Horizontal heater treater

A heater treater for treating petroleum mixtures to separate gas, sediment and water from oil comprising:

• a horizontal vessel with an inlet end and an opposite outlet end of the vessel, said vessel divided into a heated portion on the inlet end where the oil is heated to reduce its viscosity so that water can separate from the oil and a settling portion on the outlet end that provides residence time for the water and oil to separate,
• an inlet to the vessel provided in a top of the vessel at the inlet end, said inlet communicating with a top portion of a c-shaped inlet diverter provided within the vessel on the inlet end,
• said c-shaped inlet diverter having a bottom exit where the oil and water leave the diverter and enter the heating portion of the vessel, said c-shaped inlet diverter having a top exit where the gas enters the top of the vessel in the heating portion of the vessel,
• a perforated baffle separating the heating portion of the vessel from the settling portion of the vessel so that the baffle reflects heat back to the heating portion and equalizes flow of oil at the sides and the middle of the vessel as the fluid flows from the heating portion to the settling portion of the vessel,
• a u-shaped horizontal firetube provided centrally within the heating portion for heating the oil,
• a sand trap located at the bottom of the vessel in the heating portion of the vessel as a means of removing sediment from the vessel,
• a vane section located immediately downstream of the perforated baffle and extending to the walls of the vessel so that gas and fluids flowing from the heating portion to the settling portion of the vessel pass through the vane section, said vane section provided with spaced apart corrugated plates separated from each other and oriented at an angle so that the vane section serves as a demister for the gas that flows through it and serves as a coalescing device for the oil and water that flow through it,
• a water outlet provided in the bottom of the vessel at the downstream end of the settling portion,
• a gas outlet provided in the top of the vessel at the outlet end,
• an oil spillover weir provided at the exit end of the vessel and extending to the wall of the vessel on the bottom and both sides of the vessel so that an oil gap is formed between a top edge of the oil spillover weir and the top of the vessel, an oil collection compartment located on the downstream side of the weir between the weir and the outlet end of the vessel, and
• an oil outlet provided in the oil collection compartment.