Investigation On Migration And Aggregation Behavior Of Droplet Group During Dynamic Electrocoalescence Process Of High Frequency Pulse

Social development has increased the consumption and demand of petroleum.The exploitation and utilization of super-heavy oil,heavy crude oil,as well as the development of offshore oil fields have put forward new requirements for the development of efficient compact electric coalescer.Dynamic electro-coagulation technology combines the flow field and the electric field to reduce emulsion residence time while increasing the efficiency of electro-coagulation.In this paper,high-voltage,high frequency pulsed electric coalescence technology was used.By changing the electric field parameters,the flow field parameters and the properties of the emulsion,the migration and aggregation behavior of droplets in the dynamic electro-agglomeration process of high frequency pulse was studied.This article first used a digital microscope to observe the migration and aggregation behavior of the dispersed phase droplets under the flow field,electric field,flow field-electric field and performed qualitative analysis.Under experimental conditions,when the flow field acted alone,the frequency of collisions between the droplets increased,but the collided droplets did not coalesce;When the electric field acted alone,the droplets with closer distances were preferentially closer to the coalescence under the dipolar force.Under different electric field parameters,droplet aggregation rate was different;With the coupling of the electric field and the flow field,the droplet coalescence efficiency increased,and the droplets farther away from each other also tended to coalesce.When the electric field strength was too large,the large droplets broken up.Under the action of electric field and electric field-flow field,the phenomenon of chain formation appeared,but the direction of the arrangement of "water chains" was different.Secondly,320# oil was used as a continuous phase to configure different oil-water emulsions,and the effect of electric field parameters and impurity components on dynamic electric coalescence under different flow rates were explored.The experimental results showed that when the flow rate was fixed,the coalescence rate increased first and then decreased with the increase of the electric field parameter.The electric field parameter value had a greater influence on the power of dynamic electric coalescence.When the electric field parameters were superior,the increase of the flow within a certain range was conducive to the increase of the coalescence rate.The influence of impurity components in the emulsion on the physical properties of the emulsion was different: inorganic salts can significantly increase the conductivity of the dispersed phase solution;surfactants can significantly reduce the interfacial tension of the emulsion and also have an influence on the apparent viscosity of the emulsion liquid;under strong alkaline conditions,the droplet size of the dispersed phase in the emulsion was small,which improved the stability of the emulsion;the apparent viscosity of the emulsion increased with the increase of the moisture content.The influence of different impurity components on the physical properties of the emulsion leads to a different mechanism of its influence on dynamic electro-coalescence,and thus has different effects on the coalescence rate.This article studied the influence of different parameters on dynamic electro-coalescing,and laid the foundation for the development of a highly efficient and compact new type of electric coalescer.