A practical strategy for controlling flow oscillations in surge tanks

the use of accumulation vessels -production separators, electrostatic treaters, etc- as filters of feed oscillations has been proposed to optimize the offshore treatment of crude oils. this change in philosophy of control suggests letting the level to oscillate within certain limits -called band- for which existing algorithms require the measurement of the flow rate. an alternative algorithm is presented in this paper that requires only the measurement of the level. the basic concepts of the proposal are presented. it is demonstrated that besides being simpler, this algorithm has a good performance when compared to the traditional pi controller for surge tanks conception in surge tanks.