Performance Analysis Of The Combination Seal Structure Of High Pressure Screw Conveyor

Screw conveyor is one of the key equipments of the particle impact drilling system. Most of the studies of screw conveyor were at atmospheric pressure and low pressure, when medium pressure is as high as25MPa, the sealing condition of the screw conveyor is an important problem which needed to be resolved, it determines whether the system can be applied to the mining and whether it has good using performance. Mechanical seal and packing seal are two sealing technologies were widely used. The mechanical seal’s using cycle is long, but its structure is complex. The packing seal is easy to wear, and its sealing performance is poor. The combination seal has advantages of small size, less wear and tear. Considering the performance period of the equipment is short and discontinuous, decided to adopt the combination seal structure finally. The combination seal structure was consists of an O-ring and a slip ring, its principle is that with the compression of O-ring, the deformation elasticity imposed on the slip ring and makes the lip stick on the coupled surface, make the fluid sealed. But the slip rings existed does not apply to this equipment, therefore, more designs of the structure and researches of its performance are necessary. Based on the combination seal structure of the screw conveyor as the research object, the main research contents include that, design a suitable combination seal structure based on the use of the screw conveyor operating mode, mainly includes the design of the end cover, fastener, slip ring and the selection of some other components. Use the finite element analysis software ANSYS and CFX to analyze the seal structure, analyze its sealing condition and ensure the structure fulfill the basic requirements of sealing. Analyze the main parameters that affect the performance of combination seal, such as structure of slip ring, O-ring compression effects and etc. Ascertain their effects on sealing performance trends and improve the sealing structure according to the results of the analysis. Qualitative analyses were done for several factors affecting the service life of the sealing structure, mainly includes the thickness of the slip ring, the friction coefficient between the slip ring and the shaft sleeve, the contents of solid particles. Analyze the sealing condition after a certain amount of wear on the slip ring and calculate the service life of the slip ring, make sure it can be used on the screw conveyor.