GB2259565A - Balloon burner - Google Patents

Abstract

A hot air balloon burner 1 has four vaporising coil stacks 2a, 2b, 2c, 2d surrounding a central pilot burner assembly 3. Liquid LPG is delivered via piping 4, 5, 6, 7 to each of said stacks 2a, 2b, 2c, 2d under the control of a multistage valve operated by hand control lever 9. Flame head 3d diverts some flame from the central pilot burner sideways into each of said coil stacks 2a, 2b, 2c, 2d to preheat said coils as well as igniting the main burner means. Liquid LPG can be delivered selectively to one or more of the coil stacks 2a, 2b, 2c, 2d. There is an auxiliary pilot for the main pilot burner assembly. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO BALLOONS This invention relates to improvements in or relating to hot air balloons.

Hot air ballooning is a sport which is still developing but which has an enthusiastic following. There are many problems in designing a suitable, stable, gas burner arrangement for supplying hot air into the balloon envelope in an easily controlled, versatile and efficient manner and on a reliable basis. Up until now it seems that balloon burner arrangements have been somewhat crude in format utilised with a simple on/off fuel supply control.

It is known for hot air balloons to include a main burner (run on LPG) as well as a "cow" or "whisper" burner. The whisper burner can be used once the balloon is in flight in order to vary the height of the balloon without firing the main burner (thereby utilising less energy than the main burner) but conjecture arises as to the efficiency of the whisper burner. On the one hand the whisper burner burns with a yellow flame and is therefore generally thought to be inefficient and unclean in operation but it may also seem to have the potential to use less fuel because the flame is softer and creates less turbulence within the balloon itself. The main burner, on the other hand, tends to produces a degree of turbulence within the envelope, the cooler air near the surface of the envelope being disturbed with warm air being displaced from the envelope.

In any event, overall, it is believed that the design of hot air balloon burners and the control thereof is at a relatively unsatisfactory level and that there is substantial scope for improving same in order to improve the quality of the sport.

Accordingly, it is an object of the present invention to provide a hot air balloon burner which is improved in at least some respect (for example in its ease of use, efficiency and/or reliability or stability and/or having quieter combustion noise levels).

According to one aspect of the present invention there is provided a hot air balloon burner comprising a plurality of gas vaporising coil stacks or modules surrounding a pilot burner means arranged, in use, to preheat the vaporising coils which act to vaporise liquid fuel gas delivered thereto, said coil stacks or modules each being provided with main burner means ignitable from the pilot burner means.

From a second aspect of the present invention, there is provided a hot air balloon burner comprising a plurality of gas vaporising coil stacks or modules surrounding pilot burner means and each of the coil stacks or modules being provided with main burner means ignitable from the pilot burner means, the arrangement being such that liquid gas can be delivered selectively to one or more of the vaporising coil stacks/modules to provide fuel for the main burner means associated with each selected stack/module.

Many advantageous features of the hot air balloon burner will be evident from the following description and drawings.

Embodiments of a hot air balloon burner in accordance with the present invention will now be described, by way of example only, with reference to the accompanying much simplified drawings in which: FIGURE 1 shows a sectional front view of a first embodiment of a hot air balloon burner and multistage valve control in accordance with the present invention; FIGURE 2 shows a plan view of the arrangement shown in FIGURE 1; FIGURE 3 shows a sectional front view through the multistage valve control; FIGURE 4 shows a sectional view taken on line IV-IV of FIGURE 3; FIGURE 5 shows a view similar to FIGURE 1 of a second embodiment of a burner arrangement; FIGURE 6 shows a view similar to FIGURE 2 of the embodiment shown in FIGURE 5; FIGURES 7 and 8 show front and side views of an auxiliary pilot shown in FIGURE 5; FIGURE 9 shows a front view of a main pilot;; FIGURE 10 shows a detail of the main pilot shown in FIGURE 9; FIGURE 11 shows a modified pilot burner assembly; FIGURE 12 shows a modification to the hot air balloon burner of FIGURE 1 or FIGURE 5, in the form of an air intake control mechanism, and FIGURE 13 shows a sectional view taken on line XIII XIII on FIGURE 12.

Referring to FIGURES 1 to 4 of the drawings, a hot air balloon burner 1 has four vaporising coil stacks 2a,2b,2c,2d, surrounding a central pilot burner means or assembly 3. Liquid gas (usually LPG) is delivered via supply piping 4,5,6,7 (supply piping 6 and 7 shown broken away in FIGURE 1 for ease of illustration) to each of the associated coil stacks 2a,2d,2b,2c respectively under the control of the multistage valve 8 operated by hand control lever 9 in a manner to be explained later.

The pilot burner assembly 3 has an auxiliary pilot 3a and a main pilot 3b. The pilot burner assembly 3 is similar to the pilot burner assembly 102 shown in FIGURE 5 (and in greater detail in FIGURES 7 to 10) save for the flame trap and diffuser arrangement 3c. The pilot burner assembly should provide a stable pilot flame which will not blow out in adverse weather conditions unlike in prior art arrangements.

The auxiliary pilot 3a is fed with gaseous LPG (propane) through fuel line 10 by way of the hand operable auxiliary pilot control valve 11, gaseous LPG being fed directly to control valve 11 via delivery line 12 (shown broken away in FIGURE 1). The main pilot 3b is fed with gaseous LPG via delivery line 13 by way of the main pilot valve control 14, gaseous LPG from line 12 being in flow communication with line 13 on appropriate control of valve 14. Gaseous LPG is delivered through line 12 into the pilot valve block 15 containing the auxiliary pilot valve 11 and main pilot valve 14. The auxiliary pilot 3a can be lit from the spark electrode E once the piezoelectric electric ignition button 16 is pressed in a manner which should be generally self-evident.

Thus, in use, gaseous LPG delivered to the pilot valve block 15 feeds the auxiliary pilot 3a once the pilot valve 11 is opened by turning the control valve to the appropriate position manually. Once the control valve 11 is opened gaseous LPG passes through delivery pipe 10 to the auxiliary pilot 3a and on depressing the ignition button 16 and releasing same the auxiliary pilot 3a should light. Should the auxiliary pilot 3a not light the ignition device can be pressed and released again until such time as the auxiliary pilot lights but if atmospheric conditions are such that the spark ignition is not powerful enough to ignite the pilot it can alternatively be lit with a flame type gas lighter or cigarette lighter (not shown).

Once the auxiliary pilot 3a is lit and established, the main pilot valve 14 can be opened to allow gas to flow via line 13 to the larger and more powerful main pilot 3b and the main pilot ignites across from the auxiliary pilot 3a. The main pilot 3b has a device (not shown) which diverts some of its gas/air mixture outside the main pilot body 103b (see FIGURE 9) so that if the auxiliary pilot 3a should become blocked the main pilot 3b can be lit with a hand held flame type gas lighter or cigarette lighter. As should be evident from FIGURES 7 to 9 (the main pilot 3b being omitted from FIGURES 7 and 8 for ease of illustration) the auxiliary pilot 3a is positioned in front of the main pilot 3b, the main pilot being fitted with a multi-port flame head 3d.

The multi-port head 3d is provided with rings of ports p and is basically cylindrical in form. The flame head 3d diverts some of the flame from the main pilot sideways (thus avoiding "lift-off" encountered with prior art pilots) into each of the vaporising coil stacks 2a to 2d, advantageously, in order to preheat the vaporising coils very effectively as well as igniting the main burner means bl,b2,b3,b4 of the coil stacks 2a,2b,2c,2d on delivery of fuel to said main burner means. Fuel is delivered to the main burners bl,b2,b3,b4 selectively by controlled operation of the multi-stage valve 8 by way of control lever 9.Liquid LPG is delivered through inlet delivery pipe 17 (shown cut-away for ease of illustration in FIGURE 1) to all modular sections 8a,8b,8c,8d of the multi-stage valve 8 by way of the internal flow passageway 8e (see FIGURE 3) of valve 8. Each modular section 8a to 8d of the valve 8 is similar and a common valve actuating shaft 18 passes through each modular section as shown more particularly in FIGURE 3. When the right hand end (see FIGURE 1) of the control lever 9 is pulled downwardly the left-hand end is raised to push the actuating shaft 18 upwardly (since the control lever is pivoted at 19 and pivotally connected at 20 to the actuating rod 18). The actuating shaft 18 is provided with a series of four axially spaced actuating clips 18a,18b,18c,18d.Each modular section 8a,8b,8c,8d is provided with a valve closure diaphragm or member l9a,19b,19c,19d in the form of a flat plate which is urged onto its respective valve seat 20a,20b,20c,20d by associated helical coil springs S in a manner which should be readily apparent.

The actuating shaft 18 runs centrally of the valve closure members 19a to 19d and is movable axially relative thereto until engagement of the actuating clips 18a to 18d with associated closure members l9a to l9d. The actuating clips 18a to 18d are positioned at progressively greater distances from their associated closure member 19a to 19d in an upward direction in such manner that the valves vl,v2,v3,v4, comprising the multi-stage valve 8, are opened sequentially according to the distance moved upwardly of the actuating rod 18, this being controlled by the downward movement of control lever 9. The sequential opening of the valves vl to v4 allows a progressive fuel delivery to the main burner means bl to b4 of the coil stacks 2a to 2d in sequence, depending upon how far the control lever 9 is pulled downwardly.In pulling the control lever 9 downwardly actuating rod 18 is moved upwardly until actuating clip 18a engages the bottom of valve closure member 19a, thereby opening the valve and allowing gas flow communication from passageway 8e through the valve vl and through outlet ol into delivery line 4 through to coil stack 2a. At this point in time actuating clips 18b,18c,18d remain spaced from their associated valve closure members l9b to 19d.

The balloon burner 1 can be operated in this position with only one set of the main burner means bl associated with a single coil stack 2a being fired if required. If the control lever 9 is pulled downwardly from this position the second sequential valve v2 is opened allowing LPG to flow through outlet o2 and delivery line 5 to coil stack 2d and hence to the main burner ports b4 which are lit in the same manner as burner ports bl i.e. by way of the main pilot burner 3b. Clearly, further downward movement of control lever 9 progressively controls fuel delivery via outlets o2 and o3 as valves v3 and v4 are opened in order to feed delivery lines 6 and 7 to burner ports b2 and b3 of coil stacks 2b and 2c.In this manner fuel can be delivered to 1,2,3 or 4 of the coil stacks 2a,2b,2c,2d in order to fuel a selected combination of the burner ports bl,b2,b3,b4 depending upon the operating requirements for the balloon at that time.

If all sets of burner ports bl,b2,b3,b4 are ignited and it is desired to reduce the heat output, the control lever 9 can be released slowly in order to shut-down delivery to the coil stacks 2a,2b,2c,2d, progressively in a generally reverse manner to supply of fuel to the coil stacks. Thus supply of fuel is shut down firstly to burner ports b3 and then to burner ports b2, then to burner ports b4 and finally to burner ports bl, in a manner which should be evident. Thus, burners can be ignited or shut down selectively at any time in order to give a much closer control of the heat output into the balloon (not shown). If instant shut down is required the hand control 9 can be released completely and all of the valves vl to v4 will close virtually instantaneously.

Firing the main burner means b1,b2,b3,b4 progressively allows a steadier and smoother application of heat into the balloon envelope in order to maintain a steadier flying level.

Additionally, increased safety is achieved, the "modular arrangement" of coil stacks 2a to 2d means that if there is a blockage in one of the vaporising coil stacks or delivery pipes thereto, fuel delivery should still be possible to the other coil stacks so that the balloon can still be operated.

In this instance, four coil stacks or modules are provided but in alternative embodiments (not illustrated) any number of coil stacks or modules may be provided depending upon the size of balloon and operating conditions involved.

Firing the main burner ports b1, b2,b3,b4 of one of the coil stacks 2a,2b,2c,2d will be akin to firing a whisper burner in known arrangements save for the fact that the fuel will now be fully vaporised allowing a blue flame to be produced rather than a yellow flame associated with the whisper burner.

Since the design of multistage valve 8 is modular any number of other valve stages could be added to the valve in order to selectively deliver liquid LPG to other coil stacks or modules incorporated into the design.

Additionally, it is believed that operation on a single coil stack burner bl,b2,b3 or b4 will be at quieter combustion noise levels than compared with a whisper burner and of course will be considerably quieter than when all of the main burner means are on together.

Preheating of the four coil stacks 2a to 2d in the advantageous manner explained gives a much greater protection against "flame out" during the initial period of ignition which effect is caused by liquid fuel reaching the burner port bl,b2,b3,b4 jets instead of gaseous fuel.

Providing a plurality of coil stacks surrounding a pilot burner in the manner described generally within the same space utilised for a single vaporising coil with central pilot burner presents a greater surface area of liquid fuel to a heater coil surface and thus increases the vaporisation effect of the fuel within the coil network in addition to the vaporising effect being increased by the manner of flame delivery from the pilot, very substantially over prior art arrangements.

In prior art arrangements the vaporising coil diameter may be eight inches or so and, in practice, vaporisation of the LPG in the coils may sometimes be insufficient.

Advantageously, the control valve 8 has a snap action shut down to ensure substantially immediate closure of the gas supply to the main burners of the coil stacks if required so that there is no undue "after burning" once the operator requires shut-down unlike in previous balloon burner arrangements. The multi-stage valve 8 is so constructed that each modular section of the valve controls one module coil stack of the burner or burners (there could be one or more such burners in a complete hot air balloon assembly).

As the multi-stage control valve 8 is opened liquid LPG is delivered to the top of the two vaporising coils C of the first coil stack 2a (each coil stack comprises a double vaporising coil c). Since the coil stack 2a has already been preheated in an efficient manner from the main pilot directly impinging on the coils (rather than pre-heating merely by radiation), the liquid LPG readily vaporises in the coil stack and after it passes through multi-hole injectors (not shown) at the burner ports 17 a stable flame is established within the top coils of the coil stack 2a. Primary air is entrained through holes h in the external cylindrical primary heat shield 21, which heat shield embraces all four coil stacks 2a,2b,2c,2d.As the multi-stage valve is opened further, liquid LPG is delivered progressively to coil stacks 2b,2c,2d in order to establish flames in the upper coils of each of those stacks in a manner which should now be obvious.

On instant shut-down, as soon as the valve handle 9 is released internal springs s force the valve closure members 19a to 19d firmly on their valve seats 20a to 20d and the pressure of the liquid LPG in passageway 12 snaps all the valves vl to v4 shut substantially instantaneously cutting off the supply of fuel to all the burner modules 2a to 2d. The external diameter of the cylindrical heat shield 21 compares generally with the diameter of coil stack employed in prior art burners. Since each coil stack thus has a much smaller diameter of coil so that a lower volume of fuel is held within the coil length and with its greater surface area pro rata the shut-down time is reduced considerably giving a further safety factor over known burners.

Additionally, and advantageously the modular design of coil stacks allows easy replacement of one or more stacks or additional stacks to be introduced (along with an additional stage being incorporated in the multi-stage valve if required).

Additionally, and most importantly, all of the main burners can be modulated i.e. each burner can produce a stable flame at variable delivery of LPG gas for example by throttling the main gas supply valve. It is believed that this feature in itself is new. Each burner means bl to b4 could for example be modulated between 250,000 BTU/hr and 10 million BTU/hr When the main burners bl to b4 are operating at full capacity (about 2i million BTU/hr) the blue flames burn about eight feet to ten feet above the burner instead of the fifteen to twenty feet with prior art burners.

Thus, advantageously, the height of the flame can be reduced in the order of 50% enabling balloon design to be improved and clean combustion is achieved.

FIGURES 5 and 6 show a second embodiment of a hot air balloon burner 100, FIGURE 5 being a similar view to FIGURE 1 (pilot valve block and multistage valve omitted) and FIGURE 6 being similar to FIGURE 2.

FIGURE 5 shows a modified arrangement to that shown in FIGURE 1 and is intended to be operated by way of a single stage control valve (not shown) instead of the multistage control valve 8. With the single stage control valve all of the main burner means b'l,b'2,b'3 and b'4 will be connected to the outlet of the single stage valve and thus will be fired substantially simultaneously.

However, additionally, a by-pass valve (not shown) will usually be inserted in the liquid LPG fuel supply line positioned before the main supply gas valve so that the fuel supply to a chosen one of the coil stacks or modules 102a,102b,102c,102d can be fired at a reduced rate and lower noise level to act as a whisper burner. Thus, in this instance the fuel for the chosen main burner b1,b2,b3,b4 would pass through the appropriate vaporising coil stack 102a,102b,102c,102d before being ignited to yield good combustion. This is a very significant difference than the present design of whisper burners which run on gas fed straight from the LPG liquid fuel source without being passed through a vaporising coil thus yielding poor combustion.Thus the flame produced from the selected coil stack acting as a whisper burner will be a stable blue flame about 12 inches above the top of the burner at 300,000 BTU/hr rather than the yellow flame generally associated with whisper burners. It is believed that this improvement in itself is a very significant advantage over and above present designs of whisper burner.

Since the overall design of the burner 100 is similar to the balloon burner 1 further description in relation to burner 100 focuses on features of difference between the two burners 1,100. Importantly, the balloon burner 100 is provided with four inner combustion tubes or heat shields H which extend down the inside of an associated coil stack adjacent the inside surface of the coils as will be evident from FIGURES 5 and 6. In use, primary air is entrained through the bottom of these stainless steel combustion tubes H past the burners b'l,b'2,b'3 and b'4 giving seemingly maximum velocity to the air and the maximum mixing to the gas/air mixture within the coil stack. The inner heat shields H create effectively a venturi effect sucking air in and around the main burner means b'l to b'4, and yielding near perfect mixture.

Additionally, the heat shields H prevent the coils becoming over-heated from the main burner flames and avoids build up of carbon on the coils..

Additionally, and importantly, each of the main burner means bl,b2,b3 and b4 and btl,b'2,b'3,b'4 is provided with a multi-hole burner jet (jets arranged vertical) or injector head (not shown) which heads are much quieter than burners having only a few jets. Each of the burner jets could have, for example, 12 holes therein.

The main pilot flame trap and diffuser D has now been altered from that shown in FIGURES 1 and 2, to a single hole in a flat plate (see FIGURE 10). The diffuser D is easier to manufacture and does not clog as a result of any carbon in the flame and gives better repetition of flame pattern than the type shown in FIGURE 1. The arrangement shown in FIGURES 5 and 6 is the result of extensive testing which has resulted in a better performance and in simpler production. One coil stack can be used singularly for a "cloud hopper" burner or the coil stacks can be used in various multiples thereof to accommodate virtually any size of balloon. The overall height of the burner has also been significantly reduced.

The pilot burner assembly is important in the balloon burner 1,100 since it consists of the auxiliary pilot that can be lit by means of piezoelectric effect as well as a main pilot, thus giving a considerably greater measure of safety than with present balloon burners.

FIGURE 11 shows an alternative pilot burner assembly 300 which is supplied with liquid LPG through a liquid fuel line (not shown in FIGURE 11 but see liquid LPG delivery pipe 17 in FIGURE 1) to vaporising coil 301 which encircles pilot burner body 302.

On existing balloon burners, the pilot burner assembly is supplied with gaseous LPG from a master or main cylinder which supplies both gaseous and liquid LPG (note FIGURE 1 of the present application where liquid LPG is delivered through inlet delivery pipe 17 to the main burners B1,B2,B3,B4 and gaseous LPG is delivered from line 12 via pilot valves 11 and 14 to the pilot burner assembly 3). The gaseous LPG supply to the pilot is usually fitted with an adjustable regulator in order to reduce the pressure down from the vapour face pressure of approximately 120 p.s.i. at standard temperature to whatever is required by the pilot burner to operate at the design rate. As the latent heat of vaporisation reduces the temperature of the master or main cylinder and its contents, the vapour face pressure is reduced thereby reducing the output and operating efficiency of the main burners.

In such existing arrangements, there tends to be a problem if the liquid content of the master or main cylinder is reduced to a level which is too low before changing to another main cylinder for the liquid supply to the main burners. The operator may be left with insufficient fuel in the main cylinder to maintain the pilot burner for the projected duration of the balloon flight so that the flight might have to be terminated prematurely in potentially dangerous conditions.

An object of one embodiment of the present invention is to provide a means of alleviating the aforementioned problem and this may be achieved by the pilot burner assembly shown in FIGURE 11.

In order to overcome the aforementioned problem the pilot burner assembly may be redesigned to run from the liquid LPG supply from the master or main cylinder thus enabling the adjustable regulator to be omitted in addition to the gaseous supply pipe which in itself offers both financial and weight-saving advantages. The additional flight safety features of such a system should be self-evident.

The pilot burner assembly 300 has been fitted with vaporising coil 301, a smaller jet 303 to overcome higher pressure constraints, as well as a two stage primary aeration as will now be explained.

The pilot burner body 302 is provided with an upper ring of flame ports 304 just above the vaporising coil 301. The liquid LPG entering the vaporising coil 301 is vaporised therein and discharged as a gas through jet 303 under high pressure. The first stage of the primary aeration takes place in a small diameter venturi 305 with air being entrained through holes 306, the amount of air being admitted being controlled by generally cylindrical rotatable shutter 13. The second stage of the primary aeration takes place in the main body 302 with the second stage air entrainment taking place through holes 307 (only one shown).

A ring flame trap 308 is provided inside the pilot burner body 302 in order to maintain the velocity of the gas/air mixture which in turn increases the resistance to "light-back" to the injector should the aeration be excessive due to very high pressures at the injector jet 303. The number of flame ports 304 has been reduced over and above those usually provided (see for example the pilot burner body 103 in FIGURE 9). The number of flame ports 304 has been reduced in order to give greater flame stability in the pilot head, the flat plate flame trap 308 and diffuser 309 being retained.

The greater flame stability produced by the two stage aeration and the other improvements enables the pilot burner to be ignited from the piezo-electric electrode 310 directly onto one of the flame ports 304 instead of using an auxillary pilot (see for example 3a in FIGURE 1) which could not be fuelled by liquid fuel.

Therefore, further according to the present invention there is provided a pilot burner for a hot air balloon, said pilot burner being arranged to run from a liquid fuel supplied to a vaporising coil encircling a main body of the burner. More generally according to the present invention there is provided a pilot burner for a hot air balloon, said burner being arranged to run off liquid fuel supplied from a master or main cylinder which supplies liquid fuel to a main burner of the hot air balloon.

Many other advantageous features of this embodiment of the present invention will be apparent from the aforegoing description in relation to FIGURE 11.

FIGURE 12 illustrates a modification to the lower end of the hot air balloon burner 1, consisting of an air intake control arrangement (or damper) 400 to control the amount of air induced into the burner, by the velocity of the gas discharging from the burner jets B1,B2,B3,B4.

The greater the amount of oxygen mixed with a gas mixture, the more fierce the flame and therefore the greater the noise level of the ensuing combustion flame.

When entrained air has been reduced in volume the amount of oxygen is subsequently reduced proportionately resulting in a "softer" flame and therefore, in a greatly reduced noise level i.e. in a hot air balloon from 101 decibels at 3 metres distance away from the burner to 85 decibels at full output. The noise level of the main burner can also be reduced further by modulating the output down by the use of the fuel control valve (for example see control valve 11 in FIGURE 1). As both the air and fuel gas supplies are individually variable the permutations of combustion rate/combustion air are very large. Any one or all of the burner modules or coil stacks (for example 2a,2b,2c,2d in FIGURE 1) can be set to give the desired requirement at any moment in operation of the burners. When the main burner is set for maximum gas and minimum air, the resulting combustion is as quiet as existing "cow" burners but is very much cleaner due to the increased mixing afforded by the smaller size of burner tube yielding increased velocity and turbulance.

The air intake control arrangement 400 has an Lshaped air shut-off control lever 401 which can be actuated to raise and lower air control shutter blade 402 within the body 403 of the arrangement 400, by means of connecting rod 404.

Operation of the control lever 401 should be evident from FIGURE 12 which shows various operational positions of the lever (and of the shutter blade 402 and connecting rod 404) in chain-dotted lines. Pin 404a on the connecting lever 404 engages in slot 401a in the short limb of the lever.

As the shutter blade 402 moves up inside the body 403, the area of the four entry ports 405 in the circumference of the shutter body is reduced, thus reducing the amount of air allowed into the main burner 1.

Control lever pivot 406 is fitted with a fibre friction washer (not shown), and the friction varied by tension exerted by the pivot nut and bolt (not shown). If the air shutter blade 402 is required to be permanently or semi-permanently fixed in any desired position it can be locked in the required setting by tightening the wing nut (not shown) at the pivot bolt.

The shutter blade 402 has a clearance fit of approximately lmm within the shutter body 403 and this clearance in addition to air entrained through the ignition port in the main burner tube ensures that the burner cannot be operated without any primary combustion air, thus ensuring comparative clean combustion at all times.

Therefore, still further according to the present invention there is provided an air intake control arrangement arranged to control the amount of air induced into the main burner of a hot air balloon burner.

Further advantageous features of the air intake control arrangement will be apparent from the aforegoing description.

It is to be appreciated that the present invention offers many improvements at least some of which might be patentable individually or in combination. Any individual feature as aforementioned (for example modular main burner system, pilot burner, multi-stage burner etc) or as shown or implicit herein or combinations thereof or functions or methods apertaining thereto, may be patentably inventive and any specific term as used herein should not be construed as unnecessarily or unduly limiting; the scope of such a term could extend to or may be replaced or supplemented by, any reasonable equivalent or generic expression. The singular may include the plural or vice versa.Any range mentioned herein for any variable or parameter shall be taken to include a disclosure of any derivable sub-range within that range or of any particular value of the variable or parameter arranged within, or at an end of, the range or sub-range.

Therefore, still further according to the present invention there is provided a hot air balloon burner comprising a first main burner means including a gas vaporising coil as well as a second main burner means or a "whisper" burner means including a vaporising coil.

Still further according to the present invention there is provided a hot air balloon burner having one or more of the following features: (a) a main burner means producing, in use, a stable flame at a high heat output and at a low heat output; (b) a main burner means and a whisper burner means, the whisper burner burning fuel passed through a vaporising coil; (c) a whisper burner with a variable heat output; (d) a plurality of vaporising coil stacks with associated main burner means, said coil stacks or modules surrounding a pilot burner means, said pilot burner means in use, preferably, having a flame which directly impinges upon any of the coil stacks; (e) a pilot burner means comprising an auxiliary pilot and a main pilot; (f) a stable pilot burner means operated by piezoelectric effect;; (g) a main burner which can be operated over an operating range from about 10 million BTU/hr to 250 thousand BTU/hr; (h) a main burner means comprising a plurality of modular burners that can be operated simultaneously, one of said modules being operable singly in order to provide a whisper burner; (i) a plurality of vaporising coil stacks having a diameter of approximately 4" or such that a stable frame can be produced therein over a variable range; (j) a plurality of vaporising coil stacks surrounding a pilot burner, each of said vaporising stacks including an inner combustion tube or heat shield; (k) a main burner means comprising a plurality of individually controlled vaporising coils; (l) a main burner means that can be modulated between high and low operating levels, for example between 10 million BTU/hr and 250 thousand BTU/hr; ; (m) a main burner which can be modulated i.e. turned down thereby having a variable heat output; (n) a modular arrangement of replaceable main burner units; (o) a modular arrangement of multi-stage valve delivering fuel to main burner means; (p) a stable pilot burner; (q) a pilot burner having sideways directed flames, preferably, directly impinging on coils of vaporising coil stacks and, preferably, also directing flames upwardly; (r) a main burner means giving 50% reduction in flame height over prior art designs for similar energy output; (s) a preheating arrangement in which the pilot burner has flames directly impingIng upon vaporising coils, (t) a main burner with a throttle control.

Claims (42)

1. A hot air balloon burner comprising a plurality of gas vaporising coil stacks or modules surrounding a pilot burner means arranged, in use, to preheat the vaporising coils which act to vaporise liquid fuel gas delivered thereto, said coil stacks or modules each being provided with main burner means ignitable from the pilot burner means.

2. A hot air balloon burner comprising a plurality of gas vaporising coil stacks or modules surrounding pilot burner means and each of the coil stacks or modules being provided with main burner means ignitable from the pilot burner means, the arrangement being such that liquid gas can be delivered selectively to one or more of the vaporising coil stacks/modules to provide fuel for the main burner means associated with each selected stack/module.

3. A balloon burner as claimed in Claim 1 or Claim 2 having four similar vaporising coil stacks or modules, said pilot burner means being central of said stacks or modules.

4. A balloon burner as claimed in any one of the preceding claims in which, in use, liquid gas is delivered via supply piping to the coil stacks/modules under the control of a multi-stage valve.

5. A balloon burner as claimed in Claim 4 in which the multi-stage valve is operated by a hand control lever.

6. A balloon burner as claimed in Claim 4 or Claim 5 in which the multi-stage valve is modular.

7. A balloon burner as claimed in Claim 6 in which each modular section is similar and said valve has a common valve actuating shaft passing through each modular section.

8. A balloon burner as claimed in Claim 8 in which the actuating shaft is provided with axially spaced actuating clips and each modular section is provided with a valve closure member or diaphragm in the form of a flat plate urged onto an associated valve seat by spring means, axial movement of the shaft operating the closure members of diaphragms by means of the clips.

9. A balloon burner as claimed in Claim 8 in which the clips are positioned at progressively greater distances from their associated closure members in one axial direction of the shaft in such manner that said valves are opened sequentially allowing progressive delivery of fuel to the main burner means.

10. A balloon burner as claimed in any one of Claims 4 to 9 which has a snap action shut-down.

11. A balloon burner as claimed in any one of Claims 4 to 10 in which the multi-stage valve has each modular valve section controlling one coil stack or module, liquid gas being deliverable selectively to the top of each said stack or module.

12. A balloon burner as claimed in any one of the preceding claims in which the pilot burner means comprises an auxiliary pilot and a main pilot.

13. A balloon burner as claimed in any one of the preceding claims in which the pilot burner means has a stable pilot flame.

14. A balloon burner as claimed in Claim 13 in which the auxiliary pilot is fed with gaseous LPG through a fuel line by way of a hand operable control valve, said main pilot being fed with gaseous LPG by way of a hand operable main pilot control valve.

15. A balloon burner as claimed in Claim 14 in which liquid gas is delivered through a feed line from a liquid gas source, into a pilot valve block containing the auxiliary pilot valve and main pilot valve.

16. A balloon burner as claimed in any one of Claims 13 to 15 in which the auxiliary pilot is lit by spark electrode.

17. A balloon burner as claimed in any one of Claims 13 to 16 in which the main pilot has a device to divert some of its gas air mixture outside a main pilot body.

18. A balloon burner as claimed in any one of Claims 13 to 17 in which the main pilot has a multi-port flame head.

19. A balloon burner as claimed in Claim 18 in which the multi-port head is basically cylindrical.

20. A balloon burner as claimed in Claim 19 in which a flame head of the pilot burner means diverts, in use, some of the flame sideways into each of the vaporising coil stacks/modules.

21. A balloon burner as claimed in any one of the preceding claims having a primary heat shield embracing the coil stacks/modules, said shield having holes for entraining primary air.

22. A balloon burner as claimed in any one of the preceding claims in which the coil stacks/modules are of modular design.

23. A balloon burner as claimed in any one of the preceding claims in which all of the main burners can be modulated.

24. A balloon burner as claimed in Claim 23 in which each main burner can be modulated between 250,000 btu/hr and 10 million btu/hr.

25. A balloon burner as claimed in any one of Claims 1 to 3 having a single stage control valve for controlling delivery of liquid gas to said coil stacks/modules.

26. A balloon burner as claimed in Claim 25 having a bypass valve in the liquid gas fuel supply line.

27. A balloon burner as claimed in Claim 25 in which the by-pass line is positioned before a main supply gas valve so that the fuel supply to a selected one of the coil stacks/modules can be fired at a reduced rate to act as a whisper burner.

28. A balloon burner as claimed in Claim 27 in which the flame from the "whisper" burner coil stack/module is a stable blue flame.

29. A balloon burner as claimed in any one of Claims 25 to 28 provided with inner combustion tubes or heat shields each extending down the inside of a coil stack/module.

30. A balloon burner as claimed in Claim 29 in which primary air is entrained through the bottom of the inner tubes past the main burners, said inner tubes creating a venturi effect in and around the main burner means.

31. A balloon burner as claimed in any one of Claims 25 to 30 in which the main burner means has a multi-hole burner jet or injector head.

32. A balloon burner as claimed in any one of Claims 25 to 31 having a main pilot flame trap and diffuser comprising a single hole in a flat plate.

33. A balloon burner as claimed in any one of Claims 1 to 13 in which a vaporising coil encircles a pilot burner body of said pilot burner means and liquid gas is supplied to the vaporising coil.

34. A balloon burner as claimed in Claim 33 in which a two stage primary aeration is provided for said pilot burner means.

35. A balloon burner as claimed in Claim 33 or Claim 34 in which a ring flame trap is provided.

36. A balloon burner as claimed in any one of Claims 33 to 35 when dependent from any one of Claims 1 to 6 in which a piezo-electric electrode is provided to ignite the pilot burner means.

37. A balloon burner substantially as herein described with reference to FIGURES 1 to 4, or FIGURES 5 to 10, or FIGURE 11 or FIGURES 12 and 13 of the accompanying drawings.

38. A pilot burner for a hot air balloon, said pilot burner being arranged to run from a liquid fuel supplied to a vaporising coil encircling a main body of the burner.

39. A pilot burner for a hot air balloon, said burner being arranged to run off liquid fuel supplied from a master or main cylinder which supplies liquid fuel to a main burner of the hot air balloon.

40. An air intake control arrangement arranged to control the amount of air induced into the main burner of a hot air balloon.

41. A hot air balloon burner comprising a first main burner means including a gas vaporising coil as well as a second main burner means or a "whisper" burner means including a vaporising coil.

42. A hot air balloon burner having one or more of the following features: (a) a main burner means producing, in use, a stable flame at a high heat output and at a low heat output; (b) a main burner means and a whisper burner means, the whisper burner burning fuel passed through a vaporising coil; (c) a whisper burner with a variable heat output; (d) a plurality of vaporising coil stacks with associated main burner means, said coil stacks or modules surrounding a pilot burner means, said pilot burner means in use, preferably, having a flame which directly impinges upon any of the coil stacks; (e) a pilot burner means comprising an auxiliary pilot and a main pilot; (f) a stable pilot burner means operated by piezoelectric effect; (g) a main burner which can be operated over an operating range from about 10 million BTU/hr to 250 thousand BTU/hr;; (h) a main burner means comprising a plurality of modular burners that can be operated simultaneously, one of said modules being operable singly in order to provide a whisper burner; (i) a plurality of vaporising coil stacks having a diameter of approximately 4" or such that a stable flame can be produced therein over a variable range; (j) a plurality of vaporising coil stacks surrounding a pilot burner, each of said vaporising stacks including an inner combustion tube or heat shield; (k) a main burner means comprising a plurality of individually controlled vaporising coils; (1) a main burner means that can be modulated between high and low operating levels, for example between 10 million BTU/hr and 250 thousand BTU/hr; (m) a main burner which can be modulated i.e. turned down thereby having a variable heat output; ; (n) a modular arrangement of replaceable main burner units; (o) a modular arrangement of multi-stage valve delivering fuel to main burner means; (p) a stable pilot burner; (q) a pilot burner having sideways directed flames, preferably, directly impinging on coils of vaporising coil stacks and, preferably, also directing flames upwardly; (r) a main burner means giving 50% reduction in flame height over prior art designs for similar energy output; (s) a preheating arrangement in which the pilot burner has flames directly impinging upon vaporising coils, (t) a main burner with a throttle control.