Separation of dispersed liquid phase from continuous fluid phase

A method for use in the separation of a dispersed liquid phase from a continuous liquid phase, the phases together forming a phase mixture, by producing migration of dispersed phase droplets within the continuous liquid phase mixture, said method comprising the steps of:

• (1) introducing free charge that is net unipolar into the phase mixture in such manner as to cause the continuous phase to act as a medium through which volumetric distribution of the introduced charge takes place;
• (2) passing the charged phase mixture into a separation vessel, the charged phase mixture, before entering said vessel, being directed as a stream through a gas or vapor space for minimizing charge dissipation from the charged phase mixture in said vessel back to where the free charge introduction took place, there being a sufficient excess of free charge introduced such that the volumetric charge distribution causes, in said vessel, an electric field to be induced in the phase mixture and the dispersed phase to become charged, and the induced electric field and the charge on the dispersed phase interact to produce an electrical driving force acting on the dispersed phase so that said migration is due substantially to said driving force, and
• (3) allowing the migrating dispersed phase in said vessel to accumulate, within said phase mixture, adjacent to collector means for dispersed phase comprising at least one collector element of porous material having a surface region exposed to the migrating dispersed phase droplets, said porous material having sufficient porosity as to absorb dispersed liquid phase into its pores and thereby trap dispersed phase at separate sites on said surface region for promoting droplet coalescence and growth with further droplets undergoing electrically-driven migration to those sites.

A method of separating a dispersed liquid phase from a continuous liquid phase, the phases together forming a liquid phase mixture, by producing migration of dispersed phase within the phase mixture, said method comprising the steps of:

• (1) flowing a stream of the phase mixture past a pointed high potential electrode at sufficient velocity that free charge that is net unipolar is injected by field emission into the liquid mixture and is conveyed by the flowing stream away from the high potential electrode, the free charge being injected into the phase mixture stream in such manner as to cause the liquid to act as a medium through which volumetric distribution of the injected charge occurs;
• (2) causing the charged stream to enter into a separation vessel through a gas or vapor space for minimizing charge dissipation from the charged phase mixture in the separation vessel back to where the free charge introduction took place, there being a sufficient excess of free charge introduced such that the volumetric charge distribution causes an electric field to be induced in the mixture in the vessel and the dispersed phase there to become charged, and the induced electric field and the charge on the dispersed phase interact to produce an electrical driving force acting on the dispersed phase so that said migration is due substantially to said driving force;
• and
• (3) allowing the migrating dispersed phase in said vessel to accumulate, within said phase mixture, adjacent to collector means for dispersed phase comprising at least one collector element of porous material having a surface region exposed to the migrating dispersed phase droplets, said porous material having sufficient porosity as to absorb dispersed liquid phase into its pores and thereby trap dispersed phase at separate sites on said surface region for promoting droplet coalescence and growth with further droplets undergoing electrically-driven migration to those sites.

Apparatus for use in the separation of a dispersed liquid phase from a continuous liquid phase, the phases together forming a phase mixture, by producing migration of dispersed phase within the phase mixture, said apparatus comprising:

• (1) means arranged to introduce free charge that is net unipolar into the phase mixture in such manner as to cause the continuous phase to act as a medium through which volumetric distribution of the introduced charge takes place;
• (2) a separator comprising:
• (i) a vessel into which, in use of said apparatus, phase mixture, charged by the free charge introducing means, is passed;
• and
• (ii) collector means for dispersed phase comprising at least one collector element of porous material disposed within said vessel with a surface region thereof exposed to migrating disposed phase droplets in said vessel;
• (3) flow control means operable for retaining a body of said charged phase mixture in the vessel and for discharging substantially dispersed-phase-free continuous liquid phase from the separator, continuously or periodically;
• and
• (4) a gas or vapour space which separates the phase mixture in the vessel from the free charge introducing means and through which the free charge introducing means is arranged to direct a stream of charged phase mixture before entering said vessel, for minimizing charge dissipation from the charged phase mixture in said vessel back to the free charge introducing means, said free charge introducing means being arranged to introduce a sufficient excess of free charge such that the volumetric charge distribution causes, in said body of charged phase mixture in said vessel, both an electric field to be induced in the phase mixture and the dispersed phase to become charged, and the induced electric field and the charge on the dispersed phase interact to produce an electrical driving force acting on the dispersed phase so that said migration is due substantially to said driving force, the dispersed phase migration causing dispersed phase to migrate to said collector element(s), leaving substantially dispersed-phase-free continuous liquid phase for discharge from said separator by said flow control means, said porous material having sufficient porosity as to absorb dispersed lilquid phase into its pores and thereby trap dispersed phase at separate sites on said surface region for promoting droplet coalescence and growth with further droplets undergoing electrically-driven migration to those sites.

Apparatus for use in separating a dispersed liquid phase from a continuous liquid phase, the phases together forming a liquid phase mixture and the density of the liquid forming the dispersed phase being larger than that of the continuous liquid phase, by producing migration of dispersed phase within the phase mixture, said apparatus comprising a charge injector including a pointed high potential electrode;

• means for flowing a stream of said phase mixture past said electrode at sufficient velocity that free charge that is net unipolar is injected by field emission into the liquid phase mixture and is conveyed by the flowing stream away from the high potential electrodes, the charge injector being arranged to inject the free charge into the phase mixture stream in such manner as to cause the continuous phase to act as a medium through which volumetric distribution of the injected charge occurs;
• a separator comprising a separation vessel into which the charge injector is arranged to pass the charged stream through a gas or vapor space between the charge injector and separation vessel, the gas or vapor space serving to minimise charge dissipation from the charged phase mixture in the separation vessel back to the charge injector, the charge injector being arranged to inject a sufficient excess of free charge into the phase mixture such that the volumetric charge distribution causes an electric field to be induced in the phase mixture in the vessel and the dispersed phase there to be charged, and the induced electric field and the charge on the dispersed phase interact to produce an electrical driving force acting on the dispersed phase so that said migration is due substantially to said driving force;
• and flow control means operable for retaining a body of said charged phase mixture in the vessel and for discharging substantially dispersed-phase-free continuous liquid phase from the separator, continuously or periodically;
• said separator further comprising collector means for dispersed phase comprising at least one collector element of porous material disposed within said vessel with a surface region thereof exposed to the migrating disposed phase droplets, said porous material having sufficient porosity as to absorb dispersed liquid phase into its pores and thereby trap dispersed phase at separate sites on said surface region for promoting droplet coalescence and growth with further droplets undergoing electrically-driven migration to those sites, thereby leaving a quantity of substantially dispersed-phase-free continuous liquid phase for discharge from said separator by said flow control means.