Electrostatic Treaters

ETI provides systems to process and remove water and salts from crude oil. Treating elements include heat, chemicals, mixing, high voltage electrostatic grid systems, and settling time. ETI offers three types of electrostatic grid systems: (1) Plate AC, (2) Rectified AC/DC, and (3) Tri-Phase Grids with Balanced Load AC grid systems. Treaters are considered integrally firetube heated vessels with a coalescing section having electrostatic grids. Coalescers are vessels with electrostatic grids only, and if heat is required, it is done externally.


120″ OD X 40′-0″ ASME Electrostaic Oil Treater, skid mounted with internal sandjet system and outlet metering.


Reasons for Crude Oil Dehydration and/or Desalting
Crude oils must be dehydrated or desalted for pipeline/refinery purposes to mitigate corrosion, reduce shipping volume and emulsion resolution. The electrostatic grids accelerate the separation of water from the crude oil. Heat lowers the viscosity of the crude oil, provides turbulence, and agitates the chemical emulsion breaker to resolve the crude emulsion. Depending upon the dehydration requirements, the treating temperature, applied voltages and grid configuration can be optimized to provide the desired level of dehydration. Desalting is a misnomer, in so far as the desalter only dehydrates, and salt removal is a function of dehydration effectiveness. It is not a process where crystalline salt is removed.

The Process
The oil flows into a heated section where the oil is thoroughly degassed, then into a high voltage electrostatic grid section to dehydrate the crude oil. A high voltage electrostatic flux exists between adjacent grids and a low voltage electrostatic flux exists between the grids and the water interface (ground). Voltages as high as 25,000 V can be generated. In ETI grid configurations, the grids are arranged vertically in a horizontal vessel, and the high voltage is applied through high voltage feeds. Teflon insulators isolate the high voltage from the vessel walls. The oil flows vertically between the grids and water droplets settle below the grids. Generally, the coalescing section is fluid packed so that there are no gas phase concerns and instruments and controls are configured to maintain the liquid-packed section. U-tube type firetubes supply internal heat via natural draft or forced draft burner systems. Each of these heating systems employ burner management and flame safety systems. Additional safety devices, compliant to API 14-C, are available for process alarms and shutdowns. Multiple firetubes are used to achieve the targeted heat duty. Optional heat exchangers may also be used to increase heating efficiency.


Options and Features

  • Inlet Degassing Shroud
  • Sand Washing/Jetting Systems
  • Interface Sludge Removal
  • Galvalum/Zinc Anodes
  • Demisting with Vane or Mesh Pads
  • Pressured Inlet Distributor
  • Spillover Baffles
  • Alloy Materials
  • HMI Control Options
  • Heat Exchangers
  • Desalting Mixing Elements
  • Ladders and Platforms
  • Sample Look-Boxes
  • Chemical Injection Quill Assembly
  • Factory Insulation
  • Spillover Baffles
  • Sand Drain Systems
  • Interface Emulsion Pad Removal
  • Impressed Current Cathodic Protection
  • Slop Oil Treating
  • Gravity Liquid Distributors
  • Internal Coating
  • Control Panels
  • Removable Firetubes
  • Desalter Mixing Valves
  • Skid-Mounted Modules
  • 100% Reactance Transformers
  • Corrosion Coupon Holders
  • Electronic Interface Controllers