US2318985A

US2318985A - Gas burner

Info

Publication number: US2318985A
Application number: US366870A
Authority: US
Inventors: Charles I Baker
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-11-23
Filing date: 1940-11-23
Publication date: 1943-05-11
Anticipated expiration: 1960-05-11

Description

May 11,1943. BAKER' 2,318,985

I I as BURNER- 1 Filed Nov. 23, 1940 WIT/156556.

Patented May 11, 1943 UNITED STATES PATENT OFFICE GAS BURNER Charles 1. Baker, West Hickory, Pa. Application November 23, 1940, Serial No. 366,870 3 Claims. (01. 158- 116) This invention relates to gas burners, and more v particularly to burners used with automaticgas water heaters having copper coil heating surfaces and generally known as instantaneous heaters.

Gas burners of this character are generally made in two main parts, a Bunsen mixer tube and a flame-spreading member at the upper end of the tube. Also, a copper gauze is generally used as a flame check to prevent the flame from flashing back into the mixer tube. These burners are provided with aplurality of outlet burner ports which are disposed close together to insure ignition from port to port after the gas in the port adjacent the pilot light has been ignited. Due to the proximity of the ports to one another, the burning gas streams issuing from them merge together and form a sheet-like flame. As sheet flames are difilcult to quickly aerate, they are long and increase in length with an increase in the fuel rate. At times of high gas rate the sheet flame may extend far up into the heating coil where the burning gases are cooled, thus resulting in incomplete combustion,-considerable carbon monoxide in the flue gases, and deposits of. carbon over the heating surfaces. In some cases of high gas rate the gas issuing from the burner ports does not ignite until it is several inches above the spreader. This again is objectionable for the reasons just given. The copper gauze, so generally used with this type of gas burner, frequently becomes choked with dust accumulations and other foreign matter and thereby reduces the quantity of primary air to such an extent as to cause low temperature, lengthened, soot-depositing flames. The flame spreader becomes very hot, and this heat during long operating periods is destructive to the cast iron of which the spreader is made. In most automatic gas water heaters the burners must be positioned so as to face in certain directions. This requires special care or understanding of combustion conditions when placing such a burner in a water heater, and also frequently requires positioning members to keep the burner in its correct position. I

It.is among the objects of this invention to provide a gas burner for instantaneous water heaters and the like which avoids the formation of sheet flames, which permits ready ignition from port to port, which operates emciently at all fuel rates, which does not require copper gauze'or the like to prevent flash back into the mixer tube, which preheats the fuel, which can be readily positioned in a water heater without the use of special positioning members or special understanding of the burner, which burns the fuel close to the spreader, and in which the spreader member does not become overheated. The preferred embodiment of the invention is illustrated in the accompanying drawing in which Fig. 1 is a side view of my gas .bum'er partly broken away to show the spreader member in elevation; Fig. 2 is a vertical section through the burner taken on the line II--II- of Fig. l; and Fig. 3 is a horizontal section taken on the line III-III of Fig. l.

Referringto the drawing, amixer tube l for gas and air is provided in its lower end with a cross member 2 having a central vertical opening 3 therethrough adapted to receive a gas nozzle, not shown, connected to'a gas supply line. The open spaces 4 (Fig. 1) between the cross member and the wall of the tube permit primary air to be drawn into the tube and mix with the gas to form the proper combustible fuel mixture. Disposed in the upper portion of the mixer tube, which is preferably cylindrical, is a flamespreading member 6 that projects above the tube. The major or lower portion of the spreader is preferably cylindrical and is machined to seat snugly in the upper end of the tube.

The periphery of the spreader is provided with a plurality of laterally or circumferentially spaced vertical recesses or grooves I extending substantially from top to bottom of the spreader and forming with the tube separate outlet burner ports. .The portions of the spreader between these grooves therefore take'theform of vertical ribs 8, and, in accordance with this invention, at least their exposed upper portions are wide enough to prevent the streams of fuel issuing from the upper ends of the ports from mingling and thereby producing a sheet flame. In other words, each port maintains its own separate flame.

As the ports are thus too far apart to permit pilot-light ignition at one port from traveling to plished by. extending the upper portion of the spreader, including the upper portions of the ribs, outwardly across the top of the mixer tube at a predetermined distance above it. By-pass openings 9 are thus formed between the top of the tube side wall and the bottom of these overhanging portions of the ribs. The laterally extended upper portions or the ribs also serve, by projecting outwardly abruptly over thetop oi the tube to maintain the flames separated and to prevent any tendency sheet flame. To assure the by-passes being of the correct size, means is provided for limitin the distance that the spreader can be'inserted in the mixer tube. This is preferably done by having the laterally extendedupper portion of one of the ribs longer than the others so that its lower end engages the top of the tube and serves as a stop ll.

The lower portions of the ribs which engage the side wall of the mixer tube are relatively long in order to provide narrow ports which are long enough to prevent flash-back without the use of copper gauze. The spreader and its ribs extend so far down into the cool incoming gas in the tube that the ribs serve as cooling flns for the bodyof the spreader to keep it from overheating. In thus cooling the spreader, the ribs transfer heat to the incoming gas and preheat it, which is highly desirable. The portion of the spreading member within the mixer tube is preferably hollow, as shown in Fig. 2.

The top of the spreader extends out over the periphery of the tube so that condensate dripping from, the heater coils can not enter the burner ports.

According to the provisions of the patent statutes, I have explained the principle and construction of my invention and have illustrated and described what I now consider to represent its best embodiments. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. A gas burner comprising an upright mixer tube for gaseous fuel, and a'flame spreader disposed in the upper end of the tube and projecting above it, the side of the spreader being provided with a plurality of laterally spaced ribs extending from substantially the top of the oithemtouniteintoa;

spreader to a point inside of the tube to thereby i'o'rm apluralityot separate burner ports, and said ribs having extension'portions projecting outwardly across the top of the tube at a pre- 'determined distance above it to form with the top oi the tube-ignition by-passes from one of said ports to another, said outwardly projecting portions of the ribs creating separate burner flames above the by-passes and being wide enough to maintain the flames separated above the burner.

2. A flame spreader adapted to be seated in the upper end of a mixer tube for gaseous fuel and to project above it, the side of the spreader being provided with a plurality of laterally spaced ribs extending downwardly from substantially the top of the spreader to form a plurality of separate burner ports, and the upper portions of said ribs having lateral extensions all but one of which are adapted to project outwardly across the top of the tube at a predetermined distance above it to form ignition by-passes, and said one extension having a downwardly projecting portion adapted to rest on top of the mixer tube, said lateral extensions creating separate burner flames and being wide enough to maintain the flames separated above the spreader.

3. A gas burner comprising an upright mixer tube for gaseous fuel, a flame spreader seated in the upper end of the tube and projecting above it, said spreader having a body portion surrounded by a plurality of laterally spaced ribs extending substantially from its top down into the tube to form with the tube a plurality of separate burner ports, and the exposed upper portions of said ribs having lateral extensions projecting outwardly across the top of the tube, whereby separate burner flames are created, said extensions being wide enough to maintain the flames separated above the burner, all but one of said extensions being spaced a short distance above the tube to form ignition by-passes between the ports, and said one extension resting on top of the tube to control the height of said bypasses.

CHARLES I. BAKER.