US2646842A - Gas burner and secondary air supply means - Google Patents

Description

luly 2s, 1953 2,646,842

y n E. HANULr GAS BURNER vlAun; SxazcoNDA'iw AIR SUPPLY MEANS Haro/al LZ-2557@ mmymyw A TTONEYJ July 28, 1953 E. HANDLEY 25646,842 GAS mmm ANn. ."sEouDARY AIR' sugeu MEANS l 'gsneets-sheet Filed Apil 11. .1949

BY l M wwf/M ATTORNEVJ Patented July 28, 1953 UNITED STATES PATENT OFFICE GAS BURNER AND SECONDARY AIR SUPPLY MEANS 2 Claims.

This invention relates to a gas burner and secondary air supply means for use in heating plants. In my Patent No. 2,295,784 I have disclosed a burner particularly adapted for use during the early and late part of the heating season which may be readily inserted in and removed from the door of an ordinary coal burning furnace.

It is an object of the present invention to provide an improved burner of this character which is more economical to manufacture and more eiiicient in operation and which can be used for year around heating.

Specifically, it is an object of the invention to reduce the cost of the burner head and of the mounting arrangements and the control devices.

It is also an object to provide a burner of this class which is more easily adapted to heating plants of all shapes and sizes.

A further object is to improve the combustion eiliciency of the burner and particularly the flame distribution within the fire pot and the delivery of secondary air to the flame.

Briefly, the invention consists of a burner head which is formed of two sheet-metal shells which are fastened together with the edges of the shells facing each other but spaced slightly apart to provide the gas flame openings. In some embodiments, these openings may be filled with a serpentine strip which increases port velocity and reduces the noise of ignition and extinction.

Other features and objects of the invention have to do with the details of construction and operation which will be set forth in the following specification and claims.

Figure 1 is a vertical sectional view of a burner in place in a furnace and embodying a preferred form of the present invention.

Figure 2 is a top view of the burner in place.

Figure 3 is a View partly in section of an improved pressure regulator and shut-ofi valve forming part of the burner assembly.

Figure 4 is a side elevation of a modified construction in which a-serpentine insert strip is interposed between the edges of the shell.

Figure 5 is a plan view of the shell with a portion cut away to show the insert.

Referring to the drawings, in Figure 1 there is shown a. furnace I0 comprising the fire pot l2, grate I4 and fuel door opening I6. The burner assembly, generally designated I8, mounts on a plate having a horizontally pivoted upper section 22. The plates 20 and 22 abut the door opening and the unit is held in position by a door holder rod 24 which is somewhat longer than the width of the fuel door opening I6. A chain 26 is secured to the rod 24 and has a screw-eye 28 by which the mounting plate 25 may be tightly clamped in the position illustrated. Slidably secured to the closure plate 2i) is the curved circular mixture tube 30, the left-hand end of which pro-.- jects somewhat outside the door in a straight section 32 and the right-hand end of which carries the burner head 34. Surrounding the mixture tube 3B is a secondary air duct 36 of rectangular form which has a distribution box 38 by which secondary air is directed downwardly into the zone around the burner head 34.

The burner head 34 comprises two identical shell- shaped stampings 36 and 38 which are joined together by a straight connector piece 40 at the left-hand edge. This provides a narrow circumferential slot 42 through which gas and air are delivered for combustion. The automatic pilot tube 44 is also mounted 'on the door plate 20 within the secondary air duct 36 and has a downwardly extending tip 46 adjacent the burner head 34. Mounted on the door plate 2@ is a gas inlet 48 which may be connected to a gas supply by a suitable conduit. The gas inlet feeds an automatic pressure control valve 59 which serves to maintain a constant outlet pressure and feeds the gas orifice 52 through the automatic on-off valve 54 The latter is controlled from the room thermostat in the usual manner. Slidably mounted in the mixture tube end 32 is a telescoping mixer tube 54 having a slotted bracket 5E welded to the end there-of and cooperating with a set screw 58 on the bottom of the gas orifice xture 52. The mixer tube 54 may be moved toward and away from the orifice 52 and because of the relatively large diameter of the orifice fixture, the primary air opening at the end of mixer tube 54 may be controlled by the proximity of the fixture 52 to the end of tube 54.

The gas regulator valve 55 is illustrated in detail in Figure 3 from which it will be seen that the valve 60 cooperates with the seat 62 to open or close communication with the inlet at the right and the outlet at the left. The valve stem 64 is connected to a flexible diaphragm 65 and carries a weight 68. The diaphragm is thus responsive to the pressure above the seat 52 which is outlet pressure and has a normal iiuctuation which serves to adjust the Valve 6B to whatever position is required to maintain the outlet pressure constant.

For the purpose of providing manually controlled shut-off of gas, the stem 64' is provided with a headed upward extension 'HJ which is surrounded by a small tube 12 slidable in the cover 14. The tube 'l2 has a shoulder beneath the head of extension 19 and has a head 'it at its top. A bell-crank lever 'I8 is pivoted at 85 on the cover lll and is connected for manual actuation by a rod 82 which is pivotally connected to the door section 22. A suitable spring and collar arrangement at 84 provides a yielding connection to permit further movement of rod S2 after valve 69 is tightly engaged with the seat 62. For further disclosure of the details of the various elements of the burner such as the automatic pilot and thermostatic control circuit, reference may be had to my above mentioned prior patent.

In operation, it will be seen that when the unit is to be inserted in the furnace, the screw-eye 29 will be removed from the stationary door plate 20 and the entire assembly inserted through the iire door opening I9 to position the plate 29 as shown. The access door 22 may be opened and the rod 24 and chain 26 placed in position and the screw-eye 28 tightened to clamp the um't in place,

While the door E2 is open, the gas supply is shut off by reason of the rod S2 having rotated the bell-crank 78 counterclocxwise to close the valve E0. After the unit is secured in position, the pilot burner 46 may be lighted and the access door 22 closed. If the room thermostat is calling for heat this will open the automatic control valve 54 so that gas is now delivered to the orince 52 because both valves 59 and 5t are open. The mixture is accordingly deliv-ered to the burner head 34 where it is ignited by the pilot i'lame.

The iiame produced by the burner head disclosed wipes the side walls of the combustion chamber and exchanges heat from the bottom s,

up. With the horizontal gas burning port, names and hot gases are naturally sent in direction since they are projected toward the side walls and the natural tendency is for them to rise. In addition, the ineffective heating surface at the front of the lire pot below the nre door is not scrubbed with either flames or hot gases since in most furnaces there is little heating surface at this point. In the present construction, secondary air is introduced at this point and passes downwardly beneath the burner head 34 so that it may be introduced under the iiame to assure proper aeration. It has been found that a much more stable combustion and higher eicency are produced by this construction. Furthermore, the burner operates over a much wider range of inputs and one size burner can cover the range previously requiring two different sizes of burner.

In Figure 4, a modied construction is shown in which shells 90 are supported by the usual mixture tube 39 and in which the edges 9i of the shells are spaced as shown in Figure 1. The shells 99 are similar to those in Figure 1 in that they are circular and dished to provide a concave-convex unit in which the concave sides are brought together in the spaced relation above described. Approximately 75 degrees of the circle at the back of the burner is closed at 92 by bringing the edges 9i together and riveting the same. Also, at three other points 93 the edges of the rims 9| are brought together and riveted. In Figure 1, the connecting plate i9 closes oi approximately 75 degrees of the circle of the plates 36. It is preferable that at least 270 degrees of open port be provided in this type of burner. Interposed between the rims 9i is a strip 95 which is ilat at the portions 92 and 93 but which has a serpentine configuration between the spaced portions of rims 9i to provide a plurality of radially extending ports 96. This serpentine strip which creates these ports increases port velocity somewhat and has been found to reduce the noise of ignition of the unit when heat is called for by controlling thermostat. Similarly, the noise of extinction of the name is reduced. These are important factors in producing a satisfactory household unit.

This application is a continuation in part of my copending application, Serial No. 694,076, filed August 30, 1946, now Patent No. 2,490,127.

I claim:

l. In a gas burner conversion unit adapted for use in a solid fuel heating unit, a support, a mixture supply tube projectably mounted on said support to extend into the re box of said heating unit and curved downwardly at its inner end, a burner head on the inner end of said tube having a closed circumferential portion and burner ports extending circumferentially about the remaining portion with axes directed away from the supply tube, and in combination a secondary air supply tube surrounding and mounted on said mixture supply tube and correspondingly adjustably mounted with respect to said support7 said secondary air tube having an outlet extending downwardly around said curved portion of the mixture tube with an opening at the closed circumferential portion of the burner head to project incoming secondary air below the burner on said mixture tube, said mixture tube and secondary air supply tube being simultaneously adjustable with respect to said support.

2. ln a gas burner conversion unit adapted for use ina solid fuel heating unit, a support, a ymixture supply tube projectably mounted on said support to extend into the fire box of said heating unit and curved downwardly at its inner end, a burner head on the inner end of said tube con prising a pair of oppositely facing shell members spaced apart to provide a peripheral flame opening extending ciroumferentially through at least 270 degrees, said shells being shaped to provide a closed peripheral portion at one place in the circumference, and in combination a secondary air duct to extend into the fire box from said support projecting inward and downward and terminating in a downward, open-end portion at substantially the level of the burner head adjacent the closed peripheral portion of the burner head where there is no flame opening whereby secondary air may be delivered beneath the burner head.

HAROLD E. EANDLEY.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 546,340 ORielly Sept. 17, 1895 842,792 Maohlet Jan. 29, 1907 1,385,509 Vance July 26, 1921 1,482,103 Van Daam Jan. 29, 1924 1,700,886 Geurink Feb. 5, 1929 2,107,575 Matthews et al. Feb. 8, 1938 2,215,983 Smith Sept. 24, 1940 2,297,856 Ames Oct. 6, 1942 2,487,959 Zink V. 15, 1949 2,491,430 Tullis Dec. 13, 1949 2,498,162 Heller Feb. 2l, 1950 2,574,153 Meiners Nov. 6, 1951 FOREIGN PATENTS Number Country Date 487,445 Great Britain June 2l, 1938

Images