Electrostatic Principle

Water droplets dispersed in oil carry electrical charges. Applied high-voltage AC or DC field polarizes droplets creating dipoles. Charged droplets attract each other, collide, and merge into larger drops. Larger droplets separate faster by gravity. This process handles emulsions that defeat conventional separators.

System Design

Horizontal vessel with electrode grid creating electric field between 10-30 kV. Oil flows through energized zone at controlled velocity. Coalesced water settles to bottom collection section. Clean oil exits overhead. Power supply and controls manage field strength based on throughput and water content.

Separation Performance

Removes water droplets down to 1-5 microns that conventional gravity separators cannot handle. Achieves outlet oil water content below 0.5% typically 0.1-0.3%. Processes emulsions from production, desalting, or refining that resist chemical treatment alone.

Material Selection

Carbon steel vessel construction with insulated electrode supports. Electrodes use corrosion-resistant materials. High-voltage insulators prevent current leakage. Design accommodates operating pressures 50-300 psig and temperatures to 150C.

Applications

Crude oil dehydration before refining, desalter wash water removal, fuel oil water separation, produced water treatment removing residual oil, and any oil-water emulsion needing enhanced separation. Common in refineries and offshore platforms with tight space constraints.

Operating Advantages

Faster separation than gravity requires smaller vessels saving space and cost. Handles varying water cuts without chemical adjustment. Lower chemical demulsifier usage reduces operating expenses. Compact footprint suits offshore platforms and brownfield expansions.

Control Systems

Voltage adjustment optimizes separation for varying conditions. Water content analyzers provide feedback. Level controls manage interface and inventory. Interlocks shut down power if water level rises preventing electrode shorting.

Performance Factors

Temperature affects oil viscosity - warmer oil separates easier. Salt content in water improves conductivity enhancing coalescence. Oil properties like density and interfacial tension influence separation. Chemical demulsifiers often used with electrostatic treatment for best results.

Safety Features

Grounded vessel prevents electrical hazards. Interlocks shut power on high water level, low flow, or electrode faults. Explosion-proof electrical design for hydrocarbon service. Emergency shutdown systems protect personnel and equipment.

Construction Standards

Design per ASME Section VIII for pressure vessels. Electrical systems per applicable codes for hazardous areas. Electrode design with proven separation performance. Complete documentation including electrical specifications and safety systems.

ERGIL electrostatic coalescer separators deliver superior oil-water separation for challenging emulsions in refining and production applications.