The Optimal Analysis On Structure Of Triple Eccentric Butterfly Valve

With the development of the industrial technology,the general soft seal butterfly valve has not been satisfied with the demand in the industry,so the metal seal butterfly valve has been developed.The tri-eccentric butterfly valve is the most advanced during the butterfly valve development and evolvement.But,at present, the tri-eccentric butterfly valve has not been studied thoroughly at home,and has not been formed a perfect theory system,brought about the limitation of the tri-eccentric butterfly valve in its development and application to a great extent.The paper analyzed the structure of the tri-eccentric butterfly valve at length, defined the tri-eccentric butterfly valve,and educed the geometry function and its characteristic about the section of the butterfly disc.The results indicate:the parallel contour line across butterfly disc thickness is normal ellipse,thereby established function relations between its geometry parameters(long axis and short axis) of three primary sections of the butterfly disc and the tri-eccentricity;In order to avoid interference between the butterfly disc and the valve seat as well as the valve body, combining the torque,we obtained the feasible range about the rotation center of the tri-eccentric butterfly valve.In succession,we should test whether the rotation center of the tri-eccentric butterfly valve was right,brought forward a computing method and a software method to test the seal fit interference.The paper deduced the friction moment of the tri-eccentric butterfly valve and gave it a qualitative analysis.The results indicated:for the tri-eccentric butterfly valve with the same caliber,the axis eccentricity effected on the friction moment minutely;the friction moment would increase with the radial eccentricity increasing; the friction moment would decrease with the angle eccentricity increasing.So,we gave the friction moment curves respectively.The paper also deduced the seal torque of the tri-eccentric butterfly valve.The results indicated:for the tri-eccentric butterfly valve with the same caliber,the seal torque would decrease with the butterfly disc thickness increasing;the seal torque would increase with the radial eccentricity increasing;however,the axis eccentricity effected on the seal torque minutely;the seal torque would increase with the half cone angle increasing appreciably of the cone which the butterfly disc belonged to.Based on the theory analysis above-mentioned,according to the given parameters,we designed the system solution to optimal software of the tri-eccentric butterfly valve's structure.