| Ceramic ball valves have excellent properties such as high temperature resistance,high pressure resistance,and corrosion resistance.They are widely used in the black water treatment of coal chemical industry.Ceramic ball valves often face problems of leakage and high noise.Leakage and high noise will not only cause serious safety hazards but also cause property damage.Therefore,researches to improve the sealing performance of ceramic ball valves and reduce valve noise are even more urgent.First of all,in order to improve the sealing performance of ceramic ball valves,we start from two aspects.One is to improve the sealing of the middle valve body of the ceramic ball valve,increase the upper platform structure and extend the stem,increase the distance between the valve actuator and the flow channel used to control the output shaft,and avoid the actuator from being subjected to high temperature medium in the flow channel Impact.The second is to improve the structure of the sealing surface of the ball and seat of the ceramic ball valve.The advanced processing technology is used to improve the accuracy of the ceramic ball,and the cone surface seal is changed to the spherical surface seal.The sealing model of the ceramic ball valve was established,and the sealing specific pressure of the sealing surface was simulated.It was found that there was a leakage point at the sealing pair of the ceramic ball valve.In view of the leakage point,the structure of the sealing pair was optimized to improve the sealing performance of the ceramic ball valve.Then,in order to analyze the cause of the noise generated by the ball valve,SolidWorks was used to extract the flow channel model,and the fluid simulation of the ceramic ball valve under high pressure differential black water treatment conditions was performed using Fluent,and the ceramic ball valve was obtained at 20°-90° cloud diagram of the velocity and pressure fields of the internal flow field at the opening.Vibration and noise analysis of the ceramic ball,ball valve,and the entire pipeline.The ceramic ball valve has not been damaged for a long time.It can be concluded that the ceramic ball valve has no resonance.The main reason for the high noise of the ceramic ball valve is the flashing phenomenon.Eight monitoring points were randomly set at 1m from the valve outlet,and Fluent was used to calculate the noise value of the monitoring point under the condition of black water treatment when the valve was opened at 90°.The noise values were all greater than 100 dB,which seriously endangered the health of the staff,so the seat structure of the ceramic ball valve is improved and the ceramic orifice plate is added,and the noise value of the monitoring point is reduced by at least 16.1% after calculation.Finally,the salt spray corrosion test,hardness test and wear test were carried out on the zirconia ceramic material commonly used for ball valves,F304 stainless steel material and F304 stainless steel material sprayed with WC.It can be obtained that the zirconia ceramic material has the best corrosion resistance and the maximum hardness value.The highest abrasion resistance.The roughness and roundness of the ceramic sphere were measured,and the roughness and roundness values were ≤0.2μm and ≤1μm,which were less than 2 times and 30 times of the national standard.The ceramic sphere has high accuracy.Air pressure sealing experiment and hydraulic sealing experiment were carried out on the sample ball valve.The experimental results show that the sealing performance of the ball valve is good,which can reach the AA level of the national standard leakage level and the VI level of the American standard leakage level. |
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