US 12,288,681 B2 · Method of using refractory metal arc electrodes in sulfur-containing plasma gases and sulfur arc lamp based on same

Abstract

Sulfur arc lamp includes an arc chamber that has a cathode and an anode both made of refractory metals that include pure tungsten, pure molybdenum, tungsten alloy, molybdenum alloy or a composite in which tungsten is at least 90%, or a composite in which molybdenum is at least 90%; a plasma initiation gas filling the plasma chamber; power supply configured to switch on and off electric arc discharge between the cathode and anode; second chamber connected to the arc chamber for releasing sulfur vapor into the plasma arc chamber, thereby creating a sulfur-containing plasma gas when the discharge occurs, and configured to selectively remove the sulfur vapor from the sulfur-containing plasma gas when the discharge occurs, wherein the second chamber is configured to reduce a concentration of the sulfur vapor in the arc chamber below 1013 molecules per cm3 before the electric arc discharge is off.

Claims18

Dependent claims

A method of using refractory metal arc electrodes in a sulfur-containing plasma gas, the method comprising:

igniting an electric arc between an anode and a refractory metal cathode, in the sulfur-containing plasma gas, wherein the refractory metal includes pure tungsten, or pure molybdenum, or pure tantalum, or pure niobium, or a tungsten alloy, or a molybdenum alloy, or tantalum alloy, or niobium alloy, or a composite in which tungsten is at least 90%, or a composite in which molybdenum is at least 90%, or a composite in which niobium is at least 90%, or a composite in which tantalum is at least 90%,
and wherein the anode is made from stainless steel, or hydrogen sulfide corrosion resistant alloys, or hydrogen sulfide resistant conductive ceramics, or a refractory metal;
maintaining the electric arc for at least one second;
prior to switching the electric arc off, removing the sulfur from the plasma gas;
and
switching off the electric arc in a sulfur-free plasma gas.

3 more elements

A sulfur arc lamp, comprising:

a plasma arc chamber that has a cathode and an anode;
wherein the cathode is made from refractory metals;
and wherein the anode is made from stainless steel, or hydrogen sulfide corrosion resistant alloys, or hydrogen sulfide resistant conductive ceramics, or a refractory metal;
a plasma initiation hydrogen-containing gas filling the plasma chamber, wherein a concentration of hydrogen molecules in the arc chamber is NH2;
a power supply configured to switch on and off electric arc discharge between the cathode and anode;
and
a second chamber connected to the plasma arc chamber and configured to release sulfur vapor into the plasma arc chamber, thereby creating a sulfur-containing plasma gas when the electric arc discharge occurs, and configured to selectively remove the sulfur vapor from the sulfur-containing plasma gas when the electric arc discharge occurs,
wherein the second chamber is configured to reduce a concentration of molecules of the sulfur vapor in the plasma arc chamber below Ns before the power supply switches off the electric arc discharge, wherein NH2/Ns is more than 30.

5 more elements

Dependencies are inferred from the claim text.

Method of using refractory metal arc electrodes in sulfur-containing plasma gases and sulfur arc lamp based on same

Life of this patent

Method of using refractory metal arc electrodes in sulfur-containing plasma gases and sulfur arc lamp based on same

Life of this patent

Abstract

Claims18