US3187798A

US3187798A - Radiant gas burner

Info

Publication number: US3187798A
Application number: US316974A
Authority: US
Inventors: Laszlo Z Pokorny
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1963-10-17
Filing date: 1963-10-17
Publication date: 1965-06-08
Anticipated expiration: 1982-06-08

Description

June 8, 1965 L. z. POKORNY RADIANT GAS BURNER Filed Oct. 17, 1963 INVENTOR. LASZLO Z. POKOR/VY A T TORNEV United States Patent 3,187,798 RADIANT GAS BURNER Laszio Z. Pokorny, Rochester, N.Y., assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Filed Oct. 17, 1963, Ser. No. 316574 5 Claims. (Cl. 158-7) This invention pertains to gas burners, and particularly to a high CfilClCllCY radiant burner designed for use with a pressurized combustible mixture of gaseous fuel and air.

In my copending application Serial No. 316,967, filed of even date herewith, a pressurized radiant gaseous fuel burner is disclosed including a refractory shell which is heated to incandescence, and wherein the combustible .mixture is burned exteriorly thereof in a combustion chamber. The present invention relates to a pressurized radiant gaseous fuel burner of the same general type, but wherein the fuel mixture is burned internally of the refractory shell :so that the shell is heated to incandescence.

Accordingly, among my objects are the provision of a pressurized radiant gas burner; the further provision of a pressurized radiant gas burner having means for obtaining a directional heating effect; and the still further provision of a pressurized radiant gas burner having a refractory shell which is heated to incandescence and wherein the combustible mixture is burned internally of the refractory shell.

The aforementioned and other objects are accomplished in the present invention by constructing the refractory Shell in such a way that the entering combustible mix ture, after ignition, will have a velocity less than the speed of propagation of the flame.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

FIGURE 1 is a fragmentary longitudinal sectional view of a radiant burner constructed according to the present invention.

FIGURE 2 is a sectional view taken along line 2-2 of FIGURE 1.

Referring to the drawing, the radiant gas burner of this invention is shown in combination with a combustion chamber '10 having external extended surfaces in the form of fins 12. The combustion chamber connects with a flue gas header 16 which, in turn, connects with a plurality of extended surface heat exchangers, as indicated in phantom by numeral 18. The construction of the combustion shell and heat exchangers constitutes no part of this invention.

The open end of the combustion chamber 10 is closed by a mounting plate 20 suitably attached thereto, which mounting plate has a tubular extension 22 within which a burner nipple 24 is disposed. A commercial type spark plug 26 extends into the nipple 24 and has spaced electrodes 28 for initially igniting the premixed combustible mixture of gaseous fuel and sufficient air to effect complete combustion, which is supplied under pressure to the tubular extension 22. The improved radiant burner comprises a refractory shell 30, which can be composed of any suitable refractory material either ceramic or metal, which when subjected to high temperatures, can be heated to incandescence. As seen in FIGURE 1, the outer end of the shell 30 is open and communicates with the nipple 24, the shell being welded or otherwise suitably connected to the nipple 24 at the juncture 32. The inner, or opposite, end 34 of the shell 30 is closed, the shell being supported solely by its interconnection with the nipple and being wholly disposed within the combustion chamber 10.

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Moreover, as seen in FIGURE 1, the shell is of nonuniform cross-sectional area throughout its length, being of increasing cross-sectional area from the nipple 32 throughout the zone 36, and of decreasing cross-sectional area throughout the zone 38 to its closed inner end 34. Moreover, in the zone 38 the refractory shell 30 is formed with a distributed series of holes, or perforations, 40. To obtain a directional heating efiect so as to prevent overheating of the upper surface of the combustion shell, the holes 40 only extend throughout a portion of the circumference :as seen in FIGURE 2. This is particularly advantageous where the air to be heated flows in a direction transverse to the combustion shell and heat exchanger from the bottom of the assembly as depicted in FIG- URE 1.

As alluded to hereinbefore, the premixed combustible mixture is supplied under superatmospheric pressure to the nipple 24- where it is initially ignited by the electrodes 23. By virtue of the fact that the refractory shell 30 is formed with

interconnected zones

36 and 38 of increasing cross-sectional area and decreasing cross-sectional area, the combustible gaseous mixture, after ignition, will have a velocity less than the speed of propagation of the flame. In this manner the combustible mixture thoroughly contacts the inner walls of the refractory chamber and the flue gases escape through the holes 40 to the combustion chamber 10 and thence to the flue gas header 16. The flames sweep across the entire inner surface of the refractory chamber 30, and thus heat the refractory shell 30 to incandescence to provide a radiant burner structure. Moreover, after initial ignition, the electric current to the electrodes 28 can be interrupted, and the flame will be blown out of the nipple 24, because in this nipple 24 the combustible mixture has a higher velocity than the speed of flame propagation, but will be retained in the zone 36 of the refractory chamber to provide a continuous ignition for the incoming combustible mixture. In

7 addition, while in the illustrated embodiment the radiant burner is shown horizontally disposed, it can be installed vertically either upward or downward.

While the embodiment of this invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. A radiant gas burner for use with a pressurized gaseous combustible mixture including, a nipple connected to a source .of combustible mixture and through which said mixture flows, an elongate refractory shell having an open end connected to said nipple and an imperforate end remote therefrom, said refractory shell having intenconne'cted zones of increasing and decreasing crosssectional area from its connection with the nipple to its imper-forate end and a plurality of openings therethrough in the zone of decreasing cross-sectional area extending :to its imperforate end, and ignition means disposed in c said nipple for initially igniting the combustible mixture flowing through said nipple into said refractory shell whereby the mixture will burn internally of the shell throughout the length thereof so as to heat the shell to incandescence.

2. A radiant gas burner for use with a pressurized gaseous combustible mixture including, a nipple connected to a source of combustible mixture and through which said mixture flows, an elongate refractory shell having an open end connected to said nipple and an im'perforate end remote therefrom, said refractory shell having interconnected zones of increasing and decreasing cross-sectional area from its connection with the nipple toits imperforate end, .said zone of increasing cross-sectional area being imperforate and the zone of decreasing cross-sectional area being perforate, and ignition means disposed in said nipple for initially igniting the combustible mixture flowing through said nipple into said refractory shell whereby the mixture will burn internally of the shell throughout the length thereof so as to heat the shell to incandescence.

. 3. A radiant gas burner for use with a pressurized gaseous combustible mixture including, a nipple connected to a source of combustible mixture and through which said mixture flows with a higher velocity than the speed of flame propagation, an elongate refractory shell having an open end connected to said nipple and an imperforate end remote therefrom, said refractory shell having interconnected zones of increasing and decreasing cross-sectional area from its connection with the nipple to its imperforate end, said zone of increasing cross-sectional area being imperfora-te and the zone of decreasing cross-sectional area being perforate, ignition means: disposed in said nipple for initially igniting the combustible mixture flowing through said nipple into said refractory shell whereby the mixture will burn internally of the shell throughout the length thereof so as to heat, the shell to incandescence, the combustible mixture in said refractory shell having a velocity less than the speed of propagation of the flame whereby flame is retained in the, imperforate zone so as to provide continuousignition for the combustible mixture.

4.'A radian-t gas burner for use with a pressurized gaseous combustible mixture including, a nipple connected to a source of combustible mixture and through which said mixture flows, an elongate refractory shell having an open end connected to said nipple and an imperforate end remote therefrom, said refractory shell having interconnected zones of increasing and decreasing cross-sectional area from its connection with the nipple to its imperforate end, and a plurality of distributed openings throughout less than the entire periphery of the zone of decreasing cross-sectional area, and ignition means disposed in said nipple for initially igniting the combustible mixture flowing through said nipple to said refractory shell whereby the mixture will burn internally of the shell throughout the length thereof so as to heat the shell to incandescence,

5. The radiant gas burner set forth in claim 4 including a combustion chamber enclosing said refractory shell and into which the flue gases flow, the distributed openings in said refractory shell producing a directional heating effect so as to preclude overheating of predesignated surfaces of the combustion shell.

References Cited by the Examiner UNITED STATES PATENTS 1,047,331 12/12' Sweet.

1,494,499 5/24 ODowd 126-92 2,731,010 1/56 Moore et al. 12692 FOREIGN PATENTS 562,875 9/23 France. 779,669 7/57 Great Britain.

JAMES W. WESTHAVER, Primary Examiner.

MEYER PERLIN, Examiner.

Claims

1. A RADIANT GAS BURNER FOR USE WITH A PRESSURIZED GASEOUS COMBUSTIBLE MIXTURE INCLUDING, A NIPPLE CONNECTED TO A SOURCE COMBUSTIBLE MIXTURE AND THROUGH WHICH SAID MIXTURE FLOWS, AN ELONGATE REFRACTORY SHELL HAVING AN OPEN END CONNECTED TO SAID NIPPLE AND AN IMPERFORATE END REMOTE THEREFROM, SAID REFRACTORY SHELL HAVING IN TERCONNECTED ZONES OF INCREASING AND DECREASING CROSSSECTIONAL AREA FROM ITS CONNECTION WITH THE NIPPLE TO ITS IMPERFORATE END AND PLURALITY OF OPENINGS THERETHROUGH IN THE ZONE OF DECREASING CROSS-SECTIONAL AREA EXTENDING TO ITS IMPERFORATE END, AND IGNITION MEANS DISPOSED IN SAID NIPPLE FOR INITIALLY IGNITING THE COMBUSTIBLE MIXTURE FLOWING THROUGH SAID NIPPLE INTO SAID REFRACTORY SHELL WHEREBY THE MIXTURE WIL BURN INTERNALLY OF THE SHELL THROUGHOUT THE LENGTH THEREOF SO AS TO HEAT THE SHELL TO INCANDESCENCE.