US 11,857,895 B2
Bi-phase (Scott-T) transformer double volted AC electrostatic coalescer
Simone Mulas, Dhahran (SA); and Pier Domini, Abqaiq (SA)
Assigned to Saudi Arabian Oil Company, Dhahran (SA)
Filed by Saudi Arabian Oil Company, Dhahran (SA)
Filed on Nov. 3, 2021, as Appl. No. 17/453,415.
Prior Publication US 2023/0136607 A1, May 4, 2023
Int. Cl. B01D 17/06 (2006.01); B01D 17/02 (2006.01); B01D 17/04 (2006.01); B03C 11/00 (2006.01); C10G 33/02 (2006.01)
CPC B01D 17/06 (2013.01) [B01D 17/0214 (2013.01); B01D 17/045 (2013.01); B03C 11/00 (2013.01); C10G 33/02 (2013.01)] 8 Claims
OG exemplary drawing
 
1. An electrostatic coalescer for separating water from a crude oil emulsion comprising:
a vessel housing having a cavity, an inlet for receiving a crude oil emulsion, at least one outlet for output water removed from the emulsion, and a further outlet for purified crude oil;
a first pair of electrodes positioned within the cavity of the vessel housing;
a second pair of electrodes positioned adjacent to the first pair of electrodes within the cavity of the vessel housing;
a first Scott-T transformer circuit coupled to the first pair of electrodes, the first Scott-T transformer circuit receiving as an input a 3-phase power supply and outputting a 2-phase high voltage signal to the first pair of electrodes; and
a second Scott-T transformer circuit coupled to the second pair of electrodes, the second Scott-T transformer circuit receiving as an input a 3-phase power supply and outputting a 2-phase high voltage signal to the second pair of electrodes;
wherein the 2-phase voltage signal generated between the first pair of electrodes by the first Scott-T transformer circuit is of a same amplitude and phase as a voltage signal generated between the second pair of electrodes by the second Scott-T transformer circuit,
whereby a uniform and synchronized electrostatic field is established throughout the entire length of the vessel free of any phase shift in the electrostatic field resulting in water droplet coalescing and separation from the crude oil in the crude oil emulsion.