Ultra-high frequency and Self-adaptive voltage technology for water separation from oil emulsion

Abstract

Electrical dehydrators are often used to separate water from oil emulsions. However, the frequency and electric field strength are fixed during separation and cannot change with the flow rate and emulsion properties. To solve this problem, ultra-high frequency and self-adaptive voltage transformer was developed to enhance the separation efficiency and compared with ordinary high frequency transformer. To this end, a small-scale evaluation test system was designed to investigate the influence of electric fields and operating parameters on water dehydration of different emulsions. The results showed there are different optimal electric field strengths for emulsions of various properties. Higher frequency values required lower electric field strengths. Under high frequencies, the formed water chains attracted surrounding small water droplets to form larger droplets. During the separation process, the frequency was kept stable but the electric field strength adaptively changed and gradually decreased, resulting in declined power consumption. Ordinary high-frequency electric fields illustrated low dehydration efficiencies on heavy oil emulsions, high-water concentration emulsions, and water-containing polymer emulsions. By comparison, ultra-high-frequency self-adaptive electric field strengths transformer showed superior separation efficiencies, low energy consumptions, and more stability. Besides, the separated water was cleaner and exhibiting superior adaptability to adverse conditions. In sum, these findings look promising for optimizing the operation of existing electrical dehydrators and promoting the use of ultra-high-frequency and self-adaptive electric fields.