巧,成形质量可靠,既适应于自动送料情形,同时可以采用手动送料。这种模具结构亦成功地应用于G_3钉子的冲压成形。     

冰箱门框加强条自动成形模设计

介绍了门框加强条自动成形模的基本原理及设计要点,提出了一种解决弯扭片料自动送料的方法。实践表明,此方法行之有效,对类似的自动模具设计有一定的参考作用。     

磨床局部磨削高温的研究探讨

主要介绍了磨削时工件表面产生局部高温的主要原因,磨削高温对淬火工件表面质量的影响,以及在加工时为了避免局部高温应采取的一些必要措施。提出了预淬火工件表面局部高温的方法。     

45钢工件在易裂尺寸范围内的超细化热处理

此文主要研究了易裂尺寸范围内的45钢工件的超细化热处理。结果表明:45钢工件在易裂尺寸(5mm～11mm)范围内进行循环淬火时,淬火介质直接影响45钢工件的超细化热处理质量,易裂尺寸范围内的45钢工件,采用肥皂水在830℃循环淬火四次加680℃反复回火后,其超细化热处理效果最佳。     

着装违反规定 毛刺引发重伤

1998年12月16日上午，某汽车修配厂车工在接受下料任务后，把直径为32毫米的圆钢棒夹在C620—1车床上，并起动转速230转／分调试工件的同心度。调试后边停机边伸出右手经工件上方取冷却液盒，不料右手衣袖被工件上的毛刺缠挂，随着机床的转动缠绕在工件上，导致右手挤压到棒料下方而重伤。     

箱式电阻炉控制方法改进的研究

为了提高工件的质量(包括外观、硬度等)，编制正确的工艺规范是非常重要的。但是更重要的是使上述要求在生产过程中准确、可靠地实现。箱式电阻炉(以下简称箱式炉)是一种在生产、科学实验中为工件进行热处理加工、保证实现工艺规范的重要设备。工件在箱式炉中进行热处理时，加热元件、炉内价质、炉壁、工件、仪表等之间进行着热、电交换过程。     

电子束物理气相沉积制备热障涂层研究进展

介绍了电子束物理气相沉积设备的主要组成、工作原理和电子束物理气相沉积热障涂层的结构特点,并重点论述了工件转速、工件温度、靶材蒸汽入射角度、工件表面的粗糙度、粘结层预氧化、改性粘结层和双层陶瓷层等对电子束物理气相沉积热障涂层性能的影响。     

双摩擦支承卷制锥筒的工艺与原理

用物理学特性和数学分析方法对双摩擦支承安装在普通四辊卷板机上,卷制锥形工件的工艺原理进行了研究.从而使卷制锥形工件工艺变得十分简单,四辊卷板机卷制锥形工件双支承曲弯工艺的试验成功,对国内很多企业具有广泛的应用价值.     

脉冲SBR处理城市污水深度脱氮的工艺特性

采用脉冲式SBR法,对城市污水进行了深度脱氮试验研究.从理论上分析了进水次数和进水量对脉冲式SBR工艺运行特性的影响,得出了脱氮效率公式,并通过试验研究了这些因素对工艺运行的实际影响.理论分析表明,在不投加外碳源的情况下,随着进水次数的增加,脱氮效率依次增加.根据进水C/N的高低,进水方式可分为不等量递增进水、等量进水和不等量递减进水.试验表明,当原水中有机碳源充足时,不等量递减的进水方式相对于等量的进水方式投加较少的外碳源就能实现深度脱氮;随着进水次数的增加,外碳源的投量依次减少,但操作变得复杂,对于普通的城市污水建议采用3次等量的进水方式.采用脉冲式SBR只需投加少量外碳源就可以使处理后的城市污水出水TN低于2mg/L,TN平均去除率达到97.3%.     

NF和低压RO工艺处理锅炉补给水的研究

以自来水为原水,采用纳滤(NF)与低压反渗透(RO)工艺进行锅炉补给水处理研究。考察了一级NF及RO工艺、二级NF及RO工艺、NF-RO串联和RO-NF串联工艺对锅炉补给水的软化除盐效果。结果表明,NF和RO分别在0.75MPa和1.0Mpa压力下,回收率20%时处理效果最好。一级NF和一级RO可满足中低压热水锅炉补给水的水质要求;二级NF和二级RO、NF-RO和RO-NF工艺均可满足中低压蒸汽锅炉补给水的水质要求;串联工艺处理效果优于二级NF,且比二级RO节能;RO-NF和二级RO工艺可满足高压锅炉补给水的水质要求。     

Feeding livestock food residue and the consequences for the environmental impact of meat

The environmental impact of meat is high mainly due to the feed required by livestock in combination with the impacts of cultivating, transporting and processing of feed crops such as tapioca and grains. Like regular feed crops, livestock also feed on residue from the food industry, such as pulp, scrap and peels. Both types of raw material have different environmental impacts. Feeding food residue to livestock is an efficient way to upgrade a low quality material into high quality foods. In the Netherlands, food residue represents the majority of the feedstock for feed. Distinguishing crops from food residue has consequences for the ascribed environmental impact of meat. This paper separates these two streams using volume, environmental impact and their relevance in meat production. An assessment is made of three food industries (sugar beet industry, vegetable oil industry and potato product industry) that produce the largest stream of food residue, and of the pork industry, as an example of meat production. The environmental impact of food residue-based feed is allocated in three different ways: mass ratio, economic basis, and no assigned burden. We found that the amount of pork produced from food residue is substantial. The environmental impact of food residue-based feed is also significantly lower than grain-based feed. We discuss changes in vegetable and in animal product consumption that influence the environmental impact of pork. It is concluded that the use of current food residue keeps the environmental impact of livestock foods relatively low. However, a further increase in meat consumption would require more feed grains with a correspondingly larger environmental impact because food residues are used up.     

绿色饲料的地位及其生产与研究进展

分析了绿色饲料生产发展趋势及绿色饲料生产已经探索形成的若干有效模式 ,以黄淮海平原青刈黑麦研究为例 ,从青刈黑麦高产栽培技术体系研究、加工技术研究、生产系统评价等方面阐述了青刈黑麦的生产与研究进展 ,为我国绿色饲料产业化建设提供了思路。     

酒精废醪的固液分离在我国的应用

综述了国内外酒精废醪处理中的固液分离技术的进展及新成果;指出固液分离技术代表了酒精废醪资源化综合治理的发展方向,研究、开发适合我国国情的固液分离成套技术、设备是全面治理酒精废醪污染的关键。      

3D numerical investigation of thermally assisted high efficiency ductile machining of nanocrystalline hydroxyapatite

This study investigates the effects of four different variables (initial workpiece temperature, side rake angle, edge radius/feed rate, and nose radius/depth of cut) on ductile regime machining of a bioceramic material known as nanohydroxyapatite (nano-HAP) using 3D numerical simulation. AdvantEdge FEM Version 5.9 is used to conduct turning simulations of the nano-HAP workpiece. Tecplot 360 is used to analyze the results of the simulations. Because the workpiece is thin, the entire workpiece is set to a uniform initial temperature to simulate laser preheating of the material. Initial workpiece temperature, rake angle (side rake angle), edge radius, and nose radius are varied, and the effects of these operating conditions on critical feed are investigated. It is found that critical feed increases as initial workpiece temperature increases, and also as negativity of rake angle increases. For the edge radius, it is concluded that an initial increase causes an increase in critical feed – however, at some value of edge radius, critical feed shows no further increase; for the nose radius, critical feed appears to show no significant dependence.     

Fluoride removal from brackish groundwater by direct contact membrane distillation

The direct contact membrane distillation applied for fluoride removal from brackish groundwater was investigated.The self-prepared polyvinylidene fluoride membrane exhibited high rejection of inorganic salt solutes.The maximum permeate flux 35.6 kg/(m2 ·hr) was obtained with the feed solution at 80°C and the cold distillate water at 20°C.The feed concentration had no significant impact on the permeate flux and the rejection in fluoride.The precipitation of CaCO3 would clog the hollow fiber inlets and foul the membrane surface with increasing concentration factor when natural groundwater was used directly as the feed,which resulted in a rapid decline in the module efficiency.This phenomenon was diminished by acidification of the feed.The experimental results showed that the permeate flux and the quality of obtained distillate kept stable before concentration factor reached 5.0 with the acidified groundwater as feed.The membrane module efficiency began to decline gradually when the feed continued to be concentrated,which can be mainly attributed to the formation of CaF2 deposits on the membrane surface.In addition,a 300 hr continuous fluoride removal experiment of acidified groundwater was carried out with concentration factor at 4.0,the permeate flux kept stable and the permeate fluoride was not detected.     

普光净化厂加氢进料燃烧炉耐火衬里安全改造

介绍了天然气净化厂尾气处理单元加氢进料燃烧炉的结构及衬里形式,以及燃烧炉使用初期出现部分衬里损坏、下沉,甚至脱落的现象,导致燃烧炉外壁超温,影响装置正常生产;提出改造方案,解决了大型加氢进料燃烧炉衬里存在的问题。     

厌氧复合床处理抗生素废水的生产性启动研究

处理抗生素废水的厌氧复合床反应器单体有效容积为500 m3,根据反应器中有机物降解和细胞合成的关系,建立了进料有机负荷模型M_n=(1+k)n-1M₁和进料容积负荷模型N_n=(1+k)n-1N₁.根据启动过程中细菌的生长特性和进料有机负荷模型的计算,提出了厌氧复合床反应器启动运行的进料负荷技术方案,成功地进行了厌氧复合床处理抗生素废水的生产性启动.      

加氢原料缓冲罐串压事故动态模拟研究

通过工艺流程动态模拟,研究某渣油加氢装置在反应进料泵事故紧急停车后,不同工艺设计方案组合条件下,引发高压气体反串到低压原料缓冲罐的事故影响。研究结果表明:泵出口双单向阀和紧急切断阀的设计对降低超压事故的发生有很好的保护作用;切断阀关闭时间越短对原料缓冲罐超压保护越有利;安全阀和缓冲罐的设计条件须与切断阀关闭时间和单向阀数量等设计条件综合考虑。通过动态模拟方法研究工艺操作异常工况,对优化工艺设计,提高本质安全设计有参考价值。