JPS6029309B2 - Flame jet method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrafast molten metal or ceramic jet system, particularly for increasing the temperature and velocity of a molten jet for emitting a flaming jet of liquid particles at very supersonic speeds. METHODS AND APPARATUS.

Attempts have been made to provide a flame jet device having an internal burner that operates to produce a very high velocity jet of flame.

One such supersonic flamethrower was launched on July 4, 1961.
It is published on the day. No. 2,990,653, entitled "Method and Apparatus for Impingement of High-Velocity Streams on Surfaces to be Treated." The device has an air-cooled, double- or triple-walled, cylindrical internal burner whose internal cavity shape forms a cylindrical combustion chamber. Downstream of the internal combustion point, this combustion chamber is closed by a flame jet nozzle of decreasing diameter. Yet another attempt to provide an ultrafast flame jet device for such metals involves directing recalcitrant metals into a high velocity flame jet with a solid powder or small diameter rod. An apparatus has been invented which utilizes a main stream of a relatively low momentum jet to mix and discharge molten particles into a second, sub-temperature, gaseous jet of very high momentum.

Apparatus and methods of this type are described in the inventor's co-pending U.S. Patent Application No. 15,299, filed May 23, 1985.
No. 6 entitled "Method and Apparatus for Ultrafast Dual Flow Metal Flame Jets". A more recent U.S. patent application of the inventor for this method and apparatus uses an oxy-fuel flame or electric arc-generated plasma in the first stream, while the second stream uses an air-fuel flame reacting at high pressure with an internal burner device. It uses the flame stream generated. In combining these two streams, the molten particles are preferably carried by the first stream at a relatively low velocity but at a relatively high temperature, while the molten particles are transported at very high speeds against the surface being viewed. The impinging ultra-high velocity jets are ejected from the combustion chamber of the internal burner. Combustion takes place at relatively high pressure in this combustion chamber. A second stream is directed through an annular nozzle surrounding the main stream. Furthermore, the first stream and the second stream pass through the nozzle structure to the point of impact on the substrate to be deposited by the liquid particles flying at a very high velocity under the acceleration provided by the second jet of heated gas. released. The present invention relates to a unique method and apparatus for using an oxyfuel internal burner to melt metals, ceramic materials, and accelerated melting particles at extremely high speeds.

In particular, the invention describes a special method of introducing powder or rod-shaped substances into the flame produced by an internal burner, metal or ceramic particles which are applied at ultra-high speed at the end of an elongated nozzle to the substrate to be deposited. This method uses a very long flow path. Additionally, this material is introduced into the gas stream at a point in front of the largest nozzle burr or throat, thus confining the particle stream to a small diameter cylindrical core passing through the center of the nozzle hole. In the method and apparatus of the present invention, the flow of liquid metal or ceramic droplets is 1M below the diameter of the nozzle embargo.
Pass through a small diameter nozzle with a flow path length longer than the sound. Maximum particle velocity is achieved with an oxyfuel metal internal burner. The burner has an upstream internal combustion chamber and a fitted nozzle for burning fuel together with an oxidizer at high pressure.
Hot combustion chamber product gases exit through this nozzle. A rod-like or granular stream of metal or other solid material, such as ceramic material, is then introduced into the hot gas for melting and acceleration. The improvement consists in locating the point of introduction of the solid substance in the elongated nozzle throat or just upstream of the throat. A small diameter rod-shaped solid material is introduced into the gas stream through a hole in the nozzle casing that is in line with the nozzle throat.

Means is provided for supplying an inlet stream of hot gas from the internal burner combustion chamber to the nozzle throat. This nozzle throat has a radial inlet component of the velocity of the inlet stream which tends to limit the diameter of the column of particles when particulate material is used or when solid material is used. A small diameter shank or configuration maximizes heat transfer to the periphery of the rod. Preferably, the length of the nozzle hole is at least 4.5 times the diameter of the nozzle hole. Additionally, the pressure within the combustion chamber should be maintained at or above 7 marks SIG (approximately 5.27 k9w/). Referring to FIGS. 1-3, the principal elements of the improved flame jet device of the present invention are depicted, in cross-sectional view and somewhat diagrammatically, in one embodiment. The device, designated 1, takes the form of a metal flame jet "gun" and consists of a body 10 having a threaded cylindrical metal nozzle insert, designated 11.

In this regard, the body 1, which is L-shaped in longitudinal section, has a cylindrical hole 4 inside one end, which ends at the end of the hole in the transverse wall 5. Attach a screw thread to the hole 4 as shown in 4a. Further, an insertion member 11 having a T-shaped cross section and a radially enlarged flange 11a.
A thread is attached to 11b so as to match the thread 4a of the main body 10, and it is engaged there when assembled. The end face 11c of the insert member 11 faces the substrate coated with flame warm current. On the other hand, the opposite end surface 11d is adjacent to the end surface 5 of the hole, as clearly shown in FIG. The main body 10 further includes a cylindrical cavity in a part perpendicular to the part having the nozzle insert 11, which cavity forms an elongated cylindrical high-pressure combustion chamber 12. 12 has a defined volume for high-pressure combustion of oxygen and fuel which are supplied under pressure to the combustion chamber as indicated by arrows 31 and 32, respectively. An oxygen supply tube or line 14 projects into the cylindrical hole 7 within the end 10a of the body 10. There is also an inclined oxygen passage 23 which closes at one end into the inside of the combustion chamber 12 and at the pond end into a hole 7 with an oxygen supply pipe 14. A second, slightly smaller diameter fuel supply pipe 13 is adjacent to the oxygen supply pipe 14 . The end of the supply tube 13 is held in a cylindrical hole 6 in a sealed manner. The fuel is guided from the fuel inlet pipe 13 to the combustion chamber 12 through a small diameter fuel passage 24.
sent through. Passage 24 is angled in the opposite direction to passage 23 and opens into the interior of the combustion chamber adjacent one end of oxygen supply passage 23 . The fuel is either in liquid or gaseous form; if it is gaseous, it is sucked under considerable pressure into the oxygen supplied to the combustion chamber 12, thus separating the fuel in particulate form and the air. form a mixture with.

Combustion is effected within the combustion chamber 12 by ignition means, such as a spark plug (not shown), with combustion beginning at the point of fuel and air discharge, ie, at the upper end of the combustion chamber 12 in FIG. 15,1
The annular passages such as 6, 17, 18 provide cooling of the "gun" body 10, ie water or other cooling medium is circulated through the various annular passages.

Furthermore, annular passages such as 27, 28 are provided in the nozzle insert for cooling the nozzle insert. In order to effectively reduce the external temperature of the flame jet device, an annular loop (not shown) typically supplies water to all passages as indicated above. As clearly shown in FIG. 3, there are a number of oblique holes such as 19 (four in the illustrated embodiment) within the body 10.

The bore 4 receives a nozzle insert 11, said holes converging towards a point downstream of the end wall 5. These holes 19 open in the row 9a of the wall 5. The two upper inclined holes 1!9 open directly into the lower end of the combustion chamber 12,
On the other hand, the upward and inwardly sloping lower hole 19 opens into the combustion chamber 12 at its upstream end by a pair of vertical holes 20. This hole 20 is located on both sides relatively far from the small metal or ceramic powder supply hole 21. This supply hole 2
1 opens at the edge 5 of the hole 4 and at the center of the opening 19a surrounding the opening of the powder supply hole 21. This powder supply hole 2
1 is formed by a small diameter hole counterbored at 28 and further counterbored at 29. The counterbore hole 29 is connected to the powder supply pipe 22
Accepts the protruding end of the This powder supply pipe 22 forms a straight line between the powder supply hole 21 and the counterbore 28, and is sealed and fixed to the main body 10'. Means (not shown) for supplying powdered metal or ceramic material M to the powder supply hole 21 is provided. The nozzle insertion member 11 has a collecting part 25a and a diffusing part 25b, respectively.
A venturi-type nozzle passage is formed from the end 11d to the end 11c, and has a corner or corner 25c.

This throat or corner 25c is the smallest portion of the flow path defined by the intersection of the converging section and the diffusing sections 25a, 25b. The converging gas jet, indicated by arrow J in FIG.
c into a single stream that converges radially inward. Powder M coming out of the mouth or end 21a of the powder supply hole is blown inward in the radial direction, or at least the powder M is blown into the nozzle insertion member 11, that is, the collecting portion 25 of the nozzle insertion member 11.
cannot spread out to enter the high velocity gas passing through the Venturi nozzle of a. In this way, the powder is absorbed even in the part where the hole has the smallest diameter, that is, in the squeeze part 25c.
But also other parts of the hole 25 do not touch the wall of the hole 25. In one test, the diameter of the recessed portion 25c was 5/16 inches (approximately 7.94 inches), and the length of the hole 25 was 4 inches (approximately 101.6 inches). By providing a thread on the nozzle insertion member and forming it as a backing material separate from the main body 10, it is possible to protect the nozzle from being damaged or worn out during use, or by changing the shape of the nozzle part of the metal flame jet "gun". The nozzle insert can be replaced when changing characteristics. Visual observation revealed the presence of a substantially cylindrical core 26 of high velocity jet passing through the center of the nozzle hole 25 and spaced from the surface of the hole 25. This cylindrical core has a diameter of approximately 1/8 inch.
ribs). Even after many extensive works with powders ranging from aluminum to tungsten-carbide-cobalt mixtures, no evidence of powder migration creating deposits on the hole walls could be seen. The concentration or so-called "focusing" effect of the new methods and devices for directing specific powders is manifested directly with respect to the gas flow rate.

This gas flow rate is represented by the pressure maintained in the combustion chamber 12 for a given nozzle insert. Detailed micrograph studies of the adhering deposits of the jet on the substrate (not shown) downstream of the nozzle outlet 25e show that the degree of adhesion and the thickness of the adhesion layer increase with increasing pressurization of the combustion chamber pressure. It shows an increase. The combustion chamber 12 is approximately 20 Misaki SIG (approximately 14.06k9w/
For pressures greater than 100 psi, this deposit is superior to that deposited by a plasma jet gun operated by a gas at a temperature almost an order of magnitude higher than that for the oxy-fuel internal burner according to the invention. This leads to the conclusion that the high velocities available with oxy-fuel systems are more than sufficient to overcome the lower heat intensity of the lower heating unit. A relatively long nozzle hole path length is required to provide sufficient residence time of the particles to melt them in the low temperature gas.

Necessarily, the equipment operating under the method according to the invention is such that the deposited material, whether powder or solid, absorbs the combustion products before they pass through the narrowest constriction of the nozzle. It is necessary to be guided into the flow of water.

Gas velocities must be extremely high to achieve supersonic particle impact velocities on the surface being deposited. The supersonic speed for this study is approximately 1200 m/s in the ambient atmosphere.
feet (approximately 365.76 feet).

In the combustion chamber, the pressure is 200$IG (approx. 14.06k9w/
), particles travel at approximately 2,000 feet per second (approximately 609 feet per second).
．． 6 m), and when the pressure in the combustion chamber 12 is 50th SIC (approximately 35.15 k9w/earth), the speed increases to over 3000 feet per second (approximately 914.6 m). This velocity is higher than that previously recorded by the inventor's experience with the fastest jet impact velocity achieved by an explosive gun jet. Next, a second embodiment according to the invention, shown in FIG. 4, differs from the powder embodiments of FIGS. Contains substances.

However, the main principles of the first embodiment of the invention work equally well for atomizing comb or linear materials. In a simplified embodiment, the schematic "gun" 40 has a body 41 with a hole 52 in one leg. This hole is a cylindrical nozzle insertion section having a bench-shaped J nozzle type hole shown at 47, which includes a diffusion section 47a and a collection section 47b, respectively, downstream and upstream of the part with the smallest diameter of the hole in the bore part 48. Equipped with 42. The body 41 also has a combustion chamber 43 which extends to a sufficient height through the generally vertical body portion. In the bottom of this cylindrical combustion chamber, the body 41 has a conical projection 46 at right angles to the axis of the combustion chamber. A small diameter hole 53 is formed in the center of the projection 46, and the conical projection 46 is coaxially aligned with the nozzle insertion member 42. The apex of the conical projection 46 is the nozzle insertion member 42
It ends a little upstream from the inner end 42a. The small-diameter holes 53 slidably support elongated strands or lines of deposited material, which strands or lines are securely directed toward the venturi nozzle 47 by opposing motor-driven rollers 45 with the birch or line in between. The end 44a of the stem fully protrudes into the nozzle hole. The diffuser portion 47a of the nozzle extends to finely atomize the molten film that exits from the sharp end 44a of the comb or line 44 when melted. The operation of the second embodiment according to the invention is the same as the first embodiment.

Oxygen under pressure is supplied to the combustion chamber 43 through the oxygen supply channel 53, while liquid or gaseous fuel enters the combustion chamber through the fuel supply channel 54. The flow of oxygen and fuel is indicated by arrows as shown in the figure. As a result of igniting the oxygen and fuel under pressure in the combustion chamber 43, the products of high velocity combustion contact the line 44 upstream of the lumen 48 of the nozzle bore.

This maximizes heat transfer and the surface layer of the wire melts quickly. The high driving force of the nozzle throat or bore 48 and the enlarged nozzle hole 47 ensure fine atomization of the molten film as it exits the sharp end 44a of the line. A ceramic rod is used in place of the metal wire 44 in exactly the same way, and rollers 45 are similarly provided facing each other.
It may also be supplied by driving.

The metal wire or ceramic rod protrudes in the direction of the steel wire beyond the small diameter hole 53 of the conical projection 46 on the upstream side of the throat 48 in the elongated nozzle hole. 48 and the existence of the conical protrusion 46 and the alignment of this protrusion with the inlet end of the nozzle hole 47 make it difficult for the gas jet to recover. The molten particles suspended in the high velocity gas stream are maintained well separated from the walls of the diffusion section 47a, and the molten particles of metal or ceramic are suspended in the substantially cylindrical core 50.
It comes out from the ejector in the nozzle insertion part inside. This can have a diameter of about 1/8 inch (approximately 3.18 feet) to correspond to the molten powder particles exiting the elongated nozzle hole 25 of the embodiment of FIGS. 1-3. Preferably, the length of the nozzle hole beyond the point of introduction of the flow of powder, rod or solid wire is at least 5 times the diameter of the minimum diameter of the nozzle hole, i.e. It should be doubled. In addition, the pressure inside the combustion chamber is 15 rudder SIG (approximately 10.55 kgw
/c tiger) or maintained higher than both examples. In yet another embodiment, oriented as shown in FIG. 5 below, only that portion of the supersonic flame jet device, designated by nozzle 60, adjacent thereto is shown.

In this embodiment, the rotational component of the hot gas stream radiating from the combustion chamber (not shown) causes the hot gas stream to flow into the flame jet device 60.
At the point of contact with metal particles passing through the nozzle hole at high speed,
With respect to the embodiment of FIG. 5, in which optimum conditions are obtained when removed, similar elements to the embodiments of FIGS. 1, 2 and 3 are similarly numbered. A plurality of holes 19 converge along the boundary line of an extended nozzle passageway defined by a threaded cylindrical metal nozzle insert and designated at 25 for the jet device designated at 11. Provide a hole. For optimum performance, hole 19 must lie in a plane co-selective to the axis of the nozzle hole of hole 25. As a result, there is no radial directional component to the hole rut line. Also, the overall flow through hole 25 has no tangential swirl component. Under these conditions it is possible to maximize the nozzle length without particles depositing on the nozzle wall. 9
Inch (approximately 225.6 female) nozzle length provides a straight hole (
All embodiments of FIGS. 1-3 operate satisfactorily as described above, using a venturi extension (without a venturi extension).

For the bore 25, the diameter of the main portion 25b downstream of the throat served by the receiving inlet portion 25a is 5/1
6 inches (approximately 7.94 fences). A length to diameter ratio of approximately 3 to 1 is thus obtained in the embodiment of FIG. Although the operating principle that the particles are located at a distance from the wall of the nozzle hole over the entire length of the nozzle sections 25b and 25a is well understood, increasing the nozzle length up to a certain limit is not possible using the device according to the invention by the method according to the invention. This is very important in order to maximize the efficiency of the resulting supersonic flame jet device.

Such parameters and their critique can be further understood with reference to FIGS. 6 and 7.
A typical nozzle with a nozzle insert having an extended bore length as shown in FIG. 5 has a convergence portion 25a.

This iron collecting portion is conical and intersects with the extension 25b of the hole 25 and a constant diameter portion forming the throat of the nozzle hole. The wall 25a of the iron collecting portion is a flame orifice or hole 19.
Starting from the circumference formed on the outer wall of the part with . As shown, the powder in the carrier gas stream enters the astringent portion of the hole through a central passageway 21 that opens upstream of the throat and is coaxial with the hole. FIG. 6 depicts the temperature history of the gas by line 62 and by lines 64 and 66 for iron and aluminum particles passing through the nozzle, respectively.

That is, line 62 indicates the temperature of the hot gas, and lines 64 and 66 indicate the iron and aluminum particle temperatures, respectively. In a propane-oxygen flame, the combustion products are approximately 54,000 F at the entrance to the nozzle hole 25. The temperature gradient of these gases along the nozzle hole is initially low due to the recombination of dissociated components. With sufficient recombination, the gradient increases. Heat from the flame gases is transferred to the walls of the nozzle body and to the cooler particles. As an example, the iron particles are placed in the nozzle hole about 7
Enter at 50F (approximately 2u℃).

Initially the temperature of the iron particles increases rapidly within the region of intense dissociation.
When the temperature of the particles reaches the melting point AFE, the particles maintain their temperature constant at 28020F (approximately 1538.9 qo). This constant temperature occurs until the particles melt at point BF8. When BFE is carried out, the temperature of the molten metal increases again as depicted by the solid line. Therefore, BF8 is the melting point of iron. Dotted line 66 includes points AA, and B^, and shows the significant temperature difference that is obtained with lower melting temperature particles, such as aluminum. Once the particles reach their melting point, an initial constant temperature is obtained and the melting point continues until the particles are completely melted. As the particles progress through the nozzle hole, the temperature of the particles increases substantially. The solid and dotted curves for iron and aluminum, respectively, are of similar shape.
Next, regarding FIG. 7, while FIG. 6 is a diagram of the relationship between temperature and distance, FIG. 7 is a diagram of the relationship between speed and distance.

Line 68 in FIG. 7 indicates hot gas velocity and line 70 indicates particle velocity. FIG. 7 shows, at line 68, a uniform decrease in gas velocity for particles passing through the nozzle hole with loss of temperature. The value of velocity from point to point is that of the speed of sound for a gas at a particular temperature. If it exits the nozzle in an underexpanded state, the free expansion of the gas into the atmosphere will cause the velocity to increase very rapidly. For particle acceleration purposes, the optimum condition is at the nozzle throat, and in the case of FIG. 5 this condition is present throughout the long constant diameter hole section 25b.

Therefore, a long straight nozzle accelerates the particles farther than a diffuser nozzle designed to maximize gas velocity, as seen at line 70. On the other hand, a diffusion nozzle increases the radial length of the passage so that the particles have to travel to reach the wall. As can be seen, a straight or constant diameter hole nozzle will "talk" to the tip of the eye. The particle-encased core 26 of FIG. 5 illustrates one theory of particle passage through the long/slug.

Of course, local disturbances will occur in the particle velocity which imparts a radial velocity to the particles. If the radial velocity is sufficiently greater than its radial component, the particle will be able to exit the nozzle passageway before making a radial motion corresponding to the nozzle hole radius. Particles therefore exit from the passageway or hole 21 and enter the nozzle insert 11.
During the movement of particles into the pore section 25a, the pore walls will not be impacted. This hypothesis may be true for the majority of particles.

However, it is possible that some particles reach the nozzle wall within the hole 25b. The angle of impact is very small due to the high axial velocity, so these particles do not stick together (and therefore do not create a plug). In addition, at least the points BFE and B^ in FIG. If it is introduced as solid particles from the end of the combustion chamber to the hot gas exiting the combustion chamber, it is in a plastic state. That is, the particles are heated soft but not liquefied, although close to liquefaction. These soft, heated, or plastic particles easily bounce off the metal surface when they come into contact with the metal surface. Similar results occur in practice whether it is a separate zero-part flow or control of particle bounce.

/A certain distance along the spool results in a deposit of impinging particles. This is especially true if the impinging particles result from the melting of solid particles rather than the introduction of the solid particles into the high-velocity convergent gas stream exiting the hole 19 through the passageway 21. In either case the nozzle length must be limited to a value of 4 mm below that at which deposition occurs. An unexpected benefit of using a long nozzle is that the temperature of the jet gas impinging on the workpiece to be injected is lowered.

As the nozzle becomes longer, this harmful heating decreases. This is especially true when these gases are cooled below their dissociation point. The dissociated components recombining on the cooled surface provide a large source of heat and therefore require a means to dissipate such heat at the point of ejection. The above discussion and the illustrations shown in FIGS. 6 and 7 relate to a single particle of a given material and size.

For a given reactant and flow rate, the optimal nozzle length can be determined by testing. Changing the material or particle size distribution requires different nozzle lengths. For example, referring to the dotted line drawn below for aluminum in FIG. 6, the melting point B^, is located far upstream of the nozzle hole exit. "Clogging" thus occurs more quickly with aluminum than with iron and its alloys. If a long nozzle length is desired for aluminum, a reduction in the hot gas temperature curve will retard melting.

This is accomplished by diluting the oxygen stream with an inert gas, such as by adding flowing air. Longer nozzles can also be used with increased hole diameters. In order to keep the specific momentum at the same value, increasing actance flow is important to compensate for the increase in pore diameter. In addition, a delay in melting can be obtained by increasing the average particle diameter if the material introduced through the holes 21 is in solid particle form. In summary, the present invention maximizes jet particle heating and acceleration by increasing the length-to-diameter ratio of the nozzle hole.

These ratios are only possible using a cylindrical hot gas stream, especially if the swirl component is intentionally minimized or eliminated. In some cases, such as ejecting high temperature ceramics, the oxyfuel flame may not be hot enough to adequately melt the particles. In this case, the combustion reaction has to be replaced by electrically heating the flowing gas. When used in lines or traces instead of powder material, i.e. in solid particle form, in the form and manner depicted in FIG. 4, the rod begins to heat up until a liquified thin film forms on its surface.

Hot, high-speed gas blows away this thin film from the tip of a rod that runs vertically in the scale line direction along the nozzle hole. Each particle thus breaks up and melts this film. The manner in which the particles impinge and deposit on the walls of the pores is due to the impingement of fully liquefied material rather than plastic particles such as occur in the form of powder particles. Thus, the maximum nozzle length for lines and rays can be shorter than the nozzle length when introducing powder material into a hot supersonic gas stream.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a highly concentrated supersonic liquid material flame jet device according to the present invention, FIG. 2 is an enlarged view of the venturi nozzle throat of the device in FIG. 1, and FIG. 3 is a line m 4 is a partial cross-sectional view of the device of FIG. FIG. 5 is a longitudinal sectional view of a nozzle forming part of a supersonic liquid material flame jet device according to yet another embodiment of the invention; FIG. 6 is a longitudinal sectional view of a second embodiment of the present invention utilized; Under typical use, a diagram showing the temperature versus distance of the carrier gas, iron, and aluminum particles passing through the nozzle aperture in Figure 5 and the metal particles; 3 is a diagram showing the relationship of hot gas and particle velocity to distance during passage through the nozzle of the illustrated embodiment; FIG. DESCRIPTION OF SYMBOLS 1... Flame jet device, 4... Hole, 4a... Screw thread, 5... Side wall and end surface, 6, 7, 19... Hole,
DESCRIPTION OF SYMBOLS 10... Main body, 10a... End, 11... Nozzle insertion member, 11a... Flange, 11b... Thread, 11c...
End face, 12... High pressure combustion chamber, 13... Fuel supply pipe,
14...Oxygen supply pipe or line, 15, 16, 17, 18
... Annular passage, 19a... Mouth, 20... Hole, 2
1... Powder supply hole, 21a... Mouth or end, M...
Supply or ceramic material, 22... Powder supply pipe, 23
...Oxygen supply passage, 24...Fuel passage, 25...
Hole, 25a... Yield part or inlet part, 25b...
Diffusion part or main part, 25c... Throat or corner part, 25c... Nozzle discharge port, J... Arrow, 27,
28... Annular passage, 28, 29... Counterbore or counterbored hole, 31, 32... Arrow, 40... Gun, 41... Main body, 42... Nozzle insertion member, 42a... End , 43・
... Combustion chamber, 45... Drive roller, 46... Conical projection, 47... Venturi nozzle or nozzle hole, 4
7a... Diffusion part, 47b... Yield part, 48...
・Color part or throat part, 50...'○ part, 52, 53
... Hole, 53'... Oxygen supply passage, 54... Fuel supply passage, 60... Supersonic flame jet device, 62...
A line indicating the temperature of the hot gas, 64... A line indicating the temperature of the iron particles, 66... A line indicating the temperature of the aluminum particles, 68.
... Line showing high temperature gas velocity, 70... Line showing particle velocity. FIG! FIG2 FIG3 FIG4 FIG5 FIG6 FIG7

Claims (1)

Claims: 1. Continuous combustion under pressure of a continuous flow of an oxy-fuel mixture contained within a substantially closed internal burner combustion chamber, with the hot combustion product gases being produced as a high velocity hot gas stream;
The combustion chamber is discharged through a nozzle having a converging inlet portion leading to the throat of the nozzle hole of the smallest diameter and exiting through the nozzle outlet hole, supplying the material for high temperature thermal softening or liquefaction and at the discharge end of the nozzle. In a flame jet method comprising the step of ejecting at high velocity onto a surface placed in the path of the gas stream, the step of supplying the substance comprises transferring the substance in solid form to the exterior of the combustion chamber and exiting the combustion chamber. axially into the converging stream of hot combustion product gases and
into the convergent portion of the nozzle to be ejected through a nozzle hole having a length at least five times the diameter of the end of the nozzle hole;
characterized by limiting the diameter of the column of particles passing through the nozzle hole, preventing the deposition of particulate matter on the nozzle hole walls and ensuring thermal softening or melting of the supersonic flow before impacting said surface. Flame jet method. 2. A flame jet method according to claim 1, in which the hot combustion product gases are passed from the combustion chamber through a nozzle having a converging inlet portion leading to the throat of the nozzle hole of minimum diameter and exiting through the nozzle outlet hole; A flame jet method, wherein the step of discharging as a high-velocity gas stream includes the step of minimizing a swirling velocity component of the gas flow through a flow expansion nozzle orifice. 3. A flame jet method according to claim 1, in which the hot combustion product gases are passed from the combustion chamber through a nozzle having a converging inlet portion leading to the throat of the nozzle hole of minimum diameter and exiting through the nozzle outlet hole. The step of discharging as a high velocity gas stream includes forcing the gas through the nozzle bore for a length such that the temperature of the hot gas stream is reduced below the dissociation temperature of the gas stream. A flame jet method characterized by: 4. A flame jet method according to claim 1, in which the hot combustion product gases are passed from the combustion chamber through a nozzle having a converging inlet portion leading to the throat of the nozzle hole of minimum diameter and exiting through the nozzle outlet hole; A flame jet method characterized in that the step of discharging as a high-velocity gas stream comprises passing the hot combustion product gases through a nozzle, the length of the nozzle being such that the discharged particles are still in a plastic state. . 5. A flame jet method according to claim 1, comprising the step of adding an inert gas to the reactants to reduce the combustion temperature. 6. In the flame jet method according to claim 1, in order to reduce the combustion temperature and to prevent clogging of the nozzle hole by thermal softening or melt particles on the nozzle hole upstream of the outlet end of the nozzle hole, A flame jet method comprising the step of adding compressed air to the reactants to supply an inert gas contained in the compressed air. 7. In the flame jet method as claimed in claim 1, the step of supplying the solid substance into the hot gas flow includes directing the hot gas from a hole upstream of the nozzle and aligned with the axis of the nozzle hole to the throat of the nozzle hole. introducing said solid material from a point where the inlet flow has a radial velocity component, said velocity component tending to limit the diameter of the particles when said solid material is in particulate form; A flame jet method characterized in that the flame jet is rod-shaped and maximizes heat transfer between the hot gas and the surface layer of the rod when it projects through the hole into the axis of the nozzle hole. 8. In the flame jet method according to claim 1, the pressure within the combustion chamber is at least 75 PSIG (approximately 5.2
7 kgw/cm^2). 9 a jet gun body, a high pressure substantially enclosed combustion chamber within said body, and means for continuously flowing an oxy-fuel mixture under high pressure through said combustion chamber for addition in said chamber; A body includes a combustion chamber product of combustion exhaust passageway means at one end thereof, said body further having an elongated nozzle downstream of said combustion chamber exhaust passageway means, said nozzle including a converging inlet portion leading to a throat; an outlet aperture portion of extended length, said aperture having a length at least five times the diameter of said nozzle aperture throat, and said combustion chamber exhaust passage means exiting from the combustion chamber to an inlet of the nozzle inlet aperture portion. means for conveying a converging stream of hot combustion products for subsequent discharge, and means for introducing material in mass form axially into the combustion gas outside the combustion chamber for subsequent softening or melting and acceleration;
The point of introduction of the solid substance is then at the entrance to or within the convergent inlet section of the nozzle orifice, limiting the diameter of the column of particles passing through the nozzle orifice and on the nozzle orifice wall. the deposition of particulate matter is inhibited and the residence time of the particles in the gas stream is sufficient to cause thermal softening or melting of the particles before their impact on the substrate downstream of the discharge end of the nozzle hole; A highly concentrated supersonic material flame jet device characterized by: 10. The apparatus according to claim 9, wherein the axis of the nozzle hole and the axis of the combustion chamber are substantially perpendicular to each other, the combustion chamber has an end wall, and the combustion chamber discharge passage means has a plurality of circumferentially spaced, inclined, small diameter passages in the combustion chamber end wall, the passages having one end opening into the inlet portion of the nozzle bore upstream of the throat of the nozzle bore and the other end opening into the combustion chamber end wall. means for introducing a solid substance into the hot gas are small diameter holes in the body centrally located within the circumferentially spaced, slanted passages converging towards the axis of the hole. An apparatus comprising a substance supply passage, the substance supply passage being coaxial with the nozzle hole. 11. The apparatus according to claim 9, wherein the combustion chamber comprises an elongated cylindrical combustion chamber, and the main body is substantially perpendicular to the axis of the combustion chamber and projects toward and coaxially with the nozzle hole. a conical projection in said combustion chamber, the tip of said conical projection terminating adjacent an end of said nozzle at said convergent inlet portion and forming with said nozzle said combustion chamber exhaust passage means; and
The solid material comprises an elongated wire or rod, and the conical projection includes an axially extending small diameter hole, and the wire or rod of solid material is secured through the axial hole of the conical projection. Apparatus comprising feeding means, wherein the wire or rod opens into the nozzle throat at the tip of the conical projection. 12. The apparatus of claim 10, wherein the plurality of circumferentially spaced, converging, slanted small diameter passages supplying combustion chamber gas to the nozzle bore are configured to control the swirl velocity component of the gas flow through the nozzle bore. The device is oriented to eliminate tangential flow entering the nozzle aperture to minimize . 13. In the device according to claim 12,
The apparatus wherein the plurality of circumferentially spaced, converging, inclined small diameter passageways are coplanar with the axis of the nozzle bore. 14. The apparatus of claim 13, wherein the length of the nozzle hole is the maximum length such that particle deposition does not occur on the internal surface. 15. The apparatus of claim 13, wherein the nozzle hole is of a minimum length such that the temperature of the hot gas stream is reduced below the dissociation temperature of the gas stream. 16. The apparatus according to claim 13, wherein the nozzle length is such that the particle velocity is maximum at the exit surface of the nozzle. 17. The apparatus according to claim 13, wherein the nozzle length is such that the particle temperature is maximum at the exit surface of the nozzle.