Study On Flow Pattern Identification Based On Wavelet Analysis For Air-lifting System

As a special type of pump,Air-lifting pump can play a greater role in the traditional occasion that the traditional pumpcannot be used.Such as the extraction of granular,bulk solid particles and corrosive liquids,etc… Because the research on the flow field structure of the Air-lifting system is not perfect,the problem of low performance of the Air-lifting pump is caused.To improve this problem,the gas-liquid two phase flow and gas-liquid-solid three phase flow in the riser are studied on the experimental platform of the air lifting system,in order to achieve the purpose of flow pattern identification,research on the characteristics of Flow Pattern,transition mechanism,and the characteristics of each flow pattern based on wavelet analysis,the results show that:The characteristics and transition mechanism of gas-liquid two-phase flow pattern in riser are studied.With the increase of the volumetric flow rate of air,the change order of the flow pattern in the pipe is: Bubble flow,Slug flow,Churn flow and Annular flow.The characteristics and conversion mechanism of gas liquid solid three phase flow regime are analyzed.The results show that the Coalesced churn flow is most favorable for the promotion of solid particles.With the increase of the volumetric flow rate of air,the change order of the gas liquid solid three phase flow pattern in the pipe is,Slugspiral flow,Vortical-spiral flow,Wave flow,Coalesced churn flow,and Annular column flow.Based on the wavelet analysis of flow pattern eigenvalue extraction can effectively identify the flow patterns.In the gas-liquid two phase flow pattern,the four flow patterns are well identified by energy distributions mainly in one sub-and,and in the four sub-bands of 2,3,4,7.In the gas-liquid-solid three phase flow pattern,the five types of flow energy differences are mainly manifested in the 1 and the 2 sub bands,as well as the different energy distribution in the sub bands of 3,4,6,7 and 8,and also identification of the five flow patterns.The flow pattern signals of gas-liquid two-phase flow and gas liquid solid three-phase flow are identified,the results of the recognition rate was 91.4% and 88.1% respectively,achieve recognition effect.In this paper,the flow field structure theory of Air-lifting system is enriched,and it is important significance for its application in engineering.