What are the differences between the pneumatic butterfly valve of the additional air chamber and the ordinary pneumatic butterfly valve
The pneumatic butterfly valve with additional air chamber is to add an additional air chamber to the base of the ordinary pneumatic butterfly valve, and at the same time, open an orifice on the lower piston. When the pneumatic butterfly valve is encouraged, it will exchange with the gas in the additional air chamber under the effect of pressure difference.
Pneumatic butterfly valve with additional air chamber is mainly composed of upper cover plate, main air chamber (), additional air chamber and throttle hole connecting air chamber. The main air chamber is mainly a main part supporting the vibration isolation parts and generating elastic force; The additional air chamber is generally a rigid volume made of metal plate shell, which is connected with the main air chamber to increase the volume of air circulation; The orifice is mainly used to limit the moving speed of air between the main and auxiliary air chambers [2]. Compared with the ball valve without additional air chamber, the ball valve with additional air chamber increases the additional air chamber, increases the total volume and flow space of gas, and reduces the stiffness of the ball valve; The throttle orifice limits the movement speed of the gas and is the key element to generate the pressure difference between the two gas chambers. When the gas passes through the throttle orifice, it will have a damping effect, which is conducive to accelerating the attenuation of vibration [3]. Li Fu [4], etc., through adopting the experimental method and based on the theory of thermodynamics and hydrodynamics, deduced the stiffness characteristic model of pneumatic butterfly valve, proposed the calculation method of affirming the parameters of pneumatic butterfly valve, and concluded that the shape and stiffness, the volume of additional air chamber and the diameter of throttle hole are the main factors affecting the performance of pneumatic butterfly valve; Wang Jiasheng [5] and others set up the vibration simulation model of pneumatic butterfly valve with additional air chamber in the environment of Similink by virtue of the mathematical model of pneumatic butterfly valve and the calculation function of Matlab software, reminding the dynamic characteristics of pneumatic butterfly valve system to change with convergence parameters and state parameters, which is the optimal design and completion of stiffness The control of semi-active air suspension with adjustable damping provides theoretical basis and technical support, but its parameterization and visibility are not strong. With the development of high-performance computer technology and the growing maturity of nonlinear finite element theory, the main pneumatic butterfly valve manufacturers in the world analyze the characteristics of pneumatic butterfly valves through finite element software. Through theoretical analysis and separation of finite element model, this study established an effective finite element model in the nonlinear finite element software Abaqus to simulate and analyze the ball valve with and without additional air chamber, Consider the change of vertical static stiffness of ball valves without additional air chambers and with additional air chambers under different air pressures, and consider the influence of vertical stiffness changes of additional air chambers under different orifice diameters.