US2212312A - Gas burner - Google Patents

Description

20, 9 s. w. E. AND ERSSON 2,212,312

GAS BURNER Filed June 18, 1937 2 Sheets-Sheet 1 INVENTOR.

g- 4 s. w. E. ANDERSSON ,312

GAS BURNER Filed June 18, 1937 2 Sheets-Sheet '2 INVENTOR.

WATTORNEY.

Patented Aug. 20, 1940 PATENT OFFICE GAS BURNER Sven W. E. Andersson, Evansville, Ind., assignor to Servei, Inc., New York, N. a corporation of Delaware Application June 18, 1937, se ial No. 148,841

4 Claims. (e1. 152-4111) My invention relates to gas burners, and has as one object the provision of a gas burner having'an improved valve structure and safety. cut-' off mechanism to effectively shut oi! the flow of 1 gas when the burner flame is extinguished.

Another object of my invention is to provide an improved safety cut-oif mechanism which is compactly arranged in a gas burner and can be easily manipulated to instigate operation of the 10 burner.

A further object of my invention is to provide an improved air shutter control for dependably controlling the quantity of primary air admitted into a burner to provide a combustible gas mixture.

The above and other objects and advantages of my invention will be better understood as the following description proceeds, and the features of novelty which characterize my invention are 20 pointed out withparticularity in the .claims'annexed-to and forming a part of this specification.

In the drawings, Fig. 1 is a vertical sectional view of a gas burner embodying my invention; Fig.

2 is a sectional view taken on'line 2-2 of Fig. 1;

25 Fig. 3 is a vertical sectional view taken on lines 3--3 of Figs. 1 and 2 with the burner tube omitted to illustrateparts' of the safety cut-off mechanism more clearly; Fig. 4 is a sectional view taken on line 44 of Fig. 3; and Fig. 5 is a frag- 30 mentary sectional view of the top part of the burner taken on line 5-5 of Fig. 4.

Referring to Figs. 1 to 3 inclusive, the improved gas burner embodying the invention includes a body member l having a hollow boss H which 35 may be secured to a suitable support by a screw l2. The body member I3 is provided with a second boss |3 having a threaded opening H which I is adapted to be connected to a conduit of a gas supply line. The opening l4 communicates with 40 a chamber l5. which in turn communicates with a passage I3 through an opening l1 formed in a' valve seat IS. The valve seat I3 is threadedly secured at its upper endwithin body member, ID and is provided with a cross passage l3 which is 45 in open communication with passage IS. The flow of gas through the opening H in valve seat It is controlled by a valve-l3 which forms part of the safety cut-oif mechanism hereinafter to be described. 4 50 Thev passage I3 is in line with the/threaded a h opening l4 and the right hand end thereofis permanently sealed with a plug 20. The opposite end of passage l6 communicates with a chamber 2| from which a passage 22' extends to the bottom of body member ii. The passage 22 is threaded to receive an adjustment screw 23 and a removable cap screw 24 to seal the lower end of the passage. By removing cap screw 24 the adjustment screw 23 may be set .to any desired position opposite the end of passage IE to control the maximum flow of gas to the burner and hence the maximum size of the burner flame.

The adjustment screw 23 is formed with a passage having a restriction 25 intermediate its ends,

whereby the gas pressure in chamber 2| can be measuredat any time by removing cap screw 24 and securing a manometer to the lower end of passage 22. When the gas in chamber 2| is not at the desired pressure, the adjustment screw 23 may be moved to increase or decrease the flow of gas from passage l6 into chamber 2|.

The chamber 2| is L-shaped, as shown in Fig.

3, and'is open at the top of the'body member In. A member 26 having a passage 21 which converges and terminates in a discharge orifice 21 is secured to body member Ill at the opening of chamber 2|. Within passage 21 is fitted a plug 28 having grooves 29 about the edge thereof. The grooves 29 are at an angle to the direction of flow of gas in passage 21 to impart a whirling motion to the gas.

To the top of body member l0 and about the member 26 is secured a housing 30 havinga reduced narrow portion or partition 3| intermediate its ends to form a lower chamber 32. The 30 chamber 32 is provided with air inlet ports 33 and constitutes a mixing chamberin which air and gas are thoroughly mixed to provide a combustible gas mixture.

To the reduced portion 3| of housing 30 is secured the lower end of a burner tube 34 at the upper end of which is provided a cap 35 having a plurality of openings 36. The gas mixture formed in chamber 32 flows upward through burner tube 34 and is discharged at the openings 36 at which region the burner flame isproduced and maintained.

A tube '31 concentrically disposed about burner tube 34 is secured by screws 33 to the body member l0. With this arrangement, primary. air-admitted Intomixing chamber 32 through air inlet ports 33 is drawn downward though the upper open end of tube 31. With the upper end of tube 31close1y adjacent to the openings 36 in cap 35, theidirection of flow of air drawn downward in tube 31 is reversed considerably due to the fact that the now of air about the burner flame is upward, as indicated by the arrows in Fig. 1. With such charge in direction of the flow of air, particles of dust and lint in the air tend to v move upward about the burner flame and are separated'from air which is drawn downward within tube 31. The tube 31, which may be rethrough the air inlet ports 33.

ferred to as a dust prevention tube since it insures delivery of clean primary air into the mixing chamber 32, is described more fully in Forberg Patent No. 2,069,062.

About the housing 39 is arranged a vertically movable sleeve 39 having an outward extending flange 48 at its lower end. The flange 48 is bifurcated, as shown most clearly in Fig. 2, to receive a reduced portion of an adjustment screw 41. The adjustment screw 4! extends downward and is in threaded engagement with a passage 42 in body member I. By turning adjustment screw 4| from the lower open end of passage 32, the sleeve member 39 may be moved vertically to any desired position to control the quantity of primary air admitted into mixing chamber 32 In order to shut off flow of gas to the burner if for any reason the burner flame is extinguished, I provide a safety cut-off mechanism including the valve l9 in chamber l5. The valve I9 is cup- 4 shaped and formed of thin metal so that the upper open end will be flexible. The valve i9 flts within a rigid cup 43 having a flange 44 about its upper edge. A coil spring 45, which is disposed about cup 43 and bears against the flange 44 and a removable cap screw 46, is provided to urge valve l9 to its closed position on valve seat l8. While the closed end of valve l9 flts snugly within the rigid cup 43, the upper flexible edge of the valve is spacedfrom the inner wall of cup 43, so that the valve will snugly flt on the lower conical portion of valve seat l8 when the valve is urged upward to its closed position.

The closed end of valve I9 is provided with a small depression to receive the lower end of a pin' 41 which extends upward through the open ing 11 of valve seat l8 and a sleeve 48 which is formed integrally with the valve seat. A hollow guide 49 closed at its upper end flts over and is vertically movable along sleeve 48. The upper end of pin 41 bears against the closed end of guide 49 whereby downward movement 01 the guide moves valve l9 to its open position against the action of coil spring 45.

Downward movement is imparted to guide 49 by pulling a button 58-which is movable in a recess 51 at the bottom of body member ID, as shown in Fig. 1. The button 59 is arranged to move a rod 52 which extends upward through a passage in body member ID and is looped at its upper end. The looped upper end of rod 52 flts into an opening in a strip of metal 53 which is curved and extends vertically within tube 31. The strip 53 is secured at its lower flanged end to guide 49 whereby valve I9 is moved to its open position when rod 52 is moved downward by pulling button 58 out o! recess 5|.

To maintain valve l9 in its open position during operation of the burner, the upper end of strip 53 is provided with an inward extending flange 51 having an elongated curved opening 58, as shown most clearly in Fig. 4. Within the upper part of tube 31 and projecting slightly above the open end thereof is disposed a bimetallic strip 59 in the form of a split ring. The diameter of the bimetallic stri 59, which will be referred to as a thermal element, is slightly smaller than the inner diameter of tube 31 and the free ends thereof are in the region of the upper flange 51 of strip 53. The thermal element 59 is positioned adjacent a plurality of openings 66 formed in tube 31 and is secured to the latter at a region intermediate its free ends,

as indicated at 69 in Fig. 4. Adjacent its ifreev scribed.

The operation of the burner and safety cut-ofi mechanism is substantially as follows: To start the burner the button 58 is pulled outof recess 5|. This moves rod 52 downward and imparts downward movement to guide 49 and pin 41, whereby valve I9 is moved to its open position against the action of coil spring 45. This permits gas to flow from chamber I5 through the opening l1 in valve seat l8, passage 16, chamber 2|, passage 21,and discharge 'oriflce 21' to the mixing chamber 32. 'In chamber 32 gas is mixed withprimary air which is admitted through air inlet ports 33 and controlled by the sleeve or air shutter 39. The gas mixture. flows upward through burner tube 34 and openings 36 at which region" the mixture is ignited to provide the burner flame.

When button 50 is moved out of recess 5| the strip. 53 is moved downward from the position shown in Fig. 3 to the position shown in Fig. 5 with the flange 51 ,below the shoulder or stop 65 formed on ear 64 of thermal element 59. The thermal element 59 is heated bythe burner flame and expands or flexes outward to move the ears 63 and 64 away from each other. When thermal element 59 is heated sufliciently and the ears 63 and 64 have moved apart a definite distance, the shoulder 65 on ear 64 will extend or project past an edge of the opening 58 in flange 51. When this occurs button 58 may be released to move flange 51 against the stop 65, so that upward movement of strip 53 by. coil spring 45 will be prevented and valve I9 will remain in its open position. I

If for any reason the burner flame is extinguished the thermal element 59 will no longer be heated, whereby the ears 63 and 64 will move toward each other with cooling of the thermal element. With suflicient cooling or the thermal element, the stop 65 will slip oil the edge of the elongated opening 58 and no longer be efiective to prevent upward movement of strip 53. With stop 55 out of the path of movement of flange 51 E the coil spring will become efiective to movev pin 41 upward and also move valve l9 to its closed position, thereby completely shutting ofi the flow of gas to the burner.

The thermal element 59 is preferably arranged to tit snugly within tube 31 when it is heated and flexed outward during normal operation of the burner. When the tube 31 is provided with openings 66 at the region'of the thermal element 59, these openings will be fully closed when the thermal element is heated and bearing against.

ing of the thermal element and decrease the time for closing valve IS.

The cup-shaped valve l9 formed of thin metal differs considerably from the usual ball type valve that is generally used to control the flow of gas in gas burners. The flexible edge of the valve insures a snug fit of the valve on the conical or tapered valve seat l8 even when the valve and valve seat are at an angle and not in true I alignment. In addition to insuring a tight flt at all times to shut off the flow of gas, the flexibility of the cup-shaped valve l9 possesses the further distinct advantage that it is self-adjusting and does not requirethe use of materials, such as leather or rubber composition, which are not suitable for use at high temperatures.

When valve l 9 is in its open position there may be the possibility of gas leaking between pin 4'! and sleeve 48 and between sleeve 48 and guide 49. These parts are preferably made with a close sliding flt to reduce the likelihood of gas leakage. The pin 41, sleeve 48, and guide 49 may be coated with a suitable lubricant, such as graphite, for example, to seal these parts and prevent any leakage of gas. Even if a small amount of gas should leak past these parts, such gas passes into the lower part. of tube 31 and is drawn into the mixing chamber 32 with primary air. With a burner construction of this type, therefore, it is not necessary to employ any packing about a valve stem or other part which extends through an opening in a body member or valve casing and is arranged to control a valve.

- The gas burner I have provided is extremely reliable in operation and is particularly adapted for use where a burner is required that must operate with a minimum amount of attention. One such use, for example, is that of heating absorption refrigeration apparatus.

The air shutter control has beenso arranged that it will be'de'pendable and will always maintain the air shutter 39 in the position to which it is adjusted. This is effected by providing the adjustment screw 4| which is connected directly to the air shutter and-is also in threaded engagement with the passage 42 in body member "I. Movement can only be imparted to air shutter 39 by turning adjustment screw 4], the latter pref-'- erably being arranged within the body member III so that accidental movement of the air shutter cannot be effected.

By making the operating button 50,- gas pressure adjustment screw 23, and air shutter adjustment screw 41 accessible from the bottom of the body member It, the burner may be effectively employed in a horizontal position in a confined space and easily adjusted for the best operation in any particular case.

Although I have shown and described a particular embodiment of my invention, it. will be apparent that modifications and changes may be made without departing from the spirit and scope of theinvention, as pointed out in the following Y claims.

What is claimed is:

I. In a gas burner, a burner tube, a second tube disposed about said burner tube and having a plurality of openings, a valve for controlling flow of gas, resilient means for closing said valve, mechanism for manually opening said valve "against the action of said resilient means, a ringshaped thermal element located within said second tube adjacent the openings therein and responsive to the temperature of the burner flame, said thermal element being associated with said mechanism and operative to keep said valve open after operation of the burner is instigated and said thermal element is heated, said thermal element permitting said resilient means to close said valve when it is cooled and the burner flame is extinguished, said thermal element being arranged to close the openings in said second tube during operation of the burner and to permit flow of air through the openings when the burner flame is extinguished.

2. In a gas burner, a burner tube, a second tube disposed about said burner tube and forming the sole inlet for primary air, a valve for controlling flow of gas to said burner tube, resilient means for urging said ,valve to its closed position, an

elongated member disposed within said second tube and operatively associated with said valve, a thermal element in the fornr of a split ring disposed within said second tube and secured thereto at a region intermediate its free ends, said thermal element having cars at its free ends, said member having an opening to receive said ears, a

part operatively connected to said member for manually moving said member and opening said valve against the action of said resilient means, one of said ears having a catch adapted to overhang. an member when said valve is opened and said thermal element is heated to maintain said member in position to keep said valve open, and said catch moving off the edge of the opening when the burner flame is extinguished and said thermal element is cooled to permit said resilient means to close said valve.

3. A gas burner comprising a valve housing, a burner tube extending from said housing, a dust e of the opening in said elongated prevention tube surrounding said burner tube and forming the sole inlet for primary air, said dust prevention tube being provided with an opening adjacent the flame tip of said burner tube, a thermostatic element in said dust prevention tube adprevention tube.

' EVEN W. E. ANDERSSON.

Images