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Sun G.,Yanshan Petrochemical Corporation
Shiyou Huagong/Petrochemical Technology | Year: 2010

Trace contaminants in feedstock, dilution steam and chemicals could enter ethylene plant and lead to damage to cracking furnace tubes, corrosions of pipe-line and equipments, catalyst poisoning, and disadvantageous effect on polyolefin plant. The common contaminants in ethylene plant are heavy metals, nonmetals and oxides. Sulfur would bring increase of hydrogen sulfide in cracked gas. Carbonyl sulfur would reduce activity of catalyst in hydrogenations of propyne and propadiene. Arsenic could erode the furnace tubes and cause deactivation of the hydrogenation catalyst. Sodium could cause corrosion of the furnace tube, aggravate coking within the tubes and generate CO and C02.Mercury could accumulate in low temperature equipments, corrade aluminium alloy and reduce the catalyst activity. Carbon dioxide, methyl terf-butyl ether, methanol, chloride and some metal contaminants could also produce disadvantageous effect on ethylene plant. Source

Fengtao W.,Dalian University of Technology | Lutao S.,Dalian University of Technology | Liang Z.,Dalian University of Technology | Haifeng L.,Dalian University of Technology | Haili Z.,Yanshan Petrochemical Corporation
7th International Conference on Condition Monitoring and Machinery Failure Prevention Technologies 2010, CM 2010/MFPT 2010 | Year: 2010

This paper presents the experimental investigation on fault diagnosis for reciprocating compressor valves by means of the indicator diagram. The principle of valve fault diagnosis using indicator diagram is introduced. With a pressure transducer installed at the end of a channel which is embedded into the cylinder through the valve cover and valve, the pressure signal within the working chamber of a reciprocating air compressor is recorded and then smoothed. And the channel diameter should be selected appropriately to avoid the effect of channel resonance. Then the compressor valve fault can be diagnosed according to the shape of indicator diagram which is transformed from cylinder pressure. In this study, the main valve failure simulated is include intake valve leakage, exhaust valve leakage, intake valve obstruction and exhaust valve obstruction. Each valve failure will cause the pressure change in cylinder and make air compressor work abnormally. The results obtained shows the good performance of the method in compressor valve fault diagnosis. At last, the shap of the indicator diagram corresponding to different kinds of valve failure is proposed according to the experimental results. Source

Yu Z.-S.,Dalian University of Technology | Yu Z.-S.,Shanghai Institute of Technology | Li Y.,Dalian University of Technology | Yang J.,Yanshan Petrochemical Corporation | And 4 more authors.
Dalian Ligong Daxue Xuebao/Journal of Dalian University of Technology | Year: 2011

The poly (acrylonitrile-butadiene-styrene) (ABS) resins were synthesized via bulk polymerization method using nickel catalyzed high-cis polybutadiene rubber (Ni-9004), lithium catalyzed low-cis polybutadiene rubber (Li-700A) and their composite rubbers as modifiers. The influences of reaction time and content of composite rubber on the polymerization reaction, grafting parameters and microstructures of ABS were investigated. And the morphologies and mechanical properties of resins under different incorporation ratio of composite rubbers were also researched. It is shown that the grafting degree of Ni-9004 gradually increases and its grafting efficiency and volume fraction of rubber phase gradually decrease with the reaction time. Besides, an obvious phase inversion occurs in the polymerization process and the final ABS resin presents a typical "core-shell" structure. And its morphology can be distinctly improved when combined with Li-700A. Furthermore, the lower amount of composite rubber is beneficial to grafting and occlusion, which shows a positive reinforcement value; an augmented particle size and a negative value are obtained while composite rubber amount increases. Performance measurements show that the toughening effect of Li-700A can be significantly enhanced by incorporating Ni-9004. When its incorporation content reaches 75%, the notched Izod impact strength of ABS resin is improved by at least 150%, while there is no loss of the tensile strength. Source

Yu Z.,Dalian University of Technology | Yu Z.,Liaoning Key Laboratory of Polymer Science and Engineering | Li Y.,Dalian University of Technology | Li Y.,Liaoning Key Laboratory of Polymer Science and Engineering | And 5 more authors.
Cailiao Yanjiu Xuebao/Chinese Journal of Materials Research | Year: 2010

A series of acrylonitrile-butadiene-styrene terpolymers (ABS) were synthesized by bulk polymerization using polybutadiene rubber as toughener. The mechanical properties of the resultant materials were investigated. The results show that high-cis rubber BR9004 has the best toughening effect far superior to the rest, and the IZOD notched impact strength of the relative material reaches 236. 1 J/m; when it is combined with low-cis rubber 700A, the comprehensive mechanical properties of the later is comparable to Gaoqiao product (ABS 8434). The impact strength, tensile properties and elongation at break of materials increase with the increase of acrylonitrile content and molecular weight of resin phase. However, the tensile properties decrease with the rubber content increasing. The impact strength increases rapidly when the content of rubber is lower than 20%, but increases slowly when higher than 20%. ©. Source

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