US2774625A - Apparatus utilizing detonation waves for spraying powders - Google Patents
Apparatus utilizing detonation waves for spraying powders Download PDFInfo
- Publication number
- US2774625A US2774625A US463643A US46364354A US2774625A US 2774625 A US2774625 A US 2774625A US 463643 A US463643 A US 463643A US 46364354 A US46364354 A US 46364354A US 2774625 A US2774625 A US 2774625A
- Authority
- US
- United States
- Prior art keywords
- powder
- barrel
- detonation
- gun
- tube
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000000843 powder Substances 0.000 title description 63
- 238000005474 detonation Methods 0.000 title description 45
- 238000005507 spraying Methods 0.000 title description 4
- 239000000203 mixture Substances 0.000 description 14
- 239000007789 gas Substances 0.000 description 12
- 238000000576 coating method Methods 0.000 description 11
- 239000012530 fluid Substances 0.000 description 11
- 238000002156 mixing Methods 0.000 description 10
- 239000011248 coating agent Substances 0.000 description 9
- 239000012809 cooling fluid Substances 0.000 description 9
- 239000000446 fuel Substances 0.000 description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 7
- 230000008021 deposition Effects 0.000 description 6
- 239000007800 oxidant agent Substances 0.000 description 6
- 230000001590 oxidative effect Effects 0.000 description 6
- 238000002485 combustion reaction Methods 0.000 description 5
- 238000004880 explosion Methods 0.000 description 4
- 238000001816 cooling Methods 0.000 description 3
- 239000000498 cooling water Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000010926 purge Methods 0.000 description 2
- 239000011343 solid material Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000000567 combustion gas Substances 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000009828 non-uniform distribution Methods 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 229940062042 oxygen 50 % Drugs 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
- B05B7/14—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas designed for spraying particulate materials
- B05B7/1404—Arrangements for supplying particulate material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
- B05B7/0006—Spraying by means of explosions
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24C—ABRASIVE OR RELATED BLASTING WITH PARTICULATE MATERIAL
- B24C5/00—Devices or accessories for generating abrasive blasts
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- 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
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- 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
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
- C23C4/126—Detonation spraying
Definitions
- the present invention relates to improved apparatus utilizing detonation waves for spraying powders to coat surfaces and the like.
- detonation is meant a very rapid combustion in which the flame front moves at velocities higher than the velocity of sound in the unburned gases, and therefore characterized as supersonic velocities.
- Typical calculated velocities of sound at normal pressure are 1085 feet per second at 18 C. in a 50% oxygen-50% acetylene mixture, 1384 in the same mixture at 200 C. and 1122 at 18 C. in a 9.5% acetylene-90.5% air mixture; in air at 18 C.
- the sonic velocity is calculated as 1122 feet per second.
- the rate of flame propagation is far greater in a detonation than in an explosion, which is a combustion in which the velocity of flame propagation does not exceed the velocity of sound in the unburned gases.
- the velocity of the flame front in detonations thus far investigated is f-rom l to 4 kilometers per second (about 3,280 to 13,120 feet per second), as compared to, for instance, 50 feet per second for a typical explosion.
- the flame of a detonation moves into the unburned gas with a velocity which is supersonic instead of subsonic, and it is initiated by and remains associated with a shock front. Once established in a long tube, the detonation wave travels at a constant velocity (Lewis and Von Elbe, Combustion, Flames and Explosions, Academic Press Inc., 1951).
- 2,714,563 is termed a detonation gun and comprises an elongated barrel having an open end, means for introducing a detonatable body of detonatable fluid into said barrel, means for providing powder material in said detonatable body of detonatable fluid in said barrel, means for controlling the supply of fluid fuel and V 2,774,625 Patented Dec. 18, 1956 simultaneously open to admit combustible gas and oxidant (with or without the powder) to the elongated barrel of the gun,
- a third poppet valve opens to admit an inert nitrogen gas stream which flows across the combustion gas and oxidant valves to dilute any leaks from such valves which might cause flashback upon detonation of the mixture,
- This timed sequence of valve operation and spark plug firing is accomplished by driving the valves and spark energization circuit from a common cam shaft.
- the frequency of the detonations is a factor in attaining effective operation of the detonation gun.
- the most useful frequency depends on the particular use of the gun, the design of the gun, and the character of the detonating gas mixture.
- a single detonation suflices when a thin deposit on a small area is desired, for example a tungsten carbide coating 0.0005 inch thick on a steel surface one inch or less in diameter. For making thicker coatings, and coating larger areas quickly severaldetonations per second are usually desirable.
- the primary difliculty encountered in introducing powders into the barrel of the detonation gun in this manner is that excessive powder deposition occurs in the bore of the powder entry tube in the region where it joins the barrel of the detonation gun. Such powder deposition is to be avoided since it reduces the supply of powder to the barrel of the detonation gun. Additionally, these deposits periodically flake off and pass through the barrel of the detonation gun to the workpiece, thereby causing defects in the resultant coating.
- Another object is to provide such apparatus wherein the buildup of powder on the internal walls of the barrel is redistributed to a more uniform and less harmful pattern.
- Fig. l is a schematic view of a detonation gun for coating with powders employing the improved powder entry means of the invention, portions having been broken away to show internal construction;
- Fig. 2 is an enlarged view of the back portion of the powder entry means of the detonation gun of Fig 1 down to a transverse break line a-a, parts having been broken away to show internal construction;
- Fig. 2a is the forward portion of the powder entry means extending from the transverse break line aa.
- detonation gun D comprising an elongated barrel 10 having an open end 12 from which the products of the detonation and powders pass to the object to be coated.
- Cooling water circulating jacket 14 is provided around barrel 10 to prevent overheating. Cooling water is supplied to the annular space 16 between jacket 14 and barrel 10 through inlet means 18, and water passes from annular space 16 through outlet means 20.
- Fuel and oxidant are supplied to port means 22 and 24, respectively, of mixing block 26 which is provided with poppet valves 28 for regulating the flow of such fluids at timed intervals. Mixing of the fuel and oxidant takes place in mixing chamber 30 of mixing block 26 and the detonatable mixture is passed to barrel 10 of detonation gun D. .Mixing block 26 is also provided with purging gas inlet port means 36 and poppet valve means 38 for purging mixing chamber 30 and barrel 10 of gases in the intervals between each successive detonation and the introduction of the following detonatable charge into elongated barrel 10 of the detonation gun.
- Means is provided in the walls of mixing chamber 36 for insertion of ignition means 42, such as a spark plug or the like, into the mixing chamber; and energizing lines 44 are also provided.
- Powder entry tube assembly 46 passes through the rear or breech end 48 of cooling water jacket 14 and the elongated barrel 10 and passes axially through the barrel to a point downstream of the zone (in the region of ignition means 42) where ignition and the initiation of the detonation phenomenon occurs.
- the powder entry tube assembly 46 preferably comprises powder entry tube 50, two concentric cooling fluid sleeves 52 and 54 surrounding entry tube 50 over at least that portion of entry tube 50 which is positioned in the interior of barrel 10, cooling fluid inlet and outlet parts 56 and 58, respectively, and guide bracket means 60 for properly supporting entry tube '0 to prevent bending or breakage.
- a suitable powder dispenser 61 is employed for suspending the material to be coated in a gas stream in which it is carried into the barrel of the detonation gun. It has been found that the length of line 62 between the powder dispenser and the discharge end of the powder entry tube 54 should be sufiiciently great to prevent the back surging of gases resulting from the detonation in the gun barrel and consequent disruption of the supply of powder to the gun barrel. For example, in order to maintain continuous non-erractic operation, the minimum length required for a powder tube of /s inch inside diameter is 8 feet 4 inches.
- Cooling fluid passes into powder tube assembly 46 through inlet 56 to an annular space 63 between inner cooling fluid sleeve 52 and powder entry tube 50 down the length of the powder tube and returns to outlet 58 through annular space 64 between inner cooling fluid sleeve 52 and outer cooling fluid sleeve 54.
- manper cooling fluid is continually circulated through and around the cooling passages over the entire length of that portion of the powder tube which is positioned in the internally hot region within the interior of barrel 10.
- the powder entry assembly 46 shown in Figs. 2 and 2a of the drawing is mounted in such a way as to provide for easy removal and replacement of powder entry tube 50 in the assembly.
- the procedure for removal and replacement is as follows: The entire assembly is first removed from the detonation gun by loosening coupling 66 at the breech end 48 of the gun. Upon removal of the assembly from the gun, the nose nut 68 is removed and retaining nuts 75 and 76 are loosened. Thereupon powder entry tube can be removed and a new tube 50 may be then inserted in the assembly by reversing these steps.
- axial powder entry tubes in accordance with the invention have an inherent life of about five hours total coating time at the end of which the abrasive action of the powder has severely damaged the tube to the extent that replacement is required. Accordingly, it is of great importance that a powder tube assembly is provided which permits rapid removal and replacement of such axial powder entry tubes in a minimum time.
- the diameter of the powder entry tube can be of any convenient size, the maximum value being determined by cooling fluid requirements (larger diameter tubes would require cooling jackets which would nearly fill the interior of the gun barrel) and the minimum diameter limitation is determined by the powder feed rate required for coating.
- an axial powder entry tube in accordance with the invention accomplishes the following: It completely stops powder deposition in the powder tube bore and the accompanying decrease or stoppage of powder supply to the gun barrel; it redistributes the buildup of powder deposit within the gun barrel to a more uniform and, therefore, less harmful pattern; it greatly decreases the number of porous powder agglomerates deposited on the surface to be coated, thereby reducing the number of defects in the coating; and it decreases the maintenance time required on the powder entry tube.
- Non-cooled powder entry tubes have been employed for limited times but in no instance was it possible to operate for longer than one minute periods without pro-ignition of the detonatable mixture and a consequent failure in obtaining the required detonation.
- a detonation gun having an elongated barrel having an open end, said barrel having a length-to-diameter ratio suflicariatly high to permit the formation of a detonation therein, mixing chamber means directly and continuously communicating with said barrel for forming and passing to said barrel charges of detonatable fluid fuel mixture, means for supplying the components of said detonatable fluid fuel mixture to said mixing chamber means, supply means associated with said barre-l for providing comminuted solid material in said detontable fluid fuel mixture, and means associated with said barrel for igniting said fluid fuel mixture in said barrel to initiate said detonation and propel said comminuted solid material from said gun, the improvement which comprises employing, as said supply means, powder entry tube means passing substantially axially through said elongated barrel to a point downstream of said igniting means for introducing a gas-borne stream of powder into said fluid fuel mixture in said barrel.
- Apparatus in accordance with claim 1 also containing means for circulating a cooling fluid through the interior of said elongated barrel of said gun and in heat exchange contact with said powder entry tu-be means.
Description
1956 e. P. HAWLEY ET AL 2,774,625
APPARATUS UTILIZING DETONATION WAVES FOR SPRAYING POWDERS Filed 001;. 21, I954 Unitcd States Patent APPARATUS UTILIZING DETONATION WAVES FOR SPRAYING POWDERS George P. Hawley and Edward T. Tune, Speedway, Ind.,
assignors to Union Carbide and Carbon Corporation,
The present invention relates to improved apparatus utilizing detonation waves for spraying powders to coat surfaces and the like. By the term detonation is meant a very rapid combustion in which the flame front moves at velocities higher than the velocity of sound in the unburned gases, and therefore characterized as supersonic velocities. (Typical calculated velocities of sound at normal pressure are 1085 feet per second at 18 C. in a 50% oxygen-50% acetylene mixture, 1384 in the same mixture at 200 C. and 1122 at 18 C. in a 9.5% acetylene-90.5% air mixture; in air at 18 C. the sonic velocity is calculated as 1122 feet per second.) The rate of flame propagation is far greater in a detonation than in an explosion, which is a combustion in which the velocity of flame propagation does not exceed the velocity of sound in the unburned gases. According to Wilhelm Josts Explosion and Combustion Processes in Gases, McGraw-Hill Book Co., Inc. New York (1946), pages 160 to 210 of which are devoted to detonations, the velocity of the flame front in detonations thus far investigated is f-rom l to 4 kilometers per second (about 3,280 to 13,120 feet per second), as compared to, for instance, 50 feet per second for a typical explosion.
The flame of a detonation moves into the unburned gas with a velocity which is supersonic instead of subsonic, and it is initiated by and remains associated with a shock front. Once established in a long tube, the detonation wave travels at a constant velocity (Lewis and Von Elbe, Combustion, Flames and Explosions, Academic Press Inc., 1951).
Heretofore, apparatus has been proposed for utilizing detonation waves and associated phenomena to impart energy to powders provided in a detonatable fluid body and propel said powders at high temperatures and velocities against the surface of a body to be coated. Such apparatus, as disclosed and claimed in application Serial No. 275,332, file-d March 7, 1952, by R. M. Poorman et al., issued on August 2, 1955, as U. S. Patent No. 2,714,563, is termed a detonation gun and comprises an elongated barrel having an open end, means for introducing a detonatable body of detonatable fluid into said barrel, means for providing powder material in said detonatable body of detonatable fluid in said barrel, means for controlling the supply of fluid fuel and V 2,774,625 Patented Dec. 18, 1956 simultaneously open to admit combustible gas and oxidant (with or without the powder) to the elongated barrel of the gun,
2. The poppet valves are then closed,
3. Immediately thereafter, a third poppet valve opens to admit an inert nitrogen gas stream which flows across the combustion gas and oxidant valves to dilute any leaks from such valves which might cause flashback upon detonation of the mixture,
4. Immediately-after the nitrogen valve opens, and while it remains open, spark ignition fires the gun causing a detonation,
5. After detonation occurs, nitrogen from the open valve flows through the gun to drive out the hot combustion products and form a protective Wall between them and the next combustible mixture charge.
6. The nitrogen valve then closes and the cycle is ready to be repeated by the simultaneous reopening of the combustible gas and oxidant valves to form the next detonation mixture.
This timed sequence of valve operation and spark plug firing is accomplished by driving the valves and spark energization circuit from a common cam shaft.
The frequency of the detonations is a factor in attaining effective operation of the detonation gun. The most useful frequency depends on the particular use of the gun, the design of the gun, and the character of the detonating gas mixture. A single detonation suflices when a thin deposit on a small area is desired, for example a tungsten carbide coating 0.0005 inch thick on a steel surface one inch or less in diameter. For making thicker coatings, and coating larger areas quickly severaldetonations per second are usually desirable.
It was found that under some operating conditions, for instance when using oxygen and acetylene as the oxidant and fuel respectively, it is desirable to have positive closure means between the ignition chamber and the gas supplies of the detonation gun. In addition, it is advantageous under some circumstances to introduce the powder downstream of the ignition zone so that powder will not be deposited on the walls of the barrel in that zone. These features are shown and described in U. S. Patent No. 2,714,563.
It has been found that, although it is advantageous to introduce the powder into the detonation gun, through the side of the barrel downstream of the ignition zone, a number of detrimental effects resulted which effect the continued operation of the detonation gun and the quality of the resultant coating.
The primary difliculty encountered in introducing powders into the barrel of the detonation gun in this manner is that excessive powder deposition occurs in the bore of the powder entry tube in the region where it joins the barrel of the detonation gun. Such powder deposition is to be avoided since it reduces the supply of powder to the barrel of the detonation gun. Additionally, these deposits periodically flake off and pass through the barrel of the detonation gun to the workpiece, thereby causing defects in the resultant coating.
It has also been found that the introduction of powder through an entry tube positioned in the side of the barrel of the detonation gun downstream of the ignition zone tends to unequally distribute the powder in the detonatable fluid in the barrel of the detonation gun, thereby resulting in a non-uniform distribution of powder deposition on the internal walls of the barrelof the gun.
Accordingly, it is an object of the invention to provide a detonation gun containing improved means for introducing powder into the barrel downstream of the ignition zone, whereby the deposition of powders will be substantially eliminated.
Another object is to provide such apparatus wherein the buildup of powder on the internal walls of the barrel is redistributed to a more uniform and less harmful pattern.
Other aims and advantages of the invention will be apparent from the following description and appended claims.
In the drawing:
Fig. l is a schematic view of a detonation gun for coating with powders employing the improved powder entry means of the invention, portions having been broken away to show internal construction;
Fig. 2 is an enlarged view of the back portion of the powder entry means of the detonation gun of Fig 1 down to a transverse break line a-a, parts having been broken away to show internal construction; and
Fig. 2a is the forward portion of the powder entry means extending from the transverse break line aa.
In accordance with the present invention, detonation gun D is provided comprising an elongated barrel 10 having an open end 12 from which the products of the detonation and powders pass to the object to be coated. Cooling water circulating jacket 14 is provided around barrel 10 to prevent overheating. Cooling water is supplied to the annular space 16 between jacket 14 and barrel 10 through inlet means 18, and water passes from annular space 16 through outlet means 20.
Fuel and oxidant are supplied to port means 22 and 24, respectively, of mixing block 26 which is provided with poppet valves 28 for regulating the flow of such fluids at timed intervals. Mixing of the fuel and oxidant takes place in mixing chamber 30 of mixing block 26 and the detonatable mixture is passed to barrel 10 of detonation gun D. .Mixing block 26 is also provided with purging gas inlet port means 36 and poppet valve means 38 for purging mixing chamber 30 and barrel 10 of gases in the intervals between each successive detonation and the introduction of the following detonatable charge into elongated barrel 10 of the detonation gun.
Means is provided in the walls of mixing chamber 36 for insertion of ignition means 42, such as a spark plug or the like, into the mixing chamber; and energizing lines 44 are also provided.
Powder entry tube assembly 46 passes through the rear or breech end 48 of cooling water jacket 14 and the elongated barrel 10 and passes axially through the barrel to a point downstream of the zone (in the region of ignition means 42) where ignition and the initiation of the detonation phenomenon occurs. The powder entry tube assembly 46 preferably comprises powder entry tube 50, two concentric cooling fluid sleeves 52 and 54 surrounding entry tube 50 over at least that portion of entry tube 50 which is positioned in the interior of barrel 10, cooling fluid inlet and outlet parts 56 and 58, respectively, and guide bracket means 60 for properly supporting entry tube '0 to prevent bending or breakage.
A suitable powder dispenser 61 is employed for suspending the material to be coated in a gas stream in which it is carried into the barrel of the detonation gun. It has been found that the length of line 62 between the powder dispenser and the discharge end of the powder entry tube 54 should be sufiiciently great to prevent the back surging of gases resulting from the detonation in the gun barrel and consequent disruption of the supply of powder to the gun barrel. For example, in order to maintain continuous non-erractic operation, the minimum length required for a powder tube of /s inch inside diameter is 8 feet 4 inches.
Cooling fluid passes into powder tube assembly 46 through inlet 56 to an annular space 63 between inner cooling fluid sleeve 52 and powder entry tube 50 down the length of the powder tube and returns to outlet 58 through annular space 64 between inner cooling fluid sleeve 52 and outer cooling fluid sleeve 54. In this manper cooling fluid is continually circulated through and around the cooling passages over the entire length of that portion of the powder tube which is positioned in the internally hot region within the interior of barrel 10.
The powder entry assembly 46 shown in Figs. 2 and 2a of the drawing is mounted in such a way as to provide for easy removal and replacement of powder entry tube 50 in the assembly. The procedure for removal and replacement is as follows: The entire assembly is first removed from the detonation gun by loosening coupling 66 at the breech end 48 of the gun. Upon removal of the assembly from the gun, the nose nut 68 is removed and retaining nuts 75 and 76 are loosened. Thereupon powder entry tube can be removed and a new tube 50 may be then inserted in the assembly by reversing these steps.
it has been found that axial powder entry tubes in accordance with the invention have an inherent life of about five hours total coating time at the end of which the abrasive action of the powder has severely damaged the tube to the extent that replacement is required. Accordingly, it is of great importance that a powder tube assembly is provided which permits rapid removal and replacement of such axial powder entry tubes in a minimum time.
It has also been found that the diameter of the powder entry tube can be of any convenient size, the maximum value being determined by cooling fluid requirements (larger diameter tubes would require cooling jackets which would nearly fill the interior of the gun barrel) and the minimum diameter limitation is determined by the powder feed rate required for coating.
The use of an axial powder entry tube in accordance with the invention accomplishes the following: It completely stops powder deposition in the powder tube bore and the accompanying decrease or stoppage of powder supply to the gun barrel; it redistributes the buildup of powder deposit within the gun barrel to a more uniform and, therefore, less harmful pattern; it greatly decreases the number of porous powder agglomerates deposited on the surface to be coated, thereby reducing the number of defects in the coating; and it decreases the maintenance time required on the powder entry tube.
Satisfactory coatings can be obtained employing a detonation gun having axial entry tube means in accordance with the invention where the powder entry tube is inserted in the barrel to any distance from the breech up to a point downstream of the ignition zone. It has been found preferable, however, that the powder entry tube should be inserted at least to a point downstream of the ignition zone to reduce the powder deposition in the barrel and obtain high quality coating.
It has been discovered that it is important to insure axial positioning of the powder entry tube, and cooling of the tube has been found necessary due to the extremely high temperatures attained within the barrel. Non-cooled powder entry tubes have been employed for limited times but in no instance was it possible to operate for longer than one minute periods without pro-ignition of the detonatable mixture and a consequent failure in obtaining the required detonation.
What is claimed is:
1. In a detonation gun having an elongated barrel having an open end, said barrel having a length-to-diameter ratio suflicienitly high to permit the formation of a detonation therein, mixing chamber means directly and continuously communicating with said barrel for forming and passing to said barrel charges of detonatable fluid fuel mixture, means for supplying the components of said detonatable fluid fuel mixture to said mixing chamber means, supply means associated with said barre-l for providing comminuted solid material in said detontable fluid fuel mixture, and means associated with said barrel for igniting said fluid fuel mixture in said barrel to initiate said detonation and propel said comminuted solid material from said gun, the improvement which comprises employing, as said supply means, powder entry tube means passing substantially axially through said elongated barrel to a point downstream of said igniting means for introducing a gas-borne stream of powder into said fluid fuel mixture in said barrel.
2. Apparatus in accordance with claim 1, also containing means for circulating a cooling fluid through the interior of said elongated barrel of said gun and in heat exchange contact with said powder entry tu-be means.
References Cited in the file of this patent UNITED STATES PATENTS Hansen May 1, 1945 FOREIGN PATENTS Great Britain of 1943
Priority Applications (12)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
BE559805D BE559805A (en) | 1954-10-21 | ||
LU33864D LU33864A1 (en) | 1954-10-21 | ||
LU35347D LU35347A1 (en) | 1954-10-21 | ||
BE541593D BE541593A (en) | 1954-10-21 | ||
NL218430D NL218430A (en) | 1954-10-21 | ||
US463643A US2774625A (en) | 1954-10-21 | 1954-10-21 | Apparatus utilizing detonation waves for spraying powders |
FR1131392D FR1131392A (en) | 1954-10-21 | 1955-09-22 | Detonation gun |
CH327832D CH327832A (en) | 1954-10-21 | 1955-09-26 | Apparatus comprising a detonation gun for imparting energy to a powdery material |
GB29804/55A GB791705A (en) | 1954-10-21 | 1955-10-19 | Improved detonation gun for heating and spraying powders |
GB24076/57A GB869897A (en) | 1954-10-21 | 1957-07-30 | Improved detonation gun for heating and spraying powders |
FR72143D FR72143E (en) | 1954-10-21 | 1957-08-01 | Detonation gun |
US815434A US2950867A (en) | 1954-10-21 | 1959-05-25 | Pulse powder feed for detonation waves |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US463643A US2774625A (en) | 1954-10-21 | 1954-10-21 | Apparatus utilizing detonation waves for spraying powders |
Publications (1)
Publication Number | Publication Date |
---|---|
US2774625A true US2774625A (en) | 1956-12-18 |
Family
ID=23840820
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US463643A Expired - Lifetime US2774625A (en) | 1954-10-21 | 1954-10-21 | Apparatus utilizing detonation waves for spraying powders |
Country Status (7)
Country | Link |
---|---|
US (1) | US2774625A (en) |
BE (2) | BE559805A (en) |
CH (1) | CH327832A (en) |
FR (2) | FR1131392A (en) |
GB (2) | GB791705A (en) |
LU (2) | LU35347A1 (en) |
NL (1) | NL218430A (en) |
Cited By (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2920001A (en) * | 1955-07-11 | 1960-01-05 | Union Carbide Corp | Jet flame spraying method and apparatus |
US2950867A (en) * | 1954-10-21 | 1960-08-30 | Union Carbide Corp | Pulse powder feed for detonation waves |
US3004822A (en) * | 1958-01-31 | 1961-10-17 | Union Carbide Corp | Method for utilizing detonation waves to effect chemical reactions |
US3504856A (en) * | 1969-05-15 | 1970-04-07 | Louis Hinkeldey Jr | Oxygen lance assembly |
US3915381A (en) * | 1971-11-15 | 1975-10-28 | Southwest Res Inst | Method and apparatus for applying particulate coating material to a work piece |
US4215819A (en) * | 1977-12-20 | 1980-08-05 | Andruschak Oleg A | Apparatus for explosive application of coatings to articles |
US4258091A (en) * | 1979-02-06 | 1981-03-24 | Dudko Daniil A | Method for coating |
US4319715A (en) * | 1977-12-20 | 1982-03-16 | Garda Alexandr P | Apparatus for explosive application of coatings to articles |
US5285967A (en) * | 1992-12-28 | 1994-02-15 | The Weidman Company, Inc. | High velocity thermal spray gun for spraying plastic coatings |
WO1997023301A1 (en) * | 1995-12-26 | 1997-07-03 | Aerostar Coatings, S.L. | Energy bleed apparatus and method for a detonation gun |
US6146693A (en) * | 1995-12-26 | 2000-11-14 | Aerostar Coatings, S.L. | Energy bleed apparatus and method for a detonation gun |
JP2001129441A (en) * | 1999-09-16 | 2001-05-15 | Nordson Corp | Powder spray gun |
US20030080220A1 (en) * | 1999-09-16 | 2003-05-01 | Mather Brian D. | Powder spray gun with inline angle spray nozzle |
US20050023374A1 (en) * | 1999-09-16 | 2005-02-03 | Knobbe Alan J. | Powder spray gun |
US20050082395A1 (en) * | 2003-10-09 | 2005-04-21 | Thomas Gardega | Apparatus for thermal spray coating |
US20110052825A1 (en) * | 2007-09-28 | 2011-03-03 | Paxson Daniel E | Method and Apparatus for Thermal Spraying of Metal Coatings Using Pulsejet Resonant Pulsed Combustion |
CN103305785A (en) * | 2012-03-06 | 2013-09-18 | 兰州理工大学 | Pressure sensitive adhesive carrier powder continuous electro-explosive spraying device |
CN104561879A (en) * | 2014-11-25 | 2015-04-29 | 西北工业大学 | Device for exploding and spraying liquid fuels |
CN109381822A (en) * | 2018-12-03 | 2019-02-26 | 河南理工大学 | A kind of devices and methods therefor for inhibiting combustible gas deflagration flame to propagate |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SE431835B (en) * | 1977-12-21 | 1984-03-05 | Inst Materialovedenia Akademii | DEVICE FOR PREPARING COATINGS ON PRODUCTS BY DETONING |
SU1319915A1 (en) * | 1983-09-02 | 1987-06-30 | Предприятие П/Я А-3783 | Apparatus for metering and introducing powder into detonation set shaft |
HUT47463A (en) * | 1985-11-26 | 1989-03-28 | Nii Tekh Avtomobil Promy | Detonating device for producing surface layer coating |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB553099A (en) * | 1940-09-29 | 1943-05-07 | Fritz Gfeller | Improvements in processes and apparatus for spraying fusible and thermoplastic material |
US2374816A (en) * | 1942-05-18 | 1945-05-01 | Sern L Hansen | Rapid-fire gun |
-
0
- LU LU33864D patent/LU33864A1/xx unknown
- BE BE541593D patent/BE541593A/xx unknown
- NL NL218430D patent/NL218430A/xx unknown
- LU LU35347D patent/LU35347A1/xx unknown
- BE BE559805D patent/BE559805A/xx unknown
-
1954
- 1954-10-21 US US463643A patent/US2774625A/en not_active Expired - Lifetime
-
1955
- 1955-09-22 FR FR1131392D patent/FR1131392A/en not_active Expired
- 1955-09-26 CH CH327832D patent/CH327832A/en unknown
- 1955-10-19 GB GB29804/55A patent/GB791705A/en not_active Expired
-
1957
- 1957-07-30 GB GB24076/57A patent/GB869897A/en not_active Expired
- 1957-08-01 FR FR72143D patent/FR72143E/en not_active Expired
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB553099A (en) * | 1940-09-29 | 1943-05-07 | Fritz Gfeller | Improvements in processes and apparatus for spraying fusible and thermoplastic material |
US2374816A (en) * | 1942-05-18 | 1945-05-01 | Sern L Hansen | Rapid-fire gun |
Cited By (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2950867A (en) * | 1954-10-21 | 1960-08-30 | Union Carbide Corp | Pulse powder feed for detonation waves |
US2920001A (en) * | 1955-07-11 | 1960-01-05 | Union Carbide Corp | Jet flame spraying method and apparatus |
US3004822A (en) * | 1958-01-31 | 1961-10-17 | Union Carbide Corp | Method for utilizing detonation waves to effect chemical reactions |
US3504856A (en) * | 1969-05-15 | 1970-04-07 | Louis Hinkeldey Jr | Oxygen lance assembly |
US3915381A (en) * | 1971-11-15 | 1975-10-28 | Southwest Res Inst | Method and apparatus for applying particulate coating material to a work piece |
US4215819A (en) * | 1977-12-20 | 1980-08-05 | Andruschak Oleg A | Apparatus for explosive application of coatings to articles |
US4319715A (en) * | 1977-12-20 | 1982-03-16 | Garda Alexandr P | Apparatus for explosive application of coatings to articles |
US4258091A (en) * | 1979-02-06 | 1981-03-24 | Dudko Daniil A | Method for coating |
US5285967A (en) * | 1992-12-28 | 1994-02-15 | The Weidman Company, Inc. | High velocity thermal spray gun for spraying plastic coatings |
WO1997023301A1 (en) * | 1995-12-26 | 1997-07-03 | Aerostar Coatings, S.L. | Energy bleed apparatus and method for a detonation gun |
US6146693A (en) * | 1995-12-26 | 2000-11-14 | Aerostar Coatings, S.L. | Energy bleed apparatus and method for a detonation gun |
EP1084759A3 (en) * | 1999-09-16 | 2002-07-31 | Nordson Corporation | Powder spray gun |
JP2001129441A (en) * | 1999-09-16 | 2001-05-15 | Nordson Corp | Powder spray gun |
US20030080220A1 (en) * | 1999-09-16 | 2003-05-01 | Mather Brian D. | Powder spray gun with inline angle spray nozzle |
US6796519B1 (en) | 1999-09-16 | 2004-09-28 | Nordson Corporation | Powder spray gun |
US20050023374A1 (en) * | 1999-09-16 | 2005-02-03 | Knobbe Alan J. | Powder spray gun |
US20050082395A1 (en) * | 2003-10-09 | 2005-04-21 | Thomas Gardega | Apparatus for thermal spray coating |
US7216814B2 (en) | 2003-10-09 | 2007-05-15 | Xiom Corp. | Apparatus for thermal spray coating |
US20110052825A1 (en) * | 2007-09-28 | 2011-03-03 | Paxson Daniel E | Method and Apparatus for Thermal Spraying of Metal Coatings Using Pulsejet Resonant Pulsed Combustion |
US8839738B2 (en) * | 2007-09-28 | 2014-09-23 | The United States Of America As Represented By The Administrator Of National Aeronautics And Space Administration | Method and apparatus for thermal spraying of metal coatings using pulsejet resonant pulsed combustion |
CN103305785A (en) * | 2012-03-06 | 2013-09-18 | 兰州理工大学 | Pressure sensitive adhesive carrier powder continuous electro-explosive spraying device |
CN103305785B (en) * | 2012-03-06 | 2015-04-22 | 兰州理工大学 | Pressure sensitive adhesive carrier powder continuous electro-explosive spraying device |
CN104561879A (en) * | 2014-11-25 | 2015-04-29 | 西北工业大学 | Device for exploding and spraying liquid fuels |
CN109381822A (en) * | 2018-12-03 | 2019-02-26 | 河南理工大学 | A kind of devices and methods therefor for inhibiting combustible gas deflagration flame to propagate |
Also Published As
Publication number | Publication date |
---|---|
FR1131392A (en) | 1957-02-20 |
GB869897A (en) | 1961-06-07 |
BE559805A (en) | 1900-01-01 |
FR72143E (en) | 1960-03-30 |
LU35347A1 (en) | |
GB791705A (en) | 1958-03-12 |
BE541593A (en) | 1900-01-01 |
LU33864A1 (en) | |
NL218430A (en) | 1900-01-01 |
CH327832A (en) | 1958-02-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2774625A (en) | Apparatus utilizing detonation waves for spraying powders | |
EP0323185B1 (en) | Apparatus and process for producing high density thermal spray coatings | |
EP0889756B1 (en) | Self sustained detonation apparatus | |
US5520334A (en) | Air and fuel mixing chamber for a tuneable high velocity thermal spray gun | |
PT91753B (en) | PULVERIZATION APPARATUS THROUGH A HIGH SPEED FLAME CONE AND MATERIAL FORMATION PROCESS | |
EP1013344B1 (en) | System for injecting gas into a detonation projection gun | |
US6787194B2 (en) | Method and apparatus for pulsed detonation coating of internal surfaces of small diameter tubes and the like | |
US4669658A (en) | Gas detonation coating apparatus | |
US5542606A (en) | Gas detonation spraying apparatus | |
JP4091097B2 (en) | Labyrinth gas supply apparatus and method for detonation gun | |
US5445325A (en) | Tuneable high velocity thermal spray gun | |
US2869924A (en) | Apparatus for utilizing detonation waves | |
CN209260179U (en) | A kind of mixed gas dual ignition cooling device of detonation flame spraying | |
US4911363A (en) | Combustion head for feeding hot combustion gases and spray material to the inlet of the nozzle of a flame spray apparatus | |
US4377978A (en) | Firing system and burner for rotary kiln | |
BR8503232A (en) | METHOD FOR HEATING THE REDUCING GAS OF A HIGH OVEN | |
US6146693A (en) | Energy bleed apparatus and method for a detonation gun | |
US6000627A (en) | Detonation gun apparatus and method | |
CN114525464A (en) | Spraying device based on rotatory knockings | |
US3004822A (en) | Method for utilizing detonation waves to effect chemical reactions | |
CN107653429B (en) | Accumulative pressure high frequency detonation-gun | |
US5985373A (en) | Method and apparatus for applying multi-layered coatings by detonation | |
CA2247146C (en) | Self sustained detonation apparatus | |
SU1291215A1 (en) | Apparatus for thermokinetic deposition by spraying | |
WO1997023298A1 (en) | Pulsed powder feeder apparatus and method for a detonation gun |