The Research Of Sealing And Drive Technique On Descaling Devive Of Discharge On Inner Surface Of Steel Pipe

Plasma descaling technology emerged in the80’s of the last century, It’s a kind ofclean technology and was payed attention by metallurgical company of in and out ofcountry. Plasma descaling technology started later in china,At present,the Application ofuniversal was traditional cleaning methods in metallurgical industry,these methods hadSerious pollution,high energy consumption and poor cleaning.Development of plasmadescaling technology was In favor of reducing pullution to environment and improvingthe working environment of workers;and it was also in favor of breaking theinternational monopoly, improve the international competitivene of chaina’smetallurgical company.In this paper,a device which was used in cleaning inner suface ofdrill pipe was designed,its structure was simple an costed low and descaled efficiencily.At desining the device of descaling, some process parameters needed to beconsidered, for example, descaling current、source voltage of constant current、movement speed of descaling unit、electrode number and minimum breakdown voltage.In this paper,the mechanism of plasma descaling in vacuum was reserched,which basedon ’’explosive centre’’model.the mathematical model of removing oxide layer wasestablished according to the general nature of the vacuum arc.The result showed thatspeed of removing oxide layer was Inversely Proportional to descaling current,and wasalso directly proportional to the number of graphite electrode.This is consistent with thefacts.The physical characteristics of vacuum breakdown have been studied in thispaper,and the plasma arc required a minimum breakdown voltage is calculated by usingthe criterion of the vacuum breakdown.By reserching the pipe size and geometric accuracy、the number of dynamicsealing and the location of dynamic sealing,four schemes were put forward.Comparing with feasibility、complexity of the structural and economy of fourschemes,deciding to use overall seals, rope-wheel drive as descaling device’s designschemes.designing a structure of calibration wheel which was important to supportand pretension drill pipe.The mechanical properties、adapt performance to changeradius and of obstacling has been analysised,the results shew that the design of thecalibration wheel had Superior ability obstacling and has a good adaptability to the endof necking structure.Then modular designning to be done to the electronic descaling device of steer drill pipe inner surface. Using engineering software to construction a three-dimensionalmodel,and achieving virtual assembly.