The utility model provides a water jet pump which is provided with a pump body. A water absorbing opening, a working water opening and a connecting opening are made on the pump body, the connecting opening is connected with a diffusing pipe, the diffusing pipe is connected with a water outlet pipe, and a nozzle is installed in the pump body. The utility model is characterized in that the central line of the absorbing passage is a straight line which is intersected with the straight line of the nozzle central line, the included angle Alpha between the extended line of the flange end surface of the water absorbing opening and the extended line of the flange end surface of the working water opening is less than 85 degrees. The central line of the absorbing passage is a straight line which is intersected with the straight line of the nozzle central line, namely, the working water passage of the pump body is connected with the water absorbing passage through a straight line, a mixing chamber is formed in the pump body, to enable an optimal cross section rate to be formed at the working water opening and the pump body mixing chamber opening, and the jet resistance is small, thereby ensuring that the drainage and discharging performance reaches the optimal state.

Water-jet pump

In order to solve the problems of conventional single-stage adding equipment, such as high adding proportion, easy to generate cavitation, large pressure loss and low pressure ratio, an original design of double-stage parallel adding equipment is proposed. Its performance is investigated experimentally under different working flow and outlet pressure and compared with the single-stage jet equipment. Testing results show that the adding proportion of double-stage parallel adding equipment is less than that of the single-stage one, and the cavitation flow is higher. The new equipment can decrease pressure loss, inlet pressure and improve pressure ratio, which lowers the energy loss of adding equipment and raises its driving ability in application. An adding proportion of 4.6 ‰ and an outlet pressure of 0.16–0.18 MPa were realized when the double-stage parallel adding equipment was used to add foaming agent for dust suppression with foam (DSF). The marked reduction in the adding proportion of foaming agent significantly reduces foam production cost. Therefore, it is believed that the study would lay an important foundation for the widespread application of DSF in underground coal mines.

A New Design of Double-Stage Parallel Adding Equipment Used for Dust Suppression in Underground Coal Mines

Optimization of liquid jet ejector geometry and its impact on flow fields

CFD simulation and analysis of the internal flow field of the annular multi-nozzle jet pump are carried out to study the effects of nozzle section geometries on performance of the pump based on the finite volume method and realizable k-e model. The results show that the square nozzle peak efficiency is 3% higher than that of the circular nozzle and 4.1% higher than that of the triangular nozzle. According to the simulation results, the mixing mechanism of the working fluid and second fluid is analyzed on the basis of the vortex dynamics. The results show the following: the recirculation area and the friction loss of the non-circular nozzle are reduced, and the mixing effect is improved; the streamwise vortex plays a major role in the mixing process and decays to an extremely small value at the end of the throat after attenuating rapidly in the suction chamber; compared with the streamwise vortex, the strength of the spanwise vortex is relatively stronger; the spanwise vortex still fluctuates after developing to a certain extent in the throat; the maximum streamwise vorticity peak value of the square nozzle is 31% more than that of the circular nozzle and 39% more than that of the triangular nozzle; the maximum spanwise vorticity peak value of the square nozzle is 19% less than that of the circular nozzle and 12% less than that of the triangular nozzle.

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CFD-Based Study of Nozzle Section Geometry Effects on the Performance of an Annular Multi-Nozzle Jet Pump

Numerical investigation of the cavitation instability in a central jet pump with a large area ratio at normal cavitating conditions

Jet pump plays a major role in transporting materials. The efficiency of jet pump is poor and it usually has a sharp peak in the efficiency–discharge ratio curve. These are undesirable. In the past...

R Mallela

Papers

Numerical investigation of the effect of geometry on the performance of a jet pump