US2992677A

US2992677A - Gas burner

Info

Publication number: US2992677A
Application number: US763325A
Authority: US
Inventors: Williams John Roger
Original assignee: Selas Corp of America
Current assignee: Selas Corp of America
Priority date: 1958-09-25
Filing date: 1958-09-25
Publication date: 1961-07-18
Anticipated expiration: 1978-07-18

Description

July 18, 1961 J. R. WILLIAMS GAS BURNER 2 Sheets-Sheet 1 Filed Sept. 25, 1958 FIG.

v v\ v\\ FIG.

INVENTOR. JOHN ROGER WILLIAMS ATTORNEY.

July 18, 1961 J. R. WILLIAMS GAS BURNER 2 Sheets-Sheet 2 Filed Sept. 25, 1958 FIG. 3

FIG. 5

INVENTOR. JOHN ROGER WILLIAMS pmw flw ATTORNEY.

United vStates Patent 2,992,677 GAS BURNER John Roger Williams, Ambler, Pa., assignor to Selas Corporation of America, Dresher, Pa., a corporation of Pennsylvania Filed Sept. 25, 1958, Ser. No. 763,325 2 Claims. ('Cl. 158-117) The present invention relates to burners and more particularly to combustion chamber type burners having variable and interchangeable discharge orifices.

The heating of metal for hardening, brazing, or other operations has been carried out for a number of years by combustion chamber burners of the type shown, for example, in Hess 2,460,085 issued January 25, 1949.

Burners of the type shown in the Hess patent have a discharge slot for the hot products of combustion that is of a fixed length. This means that different burners having discharge slots of different lengths must be used for heating work pieces of different lengths or selected portions of a piece of work of a given contour.

It is an object of this invention to provide means for varying the effective length and shape of the discharge slot of a combustion chamber type burner.

It is a further object of the invention to provide means for use with a combustion chamber type burner to vary the number, size and location of a plurality of discharge ports so that a given burner can be used for heating a plurality of parts requiring heat at different specific points.

In carrying out the invention, there is provided a water cooled member for variably obstructing the discharge slot of a burner. This member can be shifted to vary the length of the slot, or it may be replaced by another member provided with discharge openings of fixed size and locations along the length of the burner slot.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its ad vantages and specific objects attained with its use, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described a preferred embodiment of the invention.

In the drawings:

FIG. 1 is a section through the burner,

FIG. 2 is a section taken on line 2-2 of FIG. 1,

FIG. 3 is a section showing the outlet portion of a modified form of the burner,

FIG. 4 is a partial section taken on line 4-4 of FIG. 3, and

FIGS. 5 and 6 show alternate arrangements of outlet slots in the blast adjuster.

Referring to FIG. 1, it will be seen that the burner includes a base casting 1 that is provided with a threaded inlet 2 for a fuel mixture leading to a supply chamber 3. A passage 4 extends from chamber 3 to form an inlet to the combustion chamber 5 of the burner. A burner screen 6 extends across the inlet passage. This screen can well be formed of a plurality of thin ceramic plates with one side of each plate smooth and one side being provided with a series of parallel grooves 7. When the plates are placed side by side, the grooves 7 will form passages through which the fuel mixture will flow from the supply chamber to the combustion chamber. The plates forming screen 6 rest against shoulders provided in casting 1, and are held in position by metal plates 8 that overlie shoulders formed on the screen, as best shown in FIG. 1 of the drawing. The plates 8 are held in position by screws 9, and a gas tight joint is formed along the edges of the screen by a suitable packing 11 of asbestos or similar material.

The walls of combustion chamber 5 of the burner are formed by a ceramic casing 12 that may be made of one or more pieces and which rests upon plates 8. The ceramic casing is held in position on casting 1 by a metal casing 13 that is preferably formed with spaced apart walls so that the casing can be water cooled. Cooling water inlets and outlets can be provided where convenient. As shown herein, casing '13 is fastened to the base casting 1 by suitable screws.

A discharge slot 14 extends from the combustion chamber 5 opposite inlet 4, to the exterior of the structure, and is of a length equal to the width of the combustion chamber as shown in FIG. 2. The slot is restricted in its cross section with respect to the size of the cross section of the combustion chamber. Discharge slot 14 extends through

casings

12 and 13 and between

refractory members

15 and 16 that are held in position on the outer surface of casing 13 by suitable clamps 17. It is intended that the outer surface of

members

15 and 16 have a contour conforming to the contour of the piece of work being heated and that their shape will be varied depending upon the shape of the work being heated.

The sides of that portion of discharge slot 14 extending through casing 13 are recessed as shown at 18. The recesses are continued through one end of casing 13, as shown in FIG. 2 to form a passage through the burner extending lengthwise of the discharge slot intermediate its ends. A blast adjuster 19 is snugly and slideably received in this passage. This blast adjuster is a tubular metal member which has concentrically extending into it a cooling fluid supply tube 21, and is provided with an outlet 22.

In the operation of burners of this type, a combustible mixture of gas and air is supplied to chamber 3, and passes through passages 7 of the screen to be ignited and burned in combustion chamber 5. The interior of the combustion chamber becomes intensely hot and serves to pilot the flames so that all of the combustion will take place within this chamber. The hot products of combustion are discharged at high velocity and at substantially the temperature of combustion through the restricted discharge opening 14. These hot products of combustion impinge against work that is held close to the mouth of the burner adjacent to

members

15 and 16 so that the hot products of combustion flow through the narrow space between these members and the work, to heat the work rapidly. An operation of this type is described in the above mentioned Hess Patent 2,460,085.

It has been customary in the past, to make burners with different length slots conforming to the length of the work to be heated. This means that either the work has the same length and contour or a number of burners were needed. With the present invention, however,

members

15 and 16 can easily be replaced by other members having a different contour. Furthermore, the blast adjuster 19 which can be moved axially along the passage formed by recesses 18 to vary the length of the discharge slot, and thereby change the length of the blast of hot products of combustion to conform to the length of the work to be heated. A cooling fluid such as water is supplied to tube 21 to flow through the blast adjuster and be discharged through outlet 22. This cooling fluid is sufiicient to keep the blast adjuster at a low enough temperature so that it will have a satisfactory service life. The blast adjuster does not appear to have any particular effect on the temperature or velocity of the hot products of combustion being discharged through slot 14. Thus, a single burner can have its outlet or discharge slot adjusted to be used with work of different length and shape.

In FIG. 3 there is shown a modified form of the invention in which the blast from the combustion chamber is discharged through restricted slot 25 directly against the r. I 2,992,677 a work to be heated without the'use of members similar to the

refractory members

15 and 16. A slot of this type is used primarily for local or spot heating by the hot products of combination rather than for area heating as would be the case with the burner of FIG. 1. A shown herein, the restricted outlet slot extending through casing 24 is provided on each side with a recess 26 that extends lengthwise of the slot and is continued through the ends of the casing 2'4 to form a passage as shown in FIG. 4 of the drawing. In this form of the invention, the blast adjuster 27 extends all the Way through said passage and at all times obstructs the entire discharge passage. The blast adjuster, however, is provided with a plurality of discharge passages 28 as shown in FIGS. 4 and 5. These passages are formed by walls 29 conforming to the shape and size of the passage which walls are welded in position in suitable openings formed in the blast adjuster. As shown in FIG. 5, there are four passages through which the hot products of combustion are discharged, which are designated at 28, 28a, 28b, and 280. The hot products of combustionflowing through these passages are to be directed locally, for example, against portions of work that are to be heated, while other portions of work are not being heated. A cooling fluid is continually circulated through fittings 34 on the: ends of the blast adjuster from one end to the other and around walls 29 while the burner is in operation.

FIG. 6 shows a blast adjuster having a different shape set of passages formed therein. By removing the blast adjuster shown in FIG. for example, and inserting in passage 26 a blast adjuster similar to that shown in FIG. 6, different portions of the Work would be heated or different work pieces that require heating at the specific locations in front of the passages 31, 31a, 31b, and 310.

From the above description it will be seen that I have provided a combustion chamber type burner which can be used to heat selected portions of difiierent size work pieces by merely adjusting the length or the shape of the discharge opening. This arrangement permits the use of one burner for heating many pieces by merely changing the position of or changing the entire Blast adjuster so that the blast will be of desired length and shape.

While in accordance with the provisions of the Statutes, I have illustrated and described the best form of embodiment of my invention now known to me, it will be apparent to those skilled in the art that changes may be made in the form of the apparatus-disclosed Without departing from the spirit and scope of the invention set forth in the appended claims,'a'nd that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

What is claimed is:

1. In a burner, the combination of structure including refiractory material forming a combustion chamber having an elongated and restricted discharge slot extending from said chamber to the exterior of said structure, a hollow metallic casing surrounding at least a portion of said structure and said slot to form a water jacket, said casing being provided with an opening therein the sides of which form a continuation of said discharge slot, said sides of said opening being concave in shape transverse to said discharge slot to form an enlargement therein, means ito supply cooling water to said casing to flow around said opening, a tubular member slidably received in said enlargement and operative as it is moved therealong to block ofi more or less of said discharge slot, and means to circulate cooling water through said member.

2. The combination of claim 1 in which said member is provided with a passageway diametrically thereof and of less area than said slot through which combustion products can flow from said combustion chamber.

References Cited in the 'file of this patent UNITED STATES PATENTS 421,576 Jones et a1 Feb. 18, 1880 418,807 Monroe Jan. 7, 1890 2,460,085 Hess Jan. 25, 1949 2,717,416 Fletcher Sept. 13, 1955 2,876,831 Knight Mar. 10, 1959