ClassificationCode: TH36 Document code: A
Article ID: 1001-3997 (1999) 06-0041-02
1 liquid jet pump features
Liquid jet pump is a non-rotating parts of the fluid machinery, which is through the jet media entrainment effect and the role of turbulent diffusion, the working fluid energy transfer to the slits suction liquid. Because of its simple structure, compact, good sealing performance of the pump body, hydraulic transmission Gong Li, can achieve long-distance control, and therefore suitable for high temperature, high pressure, high vacuum, deep water, strong radiation and strong corrosion conditions. At present, jet pump technology has been widely used in many fields at home and abroad, and its application in plate filter is a typical successful example.
2 liquid jet pump structure parameters
1.1 jet pump structure shown in Figure 1.
1 Nozzle 2 Pump chamber 3 Throat inlet section 4 Throat 5 Diffusion tube Figure 1 Jet pump structure diagram
Jet pump structural parameters include area ratio m, throat l2, throat length l4, roar pipe import angle α1 and diffusion angle α2 five factors. Where m = F 2 / F 1 = (d 2 / d 1 ) 2
By describing the performance of the liquid jet pump and the following three parameters to express:
Flow ratio q = Q b / Q a
The head ratio h = [(H c Z c + V c 2 / 2g) - (H b + Z b + V b 2 / 2g)] / [(H a + Z a + V a 2 / 2g) - b + Z b + V b 2 / 2g)]
Efficiency value η = qh / (1-h)
1.2 jet pump structure parameters of its performance
According to a large number of domestic and foreign scholars' research, when the value range is: m = 2-9, l 2 = 1-6d 0 , l 4 = 4-9d 2 , α 1 = 15 0 -120 0 , α 2 = 0 -14 0 , v 0 <50m / s, the results of its performance shown in Figure 2.
Figure 2 basic parameters of the impact of performance
From this it can be seen that each structural parameter has the following effect on its performance:
(1) The area ratio is the main parameter affecting the jet pump, m = 3-4 is the high efficiency area.
(2) Throat distance l 2 = 1.0d 0 , the jet pump has a high efficiency point.
(3) The diffusion angle also has a great influence on the performance of the jet pump. When 0 <α 2 <10 0 is the high efficiency area of ​​the jet pump.
(4) The inlet angle of the throat has less effect on its performance.
(5) The length of the throat has a great influence on its efficiency, and its effective area is 6d 4 <1 4 <8d 2 .
Because the experimental results with the boundary conditions selected range of different values ​​vary, so the various factors on the performance of the jet pump ability to change. 3 System for testing the vacuum generated by the jet pump
Jet pump test device by the filter, hydraulic pump, motor, pressure control valve, globe valve, flow meter, jet pump and vacuum gauge and other components. See test principle diagram 3.
Figure 3 test schematic
1 filter 2 pump 3 motor 4 pressure control valve 5,8,10,12, pressure gauge
6,15 Shut-off valve 7 Throttle valve 9, 14 Flow meter 11 Jet pump 13 Vacuum gauge
4 test results and conclusions
(1) under the influence of the respective structural parameters of jet pump performance, we adopt the value interval efficient, taking the area ratio m = 3, primary throat l 2 = 1.0d 0, the diffusion angle α 2 = 8 0, larynx Pipe into the α 1 = 12 0 , the length of the pipe l 4 = 6d 2
(2) each jet pump nozzle having a diameter of l 0 = 4mm, when d 0 = 6m, the test results shown in Fig.
Figure 4 test results
Figure 5 hydraulic schematic
According to the test results, under the premise of adopting the structural parameters, the negative pressure of the jet pump we developed can reach -0.06MPa, and the vacuum value increases as the difference of the inlet and outlet pressures increases.
5 jet pump in the plate filter on the application
We based on the principle, its application in the following filtering system.
In practical applications, we apply this jet pump to the plate filter to obtain a good sealing effect, so that the whole filtering device has no leakage phenomenon. Therefore, the use of jet pump features cleverly applied to a variety of demanding, leak-free system, the negative pressure sealing effect is very obvious.
Author: Zhao Yue (Liaoning Province Machinery Research Institute, Shenyang 110032)
Quan Yuan Jun (Shenyang Gold Cup General Motors, Shenyang)
Grace Envirotech Co., Ltd. , http://www.zjdustcollector.com