CN100446870C - Cold air dynamical spray-painting method and apparatus of delivering powder through down stream - Google Patents
Cold air dynamical spray-painting method and apparatus of delivering powder through down stream Download PDFInfo
- Publication number
- CN100446870C CN100446870C CNB2005100309143A CN200510030914A CN100446870C CN 100446870 C CN100446870 C CN 100446870C CN B2005100309143 A CNB2005100309143 A CN B2005100309143A CN 200510030914 A CN200510030914 A CN 200510030914A CN 100446870 C CN100446870 C CN 100446870C
- Authority
- CN
- China
- Prior art keywords
- nozzle
- powder feeding
- powder
- section
- downstream
- 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 - Fee Related
Links
- 239000000843 powder Substances 0.000 title claims abstract description 211
- 238000000034 method Methods 0.000 title abstract description 11
- 238000007592 spray painting technique Methods 0.000 title 1
- 238000005507 spraying Methods 0.000 claims abstract description 38
- 238000011144 upstream manufacturing Methods 0.000 claims abstract description 9
- 238000010438 heat treatment Methods 0.000 claims abstract description 4
- 239000007789 gas Substances 0.000 claims description 55
- 239000002245 particle Substances 0.000 claims description 41
- 238000000576 coating method Methods 0.000 claims description 34
- 239000007921 spray Substances 0.000 claims description 23
- 239000012159 carrier gas Substances 0.000 claims description 17
- 230000001133 acceleration Effects 0.000 claims description 9
- 210000000038 chest Anatomy 0.000 claims description 9
- 238000009826 distribution Methods 0.000 claims description 4
- 229910052751 metal Inorganic materials 0.000 claims description 3
- 239000002184 metal Substances 0.000 claims description 3
- 230000009977 dual effect Effects 0.000 claims description 2
- 239000008187 granular material Substances 0.000 claims description 2
- 230000008901 benefit Effects 0.000 abstract description 3
- 230000000903 blocking effect Effects 0.000 abstract 1
- 239000011248 coating agent Substances 0.000 description 20
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 12
- 239000000463 material Substances 0.000 description 10
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 6
- 239000004411 aluminium Substances 0.000 description 6
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 6
- 229910052782 aluminium Inorganic materials 0.000 description 6
- 229910052757 nitrogen Inorganic materials 0.000 description 6
- 230000008021 deposition Effects 0.000 description 5
- 239000011159 matrix material Substances 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 230000009471 action Effects 0.000 description 4
- 210000000867 larynx Anatomy 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000010891 electric arc Methods 0.000 description 2
- 238000010285 flame spraying Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 238000007750 plasma spraying Methods 0.000 description 2
- 229910000990 Ni alloy Inorganic materials 0.000 description 1
- 208000031481 Pathologic Constriction Diseases 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 238000010288 cold spraying Methods 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 235000013312 flour Nutrition 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000006199 nebulizer Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000036262 stenosis Effects 0.000 description 1
- 208000037804 stenosis Diseases 0.000 description 1
- 238000007751 thermal spraying Methods 0.000 description 1
- 230000008646 thermal stress Effects 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Images
Abstract
A cold-pneumatic spray coating method and apparatus by feeding powder at downstream is disclosed. Said method includes such steps as heating the working gas, delivering it to upstream of the flow channel in Laval nozzle, using the carrying gas to deliver the metallic powder to be sprayed to the downstream divergent segment via powder delivering tube, accelerating it by working gas, and spraying it. The cross-section the flow channel in divergent segment is elliptical or the combination of ellipse and rectangle. Its advantage is no pollution and blocking of nozzle throat.
Description
(1) technical field
The present invention relates to a kind of method and apparatus for preparing coating, relate in particular to a kind of cold air power spraying and coating method that utilizes metal powder material is sprayed to sample or the surface of the work method and apparatus with the preparation coating.
(2) background technology
The conventional method of preparation coating is thermal spraying, and these methods comprise flame-spraying, electric arc spraying, plasma spraying and high-velocity oxy-fuel spraying (HVOF) etc.The main points of flame-spraying, electric arc spraying and plasma spraying are that material melts fully, and the HVOF spraying only needs partial melting just to be enough to form high-quality coating.Its reason is that when HVOF sprayed, the speed of particles hit base material to be sprayed was very high.Like this, even if under the situation of partial melting, particle also can be attached on the base material securely.And a kind of new coating preparation method who occurs for last century Mo---for the cold air power spraying and coating (also claiming the spraying of cold spraying or dynamics), any fusing does not take place in powder particle to be sprayed in whole spraying process, the formation of coating relies on the high-speed of solid particle fully.In cold air power spraying and coating, particle plastic deformation that the adhesion of particle and base material causes when being mainly derived from high velocity particle bump base material and the heat that produces thus and discharge.Therefore, common some in thermal spray process since the illeffects (as scaling loss, oxidation, fusing, evaporation, gas release, crystallization, solid-state phase changes, thermal stress and the thermal deformation etc. of powder and base material) that high temperature caused in the cold air power spraying and coating process, can avoid.
Cold air power spraying and coating last century the eighties by invention such as Alkhimov and Papyrin.Cold air power spraying and coating patent US5302414 the earliest and EP0484533B1 were respectively at 1994 and nineteen ninety-five proposition.In cold air driven spray painter, high-pressure air source provides high-pressure working gas and powder feeding carrier gas.Working gas is to produce medium at a high speed, is being heated to 100～800 ℃ in advance with powder to be sprayed in heater.After carrier gas is heated, the powder to be sprayed in the powder feeder is sent into spray gun in another heater.Comprise one in the spray gun to converge-Raoul (Laval) nozzle of divergence form that the stenosis of its runner is the throat or the neck of nozzle, the upstream of throat is the nozzle convergence section, and the downstream is a divergent section.The temperature and pressure of nozzle entrance place working gas is respectively between 200～600 ℃ and between 1.5～3.5MPa.Arrive divergent section from the nozzle convergence section via throat with the working gas after the carrier gas and the powder to be sprayed of carrying thereof, expand into normal pressure and quicken, thereby form supersonic airstream.The Laval nozzle can have different geometric formats, and its principal character parameter comprises: the ratio (divergence ratio) of the length of geometric profile (is circle or rectangle as outlet), divergent section and outlet flow cross-sectional area and the thinnest position of runner cross-sectional area.
Usually, powder particle to be sprayed is by the throat upstream of powder feeding pipe injection Laval nozzle, the i.e. preceding thorax of spray gun.The pressure that this is regional and the input pressure of powder feeding pipe are approaching, can be up to more than the 3.5MPa, and this just means that also employed powder feeder must be a kind of high pressure powder feed device here.Yet the conveying of powder particle can run into a lot of problems under so high pressure, and these problems are not resolved at present as yet fully technically.The turbulent flow that resembles the powder feeding pipe end is exactly one of its weakness, and this weakness makes that powder is inhomogeneous with mixing of working gas and is difficult to accurate concentrated area by the narrowest part (throat) in the runner.Throat's cross-sectional diameter of Laval nozzle has only 1.5～3.5mm, is easy to cause powder particle to the wearing and tearing of runner especially throat, sticking trowel used for plastering and obstruction.In some cases, this obstruction has only just taken place after one minute in spraying.For example, contain the temperature of bigger particle or working gas in tin, aluminium or some Ni alloy powder or the powder when higher in spraying, thereby conventional Laval nozzle is easy to be caused spraying termination and problems such as replacing or nozzle clearing by sticking trowel used for plastering and obstruction.For fear of sticking trowel used for plastering and obstruction, the temperature of working gas is had to restricted, and this obviously is unfavorable for the raising of jet velocity.Therefore, even if sticking trowel used for plastering and obstruction do not cause spraying process to interrupt, also can influence the inherent quality of spraying coating process and coating.
In order to solve the sticking trowel used for plastering and the blockage problem of nozzle, patent WO98/22639, US2002/0071906, US2003190414, EP1445033, RU2229944, US2004166247 propose respectively: directly powder particle to be sprayed is injected Laval nozzle diverging section (downstream of throat), rather than resembling usually powder delivered to convergence section (upstream of throat).
Wherein patent US2004166247 proposes that powder feeding pipe is passed throat along nozzle flow channel from the upstream convergence section and directly is inserted into the downstream divergent section, and powder particle is directly sent to the runner of divergent section by the axis, longshore current road, end of powder feeding pipe.This invention can effectively solve the obstruction and the wear problem of nozzle, and its shortcoming is that the powder feeding pipe end is easy to produce turbulent flow.Usually, the internal diameter of powder feeding pipe is about 3mm, even if tube wall has only 0.5mm thick, the cross section outside diameter of end also has about 4mm.Like this, the effective cross section area in the nozzle diverging section of powder feeding pipe end correspondence has just had 12mm
2Above sudden change, this will cause turbulent flow or turbulent flow at this position.Because the working gas of nozzle downstream divergent section had reached supersonic speed already, above-mentioned turbulent flow or turbulent flow will have a negative impact to the steady acceleration of powder particle.This influence obviously than powder feeding pipe outlet serious many of the situation of nozzle upstream.In addition, the powder feeding pipe end still is a dead angle of working gas velocity field, and its speed is far below the average speed of this position working gas, and the powder particle of sending at this position is easy to sticking trowel used for plastering nozzle and can't be effectively quickened.
Remaining downstream powder feeding patent WO98/22639, US2002/0071906, US2003190414, EP1445033, RU2229944 have adopted at nozzle downstream divergent section sidewall and have opened powder feeding hole powder to be sprayed is directly injected the method for divergent section runner from the nozzle outside.Nozzle flow channel cross section (or jet expansion) shape that these patents are used has only circular and two kinds in rectangle.The shortcoming of round nozzle is to be directly used in long and narrow spot of spraying or zone.If be used for such occasion, just need cover base material to be sprayed.Coverage not only makes the preparation of spraying complicated, also can reduce the recovery rate of powder.Though rectangular nozzle can spray long and narrow spot or zone, have a fatal weakness: Flow Field Distribution is inhomogeneous---there is turbulent flow in nozzle inner walls four edges and corners.The existence of turbulent flow is unfavorable for the steady acceleration of powder particle, therefore is unfavorable for the raising of coating quality.
(3) summary of the invention
The object of the present invention is to provide the cold air power spraying and coating method and the device of the powder feeding of a kind of downstream, can avoid the sticking trowel used for plastering or the obstruction of nozzle, especially nozzle throat effectively; Can adopt conventional powder feeder to replace the high pressure powder feed device; Employed nozzle has that circular Laval nozzle diverging section runner does not have that turbulent flow, rectangle Laval nozzle can spray long and narrow spot or zone concurrently and the advantage that need not block.
The present invention is achieved in that the cold air power spraying and coating method of a kind of downstream powder feeding, is that gas is through expanding and acceleration in the downstream divergent section behind the nozzle throat in the convergence section with working gas heating and input Raoul type nozzle flow channel upstream; By carrier gas the metal powder granulates to be sprayed in the powder feeder is directly sent into the downstream divergent section of nozzle, accelerate to supersonic speed by wherein working gas again; It is characterized in that: powder particle to be sprayed is directly to send to nozzle downstream divergent section from the outside of nozzle by the powder feeding hole on the nozzle wall via powder feeding pipe; The divergent section flow channel cross-section is ellipse or ellipse-rectangle combination shape, the axis of all powder feeding holes of nozzle wall all is in same plane with long axis of ellipse, described transverse plane is the longitudinal section at flow channel cross-section transverse place, the outlet of all powder feeding holes all is positioned at the divergent section in nozzle downstream, and powder particle is quickened the back by working gas and sprays from the nozzle diverging section port of export.
The cold air power spraying and coating method of above-mentioned downstream powder feeding, described powder feeder are the powder feeder under the normal temperature and pressure.
The cold air driven spray painter of a kind of downstream powder feeding, comprise switch board, heater, powder feeder, pipeline, Raoul type nozzle, the preceding thorax of nozzle, gases at high pressure are divided into two the tunnel after entering into switch board, one the tunnel enters heater as working gas, thorax before working line enters nozzle sprays through Raoul type nozzle; Another road enters powder feeder as carrier gas and powder to be sprayed is taken out of, it is characterized in that: powder feeding pipe is connected to the powder feeding hole of Raoul type nozzle downstream divergent section sidewall, has powder feeding hole on the divergent section inwall of nozzle downstream; Raoul type nozzle diverging section flow channel cross-section smoothly fades to the ellipse of the port of export continuously by the very little circle of throat diameter, and promptly the flow channel cross-section at any position of divergent section all is oval; The axis of all powder feeding holes on the divergent section nozzle wall all is in same plane with long axis of ellipse, and described transverse plane is the longitudinal section at flow channel cross-section transverse place.
The cold air driven spray painter of above-mentioned downstream powder feeding, described Raoul type nozzle diverging section flow channel cross-section makes up shape by ellipse-rectangle that the very little circle of throat diameter smoothly fades to the port of export continuously, and promptly the flow channel cross-section at any position of divergent section all is ellipse-rectangle combination shape; Described ellipse-rectangle combination shape is to constitute like this: the centre is respectively 2b and l for the length of side
0Rectangle, the ellipse that major and minor axis is respectively 2a and 2b in two symmetrically smooth connection in the outside of two opposite side of this rectangle; Port of export flow channel cross-section profile is these two semiellipse arcs and length is l
0Two rectangle opposite side totally four sections closed curves that lines are formed by connecting.
The invention has the advantages that:
(1) because the outlet of powder feeding hole is placed nozzle throat divergent section afterwards, under the situation of early-stage work gas pressure, still can realize smooth powder feeding at nebulizer gas pressure, because after working gas enters divergent section through throat, pressure reduces rapidly, pressure is near normal pressure when arriving powder feeding hole, and this just makes that utilizing conventional powder feeder to replace the high pressure powder feed device to carry out cold air power spraying and coating becomes possibility.Compare with conventional powder feeder, the high pressure powder feed device not only involves great expense, and operation and maintenance complexity, safety requirements height.
(2) because the outlet of powder feeding hole is placed throat's divergent section afterwards, the temperature of working gas even can be higher than the fusing point of powder to be sprayed and can not cause the fusing of powder, because working gas is through after the throat, temperature reduces rapidly, temperature is far below its fusing point when touching powder, sometimes even be lower than room temperature, thus broken through of the restriction of conventional cold air power spraying and coating to temperature.
(3) outlet of powder feeding hole is positioned at the divergent section of nozzle, and working gas temperature herein is lower, can avoid powder long-pending to the sticking trowel used for plastering and the plug of nozzle inner walls.
(4) outlet of powder feeding hole is positioned at the sidewall of nozzle diverging section, and working gas herein produces strong swabbing action owing to jet effect to the powder particle in the powder feeding hole along the inwall flow at high speed of the nozzle of smooth gradual change.Only rely on respect to conventional method that carrier gas is to the effect of dragging of powder particle in the powder feeding pipe, this swabbing action not only helps powder feeding, but also can overcome sticking trowel used for plastering and the blockage problem of powder particle in powder feeding pipe and powder feeding hole inside.
(5) compare with circular Laval nozzle (conventional nozzle), the outlet of nozzle of the present invention is ellipse or ellipse-rectangle combination shape, can spray long and narrow spot or zone and need not block.
(6) compare with rectangle Laval nozzle, the flow channel cross-section of nozzle diverging section of the present invention is ellipse or ellipse-rectangle combination shape, there are not corner angle in the runner, therefore there is not the turbulent region, the acceleration of working gas and powder particle to be sprayed is steady, and it is long-pending to reduce the wearing and tearing of nozzle inner walls, sticking trowel used for plastering and plug.
(4) description of drawings
The invention will be further described below in conjunction with the drawings and specific embodiments.
Fig. 1 is the cold air power spraying and coating method and the device schematic diagram of downstream of the present invention powder feeding.There is shown a kind of form of powder feeding hole: powder feeding hole 5 has two, and these two powder feeding holes 5 all are positioned at the sidewall of the same side of nozzle 3 runner axis.
Fig. 2 is Raoul type nozzle 3 profiles of the present invention, and there is shown another form of powder feeding hole 5: powder feeding hole 5 has a pair of, and this lays respectively at the relative sidewall of nozzle 3 and be symmetrical distribution with respect to the runner axis powder feeding hole 5.
Among the figure: thorax before 1 working line, 2 nozzles, 3 Raoul type nozzles, 4-1 powder feeding pipe, 4-2 branch powder feeding pipe, 5 powder feeding holes, 6 switch boards, 7 heaters, 8 powder feeders, 9 coatings, 10 base materials, 11 gases at high pressure, 12 carrier gas, 13 working gas, 14 powder.
(5) specific embodiment
Referring to Fig. 1, Fig. 2, the cold air power spraying and coating method of a kind of downstream powder feeding, be that 200 ℃ to 600 ℃ working gas is imported in the convergence section of Laval type nozzle 3 runner upstreams, gas expands and acceleration in the downstream divergent section through nozzle 3 throats (part that runner is the narrowest) back; By carrier gas the powder particle to be sprayed of 5 μ m to the 120 μ m of particle diameter in the powder feeder 8 is directly sent into the downstream divergent section of nozzle 3, accelerate to supersonic speed by wherein working gas again.Powder particle wherein to be sprayed is directly to send to nozzle 3 downstream divergent section from the outside of nozzle 3 by the powder feeding hole on the nozzle wall 5 via powder feeding pipe 4-1 and 4-2; Nozzle 3 downstream divergent section flow channel cross-sections are ellipse or ellipse-rectangle combination shape, the axis of all powder feeding holes 5 of nozzle 3 sidewalls all is in same plane with long axis of ellipse, described transverse plane is the longitudinal section at flow channel cross-section transverse place, and the outlet of all powder feeding holes 5 all is positioned at the divergent section in nozzle 3 runner downstreams.
The cold air driven spray painter of a kind of downstream powder feeding comprises switch board 6, heater 7, powder feeder 8, pipeline, Raoul type nozzle 3, the preceding thorax 2 of nozzle.Gases at high pressure enter into and are divided into two the tunnel, the one tunnel behind the switch board 6 and enter heater 7 as working gas, thorax 2 before entering by working line 1 through the working gas of heater 7 heating, and the temperature of working gas is between 200 ℃ to 600 ℃ in the preceding thorax 2.Expand, lower the temperature, quicken after entering the working gas process throat in the nozzle 3.Meanwhile, another road gas enters powder feeder 8 as carrier gas and powder to be sprayed is taken out of, via the powder feeding pipe 4-2 of branch of powder feeding pipe 4-1 and process shunt and the divergent section that the powder feeding hole 5 on the nozzle wall is directly delivered to nozzle 3 downstreams.The powder particle that enters nozzle 3 downstream divergent section is accelerated to supersonic speed by working gas, and sprays to base material 10 surface formation coatings 9.Requiring emphasis is pointed out that, because powder feeding hole 5 is positioned at the downstream of nozzle 3 runners, the pressure at this place is near normal pressure, and the pressure of carrier gas just can reduce significantly like this, therefore can replace cold air power spraying and coating high pressure powder feed device commonly used with conventional powder feeder 8.
Referring to Fig. 2, have powder feeding hole 5 on the sidewall of the Raoul type nozzle 3 that is comprised in the cold air power spraying and coating method of above-mentioned downstream powder feeding and the device.Nozzle 3 divergent section flow channel cross-section size and dimensions are by the very little (2R of throat diameter
*) round continuously smooth fade to the ellipse that port of export major and minor axis is respectively 2a and 2b, that is the flow channel cross-section at any position of divergent section all is oval.The suitable length semiaxis of port of export ellipse than a/b between 1.25 to 10, better between 2 to 7; The oval semi-minor axis size b 〉=R of the port of export
*, and between 1mm to 3mm; Major semiaxis a is between 3mm to 15mm, better between 5mm to 10mm.
As the further improvement of such scheme, the divergent section flow channel cross-section size and dimension of nozzle is by the very little (2R of throat diameter
*) round continuously smooth fade to the ellipse of the port of export-rectangle combination shape, that is the flow channel cross-section at any position of divergent section all is ellipse-rectangle combination shape.Described ellipse-rectangle combination shape is to constitute like this: the centre is respectively 2b and l for the length of side
0Rectangle, major and minor axis is respectively the outside that 2a and 2b ellipse are connected two opposite side of this rectangle in two symmetrically, these two semielliptical minor axis 2b are that two rectangle opposite side of 2b coincide with length respectively; Port of export flow channel cross-section profile is these two semiellipse arcs and length is l
0Two rectangle opposite side, four sections closed curves that lines are formed by connecting altogether.The suitable length semiaxis of port of export ellipse than a/b between 1 to 10, better between 1 to 7; The length l on a limit of rectangle
0Satisfy 3a 〉=l
0〉=0, be more preferably and satisfy 2a 〉=l
0〉=b; The oval semi-minor axis size b 〉=R of the port of export
*, and between 1mm to 3mm; Major semiaxis a is between 2mm to 15mm, better between 2mm to 10mm.
Where should outlet for the powder feeding hole 5 on nozzle 3 sidewalls specifically open? studies show that under with the situation of nitrogen as the copper powders may of working gas sprayed particle diameter 25 μ m: at distance larynx L/5 places, the speed of working gas reaches v
085%; The L/4 place, v
088%; The L/3 place, v
092%; The L/2 place, v
097%; The 3L/4 place, v
099%-wherein L is the nozzle diverging segment length, v
0Be the speed of working gas at the divergent section destination county.This shows that if the outlet of all powder feeding holes 5 is all opened in distance larynx L/4 to the 3L/4 scope, the speed of working gas has reached v
088% to 99%, help acceleration to powder particle.If the outlet of all powder feeding holes 5 is all opened in distance larynx L/3 to the 3L/4 scope, the speed of working gas has reached v
092% to 99%, the most favourable to the steady acceleration of powder particle.In addition, when surpassing L/4 to the distance of throat, when particularly surpassing L/3, the pressure of nozzle flow channel is reduced near the normal pressure.In addition, because working gas temperature herein is lower, can reduce from the powder of powder feeding hole 5 long-pending to the sticking trowel used for plastering and the plug of nozzle 3 inwalls.
As previously mentioned, the axis and the transverse of the powder feeding hole 5 of nozzle 3 sidewalls of the present invention are in same plane, and the outlet of powder feeding hole 5 is positioned at the divergent section in nozzle downstream.For nozzle 3 runner axis, the layout of powder feeding hole 5 has dual mode: the first is positioned at the same side, runner axis, and it two is to be positioned at both sides.When powder feeding hole 5 was positioned at the both sides of runner axis, the number of powder feeding hole 5 must be an even number, and was symmetrical distribution with respect to the runner axis, helped reducing the powder particle sent by powder feeding hole 5 washing away and sticking trowel used for plastering the nozzle wall on outlet opposite like this.
The angle of the axis of powder feeding hole 5 and nozzle flow channel axis is very important, and in theory, this angle can be between 0 ° to 90 °.But angle is too little, and the duct of powder feeding hole 5 is long, processing difficulties.Therefore, this angle should be greater than 10 °, better greater than 30 °.If the axis of powder feeding hole 5 and the angle of nozzle flow channel axis are controlled at 10 ° to 90 °, especially be controlled at 30 ° to 75 °, not only be convenient to processing and manufacturing, and the working gas of low pressure will be owing to jet effect to the strong swabbing action of the generation of the powder particle in the powder feeding hole 5 along the flow at high speed of the inwall of the nozzle 3 of smooth gradual change.This swabbing action not only helps powder feeding, and can overcome sticking trowel used for plastering and the blockage problem of powder particle in powder feeding pipe 4-2 inside.
The size and dimension of powder feeding hole 5 is equally very important.Usually adopt circular hole (inwall level and smooth and be convenient to processing), the internal diameter of powder feeding hole 5 is identical with the internal diameter of powder feeding pipe 4-2.Powder feeding hole 5 thick excessively (as the minor axis of diameter greater than the relevant position ellipse) does not then have enough processing spaces, and powder feeding hole 5 is crossed detailed rules and regulations and is difficult to processing.Therefore, the internal diameter of each powder feeding 5 is between Φ 0.5mm to φ 5mm, better between Φ 1mm to Φ 3mm.The number of powder feeding hole 5 is not limit in principle, but will guarantee: 1) outlet of all powder feeding holes 5 is all opened in distance larynx L/4 to the 3L/4 scope; 2) the cross-sectional area sum of all powder feeding holes 5 should be at or about the cross-sectional area of powder feeding pipe 4-1.Usually, the flour opening number on the sidewall of the same side, nozzle 3 runner axis is at 0 to 3, and better 1 to 2, better 1.Powder feeding hole 5 too much will cause the powder particle velocity contrast to increase, and run foul of each other between the particle, be unfavorable for the steady acceleration of powder.Consider the wall thickness of the powder feeding pipe 4-2 that is connected with powder feeding hole 5, the distance between the adjacent powder feeding hole 5 should be 3 times to 15 times of powder feeding hole 5 internal diameters.Powder feeding hole 5 spacings are excessive, and then the speed difference of powder increases; Powder feeding hole 5 spacings are too small, then the processing difficulties in hole.
Embodiment 1:
Adopt nitrogen as working gas, copper powder particles diameter to be sprayed is at 10 μ m to 30 μ m, and matrix is an aluminium sheet.Nozzle inlet place air pressure is 2.5MPa, 380 ℃ of temperature.Adopt the high pressure powder feed device, the pressure of carrier gas is a little more than 2.5MPa.The form of nozzle as shown in Figure 2, throat diameter is Φ 2.5mm, exports to be ellipse, oval major and minor axis is respectively 14mm and 4mm, divergent section length is 65mm.Nozzle flow channel axis side walls has a pair of powder feeding hole that is symmetrically distributed with respect to the runner axis, and the diameter of phi 2.1mm of powder feeding hole, axis and nozzle axis are 45, outlet apart from the 20mm of throat.The spraying result is: deposition about 75%, coating is evenly good.
Embodiment 2:
Adopt nitrogen as working gas, copper powder particles diameter to be sprayed is at 20 μ m to 45 μ m, and matrix is an aluminium sheet.Nozzle inlet place air pressure is 3.5MPa, 400 ℃ of temperature.Adopt the high pressure powder feed device, the pressure of carrier gas is a little more than 3.5MPa.The form of nozzle as shown in Figure 1, throat diameter is Φ 2.7mm, exports to be ellipse-rectangle combination shape (just circle-rectangle combination shape), and oval major and minor axis is respectively 6mm and 6mm (positive diameter of a circle), the rectangle length of side of forming the jet expansion inner surface contour is 3.9mm, and divergent section length is 120mm.The one-sided sidewall in nozzle flow channel axis has two powder feeding holes, and the diameter of phi 2.1mm of powder feeding hole, axis and nozzle axis are 60 ° of angles, and first and second powder feeding holes export respectively apart from 55mm of throat and 65mm.The spraying result is: deposition about 65%, coating is evenly good.
Embodiment 3:
Adopt nitrogen as working gas, copper powder particles diameter to be sprayed is at 50 μ m to 75 μ m, and matrix is an aluminium sheet.Adopt conventional powder feeder, the pressure of carrier gas is 0.4MPa.Nozzle inlet place air pressure is 3.0MPa, 500 ℃ of temperature.The nozzle throat diameter is φ 3.0mm, exports to be ellipse, and oval major and minor axis is respectively 13.7mm and 4mm, and divergent section length is 200mm.The sidewall of nozzle flow channel axis one side has a powder feeding hole, and the diameter of phi 2.5mm of powder feeding hole, axis and nozzle axis are 30 ° of angles, outlet apart from the 75mm of throat.The spraying result is: deposition about 70%, coating is evenly good.
Embodiment 4:
Adopt nitrogen as working gas, copper powder particles diameter to be sprayed is at 70 μ m to 100 μ m, and matrix is an aluminium sheet.Adopt conventional powder feeder, the pressure of carrier gas is 0.3MPa.Nozzle inlet place air pressure is 3.5MPa, 500 ℃ of temperature.The throat diameter of nozzle is Φ 2.0mm, exports to be ellipse-rectangle combination shape, and oval major and minor axis is respectively 12mm and 4mm, and the rectangle length of side of forming the jet expansion inner surface contour is 3.2mm, and divergent section length is 150mm.Nozzle flow channel axis side walls has two pairs of powder feeding holes, and the diameter phi 1.5mm of powder feeding hole, axis and nozzle axis are 60 ° of angles, and first and second powder feeding holes export respectively apart from 70mm of throat and 85mm.The spraying result is: deposition is a little more than 60%, and coating is evenly good.
Embodiment 5:
Adopt nitrogen as working gas, copper powder particles diameter to be sprayed is at 10 μ m to 30 μ m, and matrix is an aluminium sheet.Adopt conventional powder feeder, the pressure of carrier gas is 0.3MPa.Nozzle inlet place air pressure is 3.0MPa, 450 ℃ of temperature.The form of nozzle as shown in Figure 2, throat diameter is Φ 2.7mm, exports to be ellipse, oval major and minor axis is respectively 13.1mm and 5mm, divergent section length is 120mm.Nozzle flow channel axis side walls has a pair of powder feeding hole that is symmetrically distributed with respect to the runner axis, and the diameter phi 2.5mm of powder feeding hole, axis and nozzle axis are 75 ° of angles, outlet apart from the 60mm of throat.The spraying result is: deposition is near 80%, and coating is evenly good.
Claims (9)
1. the cold air power spraying and coating method of a downstream powder feeding is that gas is through expanding and acceleration in the downstream divergent section behind the nozzle throat in the convergence section with working gas heating and input Raoul type nozzle flow channel upstream; By carrier gas the metal powder granulates to be sprayed in the powder feeder is directly sent into the downstream divergent section of nozzle, accelerate to supersonic speed by wherein working gas again; It is characterized in that: powder particle to be sprayed is directly to send to nozzle downstream divergent section from the outside of nozzle by the powder feeding hole on the nozzle wall via powder feeding pipe; The divergent section flow channel cross-section is ellipse-rectangle combination shape, the axis of all powder feeding holes of nozzle wall all is in same plane with long axis of ellipse, described transverse plane is the longitudinal section at flow channel cross-section transverse place, the outlet of all powder feeding holes all is positioned at the divergent section in nozzle downstream, and powder particle is quickened the back by working gas and sprays from the nozzle diverging section port of export; Described ellipse-rectangle combination shape is to constitute like this: the centre is respectively 2b and l for the length of side
0Rectangle, the ellipse that major and minor axis is respectively 2a and 2b in two symmetrically smooth connection in the outside of two opposite side of this rectangle; Port of export flow channel cross-section profile is these two semiellipse arcs and length is l
0Two rectangle opposite side totally four sections closed curves that lines are formed by connecting.
2. the cold air power spraying and coating method of downstream according to claim 1 powder feeding is characterized in that: powder feeder is the powder feeder under the normal temperature and pressure.
3. the cold air driven spray painter of a downstream powder feeding, comprise switch board, heater, powder feeder, pipeline, Raoul type nozzle, the preceding thorax of nozzle, gases at high pressure are divided into two the tunnel after entering into switch board, one the tunnel enters heater as working gas, thorax before working line enters nozzle sprays through Raoul type nozzle; Another road enters powder feeder as carrier gas and powder to be sprayed is taken out of, it is characterized in that: powder feeding pipe is connected to the powder feeding hole of Raoul type nozzle downstream divergent section sidewall, has powder feeding hole on the divergent section inwall of nozzle downstream; Raoul type nozzle diverging section flow channel cross-section makes up shape by ellipse-rectangle that the very little circle of throat diameter smoothly fades to the port of export continuously, and promptly the flow channel cross-section at any position of divergent section all is ellipse-rectangle combination shape; The axis of all powder feeding holes on the divergent section nozzle wall all is in same plane with long axis of ellipse, and described transverse plane is the longitudinal section at flow channel cross-section transverse place; Described ellipse-rectangle combination shape is to constitute like this: the centre is respectively 2b and l for the length of side
0Rectangle, the ellipse that major and minor axis is respectively 2a and 2b in two symmetrically smooth connection in the outside of two opposite side of this rectangle; Port of export flow channel cross-section profile is these two semiellipse arcs and length is l
0Two rectangle opposite side totally four sections closed curves that lines are formed by connecting.
4. the cold air driven spray painter of downstream according to claim 3 powder feeding is characterized in that: the length semiaxis of the port of export ellipse of Raoul type nozzle diverging section than a/b between 1 to 7.
5. the cold air driven spray painter of downstream according to claim 3 powder feeding is characterized in that: the semi-minor axis of the port of export ellipse of Raoul type nozzle diverging section is more than or equal to throat radius, and semi-minor axis b is between 1mm to 3mm, and major semiaxis a is between 2mm to 10mm.
6. the cold air driven spray painter of downstream according to claim 3 powder feeding is characterized in that: the length l on a limit of the port of export rectangle of Raoul type nozzle diverging section
0Satisfy 2a 〉=l
0〉=b.
7. the cold air driven spray painter of downstream according to claim 3 powder feeding is characterized in that: the layout of the powder feeding hole on the Raoul type nozzle wall has dual mode: the first is positioned at the same side, runner axis, and it two is to be positioned at both sides, runner axis; When being positioned at both sides, runner axis, the number of powder feeding hole must be an even number, and is symmetrical distribution with respect to the runner axis.
8. the cold air driven spray painter of downstream according to claim 7 powder feeding is characterized in that: the axis and the nozzle flow channel axis of the powder feeding hole on the Raoul type nozzle wall are 30 ° to 75 ° angle.
9. the cold air driven spray painter of downstream according to claim 7 powder feeding is characterized in that: the distance that exports to throat of the powder feeding hole on the Raoul type nozzle wall is in 1/3rd to 3/4ths scopes of divergent section length.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100309143A CN100446870C (en) | 2005-10-31 | 2005-10-31 | Cold air dynamical spray-painting method and apparatus of delivering powder through down stream |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100309143A CN100446870C (en) | 2005-10-31 | 2005-10-31 | Cold air dynamical spray-painting method and apparatus of delivering powder through down stream |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1958171A CN1958171A (en) | 2007-05-09 |
| CN100446870C true CN100446870C (en) | 2008-12-31 |
Family
ID=38070112
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2005100309143A Expired - Fee Related CN100446870C (en) | 2005-10-31 | 2005-10-31 | Cold air dynamical spray-painting method and apparatus of delivering powder through down stream |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100446870C (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101116849B (en) * | 2007-07-31 | 2010-05-19 | 中国船舶重工集团公司第七二五研究所 | De-Laval-Type nozzle for cold spraying |
| CN103422088B (en) * | 2012-05-22 | 2016-03-30 | 中国科学院金属研究所 | A kind of cold spray apparatus and method preparing 316L stainless steel coating |
| CN102814248B (en) * | 2012-08-01 | 2014-12-10 | 中国船舶重工集团公司第七二五研究所 | Nozzle for axial siphon powder delivering type cold spray |
| CN102861713A (en) * | 2012-09-04 | 2013-01-09 | 河南省超贝工程设备有限公司 | Ultra-high molecular weight polyethylene coating and preparation method thereof |
| CN103521404B (en) * | 2013-10-25 | 2015-12-02 | 中国船舶重工集团公司第七二五研究所 | A kind of Portable low-pressure cold spray apparatus |
| CN104878343B (en) * | 2015-05-18 | 2018-07-20 | 广东省新材料研究所 | A kind of diamond/copper composite material surface cu coating preparation method |
| CN110055484B (en) * | 2019-04-25 | 2021-08-20 | 西安智能再制造研究院有限公司 | Supersonic laser deposition spray gun, laser deposition device and laser deposition method |
| CN111185316A (en) * | 2020-03-16 | 2020-05-22 | 广东省新材料研究所 | Nozzle device, spray gun and application thereof |
| CN111441045B (en) * | 2020-05-28 | 2024-03-22 | 西安建筑科技大学 | Electron beam deposition spray head and method |
| CN114918055A (en) * | 2022-05-17 | 2022-08-19 | 广东省科学院新材料研究所 | Upstream and downstream powder feeding nozzle for cold spraying and coating cold spraying production system |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5302414A (en) * | 1990-05-19 | 1994-04-12 | Anatoly Nikiforovich Papyrin | Gas-dynamic spraying method for applying a coating |
| US6402050B1 (en) * | 1996-11-13 | 2002-06-11 | Alexandr Ivanovich Kashirin | Apparatus for gas-dynamic coating |
| US20020071906A1 (en) * | 2000-12-13 | 2002-06-13 | Rusch William P. | Method and device for applying a coating |
| CN1161188C (en) * | 2001-09-05 | 2004-08-11 | 中国科学院金属研究所 | Cold air driven spray painter |
| US6811812B2 (en) * | 2002-04-05 | 2004-11-02 | Delphi Technologies, Inc. | Low pressure powder injection method and system for a kinetic spray process |
-
2005
- 2005-10-31 CN CNB2005100309143A patent/CN100446870C/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5302414A (en) * | 1990-05-19 | 1994-04-12 | Anatoly Nikiforovich Papyrin | Gas-dynamic spraying method for applying a coating |
| US5302414B1 (en) * | 1990-05-19 | 1997-02-25 | Anatoly N Papyrin | Gas-dynamic spraying method for applying a coating |
| US6402050B1 (en) * | 1996-11-13 | 2002-06-11 | Alexandr Ivanovich Kashirin | Apparatus for gas-dynamic coating |
| US20020071906A1 (en) * | 2000-12-13 | 2002-06-13 | Rusch William P. | Method and device for applying a coating |
| CN1161188C (en) * | 2001-09-05 | 2004-08-11 | 中国科学院金属研究所 | Cold air driven spray painter |
| US6811812B2 (en) * | 2002-04-05 | 2004-11-02 | Delphi Technologies, Inc. | Low pressure powder injection method and system for a kinetic spray process |
Non-Patent Citations (2)
| Title |
|---|
| Mixing of high speed coaxial jets. R.I.Sujith, R.Ramesh, S.Pradeep,S.Sriram,T.M.Muruganandam.Experiments in fluids,No.第30期. 2001 |
| Mixing of high speed coaxial jets. R.I.Sujith, R.Ramesh, S.Pradeep,S.Sriram,T.M.Muruganandam.Experiments in fluids,No.第30期. 2001 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1958171A (en) | 2007-05-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100446870C (en) | Cold air dynamical spray-painting method and apparatus of delivering powder through down stream | |
| US4866240A (en) | Nozzle for plasma torch and method for introducing powder into the plasma plume of a plasma torch | |
| JP3007895B2 (en) | Single cathode plasma gun and anode attachment for use therein | |
| CA2688108C (en) | Cold gas dynamic spray apparatus, system and method | |
| TWI548309B (en) | Axial-feeding type plasma spraying device | |
| US6861101B1 (en) | Plasma spray method for applying a coating utilizing particle kinetics | |
| CN100406130C (en) | Cold air powered spraying method and device | |
| CN101410551B (en) | Cold-gas spray gun | |
| US6986471B1 (en) | Rotary plasma spray method and apparatus for applying a coating utilizing particle kinetics | |
| US20020071906A1 (en) | Method and device for applying a coating | |
| US6322856B1 (en) | Power injection for plasma thermal spraying | |
| US20060038044A1 (en) | Replaceable throat insert for a kinetic spray nozzle | |
| JP2006247639A (en) | Nozzle for cold spraying, cold spray device and cold spray method using it | |
| US4836447A (en) | Duct-stabilized flame-spray method and apparatus | |
| CN101954324B (en) | Plasma spray gun used for low-pressure plasma spraying | |
| CN100391617C (en) | Composite ceramic Raoult nozzle for cold spray coating | |
| US20090256010A1 (en) | Cold gas-dynamic spray nozzle | |
| WO2007091102A1 (en) | Kinetic spraying apparatus and method | |
| CN107042310A (en) | A kind of gas atomizing nozzle | |
| US9834844B2 (en) | Nozzle for a thermal spray gun and method of thermal spraying | |
| CN1709585A (en) | High-pressure gas atomizing nozzle | |
| CN1404925A (en) | Plasma spraying gun | |
| CN114481003A (en) | Hot cathode spray gun, nano plasma spraying device and method | |
| CN2714160Y (en) | High pressure gas atomizing nozzle | |
| CN2296241Y (en) | Ultrasonic electric arc spray device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20081231 Termination date: 20161031 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |