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Dong K.,University of Science and Technology Beijing | Zhu R.,University of Science and Technology Beijing | Liu W.,Beijing Safetech Pipeline Co.
High Temperature Materials and Processes | Year: 2015

In this paper, a calculation model for decarburization kinetic in solid metal melting process is studied. Firstly the macro-kinetic model is established, and the melting and decarburization process is divided into five steps, which are adsorption and dissolution of O2, liquid phase mass transfer of [C], interfacial reaction of [C] and [O], diffusion of CO gas, and melting and dropping of metal. Secondly based on the assumptions that the total decarburization process is steady at the reaction temperature of 1800 K, the interface reaction is in equilibrium state, the composition in the liquid metal is homogenous, all the activity coefficients are 1 and so on, the calculation model is simplified into equations set with six formulas, and is calculated under 10584 conditions with the help of VB software. Results show that the C or O2 deliverability is the restricted link under different conditions. Finally, a decarburization experiment of melting pig iron at the rate of 0.56 kg/(s.m2) is achieved, and it proves that the simplified calculation model is in uniform with the actual data at a low melting rate. © 2015 by De Gruyter. Source

Chen F.,ShenZhen Gas Corporation Ltd. | Zhou J.-X.,ShenZhen Gas Corporation Ltd. | Mu N.-X.,Beijing Safetech Pipeline Co.
Corrosion and Protection | Year: 2013

Urban rail transit causes severe DC stray current interference on buried pipelines. In order to understand the DC stray current impact on pipelines, a pipeline which was severely interfered by stray current was selected for testing. Polar drainage and ground drainage were used and a polarity draineger was installed in the testing device. Before and after the drainage, the cathodic protection potential data were continuously monitored at the test stub. The results show that the potential of the pipeline protection reached the normal value and the pipeline was protected. Source

Dong K.,University of Science and Technology Beijing | Wu L.,The MCC Group | Liu W.-J.,Beijing Safetech Pipeline Co. | Zhu R.,University of Science and Technology Beijing
ISIJ International | Year: 2014

The desulfurization ability of CaO-Al2O3-SiO2-TiO2 slag at 1 873 K was studied through the slag-metal desulfurization experiment by using a 10 kg inductive furnace and through theoretical calculation by using thermodynamic software FactSage. The experimental index considered were the sulfur distribution coefficient of the slag (LS) and the desulphurization ratio (νS). The effect factors were binary basicity, the mass percentage of Al2O3 and TiO2. Research results are as follows. The effect of binary basicity is significant, compared with the mass percentage factors of Al2O3 and TiO2. Under the optimal experimental conditions, with the binary basicity is 7, the mass percentage of Al2O3 is 30% and TiO2 is 3%, the corresponding highest sulfur distribution coefficient for the slag are 58.14. While the content of TiO2 in the CaO-Al2O3-SiO2- TiO2 slag is in a range lower than 3-4%, the desulfurization ability of the CaO-Al2O3-SiO2-TiO2 slag is equal to that of the CaO-Al2O3-SiO2 slag. The slag system with TiO2 can meet the desulfurization requirements of steelmaking, which is a good way for resource utilization of solid waster containing titanium. © 2014 ISIJ. Source

Dong K.,University of Science and Technology Beijing | Liu W.,Beijing Safetech Pipeline Co. | Zhu R.,University of Science and Technology Beijing
High Temperature Materials and Processes | Year: 2015

In this paper, measurement method of EAF Steelmaking decarburization rate is studied. Because of the fuel gas blown and air mixed, the composition of hot temperature off-gas is measurand unreally, and the flow rate is unknown too, the direct measurement of EAF decarburization rate by furnace gas analysis is unrealized. Firstly, the off-gas generation process is discussed. After that, dynamic concentration of CO2, CO, and O2 in off-gas and EAF oxygen supply rate are monitored in real time. Finally, the concentration and volume flow rate of off-gas are obtained to measure the EAF decarburization rate indirectly. The results of the hot state experiments show that the decarburization rate in oxidization step can reach up to about 0.53 mol/s, and the forecasting carbon concentration is 1.14% corresponding to the average carbon concentration (1.43%) in finial metal samples. The measurement of decarburization rate by off-gas analysis technique can be reasonable in EAF production process. © 2015 by De Gruyter 2015. Source

Wei L.,China National Offshore Oil Corporation | Wang Y.-Q.,China National Offshore Oil Corporation | Wang X.-Y.,Beijing Safetech Pipeline Co. | Zhang Y.-H.,Beijing Safetech Pipeline Co. | And 2 more authors.
Corrosion and Protection | Year: 2014

A subsea pipeline life cycle cost model is established, so that the pipeline operator can choose the best way to operate the pipe with the least cost. There are nine categories of cost factoss in this model. The cost can be ranked from high to low according to the difference of cost conditions. From case analysis of subsea pipeline maintenance, the optimized measures chosen from the model fit the real cases. Source

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