Tubular high-density plasma reactor, with outer treatment chamber and collinear rotatable inner cylinder
An apparatus and method for simultaneously removing materials from fluids without the need for added chemicals, and without the formation of toxic byproducts, by high-density plasma reaction chemistry is described. Applications to removal of contaminants, such as pesticides, organics, PPCPs, and pathogens, as examples, from water are discussed. Changes in the quality of the raw water are not expected to adversely affect the decontamination process.
1. An apparatus for removing materials from a fluid, comprising in combination:
a chamber for containing the fluid having an electrically conducting cylindrical wall having an axis, an inlet for introducing the fluid at one end thereof arranged such that the fluid flows axially in the cylindrical portion of the chamber, and an outlet for discharging the fluid at an opposing end thereof;
an elongated hollow, electrically conducting shaft rotatably disposed collinearly with the axis of the cylindrical portion of the chamber and having an open end and a closed end, the closed end thereof facing the end of the chamber having the inlet for the fluid;
at least one electrically conducting pin electrode having a bore therethrough, a first end and a second end, and having a frit, effective for generating bubbles in the fluid at the surface of the pin electrode from which a plasma discharge is generated, disposed in the bore in the vicinity of the first end thereof, the second end being mounted through the surface of the shaft such that the bore of the at least one pin electrode is in gaseous communication with the interior of the hollow shaft;
an electrically insulating cylinder having an axis collinear with the axis of the chamber disposed within the chamber, the cylinder having a surface through which a portion of the at least one pin electrode extends, the electrically insulating cylinder rotating with the shaft;
a motor for rotating the shaft;
a gas source for introducing a chosen gas into the open end of the shaft at a pressure such that gas bubbles exit through the frit of the at least one pin electrode and rise in a counter-current manner to the flow of the fluid; and
an electrical power supply for applying a voltage to the shaft effective for initiating and maintaining the plasma discharge between the first end of the pin electrode and the interior of the conducting cylindrical portion of the chamber.
2. The apparatus for removing materials from a fluid of claim 1 , wherein a portion of the surface of each of said at least one pin electrodes in the vicinity of the first end thereof is coated with a diamond film.
3. The apparatus for removing materials from a fluid of claim 2 , wherein said diamond film comprises a boron-doped diamond film.