US4121082A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for shielding the effluent from plasma spray gun assemblies
Assignee: Oerlikon Metco US Inc
•
Filing: 1977-04-27
•
Granted: 1978-10-17
•
Expires: 1997-04-27
Abstract
Abstract Method and apparatus for plasma flame-spraying coating material onto a substrate by means of passing a plasma-forming gas through a nozzle electrode, passing an arc-forming current between said nozzle electrode and a rear electrode to form a plasma effluent, introducing spray coating material into the plasma effluent, passing the plasma effluent axially through a wall shroud extending from the exit of said nozzle electrode and forming a hot gas shroud for the plasma effluent at least within the wall shroud.
Inventors
- 👤 John H. Harrington
- 👤 Richard T. Smyth
- 👤 John D. Weir
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 02:01
CPC Classifications
H; H05; H05H; H05H1/00; H05H1/24; H05H1/26; H05H1/32; H05H1/42; B; B05; B05B; B05B7/00; B05B7/16; B05B7/22; B05B7/222; B05B7/226; C; C23; C23C; C23C4/00; C23C4/12; C23C4/134; H05H1/28; H05H1/34; H05H1/341; H05H1/3457
Claims Analysis
Total Claims: 53
Claim 1
Independent Claim
88 words
A plasma spray gun assembly for coating substrates comprising, in combination: a nozzle electrode having a nozzle passage therethrough; a rear electrode; means for passing plasma-forming gas through the nozzle electrode; means for passing an arc-forming current between said electrodes to form a plasma effluent; means for introducing spray coating material into the plasma effluent; a wall shroud for said plasma effluent extending from the exit of the nozzle electrode; and means for forming a hot gas shroud for said plasma effluent at least within the wall shroud.
Claim 2
Dependent Claim
88 words
A plasma spray gun assembly for coating substrates comprising, in combination: a nozzle electrode having a nozzle passage therethrough; a rear electrode; means for passing plasma-forming gas through the nozzle electrode; means for passing an arc-forming current between said electrodes to form a plasma effluent; means for introducing spray coating material into the plasma effluent; a wall shroud for said plasma effluent extending from the exit of the nozzle electrode; and means for forming a hot gas shroud for said plasma effluent at least within the wall shroud.
Claim 3
Dependent Claim
21 words
A plasma spray gun assembly according to claim 1 wherein said spray coating material is in the form of a powder.
Claim 4
Dependent Claim
55 words
A plasma spray gun assembly according to claim 1 wherein said means for forming a hot gas shroud for said plasma effluent at least within the wall shroud comprises means for directing said hot gas shroud at an angle of between about 160° to about 180° with respect to the axis of the plasma effluent.
Claim 5
Dependent Claim
51 words
A plasma spray gun assembly according to claim 1 wherein said means for forming a hot gas shroud for said plasma effluent at least within the wall shroud comprises means for directing said hot gas shroud at an angle of about 180° with respect to the axis of the plasma effluent.
Claim 6
Dependent Claim
53 words
A plasma spray gun assembly according to claim 4 wherein said means for forming a hot gas shroud for said plasma effluent at least within the wall shroud includes an annular plenum chamber having jet orifice means directed at an angle of about 180° with respect to the axis of the plasma effluent.
Claim 7
Dependent Claim
18 words
A plasma spray gun assembly according to claim 1 further comprising means for water cooling said wall shroud.
Claim 8
Dependent Claim
17 words
A plasma spray gun assembly according to claim 1 wherein said wall shroud is of cylindrical configuration.
Claim 9
Dependent Claim
30 words
A plasma spray gun assembly according to claim 1 wherein said means for introducing spray coating material into the plasma effluent is disposed adjacent the exit of the electrode nozzle.
Claim 10
Dependent Claim
41 words
A plasma spray gun assembly according to claim 1 wherein said means for forming a hot gas shroud for said plasma effluent at least within the wall shroud includes an electric heater for preheating the gas for said hot gas shroud.
Claim 11
Dependent Claim
44 words
A plasma spray gun assembly according to claim 1 wherein said means for forming a hot gas shroud for said plasma effluent at least within the wall shroud includes a second plasma flame gun assembly for preheating the gas for said hot gas shroud.
Claim 12
Dependent Claim
49 words
A plasma spray gun assembly according to claim 1 wherein said means for forming a hot gas shroud for said plasma effluent at least within the wall shroud includes an internal passageway of generally serpentine configuration in said wall shroud for preheating the gas for said hot gas shroud.
Claim 13
Dependent Claim
51 words
A plasma spray gun assembly according to claim 1 wherein said means for forming a hot gas shroud for said plasma effluent at least within the wall shroud includes means for preheating the gas for said hot gas shroud to a temperature of from about 500° C. to about 1000° C.
Claim 14
Dependent Claim
66 words
A plasma spray gun assembly according to claim 1 wherein said means for forming a hot gas shroud for said plasma effluent at least within the wall shroud includes means for introducing hot gas at a flow rate of between about 1000 cubic feet per hour and about 2000 cubic feet per hour at a temperature of about 500° C. to form said hot gas shroud.
Claim 15
Dependent Claim
20 words
A plasma spray gun assembly according to claim 1 wherein said hot gas shroud is formed of an inert gas.
Claim 16
Dependent Claim
24 words
A plasma spray gun assembly according to claim 14 wherein said inert gas is selected from the class consisting of nitrogen, argon and helium.
Claim 17
Dependent Claim
19 words
A plasma spray gun assembly according to claim 15 wherein said hot gas shroud further comprises a combustible gas.
Claim 18
Dependent Claim
33 words
A plasma spray gun assembly according to claim 1 further comprising means for forming an annular curtain effect around the plasma effluent as it leaves the wall shroud and passes towards the substrate.
Claim 19
Dependent Claim
34 words
A plasma spray gun assembly according to claim 17 wherein said means for forming an annular curtain effect includes an annular manifold and orifice means mounted adjacent the outer end of said wall shroud.
Claim 20
Dependent Claim
52 words
A plasma spray gun assembly according to claim 1 wherein said means for forming a hot gas shroud for said plasma effluent at least within the wall shroud comprises means for directing said hot gas at an angle having a component extending parallel to the direction of flow of said plasma effluent.
Claim 21
Dependent Claim
55 words
A plasma spray gun assembly according to claim 1 wherein said means for forming a hot gas shroud for said plasma effluent at least within the wall shroud comprises means for directing said hot gas at an angle having a component extending in a direction opposite to the direction of flow of said plasma effluent.
Claim 22
Dependent Claim
36 words
A plasma spray gun assembly according to claim 5 further comprising second jet orifice means directed at an angle of from about zero degrees to about 180° with respect to the axis of the plasma effluent.
Claim 23
Dependent Claim
33 words
A plasma spray gun assembly according to claim 5 further comprising second jet orifice means directed at an angle having a component extending parallel to the direction of flow of said plasma effluent.
Claim 24
Dependent Claim
36 words
A plasma spray gun assembly according to claim 5 further comprising second jet orifice means directed at an angle having a component extending in a direction opposite to the direction of flow of said plasma effluent.
Claim 25
Dependent Claim
25 words
A plasma spray gun assembly according to claim 1 wherein said wall shroud has a radially-inwardly directed lip portion disposed towards the exit end thereof.
Claim 26
Dependent Claim
80 words
A process for plasma flame-spraying coating material onto a substrate, which comprises the steps of: passing a plasma-forming gas through a nozzle electrode; passing an arc-forming current between said nozzle electrode and a rear electrode to form a plasma effluent; introducing coating material into the plasma effluent; passing the plasma effluent longitudinally through a wall shroud extending from the exit of said nozzle electrode; and forming a hot gas shroud for said plasma effluent at least within the wall shroud.
Claim 27
Dependent Claim
80 words
A process for plasma flame-spraying coating material onto a substrate, which comprises the steps of: passing a plasma-forming gas through a nozzle electrode; passing an arc-forming current between said nozzle electrode and a rear electrode to form a plasma effluent; introducing coating material into the plasma effluent; passing the plasma effluent longitudinally through a wall shroud extending from the exit of said nozzle electrode; and forming a hot gas shroud for said plasma effluent at least within the wall shroud.
Claim 28
Dependent Claim
23 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein said coating material is in a powder form.
Claim 29
Dependent Claim
40 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein said hot gas shroud is directed at an angle of between about 160° to about 180° with respect to the axis of the plasma effluent.
Claim 30
Dependent Claim
36 words
A process for plasma flame-spraying coating material onto a substrate according to claim 27 wherein said hot gas shroud is directed at an angle of about 180° with respect to the axis of the plasma flame.
Claim 31
Dependent Claim
26 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 further comprising the step of passing cooling water through said wall shroud.
Claim 32
Dependent Claim
31 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein said coating material is introduced into the plasma effluent adjacent the exit of the electrode nozzle.
Claim 33
Dependent Claim
50 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein said step of forming a hot gas shroud for said plasma effluent at least within the wall shroud includes the step of passing the gas for forming said hot gas shroud through an electric preheater.
Claim 34
Dependent Claim
53 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein said step of forming a hot gas shroud for said plasma effluent at least within the wall shroud includes the step of using a second plasma flame gun assembly for preheating the gas for said hot gas shroud.
Claim 35
Dependent Claim
57 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein said step of forming a hot gas shroud for said plasma effluent at least within the wall shroud includes the step of passing the gas for said hot gas shroud through an internal passageway of generally serpentine configuration in said wall shroud.
Claim 36
Dependent Claim
51 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein said step of forming a hot gas shroud for said plasma effluent at least within the wall shroud includes the step of preheating the gas for said gas shroud to a temperature above about 300° C.
Claim 37
Dependent Claim
56 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein said step of forming a hot gas shroud for said plasma effluent at least within the wall shroud includes the step of preheating the gas for said gas shroud to a temperature of between about 500° C. and about 1000° C.
Claim 38
Dependent Claim
26 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein the gas for said hot gas shroud is a reducing gas.
Claim 39
Dependent Claim
27 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein the gas in said hot gas shroud is in a turbulent state.
Claim 40
Dependent Claim
26 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein the gas for said hot gas shroud is an inert gas.
Claim 41
Dependent Claim
29 words
A process for plasma flame-spraying coating material onto a substrate according to claim 38 wherein said inert gas is selected from the group consisting of nitrogen, argon and helium.
Claim 42
Dependent Claim
27 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein the gas for forming said hot gas shroud includes a combustible gas.
Claim 43
Dependent Claim
34 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein the flow rate of said gas in said hot gas shroud is above about 500 cubic feet per hour.
Claim 44
Dependent Claim
49 words
A process for plasma flame-spraying coating material onto a substrate according to claim 41 wherein the flow rate of the gas for forming said hot gas shroud is between about 1000 cubic feet per hour and about 2000 cubic feet per hour at a temperature of about 500° C.
Claim 45
Dependent Claim
23 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein said coating material is a fusible powdered metal.
Claim 46
Dependent Claim
22 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein said coating material is a ceramic material.
Claim 47
Dependent Claim
21 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein said coating material is a carbide.
Claim 48
Dependent Claim
38 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 further comprising the step of forming a fluid annular curtain around the plasma effluent as it leaves the wall shroud passing towards said substrate.
Claim 49
Dependent Claim
38 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein said hot gas shroud is directed at an angle having a component extending parallel to the direction of flow of said plasma effluent.
Claim 50
Dependent Claim
41 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein said hot gas shroud is directed at an angle having a component extending in a direction opposite to the direction of flow of said plasma effluent.
Claim 51
Dependent Claim
78 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein a portion of the gas for forming said hot gas shroud is introduced at an angle of about 180° with respect to the axis of the plasma effluent and a second portion of the gas for forming said hot gas shroud is introduced at an angle of from about zero degrees to about 180° with respect to the axis of the plasma effluent.
Claim 52
Dependent Claim
75 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein a portion of the gas for forming said hot gas shroud is introduced at an angle of about 180° with respect to the axis of the plasma effluent and a second portion of the gas for forming said hot gas shroud is introduced at an angle having a component extending parallel to the direction of flow of said plasma effluent.
Claim 53
Dependent Claim
78 words
A process for plasma flame-spraying coating material onto a substrate according to claim 25 wherein a portion of the gas for forming said hot gas shroud is introduced at an angle of about 180° with respect to the axis of the plasma effluent and a second portion of the gas for forming said hot gas shroud is introduced at an angle having a component extending in a direction opposite to the direction of flow of said plasma effluent.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-10-16 | 1982-04-17 | 1982-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-16 | 1986-04-17 | 1986-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-16 | 1990-04-17 | 1990-10-17 | $7700.00 | Window Closed / Lapsed |