Sun Keping

Laboratory research on shielding effect of a novel conductive cloth to microwave radiation

Abstract The electromagnetic radiation is harmful to person when its density is more than some value. It is very important to develop a new type of conductive cloth in order to preventing person from radiation. This paper presents a result of laboratory research which uses a novel sample of conductive cloth that has been made by Xin Zheng Special Protective Material Factory. From the research result we can see that the shielding effect of the novel conductive cloth to microwave radiation is well.

Investigation of electrostatics during sulphur crushing operations

Abstract Electrostatic discharge caused fire and explosion accidents at a sulphur factory in Shanghai. This work describes the test result of potential at the factory workshop, and presents several protective measures in order to prevent dangerous discharge.

Investigation on protection from ESD explosion of polyformaldehyde resin powder in pneumatic pipe

Publisher Summary This chapter presents an investigation on protection from an electrostatic discharge (ESD) explosion of polyform-aldehyde resin powder in pneumatic pipe. It provides the test result of powder resin specific charge in pneumatic pipe. A kind of improved active eliminators is installed online to reduce the specific charge. Its eliminating effect is fine. High insulation resin powder in pneumatic pipe can be charged highly. The mixture of powder-air in storage or silo may be ignited by ESD. And the fire or explosion may be caused. Explosion accidents have occurred twice during past two years in a polyform-aldehyde resin powder workshop of a plant in Shanghai. A report presented that it may be caused by ESD. To investigate the reason of the accidents, the chapter measures the specific charge of polyform-aldehyde resin powder in pipe. The powder specific charge is found high. A kind of active eliminators in this pipe of the workshop is installed. The data indicates that this kind of improved eliminator has a considerable effect.

The Research on Back Corona Physical Model on Deposited Dust Layer of collecting Electrode

Publisher Summary This chapter focuses on resistance-capacitance model of dust layer and presents a surface instantaneous voltage equation of the layer and its influential factors to deal with back corona, including its generation, development, and influence. Back corona, which decreases flash-over voltage as well as increases working space current, not only makes dust-collecting efficiency reduce obviously, but also influences a steady operation of static dust precipitator tremendously. Back corona becomes one of the obstacles baffling dust collecting stable operation. Moore illustrates the conditions of generating back corona. Bohm deduced the instantaneous expression of the depth of dust layer. Most scholars lay emphasis on the research for restrained technology of back corona, while they intentionally avoid discussing the physical process of back corona.

Research on Dielectric Oxide Film Breakdown Mechanism of IC Device in Human Body Model

Publisher Summary This chapter discusses the breakdown mechanism of the film when electrostatic discharge (ESD) pulses in Human Body Model (HBM) is applied to oxide film based on the physical model of dielectric oxide film breakdown in integrated circuit (IC) device. The chapter builds a physical model of dielectric oxide layer breakdown in IC device and provides a physical equation about capture hole-charge density in the surface of medium with time changing. With the continual development of IC devices micromation, the active area and active width of oxide layer reflect sensitively to ESD. This is possibly because density defect effect causes the oxide layer to be latched up prematurely. The chapter focuses that the dynamics characteristic must be taken into consideration under ESD pulse once more. The voltage added to oxide layer is fluctuation voltage in the electrostatic discharge in HBM rather than constant voltage and the electronic current, J through oxide layer is not constant.

RESEARCH ON FIELD CALCULATION& SAFETY EVALUATION IN POWDER SILO

Abstract The design ideas and characters of a calculation sofeware on field distribution when ohmic dielectric powder is filled into cylindrical silo are presented in this paper. Also inclusion in its discussion is the static safety evaluation in silo with practice in China. It is raised that at the beginning of the filling operation or nearly full filled, the undulating change of the field should be one of the reasons which may cause incentive ESD.