Papers by Keyword: Butterfly Valve

Abstract: A numerical simulation research was carried out on vortex and sound pressure level of the butterfly valve in the flow process based on FLUENT, which analyzed the variation of the vorticity and sound pressure level at different opening angles. There was an inverse pressure gradient in the orifice formed by the butterfly plate and pipe, which caused partial particle reflux on the back of butterfly plate in flowing, thus formed the vortex. The vortex formed on the back of the butterfly plate was decreased gradually, with the increasing opening angle of the valve in opening process. The noise was generated by the vortex separated and rupture in flowing. And the sound pressure level on the back of butterfly plate was decreased with the increasing opening angle. At the same time, the vorticity and the maximum sound pressure level position moved from the center to the rotation center of butterfly plate in opening process. The expanding orifice formed by butterfly plate upstream and the pipe and the tapered orifice formed by butterfly plate downstream and the pipe had the different throttling action to the fluid, which made the sound pressure level of upstream was higher than that of downstream in symmetrical position. The vortex generated by the separation of boundary layer would cause vortex excited vibration between plate and fluid, and then resonance occurred. The studies were carried out in the vorticity and the sound pressure level on the downstream of butterfly plate, and the changing law of those was found. It would provide a basis theory for reducing noise and avoiding vortex vibration of butterfly valve.

Abstract: The paper presents the operation of a hydraulic closed circuit equipped with a butterfly valve which can close with a step of 10o. Using four pressure transducers and one temperature transducer, the authors determined the volumetric flow rate, the average water velocity and the local pressure loss in the butterfly valve, the flow coefficient K_v and also the incipient cavitation coefficient. Recommendations for the disposal of the butterfly valve are made and conclusions are obtained regarding the range of opening degrees in which the butterfly valve is better to be used.

Abstract: This paper analyzes the unitary tensions variation on the butterfly valve disc in different conditions and at different opening angles. It performs simulations of flow inside the valve at different times in the dynamic action of opening and closing, which derive values disc forces and tensions variation in shaft. Analyzing different shapes and design parameters, the study allows an analysis of the dynamic behavior of the disc, with implications for the optimal design of butterfly valves and closing their body.

Abstract: To the valve system in the furnace hot air duct of the hot-rolled furnace in steel, the thermal Stress of butterfly valve and actuator was simulated by ANSYS. The feasibility of appropriate temperature control measures of too high temperature of butterfly valve and actuator was verified. And in the field, the transformation and the temperature measurement of butterfly valve and actuator were performed; the failure rate was calculated, to ensure that butterfly valve and actuator could meet the requirements of hot rolling.

Abstract: For the problem needed to solve during the process of steel cycle power generation, a set of pressure regulating system driven by step motor was designed based on direct-drive volume control (DDVC). An incremental fuzzy PID controller was developed for this system. Then the dynamic characteristics were simulated in Matlab/simulink. The results show that: compared with the simulation curve controlled by traditional PID, this regulating system can achieve better performance by fuzzy PID.

Abstract: The paper proposes an idea of projection weighted area in designing a new control butterfly valve. A lot of three-dimensional numerical simulations are carried out on the new valve, and the numerical simulations give a good linear relationship between relative flow coefficient and relative valve opening. An experiment setup was established to verify the results of numerical simulations, and the results show that the CFD technology to research and design the new valve plate is entirely feasible.

Abstract: A numerical approach was used to investigate the flow characteristics around a butterfly valve with the diameter of 2108 mm by the commercial computational fluid dynamics (CFD) code FLUENT6.3. The simulation was carried out to predict flow field structure, flow resistance coefficient, hydrodynamics torque and so on, when the large diameter butterfly valve operated at various opening degrees. The three-dimensional simulation results shown that there are vortexes presented near valve back region as the opening degree smaller than 40 degree; the flow resistance coefficient reduces rapidly with the increasing of opening degree and the resistance coefficient is quite small as the angle larger than 50 degree; the hydrodynamic torque reduces with the increasing of opening degree and the hydrodynamic torque is smaller than 20% of maximum torque; the torque ratio and the pressure drop ratio are reduce with the increasing of opening degree, the pressure drop ratio reduces rapidly as the opening degree is smaller than 50 degree.

Abstract: It was achieved with the benefit of excellent molding function of CAD/CAM, to solve the designing problems of rotation center of triple eccentric butterfly valve and to improve the seal performance. The Solid Edge software is applied to analyze the process of 3D modeling and motion simulation with details, as well as check both static and dynamic interference. In this way, the reasonable eccentric angle α, cone-apex angle 2β, radial eccentricity e and axial eccentricity C of valve board are acquired. It is effective to shorten the design period of triple eccentric butterfly valve, also improve the design efficiency and quality.

Abstract: Foreign development regarding devices for speed regulating of in-pipe robot inspection has been commercially applied in gas pipeline this decade, however, the results of theoretical and structural research on bypass device were scaled in and abroad after the research of literature. First, this paper deals with the new structure of a butterfly bypass-valve, the basic parts and working principle on this speed regulating unit. The using of a butterfly disc in bypass-hole of PIG (pipeline inspection gauge) can achieve a speed regulating purpose in bypass-PIG. Next, the theoretical model of pressure loss and regulating feasibility or ability of PIG are introduced by the similar mathematical model with a throttle valve. Finally, give the conclusion.

Abstract: During casting process design, CAD/CAE technology can play important role to avoid macroscopic irregularity, internal defect and assure casting performance. Based on the casting process analysis and gating system design, the numerical simulation of gray iron butterfly valve was done by hydrodynamic software Flow-3D to obtain its optimal process scheme. According to the simulation results including flow field, temperature field and defect distribution, the merits and faults of designed schemes were investigated and then the feasible gating system was proposed. The results showed that, compared with top or intermediate casting, when adopting bottom casting, steady flow of molten metal and reasonable temperature distribution could be achieved. And workpiece defects mainly distributed in riser. The predicted results are in good agreement with practical ones.