Experimental Study On The Formation And Rising Characteristics Of Bubble In Pure Water And Suspension

Bubbles are widely existed in many industrial production processes,such as chemical industry,environment,mining industry and energy,and their movement behavior directly affects the normal and efficient operation of process flow.In fact,the motion behavior of bubbles is often accompanied by multiphase flow processes such as gas-liquid or gas-liquid-solid,so the revelation and cognition of bubble motion law has always been a Hot-topics and difficult problems in research.In this paper,bubble is taken as the object of study,and a series of bubble behavior processes,are revealed by means of experimental research.such as formation,detachment and rising motion of bubble in pure water and solid-liquid suspension.The influences of tube orifice arrangement,tube orifice size,gas flow rate and solid particles on bubble movement behavior characteristics such as bubble size,shape,velocity and trajectory are studied.The difference of bubbles in pure water and suspension was analyzed.This paper aims to provide valuable rules and references for enriching bubble behavior cognition and guiding practice through systematic research and analysis.In this paper,a general experimental platform for bubble formation and rising motion in pure water and suspension was built.On this basis,the characteristics of bubble formation,departure and rising behavior in pure water were firstly observed and analyzed.The effects of nozzle top immersion,bottom immersion and side immersion modes on bubble size,shape,velocity and trajectory were studied.The experimental results show that different orifice arrangement has a great influence on the bubble formation and departure characteristics.the bubble departure period increases with the increase of the diameter of the nozzle diameter and decreases rapidly with the increase of the gas flow rate.The bubble departure period is the largest in the top immersion mode and the smallest in the side immersion mode.The bubble departure diameter increases with the increase of flow rate and nozzle diameter.and under the same condition,the top immersion mode is the largest,and the side immersion mode is the smallest.The bubble length-diameter ratio firstincreases and then decreases with the increase of nozzle diameter in the side and bottom immersion modes.The bubble length-diameter ratio increases with the increase of gas flow in the side immersion mode,decreases with the increase of gas flow in the bottom and top immersion mode,and the bubble length-diameter ratio changes more obviously in the top immersion mode.The bubble's upward movement path is an S-shaped trajectory after departure from the nozzle mouth.The vertical velocity of the bubble increases sharply at first and then flattens along the rising height.Under the same conditions,the vertical velocity of the bubble is the largest in the top immersion mode and the smallest in the side immersion mode.The fluctuation amplitude of bubble horizontal velocity and horizontal displacement with the increase of gas flow.Secondly,on the basis of the above experiments,solid-liquid suspension was prepared by adding hollow glass beads with particle size of 145 ~ 165?m into pure water.And the formation,departure and rising process of bubbles in suspension were conducted experimental research.The behavior characteristics of bubbles in suspension were studied and compared with that of bubbles in pure water,as well as the low on the size,shape,velocity and trajectory of bubbles in the process of bubble formation and rise were Acquired.The experimental results show that the influence factors of various on bubbles in suspension and pure water are basically the same.However,there are differences in the values of the corresponding characteristic parameters.The bubble length-diameter ratio in suspension is smaller than that in pure water when the side immersion mode,and larger than that in pure water when the bottom and top immersion mode.Under the same conditions,the bubble diameter and departure period in the suspension were smaller than that in the pure water when the side orifice was immersed,which indicated that the solid particles would promote the bubble departure.The bubble diameter and departure period in suspension are larger than that in pure water at the bottom and top immersion mode,which indicates that solid particles have an inhibitory effect on bubble formation and departure.At the same rising height,the bubble length-diameter ratio in the suspension at the bottom immersion mode is larger than that in the pure water as a whole.The vertical velocity,horizontal velocity and horizontal displacement of bubble in the suspension under bottom immersion mode after stabilization are smaller than those in the pure water,which indicates that the solid particles have an inhibitory effect on the movement velocity and horizontal displacement of the bubble.