苏联混凝土搅拌机的新系列

最近几年来,在混凝土搅拌机领域中,有了重大更新而愈益完善。苏联混凝土搅拌机新系列中,除了改进技术经济指标外,还统一了驱动装置。这样既能简化备件并能提高机器运转的可靠性。搅拌量为1m~3的—138混凝土搅拌机从1980年起就代替了同一容量的93-混凝土搅拌机。—138搅拌机应用在自动化混凝土工厂及钢筋混凝土予制工厂的搅拌车间中。在这种混凝土搅拌机中,采用了统一的驱动装置后,缩小了搅拌机的外型尺寸及重量。—151混凝土搅拌机装有蒸汽加热     

国外混凝土搅拌机展望

近年来国外对各种不同结构混凝土搅拌机的技术经济指标进行了大量的分析和研究。分析比较的搅拌机有自落式搅拌机(倾翻出料式,反转出料式和导料槽式),盘形强制式搅拌机和卧轴强制式搅拌机。通过对工业和建筑业用搅拌机的分析、比较以及表1的数据表明,盘形行星式强制     

盘式搅拌机优化设计的探讨

总结了国内外资料,对盘式搅拌机的搅拌速度、叶片大小和加料厚度等方面的选用作了探讨,介绍了一种降低盘式搅拌机能耗的双转盘搅拌机的设计。     

双轴强制式搅拌机的搅拌原理和使用操作

混凝土搅拌机的西德标准 DIN459中将周期式和连续式搅拌机分开。周期式工作的一组搅拌机中有各种结构类型的自落式搅拌机和强制式搅拌机。下面就周期式和连续式强制式搅拌机即双卧轴式搅拌机作一叙述。这种类型的搅拌机是机械制备混凝土最早使用的搅拌设备。自1888年登记第一个用于修筑战前高速公路的搅拌机专利起,到二次大战以后几十年的恢复时期,该设备得到了卓有成效的发展。其主要原因是该机具有搅拌均匀性好、使用范围广以及有较高的经济性等优点。强制搅拌就是通过对拌和物施加作用力,使其形成一定的物料流向,从而使拌和物达到均匀分布和混合。自落式搅拌正与此     

自落式搅拌机中生混凝土的重心及其对支点力矩的计算与程序设计

本文根据设计搅拌机的需要,采用结构化程序设计方法,编制了计算自落式搅拌机中生混凝土的重心以及混凝土和搅拌筒一起对支点的力矩的计算机程序。本程序能计算搅拌机轴线对水平面成任意角时,一定量的混凝土的重心和力矩,大大减少了手算的时间,为搅拌机的优化设计提供了可能。     

СБ—138混凝土搅拌机

苏联斯拉夫建筑机械厂制造了一台138新型混凝土搅拌机,出料容量1000升,是一种分批作用的转子型强制式搅拌机。-138型混凝土搅拌机用在钢筋混凝土预制厂和混凝土搅拌楼中,拌制混凝土和建筑砂浆,它与成批生产的-93型和62型(C-951型)混凝土搅拌机相比较具有许多优点:金属用量少、外形尺寸小、工艺技术造型美观、操作和维修条件好,在与成批生产的混凝土搅拌机通用化方面达到了高     

水工型大容量双卧轴混凝土搅拌机电气设计

本文结合水利部"948"项目"MSO9000型双卧轴强制式混凝土搅拌机"(编号:200714)的研制,根据水工混凝土的特性和大容量双卧轴搅拌机内物料的运动特点,结合工程中实际应用要求,对大容量双卧轴混凝土搅拌机功率、启动方式、安全保护、在线监控等电气特性进行了研究,并提出了适用于该搅拌机的解决方案。     

双盘搅拌机

一切混凝土搅拌机的搅拌过程是先加水泥、水、砂和添加剂,搅拌成砂浆后再加入大骨料,搅拌成混凝土。以前采用的混凝土搅拌机,无论是砂浆搅拌还是混凝土搅拌,其转速都保持不变。这样,若满足了混凝土搅拌的低速要求,就不能满足砂浆搅拌的高速需要。为了克服这个缺点,日本东京太平洋机械公司在四年前发明了用计算机程序控制的双盘搅拌机。这种搅拌机目前正在日本普及并进入美国市场。这种搅拌机具有上、下     

食物搅拌机外壳注射模设计

本文分析了食物搅拌机结构特点以及模具设计、注塑成型等工艺技术。从食物搅拌机产品设计到模具制造,对模具进行了必要的分析设计。然后再到注射模具CAE模拟,设计出了完整的模具,本次设计流程及成果对于食物搅拌机的设计具有普遍的参考价值。     

有价值的经验——在搅拌机中使用气体润滑不接触式机械密封件时所取得的经验

搅拌机用气体润滑不接触式机械密封件(低转速)在市场上出售。已经有10多年的时间。在这10年期间。已经取得了一系列经验。本文总结了若干重要的见解。当正确地使用于适当的用途之时，搅拌机气体密封件可以帮助使用者改进质量和提高产品纯度。     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.