basic operation ec
DESCRIPTION
Electrostatic CoalescerTRANSCRIPT
DPS‐Delta 2800 Southwest Drive New Iberia, LA 70562 Ph: (337) 364‐8242 Fax: (337) 364‐8247
Section IV – Control Philosophy Basic Operation
The purpose of the Electrostatic Oil Treater is to remove produced water from crude oil. See Design Basis section for inlet and outlet content percentages. The crude oil is heated up to approximately 75°C off‐skid prior to entering the oil coalescer. Heating up the oil allows for improved separation of the water from the oil. Free‐water and solids drop out towards the bottom of the vessel. Oil flows vertically upwards through the horizontal vessel. Distribution boxes and spreader boxes near the bottom and collector pipes at the top ensure uniform oil flow across the grids. As the oil and entrained water come into contact with the electrical field in the grid area, final coalescing of the water takes place. These coalesced, larger, heavier droplets of water become free to fall out of the oil section into the lower water section. The vessel will always operate 100% liquid filled.
An oil / water interface level is maintained and controlled by an interface level transmitter LIT‐1012. This transmitter will control the water outlet level control valve LCV‐1012 as the water level in the vessel increases and decreases. An additional level transmitter LZIT‐1011 is also provided as a safety trip. This will shutdown oil from flowing into the vessel. See above section III for all level set points. The clean oil continues to rise to the top of the vessel where it is collected and is discharged through the clean oil outlet line.
A temperature transmitter TIT‐1008 is also located in the oil section of the vessel. This will send an alarm to the control room alerting the operator that the oil is outside of the temperature range. The temperature set points are listed in section III above.
The oil coalescer uses high voltage current to establish an electrostatic field for coalescing of the water droplets. An externally mounted, oil immersed, high voltage 100 KVA transformer is furnished to provide power to the grid. The transformer is equipped with a reactor which provides 100% circuit utilization for continuous power. The high voltage secondary of the transformer is connected to