Study On The Flow Inside Super Sonic Separator And Its Application Technology

The Super Sonic Separation technology is a combination of cryogenic temperature condensation and hydrocyclone separation of liquid and gas. The low temperature needed for the condensation of heavy component is realized by making the state of the fluids at Super Sonic. Compared with the traditional mixture gas separation technology, it has many advantages including high isentropic efficiency, simple structure, small floor area and low cost. However, little work has been done on this subject abroad, and in our country the research is still at initial stage. In this paper, the rotating Super Sonic condensing flow behavior of gas mixture inside the Super Sonic Separator (3S) is studied. The influences of structure parameters and operation parameters are analyzed. The results are good foundation for device design and application in practice. A two-dimensional numerical model is set up by which the mechanism of condensing and separating process of 3S can be described clearly; The influence laws of structure and operation parameters are good guides for maintaining the 3S at excellent performance in operation; A technological process for 3S is established, the advantages and disadvantages of this working process is compared and it found that the 3S is an effective device for gas mixture separation. The main work and achievements are as follows:â‘ Two-dimensional and three-dimensional numerical models are established, the numerical models can illustrate the condensing and separating process of 3S. The differences between results of using the two numerical models_are were not significant. So the two-dimensional model is enough and it can describe the flowing conditions inside 3S clearly.â‘¡The influences of structure parameters including the area ratio of nozzle outlet to throat, the equivalent diameter ratio of liquid discharge port, leaning angle of liquid discharge component and conical center are investigated. The following are the conclusions:the temperature drop and average Mach number inside the tube increase as the area ratio of nozzle outlet to throat increasing. When the area ratio is too small, the velocity of the gas can not be maintained at Super Sonic. While if the area ratio is too large, a shock wave will appear at the gradual-expanding section of the tube. Both of the two conditions are unfavorable. When the pressure ratio and area ratio are fixed, the equivalent diameter ratio of liquid discharge port can not be too small. Because shock wave will also could be appeared at the gradual-expanding section of the tube when the equivalent diameter ratio is too small. The temperature of the gas before the liquid discharge port will rise sharply due to the shock wave. There is a proper leaning angle of liquid discharge component. In the working section of the tube, the average mach number of the gas decreases and its average temperature increases when the leaning angle of liquid discharge component becomes larger. While for the smaller Leaning angle, the Mach number and temperature of the gas have a little change, the losses will become large due to the aggregative flowing disturbance. The flow fields of the 3S with or without a conical center are studied and the results show that the diameter of the conical center is a very important parameter.â‘¢The influences of the pressure ratio of inlet and outlet, outlet pressure and swirl strength on the device are investigated, the results show that:Fixed other parameters, when the pressure ratio decreases, the average Mach number of the gas inside the device decreases and its average temperature increases, which is not favorable for the low-temperature condensing. Meanwhile, the device becomes more sensitive to the operating conditions of gas flow. Therefore when the actual condition is permitted, the inlet and outlet pressure ratio must be higher enough to ensure a stable operation condition. In the case of a certain area ratio, a higher outlet pressure can improve the flow condition inside the device. By changing the height of the rotating flow generation device, the rotational speed of the gas inside Super Sonic separator can be increased or decreased, which is an effective way to control the performance of the Super Sonic separator.