COMBINATION BURNER

Abstract

A combination burner apparatus includes: a housing including a peripheral wall defining an interior cavity; and side-by-side first and second burner assemblies disposed in the housing in fluid communication with the interior cavity, wherein the first burner assembly is of a first burner type, and the second burner assembly is of a second burner type different from the first burner type.

Description

BACKGROUND OF THE INVENTION

This invention relates generally to combustion equipment and more particularly to burners for use with combustion equipment.

Various types of burners are known and used for providing heat input to industrial processes such as heat treating, drying, and/or baking. As used herein the term “combustion chamber” refers to any structure containing one or more burners, for example an oven or drying chamber.

One known type of burner is an infrared or “IR” burner, designed for surface combustion where fuel and air burns on a surface layer of a permeable medium in a radiant mode.

Another known type of burner is a ribbon burner. A ribbon burner can only burn in a “blue flame” mode, where a flame front propagates in air immediately downstream of the burner.

Typically, the type of combustion is set by the physical design of the burner. That is, a burner is only an infrared burner or a blue flame burner.

One problem with this design is that a particular combustion chamber application may need to use the characteristics of both infrared burners and blue flame burners; however it may not be desirable or physical space may not be available to install multiple burners in the combustion chamber.

BRIEF SUMMARY OF THE INVENTION

This problem is addressed by a single burner having two different burner assemblies, each of which can be a different burner type.

According to one aspect of the technology described herein, a combination burner apparatus includes: a housing including a peripheral wall defining an interior cavity; and side-by-side first and second burner assemblies disposed in the housing in fluid communication with the interior cavity, wherein the first burner assembly is of a first burner type, and the second burner assembly is of a second burner type different from the first burner type.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be best understood by reference to the following description taken in conjunction with the accompanying drawing figures, in which:

FIG. 1 is a perspective view showing a combination burner;

FIG. 2 is an exploded view of the burner shown in FIG. 1;

FIG. 3 is a cross-sectional view taken along lines 3-3 of FIG. 1;

FIG. 4 is a top plan view of an infrared mesh of the burner; and

FIG. 5 is a top plan view of a ribbon assembly of the burner.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings wherein identical reference numerals denote the same elements throughout the various views, FIGS. 1 and 2 illustrate an exemplary combination burner 10. The basic components of the combination burner 10 are a housing 12, a divider 14, a pair of end plates 16, a pair of couplings 18, a first burner assembly 20, and a second burner assembly 22. Each of these components will be described in more detail below.

The housing 12 is an elongated structure configured to be mounted in a combustion chamber, to receive the first and second burner assemblies 20 and 22, respectively, and to channel a combustible mixture to the first and second burner assemblies 20 and 22.

As seen in FIG. 3, the housing 12 includes a peripheral wall 24 defining an interior cavity 26. In the illustrated example, the housing 12 forms a roughly diamond cross-sectional shape, and includes a pair of spaced-apart parallel first and second mounting flanges 28, 30 respectively at its upper end.

The housing 12 may be made from a material with suitable strength and heat-resistance characteristics for use in an oven environment. For example, the housing 12 may be formed from a metal alloy in sheet form.

The divider 14 extends down the middle of the housing 12 and serves to separate the interior cavity 26 into two individual cavities 26A and 26B. The divider 14 may be made from a similar material to the housing 12, and may be integral to the housing 12, or may be a separate component attached thereto. An upper portion of the divider 14 is oriented parallel to the first and second mounting flanges 28, 30. The divider 14 cooperates with the first mounting flange 28 to define a first slot 32, and the divider 14 cooperates with the second mounting flange 30 to define a second slot 34.

The first burner assembly 20 is received in the first slot 32. It may be retained therein for example by mechanical fit, by bonding such as welding, or by using fasteners. In the illustrated example, the first mounting flange 28 the first burner assembly 20 include aligned holes which can receive fasteners 36 such as rivets or pins.

The first burner assembly 20 is of a first burner type. As used herein, the term “burner type” refers to an identifiable burner physical configuration and associated combustion properties in operation. Nonlimiting examples of burner types include ribbon burners and infrared burners. In the illustrated example, the first burner assembly 20 is an infrared or “IR” burner. The first burner assembly includes a baffle 38 which is an elongated channel with a generally C-shaped cross-section defining an open slot 40. An infrared mesh 42 overlies the top of the baffle 38 and extends over the open slot 40. As seen in FIGS. 3 and 4, the infrared mesh 42 comprises a thin plate or strip of material with a pattern of small holes 44 formed therein. The infrared mesh 42 may be constructed from any suitable heat-resistant material such as a ceramic or a metal alloy.

The first burner assembly 20 is in fluid communication with the interior cavity 26, specifically the first individual cavity 26A. In operation, the first burner assembly 20 is able to operate in infrared mode in which a combustible mixture burns on the surface of the infrared mesh 42, heating the infrared mesh 42 to a temperature at which it radiates infrared energy. This type of heating can be useful to apply focused radiant energy to the contents of a combustion chamber.

The second burner assembly 22 is received in the second slot 34. It may be retained therein for example by mechanical fit, by bonding such as welding, or by using fasteners. In the illustrated example, the second mounting flange 30 includes holes which can receive fasteners such as rivets or pins.

With the first burner assembly 20 received in the first slot 32 and the second burner assembly 22 received in the second slot 34, the first and second burner assemblies 20 and 22 may be described as being positioned “side-by-side”.

The second burner assembly 22 is of a second burner type different from the first burner type. In the illustrated example, the second burner assembly 22 is a so-called “ribbon” burner. The second burner assembly 22 includes a ribbon assembly 46. As best seen in FIGS. 3 and 5, the ribbon assembly 46 comprises a stack of thin “ribbons” 48 (e.g. plates or strips of material) oriented vertically. Each of the ribbons 48 has a sinusoidal or wavy shape defining a series of peaks 50 and valleys 52 along its length. The ribbons 48 may be stacked side-by-side and may be bonded to each other, for example by brazing. The ribbons 48 may be aligned relative to each other so that the peaks 50 and valleys 52 define spacings therebetween having a desired pattern. For example, the ribbon assembly 46 shown in FIG. 5 has ribbons 48 or layers of ribbons 48 aligned so as to define five rows of open spaces across the width “W” of the ribbon assembly 46, commonly referred to as “ports”.

The second burner assembly 22 is in fluid communication with the interior cavity 26, specifically the second individual cavity 26B. In operation, the second burner assembly 22 is able to operate in a “blue flame” mode in which a combustible mixture is discharged from the ribbon assembly 46 and forms a flame above the ribbon assembly 46. This type of combustion provides convective heat output with a minimal infrared energy component. This type of heating can be useful to apply ambient heating to the contents of a combustion chamber.

The ends of the housing 12 may be closed off of the appropriate structure, such as the illustrated end plates 16. The end plates 16 may be closed off or may include a port 54 formed therein as shown in FIG. 2. A coupling 18 may be connected to the end plate 16 so that communicates with the port 54. This allows the burner 10 to be configured in various arrangements. For example, a single burner 10 could have one open coupling 18 and one coupling 18 closed off with a cap (not shown). Alternatively, several burners 10 could be connected in series by connecting the ports 54 of adjacent burners 10 to each other, and capping off one end of the last burner 10 in the series.

In operation, the burner 10 would be provided with a combustible mixture, using a fuel supply apparatus 56 such as a fuel valve or mixer of a known type (shown schematically in FIG. 3). As used herein, the term “combustible mixture” refers to fuel, or a mixture of fuel and an oxidizer such as air. The fuel supply apparatus 56 is configured such a first stream 58 of combustible mixture is directed to the first cavity 26A, and a second stream 60 of combustible mixture is directed to the second cavity 26B. The fuel supply apparatus may be configured such that the first and second streams 58 and 60 can differ from each other, for example they may have different flowrates, fuels (i.e. fuel compositions), and/or air/fuel mixtures. Alternatively, a single stream may feed both first and second cavities 26A and 26B, and any differential in performance between the two burner assemblies 20 and 22 may occur as a result of the physical differences in the burners.

The foregoing has described a combination burner. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A combination burner apparatus, comprising: a housing including a peripheral wall defining an interior cavity; andside-by-side first and second burner assemblies disposed in the housing in fluid communication with the interior cavity, wherein the first burner assembly is of a first burner type, and the second burner assembly is of a second burner type different from the first burner type.

2. The apparatus of claim 1, wherein the housing includes a divider separating the interior cavity into two individual cavities, each of the cavities communicating with one of the burner assemblies.

3. The apparatus of claim 2, wherein: the housing includes a pair of spaced-apart parallel first and second mounting flanges;a portion of the divider cooperates with the first mounting flange to define a first slot, and with the second mounting flange to define a second slot;the first burner assembly is disposed in the first slot; andthe second burner assembly is disposed in the second slot.

4. The apparatus of claim 1 wherein the first burner assembly is an infrared burner.

5. The apparatus of claim 4 wherein the first burner assembly includes: a baffle having a generally C-shaped cross-section defining an open slot; andan infrared mesh overlying a top of the baffle and extending over the open slot.

6. The apparatus of claim 5 wherein the infrared mesh comprises a thin strip of material with a pattern of small holes formed therein.

7. The apparatus of claim 6 wherein the infrared mesh comprises a ceramic or a metal alloy.

8. The apparatus of claim 1 wherein the second burner assembly is a ribbon burner.

9. The apparatus of claim 8 wherein the second burner assembly includes a plurality of thin ribbons stacked side-by-side so as to define a plurality of ports passing therethrough.

10. The apparatus of claim 9 wherein each of the ribbons a wavy shape defining a series of peaks and valleys along its length.

11. The apparatus of claim 9 wherein the ribbons are bonded to each other.

12. The apparatus of claim 1 wherein the housing extends between first and second ends, each of which is terminated by an end plate.

13. The apparatus of claim 1 wherein one of the end plates includes a port communicating with the interior cavity.

14. The apparatus of claim 13 further comprising a coupling connected to the end plate in fluid communication with the port.

15. The apparatus of claim 1 further comprising a fuel supply apparatus configured to supply a stream of combustible mixture, the fuel supply apparatus connected in fluid communication with the interior cavity.

16. The apparatus of claim 1, wherein the housing includes a divider separating the interior cavity into first and second individual cavities, each of the cavities communicating with one of the burner assemblies, the apparatus further comprising a fuel supply apparatus configured to direct a first stream of combustible mixture to the first individual cavity, and a second stream of combustible mixture to the second individual cavity.

17. The apparatus of claim 16 wherein the apparatus is configured such that the first and second streams differ from each in other in at least of: flowrate, fuel composition, and air/fuel mixture.