Papers by Author: Yu Guang Fan

Abstract: The method of computational fluid dynamics (CFD) is used to three-dimensional numerical simulation for the fluid flow process of ammonium persulfate crystallizer. By using standard model, this paper respectively simulated the flow field within the crystallizer in the impeller installation height of 1.2 m while stirring speed is of 60 r/min, 100 r/min and 200 r/min; and simulated the impact of the flow field inside the crystallizer when the stirring speed of 100 r/min and impeller installation height respectively is of 0.7 m, 1.2 m and 1.7 m. That calculation results show that: the velocity gradient is mainly concentrated in the area of internal draft tube and paddle around. With the increase of impeller speed, the flow velocity of the fluid within the crystallizer corresponding increases; and the energy also gradually decreases from mixing impeller to the settlement zone with the loss of the installation height, and the kinetic energy in the bottom of the crystallizer is reduced. Considering the energy and crystallization effect, selection of mixing speed of 100 r/min or so and installation height of about 1.2 m is more appropriate.

Abstract: In order to know the corrosion behavior of 16MnR in the circulating water system and determine the influential sequence of factors, such as chloride ion concentration, temperature of circulating water, pH value and calcium ions concentration, to the corrosion of 16MnR. In this article, the electrochemical impedance test of 16MnR was conducted with electrochemical test system of CS310. The orthogonal test is adopted and the influential sequence of each factor to the corrosion of 16MnR is obtained by range analysis. The result shows that the impedance spectroscopy of 16MnR in the circulating water is a single capacitive reactance arc; the parameter which controls the corrosion process is the solution resistance R_P and with the increasing of R_P, the impedance value increases thus slowing down the corrosion velocity of 16MnR; the greatest impact on the corrosion of 16MnR are chloride ion and the temperature.

Abstract: The generation method of dissolved gas micro bubble is introduced in the paper. The micro bubble producing process can be divided into two stages-nucleation and expansion through analysis. The formation process and the free energy change of the micro bubble is analyzed according to the homogeneous nucleation theory, free energy change formula of the two process is derived, and relation between bubble radius and formation bubble number under certain conditions is also discussed. It is concluded that the smaller the radius of formed bubbles, the more free energy change and initial energy are needed according to the analysis of the relation above.

Abstract: Thorough research is performed on crystallization process of ammonium persulfate，the influence of different mixing method on crystallization process of the ammonium persulfate is discussed in this paper, the influence of temperature on crystallization process is also discussed, and then the optimum mixing method for the crystallization of ammonium persulfate is achieved. All these will do great favor to improve the stability of crystallization process of ammonium persulfate .

Abstract: In research of the low temperature parts of atmospheric pressure device, by using BP neural network, the connection of PH value, Cl^-, H²S and Fe⁺² was setup which can predict Fe⁺² content accurately, and obtain the requirement accuracy, hence more accurate corrosion can be predicted and providing more suggests for corrosion protection.

Abstract: The research and formulation of chemical machinery excellent engineer cultivation system is an important basic work to realize the plan of cultivating excellent engineer. Take the process equipment and control engineering profession of our university as example, this paper introduces professional status, analyses and discusses cultivation target, opportunity and facing problems of machinery excellent engineer.

Abstract: Experiments were carried out on the heat resistance, corrosion-resistance and adhesion performance of the nano-modified urushiol titanium antiseptic paint on the top heat exchanger of Atmospheric Tower. Through the experiment, it can be found that the corrosion resistance in the environment of HCl-H2S-H2O can be effectively improved by adding a certain amount of nano-SiO2 into urushiol coating made of titanium the top heat exchanger of Atmospheric Tower for modification.

Abstract: Currently, the education of engineering college faces the pivotal problem of how to improve students' engineering practice ability. Combining the practice teaching system of engineering practice ability cultivation for the major of process equipment and control engineering in our college, four-year continuous persistent cultivation of engineering drawing ability can improve the students' engineering practice ability effectively and practically.

Abstract: In order to analyze the influences of process condition on kerosene-based Fe₃O₄, which are prepared in chemical co-precipitation, orthogonal experiment was used. How process condition influenced the size of nano-particles and saturation magnetization was studied, and the best process condition as 40ml•min^-1 NaOH adding speed, 10ml•min^-1 sodium oleate adding speed, 45°C reaction temperature, 15min holding time and pH value of 2 of coating sodium oleate was obtained. The performance of magnetic particles was characterized by transmission electron microscopy (TEM) and WSM vibration magnetometer. The diameter of Fe₃O₄ nano-particles was less than 10nm, saturation magnetization was 2.66×10⁴A•m^-1, viscosity of nano-magnetic fluid was 18mPa•s, and density was 1.13×10³kg•m^-3. This research enhanced the foundation of using nano-magnetic fluid.

Abstract: Adopting chemical coprecipitation and mechanical dispersion to prepare oil based magnetic fluid is a good way to increase the stability of magnetic fluid. This paper uses orthogonal design to analyze the influences from different factors, and The size of nano-particles and saturation magnetization were characterized by TEM and WSM vibration magnetometer. The results show that the NaOH solution adding speed of 0.4 ml/s and reaction temperature of 50 ~55 , sodium oleate solution adding speed of 0.3ml/s and heating temperature of 65 , heat-maintaining time of 20min are proper reaction conditions.