Experimental Research of the Construction of the Compact Electrostatic Coalescer

Abstract: Electrostatic Coalescer is an indispensable part of oil and water separation system in all oil fields and most of the oil fields in China are using traditional electrostatic coalescer which has many disadvantages like high input voltage, large energy consumption, covering large area and having bad safety performance. In order to solve all the problems, we have researched the structure and effect of electrostatic coalescer and developed a new style electrostatic coalescer to satisfy the actual application.The various parameters which have effect on electrostatic coalescer efficiency were systematically studied from both theoretical and experimental method, and the difference of coalescence efficiency between different structures of electrostatic coalescer was obtained. The advantage and disadvantage of different electrostatic coalesceres were analyzed, which can be referred to design new electrostatic coalescer of high efficiency. The main work of this paper is as follows:Firstly, a set of static electrostatic coalescer indoor modeling system has been designed and manufactured, and many problems like designing and manufacturing the electrode, debugging of controllable power, and emulsion questions, were solved. In the experimental process, we discovered that electrode’s structural, the emulsion propertie have a great impact on the efficiency of electrostatic coalescer. Pole plate and its superficial insulating layer’s nature, and sealing of the pole plate connecting box’s seal’s seal as well as the column electrode installation were difficulty in the experimental system. Considering the safety performance of static electricity coalescer, the above questions are also the key point of industrialized production of the new electrostatic coalescer.In order to study the plate electrode electrostatic coalescer, the white oil-water emulsion was used as the experimental medium. The research indicated that the plate electrode is only suitable to deal with the emulsion with small conductivity and the electric field intensity is the key factor that affects the efficiency of electrostatic coalescer, the coalescence time is reduced and the efficiency of electrostatic coalescer is promoted by increasing the voltage between the plates. When the electric field intensity is lower, the extension of the time that electric field act on emulsion is an effective way to promote the efficiency of electrostatic coalescer.The cylindrical electrode electrostatic coalescer was also experimental studied with diesel oil-water emulsion as experiment medium. The research indicated that the relationship between electric filed intensity and the electrode spacing is nonlinear. While theΦ50 electrode is suitable to process the emulsion with low water content, theΦ75 electrode is more efficient to treat higher water content emulsion. Moreover, the experimental results, using crude oil-water emulsion as the experimental medium, indicated that the efficiency of electrostatic coalescer to the coalescence of dispersed phase is not so good without other separation.Based on the result and data of experiment, a new style of electrostatic coalescer was designed and made to apply in the oil field and carried on the scene experiment. The result indicated obviously that the new electrostatic coalescer’s dehydration efficiency on crude oil surpassed the traditional electrostatic coalescer’s. And its energy consumption is only about 10% of the traditional ones and the process is steadier…
Key words: Efficiency of electrostatic coalescer; Electrode structure; Insulated coat; Droplet size; Water concentration