US3918889A

US3918889A - Flame arrestor

Info

Publication number: US3918889A
Application number: US243139A
Authority: US
Inventors: Joseph M Green
Original assignee: Combustion Engineering Inc
Current assignee: Cameron Solutions Inc
Priority date: 1972-04-12
Filing date: 1972-04-12
Publication date: 1975-11-11
Anticipated expiration: 1992-11-11
Also published as: CA998333A

Abstract

A shell is formed into a housing for an industrial burner which is connected to the end of a firetube into which the products of combustion from the burner are discharged. A sub-housing has a flame arrestor element mounted on its external surface and is connected to the burner housing to form a path for all combustion air.

Description

' Unite States [191 Green [451 Nov. 11,1975

1 1 FLAME ARRESTOR [75] Inventor: Joseph M. Green, Tulsa, Okla.

[73] Assignee: Combustion Engineering, Inc., New

York, N.Y.

[22] Filed: Apr. 12, 1972 [21] Appl. No.: 243,139

[52] US. Cl. 431/346 [51] Int. Cl. F23D 13/46 [58] Field of Search 431/346; 48/192; 220/88 A [56] References Cited UNITED STATES PATENTS 3,079,242 2/1963 Glasgow 431/346 3.094.978 6/1963 McCray et a1. 431/346 3.213.921 10/1965 Walker et a1. 431/346 OTHER PUBLICATIONS German Allowed Application 1.203.686, Oct. 21. 1965.

Plilllt'll) E.\'anzinerCarroll B. Dority, Jr. Attorney, Agent, or Firm-Arthur L. Wade [57] ABSTRACT A shell is formed into a housing for an industrial burner which is connected to the end of a firetube into which the products of combustion from the burner are discharged. A sub-housing has a flame arrestor element mounted on its external surface and is connected to the burner housing to form a path for all combustion air.

3 Claims, 1 Drawing Figure FLAME ARRESTOR BACKGROUND OF THE INVENTION 1. Field of the Invention:

The present invention relates to the arrangement of an industrial burner for fluid fuel, the housing in which the burner is mounted and a sub-housing incorporating a screen-type flame arrestor. More specifically, the invention relates to a modular construction, or assembly, which provides ready manual access to the burner adjustments with or without the addition of the arrestor sub-housing.

2. Description of the Prior Art:

The disclosure of Glasgow U.S. Pat. No. 3,079,242 has an arrangement of burner, flame arrestor and openings generally accepted in the oil field for years. However, although accepted, there has been a nagging problem of manufacturing the assembly economically and gaining ready access to the burner and any air controls provided.

These industrial burners are usually mounted to discharge their products of combustion down firetubes. Housed on the end of the firetube, these burners have been supplied a portion of the total air flowing into the housing to mix with the fuel before combustion. The remaining portions of the total air supports the combustion by flowing into the flame downstream of the initial combustion.

The portion of air premixing with thefuel is termed primary air. The remainder of the air is called secondary air. The primary air is controlled by an adjustable opening on the burner. The secondary air, when it is controlled, is by a form of damper, or louver, mounted downstream of the entrance of the primary air to the burner.

Upstream of the burner, and its primary and secondary air adjustments, a flame arrestor spans the entrance of the housing provided for air. The screen-like form of arrestor forms a passageway for all air to the burner, or it is a seal for the housing, depending upon your view. In either event, these structures are designed to prevent the propagation of flame through them.

The present invention is not directly concerned with the efficiency of the arrestor structure. It is concerned with preserving the form of the developed arrestor, but locating it where the complete assembly of burner and housing can be economically manufactured and the'adjustrnents made available for manual manipulation with greater convenience and efficiency.

Many years have passed in making and servicing burner housings of the general type disclosed in Glasgow U.S. Pat. No. 3,079,242. Many housings, of the type disclosed specifically in FIG. 3, have been made and sold without the flame arrestor disclosed therein. Obviously, it was a complex problem to add a flame arrestor subsequently, welding support for it into place within the housing. Further, once the arrestor was in place, it was in the way of manual access to' the burner controls. To gain large supplies of air to the housing, an arrangement related to FIG. 1 of Glasgow U.S. Pat. No. 3,079,242 was made up of welded seg ments which were expensive to manufacture and often leaked when the welding was of substandard quality.

In short, up to now, chaos has reigned over this segment of oil field design. All the basic guidelines of progressive modular design have been violated. There is a colorful oil field term for the approach made to past arrangements of housing, burner, controls and arrestorjury-rigged.

SUMMARY OF THE INVENTION It is an object of the present invention to mount a burner in a housing with all the controls desired for the burner and air to the housing, the unit being detachably secured to the end of a firetube.

It is another object of the invention to form a screenlike flame arrestor on a sub-housing structure which may be detachably secured to the end of the burner housing.

It is another object to form the housing and sub-housing to provide a clear-view access to the burner and air controls mounted within the housing.

It is another object to form and mount the arrestor on the sub-housing exterior so that its capacity may be altered without change in the size of the sub-housing'or burner housing.

It is another object to form the arrestor in sections sandwiching the air access opening in the side of the sub-housing and held in position with a single, continuous band-like element so the combustion air will flow through the arrestor from different directions.

The present invention contemplates a housing for a burner, and its controls, in a generally cylindrical shape. The burner housing is adapted to be detachably secured to a firetube down which the products of combustion of the burner are discharged.

Further, the invention contemplates a sub-housing adapted to be detachably mounted on the burner housing, a screen-like flame arrestor mounted exterior of the sub-housing and adjacent an opening through the wall of the sub-housing for air to pass into the sub-housing through the arrestor and wall opening.

It is contemplated that the housing be provided with an opening, selectively sealed, through which the burner and louvers for secondary air control can be readily reached for adjustment, replacement or repair without regard for-the arrestor structure mounted on the exterior of the housing.

It is also contemplated that the screen-like form of arrestor structure comprise elongated elements wound in layers about the housing exterior so the demand for increased capacity, within a range, can be met by simply increasing the number of layers without a corresponding change in housing size.

It is contemplated that the arrestor structure be formed of two sections, one on either side' of the opening adjacent the sections, with a solid band bridging between the sections to direct air through the two sections from two different directions and into the housing interior.

Other objects, advantages and features of this invention will become apparent to one skilled in the art upon consideration of the written specification, appended claims, and attached drawings, wherein;

The drawing is an exploded and sectioned perspective view of a burner housing and flame arrestor subhousing embodying the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The drawing depicts the burner housing and arrestor housing oriented for assembly and connection to the end of a firetube. The burner housing 1 is a shell of generally cylindrical-shape. This housing has two openings 3 and each has a flange formed about it with which connection is made to the firetube and arrestor sub-hous- More specifically. the first opening 2 has a flange 3 with which bolts connect the housing to the firetube 4. When it is desirable to remove this burner housing from the firetube, disconnection can readily be made by removing the bolts.

The second opening 5 of the burner housing has a flange 6. It is through this opening 5 that a supporting framework 7 is inserted to mount burner 7A with housing 1 so its products of combustion will be discharged into firetube 4 through the first opening 2.

Sub-housing 8 is a second shell of generally cylindrical form. This sub-housing 8 has three openings. The first opening is flanged at 9 for readily connecting it to a sealing plate 10. The second opening 11 is through the wall of the sub-housing and is located at the midsection of this sub-housing. The third opening 12 is also flanged for ready connecting to the second opening 5 of the burner housing.

On the exterior of the sub-housing 8 shell is mounted a flame arrestor 13. This arrestor 13 is specifically mounted adjacent the second opening 11 so combustion air will flow through the arrestor, down into the sub-housing and through the burner housing opening 5 to the burner.

Burner 7A is supplied, of course, both air and fuel for combustion. Fuel line 14 is depicted as connected to the burner through a firetube in the wall of the burner housing. Air to mix directly with the fuel within the burner is regulated by adjustment of openings 15. This primary air establishes the basic combustible mixture burned at the exit of the burner, additional air flowing into the flame downstream of the burner.

The additional, or secondary, air is regulated by adjusting louvers over openings 16 in a plate 17 which spans the cross-sectional area of the housing 1. Plate 17 is mounted on the framework 7, and burner. In addition to the louvered holes 16, the burner 7A extends through a central aperture so holes will be available to conduct part of the combustion air into direct mixing with the fuel supplied the burner.

The louvers are mechanically adjusted over holes 16 by linkage 18 extended through the wall of housing 1. An operator may be supplied to position this linkage and the operator may receive a signal developed in response to combustion conditions. Also, a pilot burner 19 is shown mounted on framework 7. However, all these details of equipment mounted within housing 1 are not to detract from the basic concept of the invention.

Invention lies, first, in a combination of two housings, one for the burner and the other for the flame arrestor mounted on the external surface. Second, invention is on the unique arrangement of the flame arrestor and sub-housing. The claims define these broad concepts in proper scope, considering the prior art in this field.

The flame arrestor is classified as screen-like in form. Specifically, it is of the form disclosed in U.S. Pat. Nos. 3,079,242 and 3,213,921 with significant differences. The body of the arrestor is built up with wrappings of corrugated sheets sandwiched between flat sheets. The result of one such wrapping is body 20. This body is positioned adjacent opening 11 and sealed to the opening so that combustion air flowing into sub-housing 8 is forced to flow through the passages of the arrestor body 20.

A second arrestor body 21 is mounted on the housing 8 and on the opposite side of opening 11. A solid band 22 is then placed around both

bodies

20 and 21 to seal them to each other and opening 11. Combustion air can then flow into the housing through either, or both. bodies and down through opening 11.

As air can enter the housing 8 through either body of the arrestor, it does not matter from which direction wind blows over the housing. In either case, positive pressure is exerted on the air to flow it to the burner. Therefore, the arrestor arrangement is not sensitive to wind direction.

Spacers and support structure are connected to the housing 8 to hold the arrestor bodies in place and seal them to the housing. Remaining details of structure are apparent from the drawing.

The disclosure embodies the concepts of the claims and provides a modular arrangement of burner housing, burner support structure, flame arrestor structure and sub-housing for the arrestor. The burner and air adjustments are readily available whether the sub-housing of the arrestor is mounted in the burner housing or the burner housing is supplied without an arrestor housing. A clear-view of the controls is available through sub-housing 8 as the arrestor structure is mounted on its external surface.

Also, it is apparent from the drawing that the capacity of the arrestor 13 can be readily adjusted without affecting the size of the housing 8. Should the volume of air required demand an adjustment in size of the

arrestor bodies

20 and 21, the number of wraps can be added or subtracted without affecting the housing 8 size. Therefore, the mounting of the arrestor structure on the external surface of the housing has several advantages which contribute to the invention.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and inherent to the method and apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations, This is contemplated by and is within the scope of the invention.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted in an illustrative and not in a limiting sense.

The invention having been described, what is claimed l. A mounting and housing for an industrial fluid fuel burner, including,

a first housing within which a fluid fuel burner may be mounted to discharge products of its combustion from a first opening of the housing,

a burner mounted within the housing at a position where its controls for fuel and air are readily accessible through a second opening of the housing,

means for removably connecting the housing to the end of a firetube so that the products of combustion are discharged into the firetube through the first opening,

a second housing removably connected over the second opening of the first housing and itself having two of three openings through which air flows for combustion,

3. The structure of claim 2, wherein,

the second housing is in the form of a cylinder, the second opening is in the form of a peripheral slot in the cylindrical wall, and the flame arrestor comprises two separate elements wound on each side of the slot which elements are bridged by a solid band attached to the elements, such seal forcing all combustion air to flow into the housing through the arrestor elements from two different directions.

Claims

1. A mounting and housing for an industrial fluid fuel burner, including, a first housing within which a fluid fuel burner may be mounted to discharge products of its combustion from a first opening of the housing, a burner mounted within the housing at a position where its controls for fuel and air are readily accessible through a second opening of the housing, means for removably connecting the housing to the end of a firetube so that the products of combustion are discharged into the firetube through the first opening, a second housing removably connected over the second opening of the first housing and itself having two of three openings through which air flows for combustion, means for removably sealing a first of the openings of the second housing, and a screen-like flame arrestor mounted on the external surface of the second housing and adjacent the second opening so combustion air will flow through it and into the second opening.

2. The structure of claim 1, wherein, the screen-like flame arrestor is in the form of a continuous element which is wound in layers about the second housing.

3. The structure of claim 2, wherein, the second housing is in the form of a cylinder, the second opening is in the form of a peripheral slot in the cylindrical wall, and the flame arrestor comprises two separate elements wound on each side of the slot which elements are bridged by a solid band attached to the elements, such seal forcing all combustion air to flow into the housing through the arrestor elements from two different directions.