Study On Droplet Behavior Of Dispersed Phase In Pulsed Sieve Plate Extraction Column By Four Optical Fiber Probe Technology

Pulsed sieve plate extraction column is an important liquid-liquid extraction equipment,which has been widely used in the field of spent fuel treatment because of its advantages of no rotating parts,large processing capacity and easy to be operated in long distance.The hydraulic performance(dispersed phase hold up,the distribution of dispersed phase droplet diameter,the velocity of dispersed phase droplet)of the pulsed sieve plate extraction column has a very important influence on its mass transfer capacity.In order to optimize the design,the hydraulic performance of the column need to be studied in detail.Four optical fiber probe technique has been developed for two-phase flow research in recent years.It has the advantages of high sensitivity and quick signal response.Compared with other techniques used in the study of the hydraulic performance of pulsed sieve plate extraction column,four optical fiber probe technique can not only measure the droplet diameter of the dispersed phase,the local hold up,but also measure the velocity vector of the droplet,which is of great significance to the study of the behavior of the dispersed phase droplet in the extraction column.In this paper,the four optical fiber probe technology was used and the corresponding signal processing program was improved.The deionized water was taken as continuous phase and butyl acetate,40% octanol/kerosene were taken as disperesed phase,respectively.The effect of the superficial velocity and pulse intensity on the droplet behavior of the dispersed phase,the droplet velocity and the relationship between droplet velocity and droplet diameter are investigated.The results of the butyl acetate-water system shows that with the increase of pulse intensity,the droplet diameter distribution decreased slightly;The average velocity of droplets increased slightly;And the angle between the direction of the droplet movement and the vertical direction became smaller.Two phase superficial velocity had little effect on droplet diameter distribution and droplet velocity.Under any operation condition,the angle between droplet velocity and vertical direction is distributed at 0-45 degree,and mainly distributes at 0-30 degrees.In addition,with the increase of droplet diameter,the average velocity of droplet increases sharply and then becomes stable.The research results of 40% octanol / kerosene-water system shows that pulse intensity not only affects the droplet diameter,but also affects the droplet velocity.With the increase of pulse intensity,the droplet diameter decreases and the average velocity of droplet increases.In addition,the droplet velocity also increases with the droplet diameter.For this system,the angle between the droplet motion direction and vertical direction is between 0-50 degree,and mainly concentrates on 0-40 degrees.