US2480658A - Gravity-fed gas burner - Google Patents

Description

Aug. 30, 1949. c. D. JONES GRAVITY-FED GAS BURNER Filed Feb. 17, 1944 m m N w A )5 Q u 4 6 6 a Y 1 B P i 7 a w xv.. W 1 1 3 3 3 A m a n .lll u 2 1 m M M Patented Aug. 30', 1949 UNITED STATES PATENT Chester D. Jones, Carnegie, 2a., assignor to Law son Manufacturing Company, Pittsburgh, Pa, a corporation of Pennsylvania Application February 17,1944, Serial No. 52am- This invention relates generally to burners and more particularly to burners for burning artiing box for connecting the venturi to the burner head.

8 Claims. (01'. 158-99) "ciples of this invention is shown in the accompanying drawings wherein: V

Fig. 1 is a front elevational view partly in section of the burner comprising this invention. Fig. 2 is a side elevational view partly in section of theburner. V

Fig. 3 is a-detailedview of a modification ot the valvemember.

iis an end view of the gas mixing bell chamber.

- Referring to the drawing. the burner comprises four principal parts, the bell mixing chamber iii,- the Venturi tube II, the distributing box 12 and the burner head I3. The bell mixing chamber I0 is circular and is provided witha transversely I disposed cylindrical-chamber l4 formed integral Another object is the provision of an e'flicient and economical gas burner. 1

Another object. is the provision of a burner constructed to operate with a fixed supply of secondary air and having a plurality of orifices of definite cross sectional area, the area of each orifice being determined by the heat value of the gas to be employed to maintain a constant output of heat units per hour from the burner.

This invention further contemplates the use of orifices having extreme limits of cross sectional area with graduated intermediate steps therebetween.

Another object is the provision of a burner mechanism having a ring-shaped head with an annular gas outlet port and arranged to limit the amount of secondary air admitted around the perimeter of the head to induce the flow of a suflicient amount of secondary air through the center of the head to produce a hollow cylindrical flame.

Another object is the provision of a burne having a down draft Venturi tube. Another object is the provision of a burner having a circular gas port and an inverted Venturi tube. 1

Another object is the provision of a burner which eliminates flash back and the noise of lighting or extinguishing when the burner is quickly turned on or off.

Other objects and advantages appear in the ,following description and claims.

A practical embodiment illustrating the prinwith the bell casting I ll. One end of the chamber I4 is threaded toreceive the end of the gas supply pipe IS. The other end of the chamber i4 is closed by the plug valve member I 6 which is shaped to snugly flt thev walls of the chamber l4 and extend therebeyond to provide a knurled head II for rotatably the position of the plug valve 16.

The plug valve i6 is provided with an arcuate groove l8 inwardly adjacent the head II to recated in Fig. 2.

ceive the end of the set screw 20 which retains the plug valve l8 within the chamber M. The ends of the arcuate slot I! also limit the degree of rotation of the plug valve I to 180' as indi- The inner end of the plug valve I6 is provided with a bore 2| which opens directly to the gas chamber l4 and is provided with holes or ports 22 and 23 lying in the same transverse plane, arranged to register with the port 24 in the cylindrical wall of the chamber l4, and which is axially aligned with the Venturi tube ll.

When the plug valve I6 is turned clockwise as shown in Fig. 2 the end of the arcuate slot I8 engages the set screw 20 which position aligns the valve port 22 with port 24. Ii-the plug valve I6 is rotated in a counterclockwise direction until the other end of the slot l8 strikes the set screw 20 the valve port 23 becomes anally aligned with the opening 24.

It will be noted that the valve port 22 is larger in diameter thanthe valve port 23 and the opening 24 inthe cylindrical wall of the chamber I4 om n higher B. t. u. content and it therefore requires a smaller orifice or port 23 to produce the desired flame with the available amount of primary and secondary air capable of being furmshed by the same burner. I

The primary air is admitted through the sector openings 25 at the end of the bell mixing chamber on either side of the transverse cylindrical wall of the chamber H as indicated in Fig. 2. The circular disk shutter 26 is provided with similar arcuate openings 21 which mate in alignment with the openings 25 when the shutter 26 is rotated to the proper position as shown in Fig. 4. The shutter 26 fits against the flat end of the bell mixing chamber 10 and is pivoted on and clamped in position by the screw 28 which threadably engages in a tapped hole in the outer wall of the chamber 14 in alignment with the port 24 in the inner wall of said chamber. Thus difierent angular positions of the shutter 26 adjust the amount or primary air that is admitted to the bell mixing chamber Ill.

The Venturi tube H is formed integral with and is disposed axially of the bell mixing chamber l0 and the throat 30 of the Venturi is thus 1n alignment with the opening 24 in the transverse cylindrical chamber M. The Venturi tube is straight and becomes increasingly larger in d1ameter from the throat -30 to the rectangularly shaped distributing box [2. The gas flowing down the Venturi tube impinges against the transverse wall of the box 12 which diffuses it laterally. The abrupt change in volume and transverse wall of the box I 2 is found to uniformly distribute the mixture of gas and air to the annular burner head l3 which is disposed at substantially right angles to the Venturi tube ll.

The burner head [3 is an annular hollow ring connected to the box l2 and provided with an annular gas outlet 3|. Small pins 32 are inserted in the walls of the burner head in spaced relation across the outlet 3| to hold the alternate corrugated and flat ribbons 33 and 34 flush with the mouth of the outlet 3|. The corrugations of the ribbon 33 form the gas ports in the outlet 3!.

The ring head It of the burner provides a large central opening 35 through which secondary air flows for supporting combustion within the cylindrlcal flame produced b the burner. Radial extending lugs 36 on the ring head l3 hold it in spaced relation with the combustion chamber wall 31 which is indicated by the cylindrical tube shown in Figs. 1 and 2. The lugs 36 maintain an annular space 33 around the burner head l3 for supplying secondary air for the outer part of the cylindrical flame.

The size of the mixing bell ill, the Venturi II, the box l2 and the ring head 13 are so proportioned that the proper amount of primary and secondary air is provided for gas having the characteristlcs requiring orifices of the size provided in the plug valve l6 for either artificial or natural gas and a cylindrical flame is produced. If this flame is burned in the open the cylindrical flame has a tendency to contract toward the end thereof but when inserted into the end of a combustionchamber which permits the lugs 36 to properly center the head of thenurner and produce the annular opening 38 that limits the amount of secondary air admitted around the burner head. a cylindrical flame of uniform dimension along its length is formed, because of the induced additional secondary air flow through the central opening 35. If an elbow were used to connect the venturi with the head of the burner one side of the cylindrical flame will be longer than the other. However the rectangular box l2 distributes the gas properly to the ring head It and the flame is uniform around its perimeter for the full length thereof.

In place of providing independent orifices 22 and 23 for gas having different heating characteristics a single V-shaped slot 40 may be provided in the side wall of the plug l6 which acts in conjunction with the port 24 to produce an orifice of definite size that may be made larger or smaller depending upon the direction that the valve plug is rotated. The V-slot 40 extends 180 around the wall of the plug l6 and is symmetrical with the groove 18. This modification is shown in Fig. 3. Thus if the B. t. u. content and the pressure of the gas. supply varies the valve plug it may be rotated the proper degree to change the size of the orifice formed by the V-slot 40 to obtain the proper amount of gas in accordance with the combustible characteristics of the gas. The extremities of the V-slot 40 are of such dimension that they may be used for artificial and natural gas in the same manner as the orifices 22 and 23.

Butane contains approximately 3200 B. t. u.s, propane approximately 2400 B. t. u.s, natr-al gas approximately 1550 B. t. u.s, and artificial gas and air carbureted butane or propane about 500 B. t. u.s per cubic foot. Thus the orifice for butane would have the smallest cross sectional area and the orifice for artificial gas or the air carbureted gases would have the largest cross sectional area. Assuming that these two orifices represent the limits in the cross sectional area required for the emission of gas to the burner and are represented by the orifices 23 and 22 respectively or the extremitiees of the V-shaped slot 40,

two intermediate orifices should be graduated in cross sectional area for propane and natural gas to produce the same output of heat units per hour from the burner. In fact the areas of these orifices for a burner of given secondary air flow characteristics are proportional to the B. t. u. content of the gas to be employed. Thus the orifice plug or valve I6 is provided with definite orifices for matching the substantially constant secondary air'characteristlcs of the burner to produce the same output of heat units per hour from the burner depending upon the gas selected. The appliance which the burner serves is designed to have a definite heat unit rate, such'as 30,000,

B. t. u.s per hour, which is the most eflicient operating rate for the appliance which has predetermined and substantially constant secondary air characteristics.

the flame of thebumer may occur with either of these arrangements, however when the burner head is above the venturi and mixer the tendency of flash back and noise is greater, yet it does not occur as readily when the gas is manually turned on or oil. When the gas is shut oi! quickly the gas within the burner havingvelocity continues to move to the burner ports and the mixture becomes leaner. when the venturi is Vertically disposed under the burner head the draft aids the movement of the gas and the natural rising of the lighter than air gas produces a greater tendency for the gas to flash back and make noise.

It has been found that if the mixing chamber and the Venturi tube are extended above the burner head, the velocity of the gas remaining within the burner is the only force which tends to continue the flow of the lean mixture to the burner port. This force is counteracted by the natural tendency for the gas to rise which causes the lean mixture to flow away from the burner port, resulting in slowly extinguishing the flame and thus preventing it from flashing back or. producing a noise when turned off. This advantage is particularly important when using artificial or air carbureted gases which explode loudly under conditions of flash back or quickly lighting and extinguishing the flame. The ribbon gas port is also believed to contribute to the improvement of eliminating flash back and noise as this type of burner port offers less resistance to the flow of gas therethrough and consequently the inverted venturi has a tendency to create a draft in the opposite direction to that of the flow of the gas to the burner head.

I claim:

1. An atmospheric down draft gas burner for producing a horizontal flame consisting of a horizontally disposed hollow cylindrical burner head constructed to receive a mixture of air and gas, means defining a. gas port on one end of said cylindrical burner head with its axis horizontally disposed for discharging the gas and air mixture to produce a horizontal flame, vertically disposed conducting means connected at its lower end to said hollow burner head, and means defining a and through the connecting means into the ring head burner and out the port where it burns as a fiame.

4. An atmospheric down draft burner consisting of a vertically disposed Venturi tube having a mixing chamber at its upper end, means defining a lateral conducting passageway connected at one end to the lower end of the Venturi tube,

V and a hollow burner head attached to the other end of said lateral passageway and having its axis horizontally disposed and means defining ports to discharge horizontal flames suppliedby a mixture of gas and air from said lateral connection.

' 5. An atmospheric down draft gas burner consisting of a vertically disposed Venturi tube having a mixing chamber at its upper end for receiving gas and air and discharging the mixture mixing chamber on the upper end of said conducting means above the level of the hollow burnerhead to deliver a mixture of gas and air to the burner head.

2. An atmospheric down draft gas burner for producing a horizontal flame consisting of a horizontally disposed hollow cylindrical burner head constructed to receive a mixture of air and gas, means defining a gas port on one end of said cylindrical burner head with its axis horizontally disposed for discharging the gas and air mixture to produce a horizontal flame, vertically disposed conducting means connected at its lower end to said hollow burner head, means defining a mixing chamber on the upper end of said conducting means above the level of the hollow burner head to deliver a mixture of gas and air to the burner head, means defining a horizontally disposed tubular combustion chamber into which the end of the hollow burner head is inserted, and radial spacers on the hollow burner head'to center it in said combustion chamber. 3. An atmospheric down draft burner consisting of a horizontally disposed cylindrical ring head burner, means defining a gas port in one end of the ring head burner having its axis disposed horizontally, an upwardly extending Venturi tube at the other end of the ring head burner, means to connect the lower end of the Venturi tube with down the Venturi tube to its outlet end. a hollow burner head having its axis horizontally disposed and means defining a gas port of substantially the same cross sectional area as the outlet end of the Venturi tube, corrugated ribbon in the port dividing it into a plurality of small ports, and means defining a lateral conducting passageway between the outlet end of the Venturi tube and the burner head for conveying the mixture of gas and air thereto.

6. An atmospheric gas burner for producing a horizontally disposed fiame consisting of a vertically disposed'Venturi tube, a mixing bell connected tothe upper end of the tube to receive gas and air which are mixed and discharged down through the tube, a ring head burner having its, axis disposed at right angles to the axis of the tube and having means defining a central opening, said ring head burner having means defining an annular gas port disposed about said central opening to produce a circular fiame concentric with the axis of the ring, and a distributing box connecting the lower end of the tube and the ring head to produce a uniform discharge of the combustible mixture through the gas port to form a cylindrical flame.

7. The structure of claim 6 which also includes means defining a tubular combustion chamber for receiving the gas port end of said ring head burner, and a plurality of annularly spaced radially disposed lugs on the perimetral surface of the ring head burner for centrally spacing the latter in .the tubular, combustion chamber to provide an outer annular secondary air supply passage concentric with the cylindrical fiame and the inner secondary air supply admitted through the center opening of the ring head.

8. An atmospheric gas burner of the character described, the combination of a vertically disposed Venturi tube, a mixing bell connected to the top of the tube and constructed to receive a. combustible mixture of gas and air which flows down through the tube, a distributing box at the lower end of the tube providing a space of increased volume relative to the cross section of the tube and having a transverse wall against which the air and gas impinge, a hollow ring head burner spaced from the axis of the tube and with the axis of the ring disposed at right angles to the axis of the tube for horizontally projecting a circular flame concentric with the axis of the ring, means defining a central opening through the hollow ring head burner, and a. lateral conducting means between the box and the hollow ring head burner to carry and uniformly distribute the-combustible mixture to the ring head burner.

CHESTER n; JONES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PA'I'ENTB Number Name Date 421,759 Pope Feb. 18, 1890 454,910 Kahn June 30, 1891 507,748 Page Oct. 31, 1893 686,625 Machiet Nov. 12, 1901 1,313,360 Wendell et a1. Aug. 19, 1919 Number 20 Number 8 Name Date Eddison Aug. 28, 1923 Kielberg Mar. 11, 1924 Geurink et al. Mar. 20, 1928 Mustee Dec. 17, 1929 Cunningham May 1, 1934 Hones June 26, 1934 Rogers June 18, 1935 Theunissen Oct. 22, 1935 MacKenzie Apr. 6, 1937 Matthews et a1. Feb. 8, 193a Forster Oct. 4, 1938 Chambers June 13, 1939 Thomas Nov. 4, 1941 Enbom Mar. 14, 1944 Koppel May 2, 1944 Dobrin- July 9, 1946 FOREIGN PATENTS Country Date France Nov. 4, 1919

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