Desalter emulsion separation by direct contact vaporization

A petroleum desalter which comprises:

• a desalter vessel having a feed inlet for admitting a mixture of crude oil to be desalted with desalting water to form (i) a settled water layer containing salts dissolved from the oil in the lower portion of the vessel, (ii) a settled supernatant desalted oil layer in the upper portion of the vessel and (iii) an emulsion layer formed from the oil and the water and comprising oil and water formed between the settled water layer and the settled oil layer,
• a water outlet conduit at the bottom of the vessel for removing water from the water layer,
• an oil outlet conduit at the top of the vessel for removing desalted oil from the oil layer,
• at least one emulsion outlet for removing an emulsion stream from the emulsion layer,
• a conduit connecting the emulsion outlet to at least one inlet of a flash drum,
• a mixing point located along the conduit for admitting the withdrawn emulsion to a stream of a hydrocarbon heating medium to transfer heat from the heating medium to the emulsion, to break the emulsion and vaporize water from the broken emulsion in the flash drum.

A petroleum desalter which comprises:

• a desalter vessel having a feed inlet for admitting a mixture of crude oil to be desalted with desalting water to form (i) a settled water layer containing salts dissolved from the oil in the lower portion of the vessel, (ii) a settled supernatant desalted oil layer in the upper portion of the vessel and (iii) an emulsion layer formed from the oil and the water and comprising oil and water formed between the settled water layer and the settled oil layer,
• a water outlet conduit at the bottom of the vessel for removing water from the water layer,
• an oil outlet conduit at the top of the desalter vessel for removing desalted oil from the oil layer,
• at least one emulsion outlet for removing an emulsion stream from the emulsion layer,
• a conduit connecting the emulsion withdrawal port to a settling drum having an upper outlet and a lower outlet, to settle the emulsion and remove water from the emulsion, to form an oil-enriched emulsion stream to be withdrawn from the settling drum through its upper outlet and passed to a flash drum,
• a second conduit connecting the upper outlet of the settling drum to at least one inlet of the flash drum,
• an inlet located along the second conduit for admitting a stream of the oil-enriched emulsion to the hydrocarbon heating medium to transfer heat from the heating medium to the emulsion, to break the emulsion and vaporize water from the broken emulsion in the flash drum.