# US 2008/0185366 A1 · Plasma spraying device and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0185366 A1 - Document ID: US20080185366A1 - Status: Published application - Kind: A1 - Application number: 11/701,911 - Filed: 2007-02-02 - Published: 2008-08-07 - Earliest claimed: 2007-02-02 - Assignees: Plasma Surgical Investments Limited - Inventors: Nikolay Suslov - Web page: https://patentgrep.com/patent/US20080185366A1 ## CPC - H05H 1/34: Details, e.g. electrodes, nozzles - C23C 4/134: Plasma spraying - H05H 1/3452: {Supplementary electrodes between cathode and anode, e.g. cascade} - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - H05H: PLASMA TECHNIQUE (apparatus or processes specially adapted for producing X-rays H05G2/00); PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A device and a method for plasma spraying are disclosed. The device comprises, a cathode, an anode, a plasma channel formed by the anode and intermediate electrodes, and one or more flowable material injectors. The plasma channel has a throttling portion that divides the plasma channel into a high pressure portion near the cathode formed by at least one intermediate electrode and a low pressure portion near the anode. During operation, a plasma generating gas is heated by the arc maintained between the cathode and the anode, forming plasma. When the plasma passes through the throttling portion, its speed increases to a supersonic speed, and at the same time its static pressure drops. Flowable materials are injected in the plasma flow in the low pressure portion. The particles in the flowable materials are heated by the plasma and the resultant heated particles and plasma are output from the outlet of the plasma channel. ## Claims ### Claim 1 A plasma generating device comprising: a. an anode; b. a cathode; c. a plasma channel, extending longitudinally between said cathode and through said anode, and having an outlet opening at the anode end, a part of the plasma channel being formed by two or more intermediate electrodes electrically insulated from each other and said anode; the plasma channel having a throttling portion, the throttling portion dividing the plasma channel into i. a high pressure portion positioned on the side of the throttling portion closest to the cathode, the high pressure portion being formed by at least one of the intermediate electrodes, ii. a low pressure portion positioned on the side of the throttling portion closest to the anode, a throat of the throttling portion having a cross sectional area transversely to the longitudinal direction of the plasma channel smaller than (1) the minimum cross sectional area of the high pressure portion transversely to the longitudinal direction of the plasma channel and (2) the minimum cross sectional area of the low pressure portion transversely to the longitudinal direction of the plasma channel; d. one or more flowable material injectors, each comprising: i. a flowable material chamber having an inlet; and ii. a flowable material feeder connecting the flowable material chamber to the plasma channel in the low pressure portion of the plasma channel. ### Claim 2 (depends on 1) The plasma generating device of claim 1, wherein the high pressure portion is formed by two or more intermediate electrodes. ### Claim 3 (depends on 1) The plasma generating device of claim 1, wherein the low pressure portion is formed by one or more intermediate electrodes. ### Claim 4 (depends on 2) The plasma generating device of claim 2, wherein the low pressure portion is formed by two or more intermediate electrodes. ### Claim 5 (depends on 3) The plasma generating device of claim 3, wherein the throttling portion is a supersonic nozzle. ### Claim 6 (depends on 3) The plasma generating device of claim 3, wherein the minimum cross sectional area of the high pressure portion transversely to the longitudinal direction of the plasma channel is smaller than or equal to the minimum cross sectional area of the low pressure portion transversely to the longitudinal direction of the plasma channel. ### Claim 7 (depends on 3) The plasma generating device of claim 3, wherein the throttling portion is formed by an intermediate electrode. ### Claim 8 (depends on 7) The plasma generating device of claim 7 further comprising means for cooling the anode. ### Claim 9 (depends on 8) The plasma generating device of claim 8 further comprising means for cooling the intermediate electrode forming the throttling portion separate from the means for cooling the anode. ### Claim 10 (depends on 3) The plasma generating device of claim 3, wherein each of the flowable material feeders has one of the following orientations: (a) perpendicular to the longitudinal direction of the plasma channel, (b) angled toward the anode, and (c) angled away from the anode. ### Claim 11 (depends on 3) The plasma generating device of claim 3, wherein a portion of the plasma channel between any pair of adjacent feeders is formed by two or more intermediate electrodes. ### Claim 12 A method of plasma-spraying one or more flowable materials comprising: e. creating a plasma flow; f. heating the plasma in the flow to at least 10,000° K.; g. after heating the plasma, increasing the velocity pressure of the heated plasma in the flow while concurrently decreasing the static pressure of the heated plasma in the flow; h. injecting one or more flowable materials into the flow of plasma after decreasing the static pressure of the heated plasma in the flow; i. after each flowable material is injected, heating the particles of all flowable materials in the flow by heating the plasma in the flow; and j. outputting the resultant heated particles and plasma. ### Claim 13 (depends on 12) The method of claim 12, further comprising increasing the speed of the plasma in the flow concurrently with the increasing the velocity pressure. ### Claim 14 (depends on 13) The method of claim 13, wherein the speed to which the plasma in the flow increased is supersonic. ### Claim 15 (depends on 12) The method of claim 12, wherein the step of heating the particles is performed until at least until some particles of at least one flowable material reach a predetermined temperature. ### Claim 16 (depends on 12) The method of claim 12, wherein the quantity of at least one flowable material that is injected is varied over time. ### Claim 17 (depends on 12) The method of claim 12, wherein at least one of the flowable materials is a nanoparticle precursor solution. ### Claim 18 (depends on 12) The method of claim 12, wherein at least one of the flowable materials is a mixture of hydrogen and a hydrocarbon. ### Claim 19 (depends on 12) The method of claim 12, wherein at least one of the flowable materials is one of: (a) waste and (b) hazardous material. ### Claim 20 (depends on 19) The method of claim 19 further comprising, for at least one flowable material, decomposing the flowable material into two or more elements comprising carbon.