Papers by Keyword: Slurry

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Authors: Hui Zhang, Zi Feng Ni, Qing Zhong Li
Abstract: In this paper, a kind of alkaline slurry was introduced, in which silica was used as the abrasive, H2O2 was used as the oxidize, glycine was used as the complexing agent, azimidobenzene was used as the surfactant, and borax was used as the pH regulator. The atomization polishing method was used, and the effects of the traditional polishing and atomization polishing were compared. After the atomization polishing, the surface roughness of copper was 7.61 nm and the material removal rate was 188 nm/min; After the traditional polishing, the surface roughness was 15.22 nm and the material removal rate was 236 nm/min. The dosage of polishing slurry used in the atomization polishing is dozens of times less than that in the traditional polishing.
Authors: Ai Peng Jiang, Qiang Ding, Jian Wang, Weiwei Lin, Zhou Shu Jiang
Abstract: It is the most effective resource use practices for coal slurry to be used as fuel for fluidized bed boiler. The dry desulfurization of slurry fluidized bed boiler is a large time delay system, and the load disturbance of this system changes frequently. In order to achieve stable control of SO2 emission and meet environmental requirements, a fuzzy control technology combined with the optimal feed-forward was designed. Combined with field experience, a fuzzy controller system was designed by fuzzy control technology, and then the integral process was added to achieve non-error track. To reduce the impact of desulfurizer and other factors, based on the principle of feed-forward, an objective to minimize disturbance impact was obtained, and then a nonlinear programming problem for solving the optimal feed-forward parameters was established, from which the best feed-forward form can be obtained. Results of 440T/H fluidized bed boiler show that the proposed method has satisfactory control effect. SO2 concentration can fully meet environmental emission requirements, and its fluctuation is relatively small.
Authors: Zhi Jun Cao, Jia Chen Liu, Li Bin Liu, Hao Ye, Yan Qiu Wei
Abstract: A new approach was developed for surface modification of metallic surface. By treating nano-zirconia particles and metal surface in different charge state, nano-zirconia particles can be dispersedly inlaid in metal surface owing to electrostatic and nanometer effects. By using this method, metal components of complex shapes, especially those having inside surfaces, might be easily improved, i.e., enhanced surface hardness and wear rate.
Authors: Chao Hui Zhang, Jian Bin Luo, Qiu Ying Chang
Abstract: Chemical mechanical polishing (CMP) is a widely used technique to achieve high level of global and local planarity required in modern integrate circuit (IC) industries and hard disk manufacturing process, etc., which pleas for concentrate researches. The main purpose of the present research is in an attempt to express the counterintuitive experimental aftermath: the ‘negative’ pressure, i.e., a suction force occurred in conventional commercial CMP process. A preliminary two tiers wafer-scale flow model for CMP is presented considering the roughness as well as the elasticity of the bulk pad substrate. Numerical simulations were conducted to elucidate the contact pressure and flow pressure distributions. The results show that a divergence region appears near the leading edge, which contributes to the suction pressure. A stress-richened area near the edges will give rise to over polishing. The research aftermaths agree well with the experiments, that validate the proposed analysis to some extend. This will shed lights on the mechanism of CMP process, which for a long time is considered as a black art where empirical or semi-empirical data are dependent upon to optimize the CMP parameters.
Authors: Yun Qing Gu, Qiang Wang, Qiang Liu, Yao Lin Sun, Tian Xing Fan, Deng Hao Wu
Abstract: Vortex pump is a kind of non-clogging pump, which will cause a large amount of vortex during transportation. Four kinds of mathematical model of vortex pump are introduced with continuous improvement. Moreover, the internal flow state, calculation and design method are also presented. In addition, the influent of slurry and structure parameters is introduced. After analyzed above, the design method of vortex pump can be further investigated specific to different concentration, viscosity and particle sizes under different specific speed. The focus of future research is testing internal flow by the advanced technology, building up a new flow model and proposing complete and practical calculation method.
Authors: Peng Cheng He, Peng Yun Song
Abstract: As to the centrifugal pump for slurry, the effects of solids particles on the performance of the pump have been extensively researched. It is essential to understand the effects of solids on the pump performance well in order to obtain the performance of centrifugal pump for handling slurries. Some existing correlation equations to predict the performance are analyzed and summarized in this paper. A new simple correlation equation to predict the head ratio for pumps handling solids has been developed. The simple equation has been validated by the experiment data published in the related literature. The results by the simple equation are compared with ones available in the literature. The result shows that the simple equation is in good agreement with the experimental data, and it can be used to predict the performance of centrifugal pump for slurry.
Authors: Katsufumi Ehata, Shenglei Che, Norimasa Sakamoto
Abstract: Details of a new technique for the permittivity measurement of ceramic powders at microwave frequencies are described. Permittivity of a powder is calculated from the permittivity of liquid medium and that of the slurry made from the liquid medium and the powder. Measured permittivities of BaNd2Ti4O12 ceramic powders vary by processing conditions of the powders. This result is consistent with permittivities of composite substrates made from these powders and a thermosetting resin.
Authors: Florence Ansart, Jean Pierre Bonino, P. Lenormand, Ch. Robert, Céline Viazzi
Authors: K. Shirvani, Amir Firouzi
Abstract: The diffusion aluminide coatings are widely used in the air-cooling passages to protect their surfaces against high temperature corrosion. In this study plain and Si-modified aluminide coatings were applied by slurry technique on internal surfaces of Ni-base GTD-111 superalloy cylindrical specimens derived from a gas turbine air-cooled blade. The slurries containing Al or Al plus Si powders were applied on internal surfaces by injection method. Then, the samples were heated to high temperature (800-1000°C) to form the coatings. Optical, SEM-EDS, and XRD were utilized for characterizing microstructures and phase compositions of the coatings. The thicknesses of applied coatings on internal surfaces were in the range of 30-50 μm that meets specifications for diffusion coatings in such application (i.e. 25-756m). The examinations demonstrated that both coating types were contained β-NiAl phase as the matrix. The uniformities of coatings applied on different surface positions of passageway were determined. In addition, the effects of time and temperature of coating process as well as mass of dried slurry on the coating thickness were also discussed.
Authors: Sea Hoon Lee, Yoshio Sakka, Yutaka Kagawa
Abstract: Hydrolysis and dispersing behavior of aqueous ZrB2 slurry were investigated. The isoelectric point (IEP) of ZrB2 slurry was measured to be pH 6.3. The acid and base slurry underwent rather rapid change of pH after fabrication for one and three hours, respectively. The oxygen content of the boride powder increased slowly with static ageing time in acid and neutral slurries, while the value decreased in base slurry. Application of poly(ethyleneimine) changed IEP of the boride slurry to pH 10.4. Sedimentation test informed that stability of the slurry was improved when increasing the molecular weight of poly(ethyleneimine) to 70,000 and in acid slurry (pH 3).
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