Study Of The Characteristics Of Flow Field Inside The New Type Hydrocyclone And The Mechanism Of Enhancing Performance

In the development and application of the hydrocyclone technology, the two problems that how to increase its separation performance and how to decrease its running cost are widespread concerned. In this connection, many beneficial efforts have been made and a lot of achievements have been obtained. But main of the work concentrates on the study that how the structural improvement of hydrocyclone influences its separation performance, while little on the study how the structural improvement influences the flow field of hydrocyclone. The study of the mechanism of the influence on hydrocyclone's separation performance by changing flow field is also little, which makes the previous studys on structure optimizing be of blindness to some extent. The purpose of this experiment is to reveal the inherent connection between the new type of hydrocyclone's separation performance and the structure of flow field, to provide theoretic foundation for the further optimization of hydrocyclone.This thesis has its creative points as the following three aspects :(1)It chooses the new type hydrocyclone cone parts and the new type hydrocyclone structural withdifferent inserted parts as research object on the foundation of systematic investigation of hydrocyclone; (2) It acquires the distribution regularity of two dimension time-averaged velocity field and turbulence structure field inside the new type hydrocyclone by adopting advanced LDA (Laser Doppler Anemometer)laser* The research work is sponsored by the Research Fund of High-Speed Hydraulics State Key Lab of China(0104).instrument to measure the flow field inside the new type hydrocyclone for the first time; (3)It tests the performance parameters of the new type hydrocyclone on different construction such as capacity , volume flow ratio, energy loss coefficient, total separation efficiency, reduced separation efficiency, total grade efficiency and corrected grade efficiency. On the basis of comparing these functional data, combining the corresponding laser measuring result, synthetically analyzed the inherent connection between the flow field of new type hydrocyclone and its performance.With the above research work, main conclusions have been made as follows: When solid core is put into 20° cone hydrocyclone, the characteristics of flow field has no obvious changes, but the separation performance is much enhanced compared with not inserting center parts . Injected with center parts as winged core, the flow field of 20 ° cone hydrocyclone changes much, and the separation performance becomes worse. And the more the wings there are, the worse the separation performance is. The spinning direction of the wing being positive direction is better than it being inverse direction, the winding radian of wing being semicircle is better than being half radian. When adopted hyperbola type cone part, the total efficiency and reduced total efficiency of the hydrocyclone are slightly superior to the common 20° cone hydrocyclone, separation sharpness and energy consumption are inferior and the corrected cut size is larger than that in the common 20° cone hydrocyclone. When adopted parabola type cone part, the corrected total efficiency and separation sharpness of the hydrocyclone are obviously superior to common 20° cone hydrocyclone, the energy consumption is slightly inferior and the corrected cut size is larger than that in the common 20° cone hydrocyclone. When inserting center parts to hyperbola type and parabola type hydrocyclone, the influence regulation on separation performance is similar to inserting center parts to the 20° cone hydrocyclone.The above experimental research and theoretic analysis are of great significance in both theory and practice. The researching achievements not only provide important theoretical foundation, but also are helpful in comprehensivelyunderstanding the separation mechanism inside the hydrocyclone.