The Theoretical Research Of Design On The Annular Nozzle Jet Pump

Borehole hydromining is a kind of safe and efficient new mining method . As a very important part of borehole hydromining device, with its special advantage, jet pump becomes the main subject of this thesis.Jet pump is a kind of fluid mechanism that delivers the energy by high-speed fluid as power. Because of its advantages of simple structure, easily maintenance and lower cost, without moving parts, it has obvious superiority when it is used in many processes and some poor environment. The most research about jet pump focuses on how to change its structure to improve its efficiency. Recently, with the rapid development of computing technique, numerical simulation method is instead of experimental method gradually. However, the practical research of jet pump is not so much.The theory of jet fluid is the basis of jet pump. Compared between central jet pump and annular nozzle jet pump, the annular jet pump is the right choice of borehole hydromining device with its advantages.The basic equation of annular jet pump is the main content for design. And it is the link of its property and its size. Also it is the foundation of the application research of annular nozzle jet pump. The cavitation of jet pump is a very important part of the research. The efficiency of a jet pump is affected by the cavitation directly. The geometrical structure parameters include nozzles, the setting angle and the numbers of the nozzles, the length between nozzle and inner gular tube, the length of the gular tube and its diameter and the expansion angle of the diffuser. All these parameters are different between the central nozzle jet pump and the annular nozzle jet pump. The optimal value range of these parameters is changed accordingly. After the research and analysis of these parameters, under the require of the borehole hydromining in Shuitou River coalmine in Henan province, an annular nozzle jet pump is designed.