Research And Design On Liquid Flow Control Valve Of Pill Dropping Machine

Soft capsule is a manner of packing of dropping pills, which has a bright future and a huge potential market, since it possesses various advantages, and the demand of soft capsule is increase continuously in all walks of life, especially in the field of medicine, food and tobacco. There is a special capsule form machine existing, which should be able to manufacture beaded soft capsule with different thickness of rubber. However in experiment I found that this machine cannot reach to the requirement for the reason that it cannot control the rubber thickness of the soft capsule accurately during the manufacture.This essay simply introduced how does a capsule form machine work and the work theory of glue control valve, and theoretically analyse the reason that the thickness of rubber produced by capsule form machine cannot reach to the manufacture requirement, which is the problem of the structure of the throttle orifice. Then I modelled the control valve in 3D and then used Fluent to do the 3D simulation analysis about the flow field of the glue control valve. The theoretical analysis is verified after obtained the datum of pressure, velocity and flow mass.To improve the structure of the throttle orifice of the glue control valve, this essay analysed the flow characteristics of diverse control valve, rechose the throttle orifice, redesigned the profile of valve plug for obtain the ideal flow characteristic needed, and used Matlab to obtain the equation of the profile of the valve plug by apply the least squares method. Afterwards, the redesigned profile of valve plug was remodelled and analysed by simulation experiment in Fluent. Finally, based on the datum from experiment, modification was applied on the profile of valve plug to satisfy the design requirement.In conclusion, the research has met the expectant target, and made contributions to the manufacture of the soft capsule. Meanwhile, it also gave us a deep understand of the characteristic of fluid field of the throttle orifice and the research could also offer help to the design of small flow mass throttle orifice with special requirements.