Papers by Keyword: Sealing

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Authors: Li Hui Zheng, Zhi Heng Zhang, Ming Wei Zhang
Abstract: Fuzzy ball material which imitating the structure of bacteria have been tested and developed as a new lost circulation material. The fuzzy plugging theory include three pressure distribution methods: the pressure decomposition filling mechanism, the pressure reducing filling mechanism and the pressure support filling mechanism. Fuzzy ball material relies on its own particular structure, achieving full-size sealing and self-adjustment to match the porous media. Fuzzy ball working fluids can be prepared without auxiliary equipment and its non-weighted density is 0.85~1.0g/cm3. Its density can be up to 1.2g/cm3 when it is weighted by inert materials to meet the need of near/under balanced drilling. Indoor test showed that novel working fluids have significant inhibitive capacity and sealing characteristic. There are three properties of fuzzy three ball working fluids: inhibitive capacity, anti-temperature capacity and sealing characteristic. Fuzzy ball working fluid has been successful applied in hundreds of wells to solve the problems such as collapse, severe losses and etc.
Authors: Yan Xia Li, Hao Hu, Mao Zhong Hu, Liang Yin, Dan Yang, Shi Qiu
Abstract: An air filtration and pressure boost technique for the operating room was brought forward to the construction machinery working in dust atmosphere. The constitution, rationale and design method of the air filtration and pressure boost system was introduced in details. The method was successfully used to the operating room upgrade for a small scoop-tram. A certain positive pressure differential was maintained between the upgraded operating room and the outside, which preventing the access of the outside dust to the interior room and protecting the operator.
Authors: Yi Jia, Mang Yang, Wei Er Lu, Feng Ji, Chao Bo Li, You Tong Fang, Yang Xia
Abstract: Single and multilayer of Al2O3 and TiO2 were fabricated on anodized aluminum by atomic layer deposition. The effect of processing parameters on pore sealing and anti-corrosion property was studied. It is concluded that the micropores on anodized aluminum could be sealed by atomic layer deposition oxide films through SEM and staining experiments. The anti-corrosive property is affected mainly by the film thickness and process temperature. The acidic drip and salt spray test shows that the anti-corrosion property is enhanced as the film thickness increase. With the similar thickness, Al2O3/TiO2 multilayer film has the best anti-corrosion property, while the single Al2O3 layer appears the poorest. The complementary roles between two basic materials result in the enhanced application property.
Authors: Yi Ming Zhao, Jia Guang Kan, Kun Liu
Abstract: Weakening phenomenon of argillaceous surrounding rock under water effect universal exists in the excavation and supporting process of roadway in coal mine, the destructive effect of water acting on the argillaceous surrounding rock serious threatens the coal mine safety production. In this paper, the application of chemical grouting material in the control process of argillaceous roadway under rich water condition was studied. Simultaneously the sealing and strengthening mechanism of chemical grouting and its advantages were also analyzed. A filed application of the technique was aslo conducted and the observation results in-situ identify that chemical grouting combined with high-performance supporting technology can effectively maintain the long-term stability of argillaceous roadway under rich water condition.
Authors: Qi Zhou, Xin Wang, Li Fang Zhang, Chun Lin He, Qing Kui Cai, Xin Ma
Abstract: The anodized Al alloy films are sealed in the alumina sol with anatase type of titanium oxide.Coloration experiment; acid drip test and self-cleaning efficiency are used as evaluation criterions. Orthogonal test of sol sealed films and Two Factor test are used to value the influence of technological parameters on properties of the sealed films. The results show that the corrosion resistance of sealed film doped with TiO2 was superior to that of without in neutral saline water. Three-dimensional surface morphologies obtained by OLS3100 laser confocal scanning microscope (LSCM ) show that the sealed films with are smoother than ones without TiO2 and its pits in the sealed film are less. The sealed films with TiO2 have both corrosion resistance and self-cleaning effect.
Authors: Qi Zhou, Chun Lin He, Qing Kui Cai
Abstract: Alumina sol sealing is one of new green technology for anodized Al alloy. The corrosion mechanism of films sealed by sol and corrosion behaviour of films sealed by sol, Na2Cr2O7, boiling water were analyzed by their curves of open circuit voltage-time (E-T) and potentiodynamic polarization curve. It is found that corrosion tendency of sol sealing film is less than other sealed films by E-T inspection. Fluctuation of open-circuit potential is furious in the immersing prophase and slows down in the anaphase for anodized sealed films. At this time corrosive reactions gradually reach steady state. Open-circuit potential greatly waves for the rough sealed films. Potentiodynamic polarization curves of sealed films show that passive area is the longest for films sealed by sol which has the minimum corrosive current , the passivate current, anodic current and cathode current, but the maximum pitting potential and open-circuit potential. Corrosion parameters are the second for the film sealed by dichromate. Anodic reactions are strongly inhibited by sol sealing films in Cl- corrosive solution. Sol sealing films weaken cathode O2 depolarize reaction. Cl- ions erode anodized Al material on which covered with sol film and produce corrosion. The corrosion of sol-gel film goes through two periods: pitting induced phase and pitting corrosion period.
Authors: S. Ebschke, R.R. Poloczek, Klaus T. Kallis, H.L. Fiedler
Abstract: Based on silicon on insulator (SOI) technology [, a monocrystalline membrane is fabricated, in which a buried silicon dioxide layer in the silicon material is the sacrifice layer for the cavity. The membrane is a monocrystalline silicon top layer which contains nanoholes for creating the cavity in the buried oxide (BOX). To encapsulate the cavity the holes are sealed by using different techniques like non-stressed plasma-enhanced chemical vapour deposited (PECVD)-nitride and-oxide, thermal oxidation and evaporation of aluminum. To determine the sticking behavior of the membrane different sizes of membranes are fabricated and compared due to their sticking behavior. The experimental result shows that a membrane, having the size of 25 μm × 25 μm or below, has a perfect non-sticking behavior and can be used for further fabrication (cf. Fig. 8). For comparison, Figure 9 shows a membrane which delivers sticking behavior. The knowledge of this work can be widely used for several applications that need a cavity with a monocrystalline membrane like an absolute pressure sensor with a fully integrated CMOS-circuit on top of it [. This delivers a large variety of possibilities for novelty MEMS devices in different fields of research.
Authors: Shi Juan Wang, Ke Long Yu
Abstract: The movement characteristics of hydraulic exciting piston is a small displacement and high reversing frequency. The movement of the piston is to adapt to the requirement of quick reversing resistance. The mating surface seal uses to reduce the motion resistance to meet the requirements of the piston movement. Piston position should be in the oil chamber oil area to meet the requirements of the piston movement and oil circulation. Elastic beam with hydraulic cylinder is connected together . This structure is conducive to the piston and the connection of elastic beam and the installation of the oil cylinder. The causes of the different moving displacement of piston is leaking.
Authors: Yu Kun Fu, Chuan Jun Han, Juan Wang, Yang Yi
Abstract: In order to enhance the sealing performance of rubber core in ram blowout preventer, this paper designed a new structure of the rubber core which embedded a half-PTFE ring in the central of rubber core based on the characteristics of failure mode on the contact surface. Through carrying out the experiment on the rubber under different temperature and pressure to determine the constitutive relation of the rubber core, this paper has established the 3D model of rubber core and drill pipe, accomplished the contact finite element analysis under 20MPa and compared with the general rubber core. The results show that in the contact surface between the new rubber core and the drill pipe, the whole rubber core is in stress concentration area, and the contact stress is bigger than the values of normal core with the drill pipe. When the well blowout occurred, it will have a greater sealing pressure between the PTFE ring and the drill pipe, which plays a greater role in blowout control. For the small friction coefficient between PTFE ring and drill pipe, the scuffing is reduced from the drill pipe and the service life of rubber core is extende
Authors: Mao Qing Zhang, Shao Ying Zhang, Wen Jun Wei, Hai Tao Li
Abstract: In this paper, the tooth profile of a kind of full conjugate helical gear pump was designed. The tooth profile of each of the gears is composed of three curves which are an addendum arc, an involute and a dedendum curve. The dedendum curve of one gear is the conjugate curve of the addendum arc of the other gear. The addendum arc and the dedendum curve are joined tangentially by an involute. The equations of the curves were deduced by using differential geometry. The ranges of parameters in these equations were also obtained. The meshing characteristics of the gears were analyzed. Two gears transmit continuously with a fixed ratio. Two gears engage each other point by point continuously along the entire profile and formed a continuous space meshing curve. The trapping oil phenomenon could be eliminated and the sealing property could be better than conventional involute gear pumps. The results of calculation and analysis of an application example showed the theoretical analysis and the practicability of the design were valid.
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