JPH0275812A - Generator for hot air by gas - Google Patents

Abstract

PURPOSE: To generate a flow of hot air by a gas without injecting a flame beyond a conduit, by a method wherein a flame crushing grill disposed downstream of a flame collision grill is arranged to be larger in opening than the flame collision grill so that the flame is kept from being injected beyond a conduit. CONSTITUTION: A flame collision grill 35 is disposed crossing an inner hole 33. A flame crushing grill 36 closes the front end of the inner hole 33, and the grill 35 has an opening of about 20%. On the other hand, the grill 36 has the opening of about 27% and a plurality of the grills are arranged in succession with the openings thereof gradually increasing so that division stages are accomplished many times. This arrangement is more favorable for the oxidation of a flame, eventually better for the shortening of the flame. The front end 45 of an outer tube 43 is bent inward to support the end 46 of a conduit 41 from the front thereof. The conduit 41 contacts the flow of a burned gas to be kept at a high temperature as well. As the outer tube 43 does not contact the tube 41 except that it does due to zones greatly reduced, the high temperature will not be transmitted to the outer tube 43.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for generating a stream of hot air, in other words a device for delivering a stream of hot air across the free end of a conduit.

Such devices are known. For example, a hair dryer, in which the air flow is produced by a blower and heated by an electrical resistance.

Also known are devices for generating a flow of hot air m=more precisely a flow of a mixture of hot air and combusted gas 11. In the generator, the gas stream is heated by combustion of combustible gas. Such equipment is used, for example, in the molding of PlusDeck materials.

In gas hot air generators, it is necessary to prevent the flame produced by the combustion of the gas from reaching beyond the free end of the conduit. This condition is difficult to meet. This is because the flame tends to extend to the point where the gas meets an influx of fresh air for one minute for complete combustion.

To solve this problem, it has been proposed to use relatively long conduits. In addition to the disadvantageous effect of making the device bulky and heavy, this solution is not effective. This is because the length of the flame increases with the length of the tube for the reasons given above.

Another known technique is to employ a large diameter tube and simultaneously send out a stream of hot air from the downstream end of the tube while allowing outside air to enter. however,
The result is that the velocity and effectiveness of the hot air flow is reduced.

The purpose of the present invention is to prevent the flame from erupting beyond the conduit.
The object of the present invention is to provide a device for the generation of a gaseous hot air flow without the above-mentioned disadvantages of previously known solutions.

The present invention provides means for producing a gas mixture of air and a moving combustible gas, a flame impingement grate disposed across the path of the gas mixture, and a flame impingement grate resulting from the combustion of the combustible gas. a conduit for conducting a flow of a mixture of gas and hot air, the downstream end of the conduit being open to the outside atmosphere; The generator further includes at least one flame crushing grate disposed in the stream of the flame impingement grate across the path of the gas mixture, the flame crushing grate having a larger aperture size and/or a larger aperture size than the flame impingement grate. Or, it relates to a hot air flow generator characterized by having an aperture ratio.

Preferably, the impingement grid and the crushing grid define therebetween a combustion chamber laterally bounded by substantially continuous side walls.

For a burner with a flow rate of approximately 40 g/h of LPG at approximately 1.5 bar, it is advantageous for the minimum, maximum and preferred values of each geometrical parameter to be approximately as follows: It is. It goes without saying that these values will change if the flow rate changes.

- longitudinal distance between two grids: 6+si,
12 mm, 9sl10-111 Collision grid opening diameter: 211I111411113 Cocoon 1°-m-Collision grid opening ratio: 15%, 25%, 20%.

m - Diameter of the openings of the grinding grid: 2.5mm, 4.5 companies, 3.5 companies.

−Aperture ratio of one grinding grid: 22%, 34%, 27%.

m - distance between the grinding grid and the free end of the conduit = 40a
m, 60mm, 45mm.

-Inner diameter of one conduit: 25w+m, 4(lnm, 30w+m.

The invention! According to an embodiment, the device includes a body forming a hollow handle into which a replaceable cartridge as a gas source can be inserted, the handle forming an obtuse angle with the conduit. ing. Moreover, the open end (+13) of said hollow gripping part is such that the suito Uke can place the generator of hot air flow in stable equilibrium at said open end on the surface of its gripping part. Preferably, it defines a surface that is inclined with respect to the longitudinal direction (112).

According to a second aspect, the invention aims at facilitating the ignition of the device without requiring any manipulation to temporarily change the properties of the air-gas mixture.

In this second aspect, the invention applies not only to a hot air flow generator as described above, but also to a device for generating a hot air flow, which can be obtained by mixing flammable gas and air in a determined ratio. a combustion means having an ignition chamber filled with said mixture and from which an ignition flame can propagate to form a main combustion flame; Applies to all gas combustion equipment.

According to the invention, the ignition chamber is remote from the flow path and communicates with said flow path by an intervening space. In the intervening space, the velocity of said flow is relatively low and/or the proportion of combustible gas in the gas mixture before ignition is higher than when introduced by the mixing means.

In an embodiment, the device comprises means for impeding flow downstream of said space, said means comprising a grid with openings placed across the flow of the gas mixture. Gong (can be done)

According to a third aspect, the present invention relates to a gas combustion device,
Primarily, but by no means to the exclusion of others,
Concerning a hot air flow generator as described above.

This generator can be used in various directions to form a jet of flammable gas supplied under pressure from a reservoir of liquefied gas and to form a gas mixture with air. , includes an injector with a small diameter hole and includes means for transferring the heat generated by combustion of the gas to the injector.

If such a device is used such that the liquefied gas reservoir is higher than the injector, the liquefied gas may flow by gravity toward the injector. The heated injector promotes vaporization of the liquefied gas and prevents excessive flow of the liquefied gas past the injection hole.

However, the heat flow transferred to the injector is not always sufficient to vaporize the liquefied gas supplied to the injector.

To solve this problem, the present invention provides means placed upstream of the injection hole to limit the gravitational flow of liquefied gas into the injector.

According to one embodiment of the invention, this restriction means is arranged in the path of the gas supplied under pressure and has a small diameter passage, preferably between about 0.1++i and about 0.3■. Contains a diaphragm with holes.

Other features and advantages of the invention will become more apparent from the following detailed description and accompanying drawings.

In the following description, the terms "front" and "after" are used to mean downstream and upstream of the gas flow in the device, respectively, and correspond to the left and right sides in Figures 1 and 4a. .

The hot air generator shown in FIG. 1 has a zamak (z a m a
k) It has a mold body 1 and a plurality of vent holes (not shown). The main body 1 is generally in the shape of a saucer, consisting of a bottom 3 with a circular opening 4 in the center and a side wall 5 provided with the aforementioned plurality of ventilation holes. The side wall 5 widens conically from the bottom 3 and extends away from the bottom with a cylindrical section 6. From the bottom, an annular flange 7, which surrounds the opening 4 at a distance, extends outwardly from the body and forms a support part for the cylindrical member 8. The frustoconical side wall 5 has an inner protrusion 9 on its circumferential surface. The outer projecting part 2 extends towards the inside of the body by two wings 10 bent towards each other, which together with the projecting part 2 act as a piezoelectric igniter. A storage area for the electric I2 is defined. FIG. 3 is a top view of the body I, but also shows the two cylindrical shafts 13 hanging from the bottom toward the inside of the body 1.

The brass mixing tube 14 extends concentrically with the main body I, and the main body! It has a front end that is slightly recessed with respect to the open end of the opening, and a rear end that is located beyond the bottom part 3. The side wall of the tube I4 is provided with a plurality of openings 15 connecting between its outside and an axial inner bore 16. These openings are on the surface of the bottom 3 of the body.

At its front end, the mixing tube 14 has an externally threaded external diameter reduction 18 which is formed by an annular shoulder 1
It ends with 7.

The injector 19 has a gas injection hole 20 at its front end, is inserted into the bore 16 at the rear of the tube 14, and is stopped with respect to the tube 14 by an annular flange 60. A filter 21 made of a porous material is disposed across the interior space of the injector, and a disk-shaped diaphragm 22 with holes 23 is provided at the rear end of the injector. The clamping portion of the diaphragm 22 is fitted axially between the inner shoulder of the injector and the fitting projection 24.

The rear end of the mixing tube 14 is surrounded by an annular nut 25 threaded on the inner surface of the rear end, which in conjunction with an outlet fitting 26 shown in broken lines connects the combustion gas supply cock. is a part of it.

At the front end of the annular nut 25 there is an annular edge 27 extending towards the axis, which edge cooperates with the shoulder of the tube 14 to
Prevent l 4 from moving forward. The front end of this annular nut is inserted into the receiving part 8 of the main body I with radial play.

As shown in FIG. 2 in an axial view from the rear, the mixing tube 14 is secured to a cross-shaped partition 28 made of brass fibers at its front with screws; The end is stopped with 7 Nmm of tube 14. The cruciform partition 28 has a central member 29 forming a sleeve, from which four arms extend radially at right angles to each other in a direction opposite the axis 58 of the middle member 14.

The three arms, numbered 30, have the same circumferentially reduced width and extend continuously from front to back.

The fourth arm 31 , on the other hand, has a larger circumferential width and is provided with an internal notch 32 that communicates with the axial bore 33 of the sleeve 29 .

In the wall of the arm 3I located behind the notch 32, a truncated conical opening 34 is provided in the axial direction, the small diameter part of which is adjacent to the notch 32.

A flame impingement grid 35 is positioned across the bore 33 . The grid is supported towards the rear on the shoulder of the bore and is prevented from moving, for example by an interference fit. The flame crushing grate 36 closes the front end of the bore 33 and is axially immobilized between the shoulder of the bore and the annular snap-in projection of the sleeve 29.

Arms 30 and 31 have front end faces 38 located in the same radial plane, and beyond which end faces are axially 7 flange 39 defining the inner span of a cylindrical surface with an axis 58. There is. A conduit 41 for hot air is fitted within the inner span, and its rear end is stopped against the front end face 38. On the other hand, the outer ends 42 of arms 30 and 31
forms a convex cylindrical span, on which the outer pipe 4
3 is inserted. At its rear end, the tube 43 is fitted into a telescoping strip 44 positioned circumferentially relative to the arm 30. In the right hand of arm 31, the tube is undeformed. The front end 45 of the outer tube 43 is bent inward to support the end 46 of the conduit 41 from the front.

The cross-shaped partition 28 and the tubes 41, 43 are connected to the ends 4 of the tubes.
5 and 46 with each other and their pipes and spans 4
0.42 and the joint action of the partial inset 44 makes it solidly integrated.

The grid 35, 36 and the mixing tube I4, which is completely screwed into the cross-shaped partition, are firmly integrated. Two tension members (not shown) made of stainless steel are screwed to a plurality of protrusions 13 of the main body 1 through blind holes, and are supported in front by a plurality of shoulders against a sleeve 29 of a cross-shaped partition 28. At the end of these shoulders, the tension member is provided with centered cylindrical projections which are arranged in a plurality of cutouts 47 around the sleeve 29.
jointly with the main body to ensure rotation prevention and centering of the cross-shaped partition with respect to the main body. Also, an elastic wave washer 48 is fitted inside the flange 7 between the annular nut 25 and the bottom 3 of the body. This washer tends to push the body,
Thereby there is a tendency to push the tensioning member against the annular ring 25 and thus against the mixing tube 14 and the cross-shaped partition. All the parts described above are thus assembled and centered with respect to each other. The piezoelectric ignition device is fitted axially between the rear end of the outer tube 43 and the bottom 3 of the main body 1, and its actuating button 49 is inserted through an opening provided in the bottom. It sticks out from the bottom.

The protruding part 9 of the body l serves as a rear support for an axially oriented spark plug 50, the truncated conical part 51 of the spark plug being arranged in a notch 53 of the protruding part 9 and connecting the shoulder of the protruding part with the plug. Under the pressure of a coil spring 52 which is compressed between, it cooperates with the frustoconical opening 34 of the arm 3I of the cross-shaped partition. The front end of the spark plug is opening 3
4 and entered into the notch 32 of the arm 3I,
The end of the electrode 54 protrudes. A cable 54 connects the electrode and the igniter.

The tension members for centering are the arms 30 and 31 of the cross-shaped partition.
The igniter 12 passes through a third quarter circle formed by the two arms 30.

The operation of the hot air generator will now be explained.

one of the flammable gases, such as butane or propane,
Alternatively, a mixture of these two gases is supplied from a liquid gas reservoir and is ejected from the injection hole 20 of the injector 19 under pressure.
It is injected into the inner bore 16 of the mixing tube 14. The gas then entrains the air that has entered through the radial openings 15. Gas and air mix uniformly in the front part of the bore, which has a smaller diameter than the part where the opening 15 widens abruptly.

The mixture enters the bore 33 of the cross-shaped partition, passes through the flame impingement grate 35 and passes through the bore 33 between the grate 35 and 36.
The combustion chamber 56 is made up of a portion of the combustion chamber 56.

This combustion chamber is closed over its entire axial length and over a major part of its circumference and communicates by a single passage with the ignition chamber, which is constituted by a notch 32 in the cross-shaped partition arm 3I. ing. This ignition chamber is
Located away from the axial path of the gas flow. Combustion chamber 5
The passage between 6 and the ignition chamber 32 effectively constitutes the only entrance to the ignition chamber. The frustoconical opening 34 is virtually hermetically sealed by the frustoconical part 51 of the plug, which is pressed by a spring 52, and outside the notch 32 (llFji is closed by fitting the tube 43 onto the span 42 of the arm 31). The outer end of 32 is also hermetically sealed. Therefore, no gas flow enters chamber 32 and chamber 32 retains a stationary gas mixture. Furthermore, the presence of flame crushing grate 36 This loss results in a loss of combustible gas in the gas mixture contained in the two chambers 56 and 32, which is relatively slowed down in the combustion chamber 56. The gas flow rate is greater than the corresponding amounts of gas and air entering the mixing tube 14. These conditions are such that the ignition chamber 32
This is convenient for generating and dissipating flames in the room 56, and is also convenient for spreading flames to the room 56.

When the button 49 of the igniter 12 is pressed, a spark is generated between the end of the electrode 54 of the plug 50 and the nij end face of the arm 31 of the cross-shaped partition. The front end surface of the arm 31 faces the electrode, and the two are separated by about 411 IIl. This spark causes the gas in chamber 32 to ignite, and the flame propagates into chamber 56.

In the embodiment described above, approximately 40 g at 1.5 bar
In the case of a burner that flows LPG at /h, the spacing between gratings 35 and 36 is 9111. The grid 35 has a central hole with a diameter of 1.2 mm, and the chambers 56 and the axes 58 of the tubes 14.41, 43
It has four holes with a diameter of 3 mi at four symmetrical locations around the hole. These five holes have a cross-sectional area of 150 mm at the rear end of the combustion chamber 56 relative to the outer diameter of 13.8 m+1.
This corresponds to a passage cross-sectional area of 29,t+am'' for mn''. Therefore, the aperture ratio is about 20%. The grid 36 has five holes of diameter 3.51, one of which is on the axis and the other four are distributed at four symmetrical positions around the axis. The corresponding passage cross-sectional area is 4
8.1 mm", while the cross-sectional area at the front end of this chamber is 177+u+1, giving an aperture ratio of about 27%. Due to this geometry, the flame is split by the first grid 35 and then , tend to come together again in the room 56, but meet the second grid 36 and split anew.

Now, splitting the flame has favorable consequences for flame oxidation. By arranging a plurality of successive grids whose aperture ratios are gradually increasing, the dividing steps are carried out several times, which is more favorable for flame oxidation and therefore for flame shortening.

The oxidation is also said to be aided by the introduction of fresh air through a plurality of suction openings (not shown) in the body 1, created by the dynamic flow of the burnt gases across the cross-shaped partition 28. You'll understand.

The sleeve 29 of the cross-shaped partition 28 is adjacent to the combustion chamber 56 and is therefore heated strongly. The mixing tube 14 is in good thermal contact with this sleeve and, over a large part of its longitudinal direction, between the shoulder 17 and the rear widening of the bore I6 there is a high degree of heat towards the rear. It has a significant sidewall cross section to ensure the flow of water. The injector 19 is in good thermal contact with the tube 14 by means of a flange 60, which is pressed against the shoulder of the tube by the end of the threaded fitting 26. A gas-tight gasket 57 is inserted between the end of the fitting 26 and the tube 14 as well as the flange 60. Since the injector is maintained at a sufficiently high temperature in this way, there is no danger that the liquefied gas that has reached the filter 21 will vaporize there and cross the injection hole 20.

The diaphragm 22 makes it possible to restrict the flow of liquefied gas into the filter 21 even when the device is in a position such that the liquefied gas storage container is above the injector.

Conduit 4! is also maintained at high temperature in contact with the stream of burned gas. However, this high temperature is not transferred to the outer tube 43 because the outer tube 43 is not in contact with the tube 41 except by the highly condensed zone. The tube 43 also contacts the arms 31 and 30 of the cruciform partition with a constricted surface, the cross-section of the arms also making it possible to significantly limit the introduction of heat into the tube 43. The outer surface of tube 43 is therefore unaffected by heating. As for main body 1, main body 1 directly has 6 mixing tubes 1 in a cross-shaped partition.
No contact with 4. The body 1 is in contact with the cruciform partition only via a centering tension member, and an annular nut 25--which itself has a constricted surface in contact with the tube 14. It is in contact with the tube 14 only through the corrugated washer 48.

The piezoelectric ignition device 12, which is attached to the main body l, is subject to a temperature rise of only 50 degrees or less, and there is no risk of deterioration.

The hot air generator shown in FIGS. 4a and 4b is
Injector with mixing tube 14 and filter 21! 9, annular nut 25, packing 57, cross-shaped partition 28, grates 35 and 36, conduit 41, outer tube 43, and spark plug 5
0, and the same parts as in FIG. 1 have the same numbers and are arranged and assembled in the same way. Therefore, these parts will not be explained in detail again. However, the cross-shaped partition 28 can be left without the cutout shown in FIG.

This is because such a cutout is unnecessary in the embodiments of FIGS. 4a and 4b.

The rigid assembly formed by parts 14.28.35.36.41 and 43 includes a regulator 01 for regulating the flow rate of pressurized liquefied gas and an annular nut connected to the threaded cut of the regulator. The outlet joint 102 is connected to the outlet joint 102 by screwing. This regulator is of conventional construction and will not be described in detail. This regulator includes a rotating grip 103 for adjustment, and a replaceable gas cartridge 10.
A threaded fourth part 104 for the outlet 105 of 6, an airtight seal 107 provided therein, mainly comprising a push member that ensures that the outlet valve of the cartridge opens when the cartridge is screwed into the recess 1 (104). colour.

The device further includes a body 108 made of plastic woven with glass fibers, which body is formed as a combination of two halves as shown in FIGS. 4a and 4b. The two halves are joined together by a screw 109 across the projection and perpendicular to said plane. This main body 108 is generally in the shape of a curved pipe,
Its end 110 surrounds the tube 14 and the cruciform partition 28 as well as part of the tube 43;
is oriented in the axial direction. Further, the other part 111 of the main body surrounds the cartridge 106 to form a grip, and is oriented toward the axis 112 of the cartridge. These two portions 110 and 111 make an obtuse angle of approximately 120'', which corresponds to the angle made by axes 58 and 112.

The part forming the grip I11 widens in the vicinity of its free release end 113, and the cartridge:
allows for attachment and detachment. This end II3 is connected to the shaft 112
It is located in a plane slightly inclined to the
Although the center of gravity of the device is outside the axis 112 and above the support surface defined by the end 113, it is possible that the axis 112 is slightly offset from the vertical and the device can be placed at this end on a horizontal support surface. can. In addition to the opening in the end 113, the grip N< 111 has a cutout 114 through which part of the side of the cartridge 106 can be seen. An opening is also provided near the front end of the handle, through which the columnar portion 125 of the regulator 101 passes, through which the shaft of the operating handle 103 passes.

Also, in order to include the ignition trigger 115, the body portion 1
One opening is also provided on the concave side of the connecting portion between 10 and 111. The trigger is made of plastic and is slidably mounted on a brass pin 116 extending parallel to the axis 58. The pin 116 is supported at both ends by an outer portion 117 and an inner portion +18 of the main body.

The piezoelectric ignition device B I 2 ' is similar to the ignition device 12 of FIG. facing forward. The housing of the ignition device 12' is limited above it (in the conditions in which the hot air generator is normally used), in other words towards the shaft 58, by the inner wall 119 of the body 108, and below it by the inner wall 119 of the body 108. one inner wall 120 and a trigger 115;
In front thereof it is limited by an upward projection +21 of the trigger. At the rear, the ignition device is switched off by a regulator 101. The trigger 115 can be operated with the index finger of the hand that grips the grip portion 111. When you pull the trigger backwards, the protruding part! 2I presses button 49' to generate a voltage pulse, and the voltage pulse hits the inner wall! 19 to the plug 50 via a cable 55' passing through it. The plug 50 is pressed into the frustoconical opening 34 of the cross-shaped partition 28 by a spring 52' which is supported at the rear by a protrusion extending from the inner wall 119 and which acts in the same manner as the spring 52 in the mm diagram. ing. The trigger 115 is sandwiched between the return spring of the button 49' of the ignition device, the inner wall 123 of the main body 10B, and the trigger, and is attached to the shaft 5.
8 and another coil spring 122, which returns it to the forward rest position. The button 49' and the spring 122 are placed above and below the pin 116, respectively, to ensure balance of forces and good guidance of the trigger slide.

An annular nut 25 is centered within an annular inner wall 124 of body 108. This center method is grip ff1
The center point and opening 1 of the cartridge 106 inside the
Together with the centering of the columnar portion 125 in 26, it serves to connect the main body to the rigid assembly housed therein. This coupling configuration further reduces heat loss to the body 108 compared to the heat received by the body of FIG.
As a result, the loss of heat to the ignition device 12' is also reduced.

The rest of the operation of the apparatus of FIGS. 4a and 4b is similar to that described in connection with FIG. 1.

In this device, the cartridge 106 can also be replaced by a connection fitting to a larger volume gas reservoir.

This fitting consists of a tube having at its downstream end a structure similar to the valve of cartridge 106, and at its upstream end a suction I for receiving a flexible tube, hermetically and rigidly joined by a flange. It has a co-structure.

The other end of the flexible tube is hermetically connected to the fitting of the LPG reservoir by a tightening flange.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a first embodiment of a hot air generator according to the present invention, taken along line 1-1 in FIG. 2 and 3 are front views of two components of the hot air generator of FIG. 1; FIG. Figures 4a and 4b are partial sectional views of a second embodiment of the hot air generator according to the invention.

Claims (1)

[Claims] 1. A means for producing a gas mixture of air and a moving flammable gas, a flame impingement grid (35) disposed across the path of the gas mixture, and a means for generating a gas mixture of air and a moving combustible gas; a conduit (41) for conducting the flow of a mixture of burnt gases and hot air resulting from combustion, the downstream end (46) of the conduit;
and a conduit (41) open to the outside atmosphere, the generator further disposed downstream of the flame impingement grate across the path of the gas mixture. at least one flame crushing grate (3
6), characterized in that the flame crushing grate has a larger aperture size and/or aperture ratio than the flame impingement grate. 2. A hot air compressor according to claim 1, characterized in that the impingement grate and the crushing grate define between them a combustion chamber (56) laterally bounded by substantially continuous side walls (33). Flow generator. 3. For a burner with a flow rate of approximately 40 g/h of LPG at approximately 1.5 bar, the longitudinal distance between the two grates is between approximately 6 mm and approximately 12 mm, preferably 9 m.
Claim 1 or Claim 2 characterized in that it is around m.
The hot air flow generator described. 4. Generation of a hot air flow according to any one of claims 1 to 3, characterized in that the diameter of the openings of the impingement grid is between about 2 mm and about 4 mm, preferably around 3 mm. Device. 5. When the aperture ratio of the collision grid is between about 15% and about 25%,
Claim 1 characterized in that it is preferably around 20%.
A device for generating a stream of hot air according to any one of claims 1 to 4. 6. The diameter of the opening of the crushing grid is approximately 2.5 mm and approximately 4.5 m.
6. A device for generating a flow of hot air according to any one of claims 1 to 5, characterized in that the length is between m, preferably around 3.5 mm. 7. The aperture ratio of the crushing grid is between about 22% and about 34%,
Claim 1 characterized in that it is preferably around 27%.
A hot air flow generating device according to any one of claims 1 to 6. 8. The distance between the grinding grid and the free end of the conduit is approximately 40
8. A device for generating a hot air flow according to any one of claims 1 to 7, characterized in that the diameter is between about 60 mm and about 60 mm, preferably around 45 mm. 9. Claim 1 characterized in that the inner diameter of the conduit is between about 25 mm and about 40 mm, preferably around 30 mm.
A device for generating a stream of hot air according to any one of claims 1 to 8. 10. Device for generating a flow of hot air according to claim 1, characterized in that the conduit is radially surrounded by an outer tube (43). 11. Sleeve with an axial bore defining the combustion chamber (
29) and a cross-shaped partition (28) having a plurality of radial arms (30, 31), at least one of the plurality of arms (31) communicating with the bore. It has a notch (32) and through the opening (34),
11. A device for generating a flow of hot air according to any one of claims 1 to 10, characterized in that a spark plug projects into the internal notch. 12, comprising a large cross-section mixing tube (14) screwed at the front into a cross-shaped partition sleeve (29) and supported by an abutment surface (17) on the sleeve;
4) is supported on the flange (60) of the injector (19), characterized in that both these supports are made in such a way as to achieve good thermal contact between the parts. 12. The hot air flow generator according to claim 11. 13. Replaceable cartridge as gas source (106
) in accordance with any one of claims 1 to 12, characterized in that it comprises a body (108) forming a hollow handle (111) into which the hot air container (108) can be inserted. Flow generator. 14. The longitudinal length of the hollow grip is such that the open end (113) of the hollow grip can place the generator of hot air flow in stable equilibrium with the open end on a horizontal receiving surface. 14. Device for generating a hot air flow according to claim 13, characterized in that it defines a surface that is inclined with respect to the direction (112). 15. includes an ignition chamber (32) communicating with the combustion chamber (56) and means (12, 50) for generating an ignition flame within the ignition chamber that can propagate to the combustion chamber; A device for generating a stream of hot air according to any one of the preceding claims. 16. The means for producing a mixture of air and combustible gas is an injector with injection holes (20) of small diameter for forming a jet of gas supplied under pressure from a reservoir of liquefied gas. (19), means (29, 14) for transmitting heat generated by combustion of gas to said injector, disposed upstream of the injection hole to limit the gravitational flow of liquefied gas into said injector; 16. A device for generating a stream of hot air according to any one of claims 1 to 15, characterized in that it comprises means (22) in which the hot air stream is heated. 17. The restriction means is a diaphragm (2
17. The hot air flow generating device according to claim 16, characterized in that it comprises: 2). 18. The hot air flow generating device of claim 17, wherein the diameter of the passage hole is between about 0.1 mm and about 0.3 mm.