US2638975A - Combustion chamber for gaseous fuels - Google Patents

Description

May 19, 1953 M. F. BERRY 2,638,975

COMBUSTION CHAMBER FOR 'GASEOUS FUELS Filed April 23, 1948 v 5 Sheets-Sheet l wvewro/a MICHAEL BERRY 4 M. FZ BERRY COMBUSTION CHAMBER FOR GASEOUS FUELS 5 Sheets-.Shet 2 Filed April 23, 1948 F IG. 4

INVENTOR- M/GHAEL E BERRY M .1 M. F: BERRY ,COMBUS-TION CHAMBER FOR cAsEous FUELS Filed Apfli as; 1948 5 Sheets-Sheet 3 //vv/vr0/?. MICHAEL E BERRY May 19, 19 53 M. F.'BERRY 2,638,975

' COMBUSTION CHAMBER FOR GASEOUS FUELS 7 Filed April 23, 1948 V 5 sheets-shed 4 INVENTOR.

MICHAEL E BERRY .0. Limp y 19, 195,3 I M. F. BERRY- 2,638,975

comsus'rrou CHAMBER FOR GASEOUS FUELS .Filed April 23, 1948 5 Sheets-Sheet 5 I 11v VEN 70R MIGHAEL E BERRY Fla/5 11W Patented May 19, 1953 UNITED STATES PATENT OFFICE Application Aim-i123, 1948, Serial Ne. 22,844

This invention relates to improvements in heating devices, and more particularly to an improved burner for natural, manufactured, mixed or liquefied petroleum gas which is particularly useful in converting existing solid fuel furnaces for burning gas.

Although there are many of the so calle'd conversion burners on the market, they are not always as efficient as could be desired, both from the standpoint of fuel consumption and from the standpoint of heat transferring emciency when used in conjunction with the type of rurnaces with which these devices are ordinarily installed. That is, a large amount of the heat of combustion goes up the stack and is lost due to the i'nefiiciency with which the heat is transferredto'the wall of the furnace. I I

"Still another disadvantage of the prior art devices reside in their inability to op'eiate properly with varying gas pressure. A burner designed to operate on one pressure performed inadequately on a lower pressure or not at all. This was particularly undesirable since, usua11y,at the time when the heat is needed the most, the gas pressure is lowest. I

Furthermore, during the cycling of the hurrier, turning on and off, it is not uncommon at the present time for the burners to shut off or turn on with a minor explosion, resulting in the extinguishing oi the flame as well as being annoying in its sound.

Other disadvantages resided in the provision of structures whi'ch were often too complicated for the average furnace man to install, re air or service and sometimes required extreme mutilation of the furnace and resulted in the installation being a major operation.

By my present invention, I have provided a burner which operates in a highly eifci'ent manner with varying pressures oi ga's. Furthermore, the structure is so designed that even the more unskilled of furnace nien can install them -r'operly. The burner is so constructed that a inininium amount of work is required during the installati'on which can be made quickly arid easily.

invention and the invention itself will become 3 Claims.- (Cl; 158- 115) Eri more apparent from the follewing description of an embodiment thereof, which description is illustrated by the accompanying drawings.

In the drawingsi Fig. l is a perspective view of the burner of my invention complete with the controls and pilot light;

Fig. 2 is an enlarged plan view of the burner;

Fig. 3 is' a perspective View of the burner per se with the ceramics broken away to show themtenor construction;

Fig. 4 is a pian View of a spider which is used in conjunction with the riser to support the burner ceramics;

Fig. 5 is a section taken on the line 5--=5' of 4;

Fig. dis a section taken on the line 6==6 of Fig. 5;-

Fig. 7 is an ex'pio'ded plan view of the ceramic supporting pan removed from the spider;

Fig". 8 is a top plan View of the-spider and its ceramic supporting pan, showing the location of the pilot lights; 7

Fig. 9 is a view, partially diagrammatic and partially in plan of the lower ceramic for the burner;

Fig. 10 is a fragmentary section of one of the fewer ceramic parts taken on the line Hi oi 9;

Fig. i1 is an e'levatioiial view of one of the upper ceramic segments;

Fig. 12 is a similar View of one of the upper ceramic parts rotated degrees froth that of Fig. 11;

Fig. 13 is a bottom plan View 01"- the ceramic section? Fig'. 14 is a plan View of a ceramic uard and flame dispersion element;

Fig. 15 is a vertical media]. section through the burner along the lines indicated by the lines i'5'l5' of Fig. 14 and showing the position talren by the flame dispersion element; and

Fig. 16 is an enlarged elevational View of one of the pilot lights and its accompan m thermocouple. v

As reviously stated, the burner of my inventiofi is' particularly adapted for use in converting sfolid fu'el burning furnaces to gaseous fuel burning furnaces. It Will be appreciated, however, that in the broader aspects of the invention, it is useful for the replacement or the burners in present gas fired furnaces or in original equipi'nent. The invention will, however, be explained in connection with its use as a conversion burner.

As best shown in Fig. 1, a base' It or tripod formation is provided in which is supported a notch 25. on the riser.

threaded rod H, the same being secured in adjusted position by a lock nut [2. The rod in turn supports the burner, being threaded into a boss l3 Fig. 3 integral with an elbow M of the mixing chamber. Although in this instance the rod is shown as having right hand threads, it may be desirable to provide a right hand thread on one end and a left hand thread on the other end to assist and facilitate in the final adjustment of the burner for height after installation. Different length rodscan be used if desired.

The elbow M, Fig. 1, has one end disposed in a horizontal position and is provided with a threaded bell I6 for the reception and support of the outer horizontal mixer pipe [1. The other end of the elbow extends vertically and is tapered at It? for close fitting engagement with the flared end [9 of the riser pipe 20.

The lower end of the riser pipe is notched at 22, adapted for seating engagement with a pin 23 carried by the elbow Fig. 1. The position of the pin and notch are such that the riser cannot be assembled on the pipe in the wrong manner. The taper is such as to provide a tight joint when the riser is in place on the elbow.

The riser 20 is also provided with a notch 24 in its upper end for cooperation with the ceramic support spider later described.

As illustrated in Fig. 1, the outer mixer pipe ll extends longitudinally toward and into a housing 28 which houses the gas control valve, not shown.

As best shown in Fig. 2, the riser supports a spider, which in turn supports a baffle and a ceramic support plate, and the ceramic support plate supports the ceramics which comprise the combustion chamber.

The spider, Figs. 4 to 6 inclusive, includes a hub 50 from which radiate four arms, to 54. The hub is provided with a bore 5%}, of a diameter to allow the hub to be telescoped over the upper end of the riser 20. The upper end of the bore is provided with an inwardly extending flange 51 adapted to seat on the upper end of the riser. The flange 51 has a downwardly extending boss 58, of curved formation, which, when the hub is in proper position on the riser, seats in the Thus the not-ch 22 on the bottom of the riser engaging with the pin 23 determines the correct position of the riser and th notch and boss 24 and 58 determine the position of the spider assuring that they cannot be readily assembled in the wrong position. It may be made of any suitable metal, such as cast iron.

The arms 5!, 52, 53 and 54 are each provided with bosses GI, 62, G3 and 64 in which are disposed vertically extending pins SI, 62, 63 and 54. The pins 6!, B2 and G3 are disposed the same distance from the center of the spider, but the pin 64' and the boss M are disposed at a greater distance from the center. In this instance, on 4" and 4 radii respectively. Likewise, the arm 54 is longer than the other arms to provide support for the pilot light as will later appear.

diameter or opening across the plate through the flange ltl. The plates are adapted to be seated on the arms of the spider and are provided with openings H, l2, l3 and 74 for engagement with the pin 6! to M inclusive. It will be noted that the opening M is displaced greater distance from the center than the others for alignment with the pin 64'. Thus, the plates cannot be incorrectly placed on the spider if the pins are to go into their respective openings in the plate. This assures proper alignment of the plates on the spider.

As best shown in Figs. 2 and 3, a sheet metal baffle plate 66 which is of the same general contour as the ceramic support plate, but larger, is provided, this being placed on the spider prior to the placement of the ceramic support plate. The baffle may vary in size, depending upon the size of the fire pot, it being preferable that it extend relatively close to the fire pot wall. A notch, or gap, is provided in the bafile at t! to allow the pilot to extend therethrough. It can be made in two parts if desired, since this facilitates assembly, particularly where the door opening of the furnace is small.

The ceramic combustion chamber is supported by the plates 60 and Gil. It is formed in parts which cooperate with each other to form a chamber for distribution of the gasses and to eifect the proper combustion thereof, as well as to direct the flame toward the wall of the furnace. The parts include lower sections which rest on the support plate and upper sections which rest on the lower sections.

The lower sections, Figs. 1, 3, 9 and 10, as best shown in Figs. 9 and 10, preferably comprise three separate sections 15, which are arranged in abutting relationship to form a ring. The bottoms 16 of the sections are substantially flat for seating engagement with the plates fill-6G. Each bottom wall is formed with a groove 19 which extends across the bottom and into which the ribs 65 are adapted to extend. It will thus be apparent that the position of the ceramics on the support plate is determined by the engagement of at least one of the ceramics with the ribs so that proper orientation is assured. This channel and the ribs, as well as the groove 65, provide a duct extending from the inside opening of the ceramics to the periphery for cooperation with the pilot lights as will later more clearly appear.

The upper surface of the ceramic ring, as can best be seen in Fig. 10, is inclined downward from the outer wall to the inner wall, and is provided with a groove 30 which extends around the ceramic spaced from the inner wall. The surface between the groove and the inner wall provides a ridge 8| which, together with the groove, is a supine S. The upper surface, from the outside wall 69 into the groove is provided with a plurality of channels or grooves 83 extending substantially tangentially to the central opening in the spider 50. The channels are deeper toward the outer ends, being at this point of U shape, the legs of the U shortening towards the inner end of the channels so that the channels which intersect the groove 89 at its center are substantial semi-circular at this point as is most clearly shown in Fig. 10. The channels are substantially equally spaced except at the point approximately midway between the ends of the sections, where instead of achannel there is provided an upwardly extending lug 85; this lug may be of rectangular form and extend from the outer edge to the groove 80 and serves as a locator lug for the upper ceramics. The tangentialv grooves, as

toward the thermocouple and the one from the port I36, toward theduct H18.

In this particular instance, the thermocouple, when heated by the flame, generates sufficient voltage to hold a magnetic valve open.- Should it become cool, the voltage decreases and the valve is released and cannot be opened, until opened manually, when the pilot is relit.

Preferably, only one thermocouple control is used as shown. The gas supply for the inner pilot [H is connected in the supply line between the magnetic valve and the main burner valve.

The device may be installed in a furnace by simply removing the grates and their controls and the ash pit door. The base Ill, together with the elbow l4 and the tube ll, are first set in position. The riser 20 is then placed in position and the remainder of the burner par-ts assembled as described.

The control box with its associated controls is then installed, the tube 2'! being telescoped into the tube ll. The pilot lights are assembled in the manner shown, they being connected to the gas line ahead of the main burner valve.

Lighting of the pilot is effected by the lighter tube 2% which extends from the port 21', a valve control 202 being provided all in a manner well known to those versed in the art.

Preferably, the ceramics are placed in position last after the pilot lights are in place. ously stated, the design is such that there is only one easy way for the parts to go together and a set of very simple instructions enable the most unskilled to make the installation.

After the installation is complete, the pilot lights are then lit, by holding the magnetic valve manually until the heat from the pilot against the thermocouple causes enough voltage to be generated to retain the magnetic pilot light valve in the open portion. The inner pilot light is preferably provided with two ports, one of which is directed toward the duct 85, and the other toward the top of the riser. When the outer pilot is lit, the gas from the inner pilot is directed through the duct 65 and is ignited by the outer pilot.

The gas coming up through the riser hits the boss 95 or in the case of Fig. 15, the member Hi3, which is coaxial with the riser and causes an even distribution of the gas toward all sides. Part of the gas escapes through the port or duct I68 and is ignited by the outer pilot and at approximately the same time or just prior thereto ignition occurs from the inner pilot. The ignition is quiet, complete and without explosion, since there is no opportunity for the combustible mixture to accumulate prior to ignition.

The contour of the inside of the chamber is such that the gas hits the boss B3, then swirls upward into the channel 95 after which it is directed downward into the groove 80 which causes the burning mixture to turn back upon itself and then to pass outward through the tangentially arranged ports toward the furnace wall. Tie primary combustion occurs inside the chamber, and the combustion is completed by the secondary combustion after the burning mixture leaves the ports. I have found that with natural such as is obtained in Ohio, a temperature of 1490 degrees is reached at the ports. The hot gases forced out of the ports of the burner are directed against the furnace walls so that the heat in the gases is absorbed by the walls and transferred through them to the fluid used for heating the rooms.

The ceramics which may have a combined As previ- K weight of as much as 37 lbs. provide considerable body for the storage of heat and retain the heat for some time after the burning ceases. This is a desirable feature, particularly in conversion burners since they are most often used in gravity operated furnaces. The carry-over time for the heat is thus extended and the ofi cycle, or cold period, is lessened.

By constructing the ceramics as described, their life is materially increased because there is no cracking during the heating and cooling periods since the component parts are free to expand and contract relative to each other. Furthermore, although this expansion and contraction does occur, the parts always retain the same relative position the top ceramics being prevented from shifting vertically by the tongue and groove connection and being held toward each other by the slanting surface connection with the lower ceramics. The top ceramics cannot shift circumferentially so as to cause the ports turned by the top and bottom grooves due to the introduction of the lugs or bosses on the bottom ceramics with the grooves in the top ceramics. The bottom ceramics are retained in position by the flanges B283 and the ribs t5. Thus, all the parts, when once properly assembled, retain their position and can only be moved therefrom intentionally.

When the burner is shut off the two pilot lights keep the flame burning until the last of the combustible mixture is burned, thus preventing the minor explosion or bloop commonly heard when burners shut off.

Having thus described my invention, I am aware that numerous and extensive departures ma be made therefrom Without departing from the spirit or scope of the invention as defined by the appended claims.

I claim:

1. A combustion chamber for a burner comprising a metallic base ring, a lower combustion chamber ring comprising two or more sections supported loosely on the base ring, a cap for the combustion chamber comprising at least two sections for seating engagement on said combustion chamber ring and means on the combustion chamber ring and cap for interlocking engagement with each other to hold the same in position, said combustion chamber ring and cap being formed with cooperating grooves extending from the interior of the chamber to the exterior to provide fuel combustion exhaust ports, the axes of said ports extending tangentially to a circle concentric with the combustion chamber ring but within the circumference thereof, said cap being formed with an annular channel to provide a combustion chamber wherein the products of combustion are caused to assume a tortuous path through the burner, and a protecting member disposed in said chamber having a downwardly extending center portion and legs extending therefrom for engagement in at least some of said grooves to support said member adjacent the top of the chamber.

2. A combustion chamber for a conversion burner arranged to be connected to a riser tube for'conducting a combustible mixture to said chamber comprising a base for said chamber comprising a metallic ring shaped member having a peripheral flange, a first ceramic member comprising a plurality of segments disposed on said base in engagement with said flange and formed with upper surfaces which slant downward toward the center, a second ceramic member comprising at least a pair of members having interlocking tongues and grooves for engagement with each other and having a lower surface slanting downward toward the center for engagement with said first ceramic member, said members being formed to cooperatively form a combustion chamber with ports extending therefrom and opening exterior-1y of the chamber, a metallic member having a downwardly extending rounded center portion disposed oppositeto the end of the riser tube for dispersing the flame and guarding said second ceramic member from direct impingement of the flame, legs for said member in engagement with the lower ceramic member for supporting the guard adjacent the top of the chamber.

3. In a furnace burner adapted for use with a fuel mixing mechanism; comprising a combustion chamber adapted to be connected to said fuel mixing mechanism and including a support member, a base plate mounted on said support member, a circumferential rim on said base plate, a pair of substantially radial ribs on said base plate defining a channel formed therein, said combustion chamber comprising a plurality of ceramic members supported on said base plate to provide a lower combustion chamber element, said members resting on said plate within said rim and being thereby held in a predetermined lateral position on said plate, at least one of said members being formed with a groove on its lower surface adapted to embrace said ribs to close the channel formed thereby and to locate said combustion chamber element angularly on said base plate, a pilot light mounted on said support plate adapted to burn opposite the outer end of said channel, an upper portion for said combustion chamber comprising at least two upper ceramic members, said upper and lower members being formed so that the lower members hold the upper members in position, said ceramic members being formed to provide a primary combustion chamber and burner ports extending through said members from said chamber.

MICHAEL F. BERRY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 345,825 Barnhart July 20, 1886 547,473 Ball Oct. 8, 1895 1,379,538 DeSilva May 24, 1921 1,414,360 Hicks May 2, 1922 1,466,014 Germer et a1 Aug. 28, 1923 1,498,644 Clark June 24, 1924 1,582,634 Caldwell Apr. 27, 1926 1,741,584 Reintjes Dec. 31, 1929 1,851,745 Weatherbee Mar. 29, 1932 1,919,285 Weatherbee July 25, 1933 1,962,756 Zander June 12, 1934 2,183,836 Gordon Dec. 19, 1939 2,275,555 Power Mar. 10, 1942 2,287,246 Hess June 23, 1942 2,362,972 Brownbeck Nov. 21, 1944 2,427,545 Berger Sept. 1 1 2,429,022 Groetchen Oct. 14, 1947

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