Separation of dispersed phase from phase mixture

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

• (a) 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 by charge motion relative to the continuous liquid phase;
• (b) passing the charged phase mixture into a dispersed phase collection region in which charged phase mixture and a dispersed phase collector surface are brought into contact with one another, the charged phase mixture, before entering said collection region, being directed as a stream through a gas or vapor space for minimizing charge dissipation from the charged phase mixture in said collection region 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 collection region, 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
• (c) allowing the migrating dispersed phase to accumulate within said dispersed phase collection region adjacent to said collector surface.

A method of separating a dispersed 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:

• (a) 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 continuous phase to act as a medium through which volumetric distribution of the injected charge occurs by charge motion relative to the continuous liquid phase;
• (b) causing the charged stream to enter into a separation vessel through a gas or vapor space for minimising charge dissipation from the charged phase mixture in the separation vessel back to where the free charge introduction took place, there being an 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
• (c) maintaining the liquid mixture in the vessel for sufficient time for dispersed phase to migrate to the internal wall surfaces of said separation vessel and accumulate in contact with those wall surfaces.

Apparatus for use in the separation of a dispersed 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:

• (a) 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 by charge motion relative to the continuous liquid phase;
• (b) a dispersed phase separator comprising:
• (i) a collector surface for dispersed phase;
• and
• (ii) means defining a dispersed phase collection region in which, in use of said apparatus, phase mixture, charged by the free charge introducing means, and said collector surface are brought into contact with one another;
• and
• (c) a gas or vapor space which separates the dispersed phase collection region 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 collection region, for minimising charge dissipation from the charged phase mixture in said collection region 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 collection region, 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 accumulate within said dispersed phase collection region adjacent said collector surface.

Apparatus for use in separating a dispersed 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 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 electrode, 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 by charge motion relative to the continuous liquid phase;
• 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 an 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 electric driving force acting on the dispersed phase so that said migration is due substantially to said driving force, and means operable or operative to maintain the liquid mixture in the vessel for sufficient time for dispersed phase to migrate to the internal wall surfaces of said separation vessel and accumulate in contact with those wall surfaces.