Study On The Characteristics Of Liquid Gas Jet Pump

Jet pump can be used not only as a kind of fluid machinery transmissionquality and transmission of energy, but also can be used as mixed material andthe instantaneous reaction equipment. Its simple structure can reduce thedifficulty of installation and maintenance, it have safe and reliable operation andlow operating cost tubular, the structure with welded or threaded connectionmakes it easier to get the security seal, so it is often used for conveying hightemperature and high pressure,inflammable and explosive and radioactivedangerous liquid. He working principle and the structure of jet pump alsodetermines it can directly use the pressure as motive power, not need to consumeextra energy. But Jet pump also exposed some problems at work, and its energyutilization rate is low and have more serious loss in the mixing process, thatresult in jet mixing efficiency has been in20%—40%, which restrict its furtherapplication in the comprehensive application.In the automation of mine drainage system, liquid gas jet pump was usedto give the centrifugal water pump sucks water.Liquid gas jet pump efficiencyand stable operation is a necessary condition for the operation of the whole system. Among the practical operation, jet system can make the centrifugalpump body reaches a specified degree of vacuum, but the extraction rate andefficiency are relatively low, and have a waste of energy and time, and at thesame time affect the pumping performance of the whole drainage system, evenin case of emergency the vacuum degree can not be achieved, which lead toclogged drains, cause major loss.Aiming at the problem of the efficiency of jet pump, the existed researchmostly concentrated in the nozzle, pipe and nozzle area ratio, diffusion angleand throat length diameter ratio. This paper on the basis of existing researchresults, the suction chamber diameter, length of suction chamber, the position ofthe suction pipe and the throat contraction angle of jet pump gas can also is themain factor to affect the efficiency, and the jet pump is analyzed in theory andexperiment. Theoretical research is mainly carried out by simulation using thefluent software simulation, under the different parameters of the structure of thejet pump model of liquid and gas, using the method of variable control, get thepressure contours, velocity contours and pressure curve of the key parts of theliquid gas jet pump under different structural parameters.Through the analysisof the internal flow field of jet pump, the suction chamber length and position ofthe suction tube have little effect on efficiency of the liquid gas jet pumpsuction,and they can be neglected.With the increase of throat contraction angle, jet pump suction efficiencyincreases first and then decreases, there is an optimal throat contraction angle range is between13.5degrees and17.1degrees. With the increase of thediameter of the jet pump suction, suction efficiency also increases first and thendecreases. The optimal suction chamber diameter is between1.56times and1.68times the diameter of the jet pipe. Experimental study of jet pump mainlyprocess components that the same size as the numerical simulation and did theexperiment by group according to the principle and process of automatic minedrainage. Then record and analysis the experimental data, finally come to thesame conclusion with numerical simulation, which verify the correctness ofnumerical simulation.