Glow discharge cell and related glow discharge assembly
View Patent ↗The invention relates to a glow discharge cell including a gas evacuation chamber and a gas outlet port integrated in a first bent tube, the branches of which are perpendicular and with different diameters; a gas inlet port formed by a second straight tube along which a plasma is formed and which is partially inserted into the first branch of the first tube; and a primary electrode encapsulated in the first branch of the first tube and facing the second glass tube and being partially inserted therein.
1. A glow discharge cell, comprising:
a gas inlet port, intended to allow a gas flow to access;
a plasma formation chamber integrated in the gas inlet port;
a primary electrode, in contact with the plasma formation chamber;
a gas evacuation chamber, intended to allow the relaxation of species formed in the gas and/or the neutralization of free radicals; and
a gas outlet port, which is attached to the evacuation chamber and is intended to lead the gas flow out of the glow discharge cell;
wherein:
the gas outlet port and the gas evacuation chamber are formed by a first glass tube, bent in shape, the plasma formation chamber being provided in a first branch of the first glass tube and the gas outlet port being provided in a second branch of the first glass tube, the second branch being smaller in diameter than the first branch and perpendicular thereto;
the gas inlet port and the plasma formation chamber are formed by a second glass tube, straight and arranged parallel to the first branch of the first glass tube and being partially inserted into said first branch, so that the second glass tube is in contact with the inside of the gas evacuation chamber; and
the primary electrode is encapsulated in a wall of the first branch of the first glass tube, said primary electrode further being arranged facing the second glass tube and being partially inserted therein.
2. The glow discharge cell according to claim 1 , wherein an end of the primary electrode that is farthest from the plasma formation chamber is provided with a safe high-voltage connector that can be connected to a cable with a Bayonet Neill-Concelman ending (SHV-BNC).
3. The glow discharge cell according to claim 1 , wherein the primary electrode is connected to a pin of a safe high-voltage Bayonet Neill-Concelman Jack connector, with the interposition of a silver, platinum or metal alloy filament with an electrical conductivity of the same order of magnitude.
4. The glow discharge cell according to claim 1 , wherein the wall width of the first branch of the first glass tube and the wall width of the second branch of the first glass tube are different from each other.
5. The glow discharge cell according to claim 1 , wherein the second glass tube has the same diameter as the second branch of the first glass tube.
6. The glow discharge cell according to claim 1 , wherein the first branch of the first glass tube is provided with a narrowing at an end closest to the wall encapsulating the primary electrode.
7. A glow discharge assembly comprising at least the following elements:
a glow discharge cell, according to claim 1 ;
a gas source, in communication with the gas inlet port of the glow discharge cell;
a secondary electrode arranged coaxially with respect to the gas inlet port of the glow discharge cell and in contact with the plasma formation chamber; and
a voltage source, connected to the primary electrode and the secondary electrode.
8. The glow discharge assembly according to claim 7 , wherein the secondary electrode is a hollow metal rod, said hollow metal rod being arranged on insulating centring rings, provided inside the gas inlet port of the glow discharge cell.
9. The glow discharge assembly according to claim 7 , wherein an end of the secondary electrode farthest from the plasma formation chamber is connected to one end of a T-shaped conduit having three ends, and at least one remaining end of the T-shaped conduit in turn is connected to a gas source.
10. The glow discharge assembly according to claim 9 , wherein:
the secondary electrode is connected to a first end of the T-shaped conduit;
the second end of the T-shaped conduit is facing the secondary electrode and is provided either with a plug or with a hollow element; and
the third end of the T-shaped conduit is perpendicular to the secondary electrode and is connected to a gas source provided with a flow regulator.
11. A sterilization system comprising a glow discharge assembly provided with at least:
a glow discharge cell, according to claim 1 ;
a gas source, in communication with the gas inlet port of the glow discharge cell;
a secondary electrode arranged coaxially with respect to the gas inlet port of the glow discharge cell and in contact with the plasma formation chamber; and
a voltage source, connected to the primary electrode and the secondary electrode;
wherein said system is configured such that the gas flow from the gas source is mixed with a stream of polluting particles, before accessing the plasma formation chamber of the glow discharge cell.
12. The sterilization system according to claim 11 , wherein the secondary electrode is a copper, copper alloy, silver, silver alloy or metal alloy electrode with an electrical conductivity of the same order of magnitude.
13. A reactor system comprising a glow discharge assembly provided with at least:
a glow discharge cell, according to claim 1 ;
a gas source, in communication with the gas inlet port of the glow discharge cell;
a secondary electrode arranged coaxially with respect to the gas inlet port of the glow discharge cell and in contact with the plasma formation chamber; and
a voltage source, connected to the primary electrode and the secondary electrode;
wherein said system is configured such that the gas flow from the gas source is mixed with reactive particles, before accessing the plasma formation chamber of the glow discharge cell.
14. The reactor system according to claim 13 , wherein the reactive particles are arranged on the secondary electrode, said secondary electrode being a hollow metal rod placed on centring rings made of insulating material and provided inside the gas inlet port of the glow discharge cell.
15. A detector system comprising a glow discharge assembly provided with at least:
a glow discharge cell, according to claim 1 ;
a gas source, in communication with the gas inlet port of the glow discharge cell;
a secondary electrode arranged coaxially with respect to the gas inlet port of the glow discharge cell and in contact with the plasma formation chamber; and
a voltage source, connected to the primary electrode and the secondary electrode;
being further provided with a detection unit, configured to detect at least one region of the spectrum of the radiation emitted by the plasma produced in the plasma foundation chamber.