WO1996029543A1

WO1996029543A1 - Pressurizer for burner fuel container

Info

Publication number: WO1996029543A1
Application number: PCT/US1996/003781
Authority: WO
Inventors: Michael Ben-Zvi
Original assignee: Avneri, Jonathan; Grinberg, Zvika; Avneri, Arie
Priority date: 1995-03-23
Filing date: 1996-03-21
Publication date: 1996-09-26
Also published as: IL113115A0; AU5662196A

Abstract

Fluid fuel combustion apparatus including a fuel container (100), a fuel burner (145) coupled to the fuel container, and a pressurizer (165) operated by combustion of fluid fuel and operative to apply pressure to fuel in said container.

Description

PRESSURIZER FOR BURNER FUEL CONTAINER

The present invention relates to fluid fuel combustion apparatus in general, and to fluid fuel combustion apparatus including a pressurizer in particular.

Fluid fuel combustion apparatus is well known in the art. Fluid fuel combustion apparatus includes apparatus burning liquid fuel as well as apparatus burning gaseous fuel. Fluid fuel combustion apparatus includes apparatus designed mainly to produce heat, such as a stove; for cooking, such as a fuel burner; and apparatus designed mainly to produce light, such as a lamp.

Fluid fuel combustion apparatus is described in U.S. Patent 3,933,146 to Hastings and in U.S. Patent 4,126,177 to Hastings.

Pressurization apparatus used in fuel fluid combustion apparatus usually includes apparatus operative to introduce air under pressure directly into the fuel container, with the air being in direct contact with the fuel. The fuel container is generally maintained in a pressurized state at all times.

A method and apparatus for applying pressure to the ullage space in a beer or wine container is described in UK Patent Application 2,010,975.

The present invention seeks to provide improved fluid fuel combustion apparatus including a pressurizer.

There is thus provided in accordance with a preferred embodiment of the present invention fluid fuel combustion apparatus including a fuel container, a fuel burner coupled to the fuel container, and a pressurizer operated by combustion of fluid fuel and operative to apply pressure to fuel in the container.

Further in accordance with a preferred embodiment of the present invention the fuel burner is a burner which principally produces heat.

Still, further in accordance with a preferred embodiment of the present invention the fuel burner is a burner which principally produces light.

Additionally in accordance with a preferred embodiment of the present invention the pressurizer includes a heat actuated gas flow generator.

Moreover in accordance with a preferred embodiment of the present invention the gas flow generator is operative to provide a flow of gas under pressure to the interior of the fuel container.

Further in accordance with a preferred embodiment of the present invention the pressurizer also includes a one-way valve associated with the gas flow generator.

Still further in accordance with a preferred embodiment of the present invention the gas flow generator and the one-way valve associated therewith are operative to provide a flow of gas under pressure to the interior of the fuel container.

Additionally in accordance with a preferred embodiment of the present invention the pressurizer also includes an expandable gas container located at the interior of the fuel container and arranged to receive the flow of gas under pressure.

Moreover in accordance with a preferred embodiment of the present invention the pressurizer also includes a piston located at the interior of the fuel container and arranged to be displaced by pressurized gas supplied to one side thereof from the gas flow generator.

Further in. accordance with a preferred embodiment of the present invention the fuel container is formed of a plastic material.

Still further in accordance with a preferred embodiment of the present invention the heat actuated gas flow generator is disposed above the fuel burner.

Additionally in accordance with a preferred embodiment of the present invention the fluid fuel combustion apparatus also includes a gas pressure dissipation valve.

Moreover in accordance with a preferred embodiment of the present invention the gas pressure dissipation valve is automatically operated to prevent overpressurization of fuel in the fuel container.

Further in accordance with a preferred embodiment of the present invention the gas pressure dissipation valve is selectably operable upon termination of combustion of the fuel, thereby to maintain the fuel in the fuel container in a generally unpressured state when the combustion apparatus is not in use.

Still further in accordance with a preferred embodiment of the present invention the pressurizer includes a heat actuated gas pressure generator.

Additionally in accordance with a preferred embodiment of the present invention the gas flow generator is operative to provide a flow of gas under pressure to the interior of the fuel container.

Moreover in accordance with a preferred embodiment of the present invention the pressurizer also includes an expandable gas container located at the interior of the fuel container and arranged to receive said flow of gas under pressure.

Further in accordance with a preferred embodiment of the present invention the expandable gas container is at least partially filled with a vaporizable fluid.

Still further in accordance with a preferred embodiment of the present invention the vaporizable fluid comprises water.

There is also provided in accordance with another preferred embodiment -of the present invention a method for fuel combustion including providing a fuel container, burning fuel from the fuel container, and applying pressure to fuel in the container by combustion of fluid fuel.

The present invention will be understood and appreciated from the following detailed description, taken in conjunction with the drawings in which:

Fig. 1 is a simplified pictorial illustration of fluid fuel combustion apparatus including a pressurizer, the apparatus constructed and operative in accordance with a preferred embodiment of the present invention;

Fig. 2 is a sectional view of a portion of the apparatus of Fig. 1 along the dines II-II;

Fig. 3 is a simplified pictorial illustration of the apparatus of Fig. 1 during operation;

Fig. 4 is a simplified pictorial illustration of fluid fuel combustion apparatus including a pressurizer, the apparatus constructed and operative in accordance with an alternative preferred embodiment of the present invention;

Fig. 5 is a simplified pictorial illustration of fluid fuel combustion apparatus including a pressurizer, the apparatus constructed and operative in accordance with a further preferred embodiment of the present invention; and

Fig. 6 is a simplified pictorial illustration of the apparatus of Fig. 5 during operation;

Fig. 7A is a simplified pictorial illustration of fluid fuel combustion apparatus including a pressurizer, the apparatus constructed and operative in accordance with another preferred embodiment of the present invention;

Fig. 7B is an enlarged view of a portion of the apparatus of Fig. 7A and

Fig. 8 is a simplified pictorial illustration of the apparatus of Fig. 7A during operation. Reference is now made to Fig. 1 which is a simplified pictorial illustration of fluid fuel combustion apparatus including a pressurizer, the apparatus constructed and operative in accordance with a preferred embodiment of the present invention. The apparatus of Fig. 1 includes a fuel container 100 containing fuel 110.. The fuel container 100 may be formed of metal, plastic, or any other suitable material, such that the fuel container 100 is capable of withstanding internal pressure in an operating range typically between 5 and 8 atmospheres.

The fuel 110 may be any fuel as, for example, gasoline, butane, alcohol, acetylene, liquefied natural gas, kerosene, fuel oil or any other combustible oil, or in general any liquid fuel or any liquefied gaseous fuel.

The apparatus of Fig. 1 further comprises a sack 120, located within the fuel container 100. The sack 120 is preferably formed of an elastic material such as rubber or synthetic rubber. For example, any rubber or synthetic rubber suitable for use in a bicycle tire inner tube is generally suitable for the sack 120.

The size of the sack 120 is preferably such that, when fully inflated, the sack 120 fully occupies the interior of the fuel container 100.

The apparatus of Fig. 1 further comprises a one-way pneumatic valve 125 of the type generally used in pneumatic tires. The pneumatic valve 125 is firmly mechanically attached to the sack 120, typically by a pressure fitting. The pneumatic valve 125 is firmly mechanically attached to an upper surface of the fuel container 100, typically with an internal screw fitting.

The apparatus of Fig. 1 further comprises a fuel supply tube 135, typically formed of brass or plastic, as, for example, a foam tube FM1/B-₄, commercially available from Jia Teh Precision Instrument Manufacturing Corp. Ltd., Taiwan. The apparatus of Fig. 1 further comprises a wick lid 137 operative to wick the fuel 110 through the tube 135. One example of a suitable wick lid is a wick lid FM1/B-3, available commercially from Jia Teh Precision Instrument Manufacturing Corp., Ltd. , Taiwan.

The apparatus of Fig. 1 further comprises a fuel valve 140, which may be the same or similar to the pneumatic valve 125.

The apparatus of Fig. 1 further comprises a fuel burner 145. The fuel burner 145 is typically removably attached to the fuel container 100, preferably via a screw thread fitting, as is well-known in the art. The fuel burner 145 comprises a fuel burner tube 150, which may be of similar construction to the fuel supply tube 135, but is preferably formed of brass.

The fuel burner 145 also comprises a manually controlled fuel regulator 155 of the type normally used in fluid fuel combustion apparatus.

The fuel burner 145 also comprises a nozzle 160, attached to the end of the fuel burner tube 150. As is well known in the art, the nozzle 160 is arranged to provide a flow of fuel from the fuel burner tube 150 to the atmosphere for burning.

The apparatus of Fig. 1 further comprises a pressurizer 165. The pressurizer 165 comprises a pressurizer tube 170. The pressurizer tube 170 is attached at the lower end thereof, preferably with a screw thread, to the pneumatic valve 125.

The pressurizer tube 170 is formed with an upper end 175 preferably in a generally circular shape, although another shape may be used. The upper end 175 is preferably at least 10 centimeters in length. The end of the upper end 175 is closed to the atmosphere.

Reference is now additionally made to Fig. 2, which is an expanded sectional view of a portion of the apparatus of Fig. 1 along the lines II-II. The upper end 175 comprises an outer tube 180, preferably formed of brass, typically of 7 millimeter minimum diameter.

The upper end 175 also comprises an inner pressure regulator 185, preferably formed of an iron wire.

The upper end 175 also comprises a heating element 190, preferably formed of resistive heating wire wound spirally around the inner pressure regulator 185. The heating element 190 is preferably wound with at least 10 windings per centimeter. The heating element 190 is wound tightly around the inner pressure regulator 185, so as not to permit the free passage of air between the inner pressure regulator 185 and the heating element 190.

The sizes of the outer tube 180, the inner pressure regulator 185, and the heating element 190 are such that a small space, preferably between .01 and .05 millimeter, is provided between the outer tube 180 and the heating element 190 to allow the passage of air therethrough.

Referring again to Fig. 1, the upper end 175 also comprises a one-way air supply valve 195, the nozzle thereof being disposed outwards, so that air, from the atmosphere, is allowed to enter the upper end 175 via the air supply valve 195, but not to exit via the air supply valve 195.

The air supply valve 195 is formed of a heat- resistant material, preferably metal. An example of an appropriate air supply valve 195 is a valve comprised of a nozzle seat FM1/B-6, a small spring FM1/B-9, and a nozzle FM1/B-7, all commercially available from Jia Teh Precision Instrument Manufacturing Corp. Ltd. , Taiwan. Typically, the air supply valve 195 is soldered to the upper end 175. The air supply valve 195 is preferably situated so that it is not within flame during the operation of the apparatus of Fig. 1.

The pressurizer 165 further comprises a pressure release valve 200, similar to the one-way air supply valve 195, except that the nozzle is disposed inwards. The pressure release valve 200 is operatively associated with the manually controlled fuel regulator 155, such that, when the manually controlled fuel regulator 155 is closed, the pressure release valve 200 is operated so as to release the pressure within the sack 120. Preferably, the pressure release valve 200 is also operative to automatically release the pressure within the sack 120 whenever the pressure within the sack 120 is above a predetermined limit, as for example, 8 or 9 atmospheres.

The operation of the apparatus of Fig. 1 is now briefly described. When the manually controlled fuel regulator 155 is closed, the pressure within the sack 120 and within the fuel 110 is low, typically within a range between 0.5 atmosphere and 1.5 atmosphere, depending on the ambient temperature.

The user of the apparatus of Fig. 1 opens the manually controlled fuel regulator 155 and ignites the fuel exiting from the nozzle 160. Typically, in the case of liquefied gaseous fuel, the flame is low because of the low pressure of the fuel 110. In the case of liquid fuel when the pressure of the fuel 110 is below 1.0 atmosphere, the pressure of the fuel 110 must be raised to at least 1.0 by means of conventional pressurization apparatus (not shown) , as is well known in the art.

As fuel exiting from the nozzle 160 burns, the upper end 175 is heated. Air located between the outer tube 180 and the heating element 190 is heated and expands. The one-way air supply valve 195, as explained above, does not allow air to exit from the upper end 175. Therefore, heated air from the upper end 175 flows down the pressurizer tube 170 into the sack 120. As air flows down the pressurizer tube 170, the one-way air supply valve 195 allows additional air to enter and be heated.

Reference is now additionally made to Fig. 3, which is a simplified pictorial illustration of the apparatus of Fig. 1 during operation. The sack 120 expands from the pressure of the entering heated air and is also heated by the air. The heating of the sack 120 in turn heats the fuel 110. Both the expansion of the sack 120 and the heating of the fuel 110 cause an increase in pressure in the fuel 110.

The increase in pressure in the fuel 110 raises the pressure of the fuel 110 to a higher level, causing the flame to burn more intensely. The more intense flame heats the upper end 175 more effectively, thus enhancing the process of raising the pressure in the fuel 110 as describe above.

The process continues until an equilibrium pressure is reached. At the predetermined equilibrium pressure the pressure release valve 200 automatically releases pressurized air into the atmosphere, thus limiting the expansion of the sack 120 and limiting the increase in the pressure of the fuel 110. Typically, equilibrium pressure is reached fairly quickly as, for example, in ten seconds. The pressure at equilibrium is dependent on many factors, including the size and construction of the apparatus of Fig. 1, and is typically between 1.5 and 5.0 atmospheres.

When the user of the apparatus of Fig. 1 closes the manually controlled fuel regulator 155, thus extinguishing the flame, the pressure release valve 200 is operated, as explained above with reference to Fig. l, so as to release the pressure within the sack 120 and to deflate the sack 120. The pressure within the sack 120 and within the fuel 110 is typically thus reduced to l.0 atmosphere, and may be further reduced as the fuel 110 and the sack 120 cool to ambient temperature.

Reference is now made to Fig. 4, which is a simplified pictorial illustration of fluid fuel combustion apparatus including a pressurizer, the apparatus constructed and operative in accordance with an alternative preferred embodiment of the present invention. The apparatus of Fig. 4 is similar to the apparatus of Fig. 1, except as described below.

In Fig. 4 the upper end 175 of Fig. l, which is closed to the atmosphere as described above with reference to Fig. 1, is replaced with a similar upper closed cycle portion 210. The upper closed cycle portion 210 extends downwards into the fuel 110, where the end of the upper portion 210 is open to the fuel.

The operation of the apparatus of Fig. 4 is now briefly described. The operation of the apparatus of Fig. 4 is similar to the operation of the apparatus of Fig. 1, as described above. The apparatus of Fig. 4 draws vapors from the fuel 110 for heating, rather than drawing air from the atmosphere as in the apparatus of Fig. 1. It is appreciated, therefore, that during the operation of the pressure release valve 200, fuel 110 will be vented to the atmosphere. The apparatus of Fig. 4 is therefore preferred only in applications where the venting of fuel 110 to the atmosphere is acceptable.

Reference is now made to Fig. 5, which is a simplified pictorial illustration of fluid fuel combustion apparatus including a pressurizer, the apparatus constructed and operative in accordance with a further preferred embodiment of the present invention. The apparatus of Fig. 5 is similar to the apparatus of Fig. 1, except as described below.

In place of the sack 120 of Fig. l, the apparatus of Fig. 5 comprises a piston assembly 220. The piston assembly 220 comprises a piston, preferably constructed of plastic. The piston is located within the fuel 110, and is sealed therefrom with a gasket 230 such that gases actuating the piston are prevented from entering the fuel 110. The side of the piston assembly 220 which is not in contact with the fuel 110 is operatively attached to the pressurizer tube 170.

The operation of the apparatus of Fig. 5 is now briefly described. Reference is now additionally made to Fig. 6, which is a simplified pictorial illustration of the apparatus of Fig. 5 during operation. The operation of the apparatus of Fig. 5 is similar to the operation of the apparatus of Fig. l, as described above. When the apparatus of Fig. 5 is lit, the hot gases cause the piston assembly 220 to rise, pressing against the fuel 110, and to be heated, thus raising the pressure of the fuel 110 in a manner similar to that described above with reference to Fig. 1.

When the user of the apparatus of Fig. 5 closes the manually controlled fuel regulator 155, thus extinguishing the flame, the pressure release valve 200 is operated, as explained above with reference to Fig. 1, so as to release the pressure within the piston assembly 220 and to allow the piston 220 to lower. The pressure within the fuel 110 is typically thus reduced to 1.0 atmosphere, and may be further reduced as the fuel 110 and the piston assembly 220 cool to ambient temperature.

Reference is now made to Fig. 7A, which is a simplified pictorial illustration of fluid fuel combustion apparatus including a pressurizer, the apparatus constructed and operative in accordance with another preferred embodiment of the present invention. The apparatus of Fig. 7A is similar to the apparatus of Fig. 1, except as follows.

The apparatus of Fig. 7A preferably does not comprise the pneumatic valve 125 of Fig. l. in place of the pressurizer 165 of Fig. 1, the apparatus of Fig. 7A preferably comprises a pressurizer 250. The pressurizer 250 of Fig. 7A is preferably similar to the pressurizer 165 of Fig. 1, except that the pressurizer 250 of Fig. 7A preferably does not comprise the air supply valve 195 and the pressure release valve 200 of Fig. 1.

Reference is now additionally made to Fig. 7B, which is an enlarged view of a portion of the apparatus of Fig. 7A. The pressurizer 250 of Figs. 7A and 7B is preferably at least partially filled with a volatile or vaporizable fluid 255, typically in the upper end 175 as seen in Fig 7A. The vaporizable fluid 255 may comprise any suitable vaporizable fluid, preferably a non- combustible fluid, typically water. The volume of the vaporizable fluid 255 is preferably approximately one cubic centimeter for each centimeter of length of the upper end 175, with a minimum volume of approximately two cubic centimeters. When the apparatus of Fig. 7A is not in operation, the vaporizable fluid 255 is typically located largely in the upper end 175, as seen in Fig. 7B.

The operation of the apparatus of Fig. 7A is now briefly described. The operation of the apparatus of Fig. 7A is generally similar to the operation of the apparatus of Fig. 1, described above, except as follows.

Reference is now additionally made to Fig. 8, which is a simplified pictorial illustration of the apparatus of Fig. 7A during operation. As the upper end 175 is heated as described above with reference to Fig. 1, air in the upper end 175 expands and enters the sack 120. The sack 120 expands and heats as the heated air enters the sack 120. In addition, as the upper end heats the vaporizable fluid 255 also heats and therefore vaporizes partially or completely. Vapors formed by vaporization of the vaporizable fluid 255 expand into the sack 120 and also contribute to expansion of the sack 120.

It is appreciated that, upon cooling of the apparatus of Fig. 7A, the portion of the vaporizable fluid 225 which previously vaporized will generally condense, contributing to a lowering of pressure inside the sack 120, thus also lowering the pressure of the fuel 110, similarly to the process described above with reference to Fig. 1.

It is appreciated that, during cooling of the apparatus of Fig. 7A, which preferably does not include the pressure release valve 200 of Fig. 1, pressure of the fuel 110 will generally be reduced more slowly than in the system of Fig. 1, as the sack 120 cools and the vaporizable fluid 255 condenses.

It is appreciated that, in the preferable case where the vaporizable fluid 255 is non-combustible, a rupture of the sack 120, typically due to excess pressure therein, will tend to mix the vaporizable fluid 255 with the fuel 110 and prevent further combustion of the fuel 110. This effect may tend to increase the safety of operation of the apparatus of Fig. 7A.

It is appreciated that the apparatus of the present invention is applicable to any type of fluid fuel combustion apparatus, including, for example: apparatus designed mainly to produce heat, such as a stove; apparatus for cooking, such as a fuel burner; and apparatus designed mainly to produce light, such as a lamp.

It is appreciated that various features of the invention which are, for clarity, described in the contexts of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment may also be provided separately or in any suitable subcombination.

It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention is defined only by the claims that follow:

Claims

1. Fluid fuel combustion apparatus comprising: a fuel container; a fuel burner coupled to the fuel container; and a pressurizer operated by combustion of fluid fuel and operative to apply pressure to fuel in said container.

2. Fluid fuel combustion apparatus according to claim 1 and wherein said fuel burner is a burner which principally produces heat.

3. Fluid fuel combustion apparatus according to claim 1 and wherein said fuel burner is a burner which principally produces light.

4. Fluid fuel combustion apparatus according to any of the preceding claims and wherein said pressurizer comprises a heat actuated gas flow generator.

5. Fluid fuel combustion apparatus according to claim 4 and wherein said gas flow generator is operative to provide a flow of gas under pressure to the interior of the fuel container.

6. Fluid fuel combustion apparatus according to claim 4 and wherein said pressurizer also comprises a one-way valve associated with the gas flow generator.

7. Fluid fuel combustion apparatus according to claim 6 and wherein said gas flow generator and said one¬ way valve associated therewith are operative to provide a flow of gas under pressure to the interior of the fuel container.

8 . Fluid fuel combustion apparatus according to claim 7 and wherein said pressurizer also comprises an expandable gas container located at the interior of the fuel container and arranged to receive said flow of gas under pressure.

9 . Fluid fuel combustion apparatus according to claim 7 and wherein said pressurizer also comprises a piston located at the interior of the fuel container and arranged to be displaced by pressurized gas supplied to one side thereof from said gas flow generator.

10. Fluid fuel combustion apparatus according to claim 1 and wherein said fuel container is formed of a plastic material .

11. Fluid fuel combustion apparatus according to claim 4 and wherein said heat actuated gas flow generator is disposed above said fuel burner .

12. Fluid fuel combustion apparatus according to claim 1 and also comprising a gas pressure dissipation valve .

13 . Fluid fuel combustion apparatus according to claim 12 and wherein said gas pressure dissipation valve is automatically operated to prevent overpressurization of fuel in said fuel container.

14 . Fluid fuel combustion apparatus according to claim 12 and wherein said gas pressure dissipation valve is selectably operable upon termination of combustion of said fuel , thereby to maintain said fuel in said fuel container in a generally unpressured state when said combustion apparatus is not in use.

15. Fluid fuel combustion apparatus according to claim 1 and wherein said pressurizer comprises a heat actuated gas pressure generator.

16. Fluid fuel combustion apparatus according to claim 15 and wherein said gas flow generator is operative to provide a flow of gas under pressure to the interior of the fuel container.

17. Fluid fuel combustion apparatus according to claim 16 and wherein said pressurizer also comprises an expandable gas container located at the interior of the fuel container and arranged to receive said flow of gas under pressure.

18. Fluid fuel combustion apparatus according to claim 17 and wherein said pressurizer is at least partially filled with a vaporizable fluid.

19. Fluid fuel combustion apparatus according to claim 18 and wherein said vaporizable fluid comprises water.

20. A method for fuel combustion comprising: providing a fuel container; burning fuel from the fuel container; and applying pressure to fuel in said container by combustion of fluid fuel.