FR2472720A1 - MIXING DEVICE FOR A GAS TORCH - Google Patents

Abstract

THE INVENTION CONCERNS A GAS TORCH STRUCTURE 31 ALLOWING A BETTER MIXING OF COMBUSTIBLE GAS WITH OXYGEN, THE OXYGEN FLOW BEING DIVIDED INTO A PLURALITY OF SEPARATE CURRENTS WHICH ARE THE SUBJECT OF AN INDEPENDENT MIXING WITH THE GAS FOR GIVE WELL MIXED GAS-OXYGEN CURRENTS BEFORE INTRODUCING A MANIFOLD 35 FOR THE SUPPLY 36 OF THE TORCH NOZZLE. THE OXYGEN ARRIVES THROUGH A SINGLE CHANNEL 41 AND IS DISTRIBUTED IN MIXING CHANNELS 42 WHICH OPEN INTO A COLLECTOR 35. A THROAT 43 SERVES AS A COLLECTOR FOR THE COMBUSTIBLE GAS INTRODUCED AT 29 AND CUT THE CHANNELS 42. THE STRUCTURE OR CAP 31 CAN BE INSERTED REMOVABLE IN A TORCH BY ELSEWHERE CLASSIC.

Description

1. The present invention relates to oxyacetylene torches and

gas analogs, and in particular torches which are used for spray deposition of a metal

  or other powdered materials to form a coating

lying on a substrate.

A torch of this type must be capable of applying

quent intense heat to the powdered material to be sprayed, and the problem of a high supply of heat for a torch of a given size becomes more difficult with the provision of materials at high temperature or their incorporation in the formulation of a powder. A larger heat supply requires a greater flow of oxygen and combustible gas, and therefore larger gas passage channels, with a

  greater susceptibility to flashbacks,

quent a shock wave transmission through the gas mixture distribution system; the incidence of shock waves in the mixing location is sufficient to extinguish the torch, which is inconvenient for obtaining

  of a uniform layer or for the performance of other functions

  torch and sometimes involves rejection or

costly rework of the article with a sub-

trat incompletely coated.

  The object of the present invention is to provide an improved torch of the type indicated above which allows

avoid or significantly reduce operational problems

  of the devices of the prior art.

Another object of the present invention is to pre-

see a torch of the type indicated above having an inherent ability to provide significantly greater heat

per volume unit.

  A specific object of the present invention is to provide a torch satisfying the preceding objects and

  having a much greater inherent capacity in order to avoid

  ter decommissioning in the presence of flashbacks.

  Another object of the present invention is to pre-

  see an improved mixture of combustible gas with oxy-

  gene, in a range of pressures and feed rates significantly wider than the range obtained in the past

with such a blowtorch.

  A general object of the present invention is to

satisfy the preceding objects with a minimum of modification

  existing torch structures, with a sim-

  inherent plicity of construction, ease of maintenance,

and without abnormal expense.

The foregoing objects, as well as other objects, are obtained in the present invention in a torch having a mixing cavity in which a mixing cap is removably mounted. The plug incorporates a plurality of identical elongated mixing channels, each channel having essentially the same length as in the prior art, and with a capacity-gas flow combination equal to or greater than the nominal values of the devices.

of the prior art, an oxygen stream being divided into

identical smaller rants, separated from each other, which are supplied to separate areas where they suck the combustible gas in the mixing length of the mixing channel

  associated. The result is a markedly reduced susceptibility.

  due to the flashbacks which reach the

  mixture, and an even lower susceptibility of lime

  failure due to flashbacks.

The present invention will be well understood during

the following description made in conjunction with the drawings below

  seals in which: Figure 1 is a simplified side elevation view of a torch for powder coating or flame spraying according to the present invention; Figure 2 is a longitudinal sectional view,

  enlarged scale, details of an inter-mixing cap

  changeable of figure 1, in the simple fragmentary context

  of the structure of the torch body; and Figures 3 and 4 are, respectively, views

  at the left and right end of the mixing bolt in figure 2.

Firstly in connection with FIG. 1, the pre-

sente invention is shown in the case of a flame spray gun which comprises a body 10 with a mixing zone 11, a handle 12 extending below the body to allow manipulation. Separate fuel gas and oxygen supply connections 13-14 are provided at the rear in places situated vertically at a certain distance from each other, as well as another connection allowing the connection of a conduct of a fluid under

pressure, for example of compressed air, to be used for mixing

  ge of the powder material and its routing so that it is discharged through the end of a nozzle 16, the powder material being introduced by gravity from a container 17 fixed

  removably to the body 10. The oxygen-gas mixture

  The fuel is supplied from the mixing zone II to the discharge nozzles located at the end of the nozzle, via a conventional distribution system. The

pistol structure shown can be conventional, incorporated

  carrying in 18-19 and 20 bodies for selective regulation of the respective separate flow rates of combustible gas, oxygen and pressurized powder transport fluid, and another means

adjustable shown in 21 is used to control the flow of the

  dre released, coming from the container 17, by action on a trigger 22 with the thumb, the trigger causing the departure and

  stopping the circulation of powder. The new characteristic

  4. of the present invention relates to the mixing region 11 and will now be described in detail in conjunction with the

Figures 2, 3 and 4.

In FIG. 2, the mixing zone 11 of the body 10 is represented as being internally characterized by

  an elongated mixing cavity with a cylindrical bore

  primary plate 25 at the inner end of which an orifice

  central oxygen supply is served, one shoulder-

ment 26, by a reduced cylindrical channel 27 under the control of the means 18. A second shoulder 28 defines the downstream end of the mixing cavity, and between the shoulders 26 and 28, a fuel gas supply orifice directed into the meaning

  radial is served by a similar channel 29 under the command

  of the means 19. Downstream of the shoulder 28, a threaded counterbore extends to the outside of the body, and is closed

by a removable cap 30 with seal.

  flexible, generally cylindrical, 31 of the present invention comprises a threaded flange 32 with which it is mounted in the counterbore 47, up to the abutment point of the shoulder

  downstream at 26, its end 33 for supplying oxygen to the

reduced mensions being received by sliding in the channel 27. Flats for tools such as the hexagonal part 34

  at the downstream end of the mixing cap 31 allow mounting

  tage and disassembly of the cap, it being understood that a cavity

important 35 (hereinafter called collector cavity) is de-

  finished between the plugs 30-31, an outlet channel 36 allows

  both to supply the mixture of combustible gases to the distribu-

gas and at the end of the nozzle.

  According to the present invention, the heat capacity

  a blowtorch such as the blowtorch being described

is significantly greater than that of the torches of the prior art, thanks to the presence of multiple means which make it possible to mix separate streams of oxygen

  with a combustible gas, the mixing occurring before the

load independently mixed currents in cavity 35

  of the collector to be distributed via a ca-

  nal 36 to nozzle 16 of the torch. In the embodiment 5 represented, this result is obtained with more security.

  high and sensitive to flashbacks

  ment reduced, thanks to the only filling plug 31 and the combined effect of the plug, the bore of the cavity and the two gas supply ports 27-29. To facilitate construction and make it more precise, the mixing cap 31 preferably comprises an upstream part 37 and a downstream part 38 force-fitted

in the end 39 on the plug side of part 37, in the

sage 40 extending most axially in the extreme

  mity from the adjacent part 38. The remainder of the unplugged bore 40 defines a manifold in which the oxygen admitted into an elongated central bore 41 of the part 37 can be

  distributed evenly into several identical systems of

  separate and elongated mixing channels 42 which are situated in the downstream part 38. The mixing channels 42 are represented as being 3 in number, as being situated at the same distance from each other around the axis of the plug 31,

and all the channels 42 open into the cavity 35. A groove

  circumferentially continuous ring ge 43 near the former

  upstream end of the part 38 serves as a manifold for the gas supplied at 29, the radial depth of the groove 43 completely cutting off the mixing channels 42. Short connecting channels 44, each aligned with one of the mixing channels 42 and smaller in diameter than these channels

  provide an independent flow of oxygen to each of the

  mixing facilities, by suction with locally available gas

also in throat manifold 43. O-rings

  be the plug 31 and the mixing cavity must at least

  be placed at opposite axial ends of the pass zone

sage of the combustible gas between the channel 29 and the groove 43; in the embodiment shown, the body of the part 38 of the plug is lightened in the area comprising the groove 43, and consequently a seal 45 is provided downstream in the circumferential groove formed between this lightened area and the threaded flange 32, while a seal 46 is provided upstream in a circumferential groove made in the zone 6 for mounting the end 33 in the channel 27 for supplying oxygen. Given the division of the currents, and the greater capacity of the mixing plug 31, the oxygen intake channel 41 may be of a capacity greater than the channels of the prior art, each mixing channel 42 having

  a capacity lower than that of channel 41 while allowing

both a flow of the same order as the mixing configurations

  ge to a prior art channel. Preferably, the length / diameter ratio of each mixing channel 42 is at least

  minus 10/1, this ratio can be around 15/1 for as-

  ensure a complete mixture before its presence in the collection

35.

It will be noted that the device of the present invention

  vention achieves all defined objectives. We found that

  the multiple and independent mixture of oxygen and

bustible virtually eliminated flashbacks

  can put the torch out of service by

what the risks of a simultaneous occurrence of such re-

  flame towers in mixing channels 42 are virtual-

  slightly zero. In addition, thanks to the fact that the lightened area of the part 38 is close to the bore 25, and that the body 37 fills almost the rest of this bore, there is a very small volume of gas when the torch stops. ; in the case where acetylene is used as combustible gas, there will thus be a markedly reduced tendency to the accumulation of carbon deposits during shutdown, allowing longer periods of use of the torch without cleaning the cap 31 and the mixing cavity 25. It has been found that the heat capacity of a torch of given size of the type indicated above could be increased by several

  times almost in accordance with the number of met functions

  insured independent diapers; for example, an increase multiplied by 3 in the thermal output has been obtained with the device described above - during operation in

oxyacetylene torch, which made it possible to obtain re-

better quality clothing with materials requiring 7.

more heat.

  The present invention is not limited to the examples

  which have just been described, it is

milking subject to variations and modifications which appear

will be understood by those skilled in the art. 8.

Claims (16)

  1 - Gas torch comprising a body comprising   a mixing cavity, a common oxygen supply channel   connecting with the cavity to an oxygen discharge orifice and a fuel gas supply channel communicating with   the cavity to a gas discharge port, a discharge nozzle   charge communicating with the cavity at a location offset from the orifices, and a mixing plug means removably attached to the body and extending inside the cavity, the plug means comprising an internal channel elongated and continuous, a first means sealing an ex- end of the plug means to allow exclusive communication of the discharge through the oxygen orifice in one end of the internal channel, a second means sealing   the other end of the plug means for the exclusive discharge   sive in the nozzle of the current circulating in the internal channel, the orifice of combustible gas discharging exclusively   in the closed volume between the first and second sealing means   and the plug means comprising a suction channel   tion of gas communicating between the closed volume and the internal channel, characterized in that the internal channel is a channel   among a plurality of channels, and in that the suction channel   fuel gas ration is one of a plurality of corresponding channels, each gas suction channel cooperates rant to suction independently with one of the   channels to the exclusion of other internal channels. 2 - Mixing plug means for gas torch, characterized in that it comprises first and second elongated plug bodies placed end to end on a central axis mun, the first plug body comprising a cross channel central health having inlet and outlet ends for supplying oxygen to the second body, the second body comprising a plurality of through channels distant from each other at a certain angle, spaced from said axis and parallel to it, the channel of the first body communicating with all the channels of the second body at the assembled ends of the bodies, the second plug body having a groove 9. forming a gas collector open radially outward and continuing on the circumference which completely cuts all the channels of the second body in an axial location between its ends, a first circumferential sealing means-   continuous on one of the bodies in an axial location located be the groove and the inlet end of the channel of the first body, and a second circumferentially continuous sealing means on the second body at an axial location which is offset   downstream from the gorge, after which, after my-   sealed stage of the mixing plug means on a body of torch with a neck-shaped mixing cavity   excavator with a central and long oxygen supply channel   tudinal and with a supply channel for combustible gas   dial between the axial locations of the first and second mo-   sealing yen, a single stream of oxygen can be independently mixed with the combustible gas at each intersection of the throat with one of the channels of the second body, thereby allowing the provision of multiple independent mixing streams fuel for backflow by through the channels of the second body.   3 - Mixing plug means according to the claim   tion 2, characterized in that the effective diameter of the channels of the second body is smaller on the upstream side of the place throat intersection only on the downstream side.   4 - Mixing plug means according to one of the vendications 2 or 3, characterized in that at the ends as-   one of the cap bodies, one of the cap bodies   carries an enlarged bore of a diameter allowing to establish a correspondence between the oxygen collector and all   contiguous ends of the body channels.   - Mixing plug means according to one of the vendications 2 or 3, characterized in that the effective diameter   tif of the channel of the first body substantially exceeds the effective diameter of each channel of the second body on the downstream side of   where the throat intersects. 6 - Mixing plug means according to the claim tion 2, characterized in that the upstream end of the second 10. body has an enlarged bore with a diameter allowing to establish a correspondence between the oxygen collector   gene and all the contiguous ends of the channels of the second body, this bore having an axial depth-not reaching the axial location of the groove, and in that the contiguous end of the first body has a reduced part in   form of stud which is mounted in the bore and the extent of which due axial is less than that of the bore.   7 - Mixing plug means according to the claim   tion 2, characterized in that each sealing means comprises takes a circumferentially O-ring groove continuous.   8 - Mixing plug means according to the claim tion 6, characterized in that the first body has a radial shoulder at the base of the stud-shaped part, this shoulder abutting against the contiguous end of the second body. 9 - Mixing plug means according to the claim tion 6, characterized in that the stud-shaped part is force-fitted into the bore. - Mixing cap means according to the claim tion 2, characterized in that the upstream end of the first body has a reduced part in the form of a stud in   which is the first sealing means.   11 - Mixing plug means according to the claim   tion 10, characterized in that the first sealing means   includes a groove for circumferential O-ring lie-continue.   12 - Mixing plug means according to the claim tion 2, characterized in that the second body has mounting threads extending circumferentially in one right located downstream of the second sealing means.   13 - Mixing plug means as claimed cation 12, characterized in that the second body has a reduced downstream end containing the channels of the second body, and key receiving flats on the end reduced downstream. 11.   14 - Mixing plug means as claimed cation 2, characterized in that the number of channels of the second body rises to three, the channels being placed at equal dis-   tance from each other around the axis. 15- Gas torch, characterized in that it comprises a torch body, a nozzle end removably attached to the body, the body comprising a mixing cavity with a fuel gas supply orifice in the cavity a place offset from the orifice oxygen supply in the cavity, a mixing cap   ge removably mounted on the body and inside the cavity having separate gas intake portions in sealing relation with the respective orifices, the plug   chon comprising a plurality of elongated, parallel mixing channels, distant from each other, for discharging separate streams of mixed gas at the downstream end of the   plug, the plug also comprising an inner channel means separate dull to divide the oxygen stream to provide it independently to the mixing channels and to allow independent suction of combustible gas into the channels by the respective oxygen streams thus divided, a manifold means at the discharge end of the plug to receive the mixed gas streams independently, and a gas distribution channel between the manifold means and the tip of the nozzle. 16 - torch according to claim 15, character- laughed in that the mixing cavity is generally cylindrical   dric around an elongated axis, in which the plug is generally cylindrical so as to fill substantially its volume, the stopper having a circumferential groove-   the fuel gas manifold in communication with the gas orifice, the groove having a depth such that it completely cuts off all of the mixing channels, and the suction connections separated from the oxygen current channels   divided to the mixing channels at their local intersection pective with throat.   17 - Mixing plug means according to the claim 12. tion 2, characterized in that the effective ratio between length and diameter of each of the channels of the second body is at least 10/1 along the length downstream of the gorge. 18 - Gas torch, characterized in that it comprises a body comprising a mixing zone, an oxygen supply means comprising a plurality of channels of oxygen streams communicating independently with said zone as discharge orifices distant from each other in distant mixing locations   others, a means of supplying compressed fuel gas   nant a gas collector communicating with the orifices of discharge, the mixing zone comprising a plurality of ca-   separate, continuous, elongated, and internal mixing channels, with the upstream end of each mixing channel aligned   with an orifice different from the discharge orifices and in Suction lation with local combustible gas in the manifold when there is oxygen flow in the means of supply of oxygen, and a communication discharge nozzle tion with the downstream ends of the internal mixing channels for the passage of mixed gases collected in the col- reader.