OVENS, BURNER TUBE ASSEMBLIES, AND METHODS FOR DELIVERING AIR TO A GAS POWER BURNER
Ovens for heat treating products may include a gas power burner having a burner tube assembly, a venturi tube assembly, and a blower mount. The burner tube assembly has a plurality of air inlet holes extending from an outer surface to an inner surface of the burner tube. The blower mount has an opening spaced from the outer surface of the burner tube for receiving a flow of combustion air directed in a first direction toward the burner tube. The opening of the blower mount is disposed out of axial alignment with the plurality of air inlet holes such that a portion of the burner tube and the blower mount form an air manifold for redirecting the flow of combustion air from the first direction around the burner tube and towards the air inlet holes. Methods for delivering air to a gas power burner are also disclosed.
This application claims the benefit of U.S. Provisional Application No. 60/915,012, filed Apr. 30, 2007, entitled “Ovens, And Burner Tube Assemblies, Cold Air Return Baffles, Finger Ducts, And Removable Wheels Therefor”, which is hereby incorporated in its entirety herein by reference.
This application is related to commonly owned, and co-filed U.S. patent application Ser. No. ______, entitled “Ovens Having A Cold Air Return Baffle And Methods For Circulating Air In An Oven,” by Bramhall, (Docket No. 2869.015B); U.S. patent application Ser. No. ______, entitled “Ovens, Finger Ducts Therefor, And Methods For Distributing Air in A Finger Duct” by Bramhall, (Docket No. 2869.015C); and U.S. patent application Ser. No. ______, entitled “Methods For Moving Ovens, And Ovens Having Means For Releasably Attaching To A Plurality Of Casters,” by Bramhall, (Docket No. 2869.015D), which are hereby incorporated herein by reference in their entirety.
FIELD OF THE INVENTIONThis invention relates generally to ovens, and more specifically, to burner assemblies and methods for delivering air to a gas power burner.
BACKGROUND OF THE INVENTIONOvens for heat-treating products oftentimes employ a burner for combusting a fuel such as gas for heating the oven.
Food preparation ovens such as food preparation ovens for preparing pizza and other types of food products employ jets of hot gaseous fluid such as hot air for baking or cooking the food product.
U.S. Pat. No. 4,846,143 issued to Csadenyi discloses a gas power burner for a food preparation oven. The gas power burner has a burner tube having an air aperture in the side thereof located concentrically with respect to a cylindrical tube of an air blower adaptor. The air aperture is also located along the burner tube at a position which is intermediate an air inlet apertures of a mouth portion and a burner head portion.
U.S. Pat. No. 4,045,160 issued to Michels discloses a fuel gas burner having a nozzle element having radially extending circumferential vanes. A resulting fuel-air mixture, which has a swirling motion imparted by the slots, is ignited and propelled radially outward against the frusto-conical surface of the combustion block to produce a generally flat-flame. This produces a relatively large expanse of heat radiation directed toward the area to be heated.
U.S. Pat. No. 4,457,291 issued to Henke discloses a power burner system having a circular-shaped flame spreader positioned in the path of a gas-air mixture exiting a burner tube. The flame spreader serves to shape a substantially elongated teardrop heat source into a substantially spherical heat source within a heating chamber. Also disclosed is a mechanical modulating valve coupled to a gas supply line between an electrical on-off valve and a gas power burner for varying the flow rate of gas to the gas power burner.
U.S. Pat. No. 6,481,433 issued to Schjerven, Sr. et al. disclose a modulator which regulates the amount of gas flowing to the burner to maintain a uniform temperature in the oven in response to thermocouple sensors in a cavity control.
There is a need for further ovens and burner tube assemblies therefor.
SUMMARY OF THE INVENTIONThe present invention, in a first aspect, is directed to a burner tube assembly for a gas power burner. The burner tube assembly generally includes a burner tube, a venturi tube assembly, and a blower mount. The burner tube includes a first end, a second end, a longitudinal axis extending from the first end to the second end, and a plurality of air inlet holes extending from an outer surface to an inner surface of the burner tube adjacent to the second end. The venturi tube assembly is disposed longitudinally in the burner tube and has an inlet portion disposed adjacent to the second end and a burner head portion disposed adjacent to the first end. The blower mount has an opening spaced from the outer surface of the burner tube for receiving a flow of combustion air directed in a first direction towards the burner tube. The opening of the blower mount is disposed out of axial alignment with the plurality of air inlet holes so that a portion of the burner tube and the blower mount form an air manifold for redirecting the flow of combustion air from the first direction around the burner tube and towards the plurality of air inlet holes.
The present invention, in a second aspect, is directed to an impingement oven which includes a housing having a chamber for receiving and heating a heat treatable product, and a gas power burner having a burner tube assembly as described above for supplying heat to said chamber.
The present invention, in a third aspect, is directed to a method for delivering air to a gas power burner. The method includes, providing a flow of combustion air along an axis in a first direction toward an outer surface of a burner tube, redirecting the flow of combustion air around at least a portion of the outer surface of the burner tube, and transferring the flow of the redirected combustion air from an outer surface of said burner tube to an inner surface of said burner tube in a direction different from the first direction.
The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, may best be understood by reference to the following detailed description of various embodiments and the accompanying drawings in which:
The present invention is directed to ovens for heat treating products and may include food preparation ovens that use a gas power burner that meters combustible gas at a rate of about 75,000 BTU/hr.
In a one aspect, the present invention is directed to a burner tube assembly for a gas power burner for use in an oven for heat treating products and may include ovens for preparing pizza and similar types of food products. For example, the gas power burner may be used in an impingement oven having a conveyor wherein food products are baked or cooked by means of jets of hot gaseous fluid such as hot air and wherein the hot air jets are impinged directly upon localized areas of the food product. The gas power burner may also be used in ovens which do not include a conveyor. The burner tube assembly may employ a draft induction air manifold that utilizes, for example, a plurality of equally and circumferentially spaced air apertures formed in the burner tube to ventilate a burner tube to evenly introduce the air with gas for combustion as explained below.
With reference to
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Burner tube 20 may include a hollow cylindrical metal tube having a first or front end 22, a second or rear end 24, a longitudinal axis L extending from first end 22 to second end 24, and a plurality of air inlet holes 28 (only one of which is shown in
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With reference again to
With reference again to
For example, as shown in
As described above, burner tube 20 has a plurality of relatively small inlet holes 28 extending therethrough spaced around the circumference of the burner tube for receiving air from blower mount 30 and introducing the air towards the four inlets in inlet portion 64 of the venturi tube assembly as illustrated by the arrows in
Blower mount 30 may be fabricated from two halves 32 and 34 as shown in
Compared to conventional gas power burners which employ a single relatively large hole in the burner tube spaced from the inlet portion of the venturi assembly for receiving all the air directly from the air blower and wherein the relatively large hole in the burner tube is aligned with the axis of the tube from the blower, the present invention by employing a plurality of relatively smaller sized holes and offsetting the holes from the axis of and flow direction from the blower may result in several benefits over conventional gas power burners. For example, the present invention may provide a more evenly distributed air flow towards the base of the venturi tube assembly, a more even pressure around the base of the venturi tube assembly, and an increase the efficiency of the combustion of the gas for a higher yield in performance.
The burner tube may be about 9 inches (230 mm) long and have a diameter of about 3 inches (76 mm). The inlet holes may be about 5/16 inch (4-8 mm) in diameter. The inlet holes may be disposed about ½ inch (14 mm) from the end of the burner tube. The burner tube is desirably capable of withstanding temperatures in the range of about 1,450 degrees Fahrenheit (about 788 degrees Celsius).
In operation of the gas power burner, the flame spreader provides a turbine effect to “throw” the flame from the end of the gas power burner.
Thus, while various embodiments of the present invention have been illustrated and described, it will be appreciated to those skilled in the art that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.
Claims
1. A burner tube assembly for a gas power burner, said burner tube assembly comprising:
- a burner tube having a first end, a second end, a longitudinal axis extending from said first end to said second end, and a plurality of air inlet holes extending from an outer surface to an inner surface of said burner tube adjacent to said second end;
- a venturi tube assembly disposed longitudinally in said burner tube and having an inlet portion disposed adjacent to said second end and a burner head portion disposed adjacent to said first end;
- a blower mount having an opening spaced from said outer surface of said burner tube for receiving a flow of combustion air directed in a first direction toward said burner tube, said opening of said blower mount disposed out of axial alignment with said plurality of air inlet holes; and
- wherein a portion of said burner tube and said blower mount form an air manifold for redirecting the flow of combustion air from the first direction around said burner tube and towards said plurality of air inlet holes.
2. The burner tube assembly of claim 1 wherein said plurality of air inlets holes are obscured from view through said opening of said blower mount.
3. The burner tube assembly of claim 1 wherein plurality of air inlets holes direct the flow of combustion air in a plurality of generally radial directions towards said longitudinal axis of said burner tube.
4. The burner tube assembly of claim 1 wherein said plurality of air inlet holes is generally evenly spaced around said burner tube.
5. The burner tube assembly of claim 1 wherein said plurality of air inlet holes comprises four air inlet holes.
6. The burner tube assembly of claim 1 wherein said burner tube comprises a cylindrical tube.
7. The burner tube assembly of claim 1 further comprising a flame spreader disposed adjacent to said second end.
8. The burner tube assembly of claim 1 wherein said flame spreader comprises a center portion defining a cone, and a plurality of outwardly extending angled fins.
9. An impingement oven comprising:
- a housing having a chamber therein for receiving and heating a heat treatable product; and
- gas power burner comprising a burner tube assembly of claim 1 for supplying heat to said chamber.
10. The impingement oven of claim 9 further comprising a movable conveyor.
11. The impingement oven of claim 9 wherein said gas power burner further comprises a modulating gas valve for regulating the supply of gas to the gas power burner between 0-percent and 100-percent.
12. A method for delivering air to a gas power burner, the method comprising:
- providing a flow of combustion air along an axis in a first direction toward an outer surface of a burner tube;
- redirecting the flow of combustion air around at least a portion of the outer surface of the burner tube; and
- transferring the flow of the redirected combustion air from an outer surface of said burner tube to an inner surface of said burner tube in a direction different from the first direction.
13. The method of claim 12 further comprising obstructing the flow of combustion air along the axis with a portion of the outer surface of the burner tube.
14. The method of claim 12 wherein the transferring comprises transferring the flow of redirected combustion air through a plurality of air inlets holes spaced from the axis.
15. The method of claim 12 wherein the transferring comprises transferring the flow of redirected combustion air through four air inlet holes spaced from the axis.
16. The method of claim 12 wherein the transferring comprises transferring the flow of redirected combustion air in a plurality of generally radial directions toward a longitudinal axis of said burner tube.
17. The method of claim 12 wherein the transferring comprises transferring the flow of redirected combustion air generally evenly toward a longitudinal axis of said burner tube.
18. The method of claim 12 further comprising regulating the supply of gas between 0-percent and 100-percent to the gas power burner.
19. The method of claim 12 further comprising providing a flow of gas to a venturi tube disposed in the burner tube, and spreading a flame generally radially from the burner tube.
Type: Application
Filed: Apr 29, 2008
Publication Date: Oct 30, 2008
Inventor: Marcus E. BRAMHALL (Dallas, NC)
Application Number: 12/111,490
International Classification: F24C 3/00 (20060101);