Principle of Operation
The Vertical Electrostatic Oil Depositor (VEOD) was designed to apply a very thin lubricant coating on the surfaces of metal strip material as it passes through the oiler. The accuracy and reliability of this equipment has led to its use by major producers of electroplated steel and aluminum throughout the world.

The Trion Vertical Electrostatic Oil Depositor consists of three main sections:

• Tank Section:
  Contains the oil reservoirs, nozzle mounting panels and the air
  plenums into which the controlled air flow is piped.
• Electrostatic Charging Section:
  The ionizer cartridges are located in
  this area. The cartridges are removable for ease in cleaning and servicing.
• Repelling Plate Section:
  Houses the repelling plates which aid in depositing the charged oil mist on the strip.

The nozzle system educts oil from the reservoirs, atomizing it into micron sized particles in the fog chamber. Any large droplets impinge on and flow down the sides of the chamber, returning to the reservoir. A constant air pressure to the nozzles produces oil mist at a fixed rate, filling the chambers with a uniform oil fog. Approximately 100 times more oil mist is produced than is required to satisfy the maximum operating conditions.

Controlled airflow enters the fog chambers from the air plenums, moving the oil mist past baffles which help remove any larger droplets. The oil mist then moves into the Electrostatic Charging Section where a corona discharge field from the ionizing wires charges the oil particles negatively. After the mist passes through the ionizers, the negatively charged repelling plates force the charged mist particles toward the surfaces of the moving strip. Since the strip is at ground potential, the charged mist particles are also attracted toward the strip.

Because the oil mist is produced at a constant rate, the weight of oil deposited on the strip is related to the airflow volume introduced into the machine by the flow control system. When the line speed or strip width changes, the controlled airflow volume is adjusted by the control system to maintain the deposited oil weight at the selected value.

The ionizing cartridges and repelling plate section are designed to ensure that essentially all of the oil mist which passes through the cartridges is deposited on the strip.