US3053315A - Burner lighting system - Google Patents

Description

P 1962 F. w. DE;ADY, JR., ETAL 3,053,315

BURNER LIGHTING SYSTEM Filed Feb. 9, 1960 INVEN TORS FREDRICK w. 00m, JR. GLEN A.WHITE BY, jwmfi ATM AT TOR N E! the furnace creating a fire hazard.

United States Patent 3,053,315 BURNER LIGHTING SYSTEM Frederick W. Deady, Jr., Indianapolis, and Glen A. ite, Westfield, Ind., assignor to Carrier Corporation, Syracuse, N.Y., a corporation of Delaware Filed Feb. 9, 1960, Ser. No. 7,574 4 Claims. (U. 158-115) This invention relates to gas burner systems and more particularly to an improved gas burner system having desirable burner lighting characteristics and to an improved valve for such systems.

Gas burner systems of the type which are used in gas furnaces or gas fired boilers have frequently in the past been constructed using a direct gas line between the gas burner and the main shutoff valve which is responsive to a temperature or other condition giving adequate control of system. While from the standpoint of simplicity and economy, such an arrangement may be satisfactory, there are many instances in which the described arrangement gives inadequate control of the burner firing rate. Such systems characteristically ignite he burner with a pop or puff because a combustible mixture of air and gas tends to accumulate in the furnace before complete ignition takes place. This type of ignition is undesirable from a consumer standpoint because of the noise occasioned thereby. Also, the sudden ignition of the combustible mixture of gases which accumulates in the furnace may cause flames to issue from the secondary air opening in In addition, such a system may be hazardous because the sudden rush of combustion products upon initial lighting of the burner may be sufficient to extinguish the pilot light in the burner sysem. In extreme cases the pressure of a combustible mixture may be suflicient to snuff the pilot light out or to cause flash back in a venturi tube which feeds the primary air-gas mixture to the burner. For these reasons, it is highly desirable that gas burner ignition take place slowly so that the burner has an opportunity to completely light before full gas pressure is supplied to it, thereby preventing the accumulation of an unignited combustible gas mixture.

In order to overcome the difficulties inherent in a system wherein a main shutoff valve having a relatively rapid return of opening and closing controls the gas supply to a burner, it has been previously proposed to insert an auxiliary valve having slow opening characteristics between the shutoff valve and the gas burner. In such proposals, the auxiliary valve has been of the diaphragm type with the diaphragm responsive to the pressure of gas issuing from the shutoff valve. This approach is inherently disadvantageous because the valve senses upstream pressure rather than the pressure of gas at the burner and it is the latter pressure which is the primary cause of the problems sought to be overcome. In addition, the use of such valves is impracticable in systems where the main gas pressure supp-lied to the valve is variable or modulated because a specific gas pressure is necessary for such a valve to fully open. If the valve is adjusted to fully open at the lowest gas pressure which may be encountered, it will tend to open too quickly on higher pressures and therefore fail to serve its intended function. Furthermore, such valves may close only as quickly as they open and consequently are inefiective in a fast cycling system.

Accordingly, it is an object of this invention to provide an improved gas burner system wherein the gas pressure at the burner slowly rises upon turning on of the gas so that burner ignition takes place at a low rate and gradually increases to full capacity over a controlled time interval in response to downstream pressure at a burner or burners.

It is a further object of this invention to provide an Patented Sept. 11, 1962 improved gas valve insertable in a gas line between a main shutofi valve and a gas burner in pre-existing systems which will control the rate of rise of gas pressure at the burner in response to the pressure of gas at the burner.

It is a still further object of this invention to provide an improved gas valve having the characteristics of opening slowly and closing quickly and in which rupture of the valve diaphragm will not permit escape of a large quantity of gas.

These and other objects of this invention are achieved in the illustrated embodiment described by inserting an improved burner regulator valve between a main shutoff valve and a gas burner in a gas line. The improved burner regulator valve may comprise a valve body di vided into a first chamber and a second chamber by a spring biased diaphragm. A valve plug having a clearance with a valve orifice meters gas flow through the valve in response to the position of the diaphragm. The rate of movement of the diaphragm is controlled by venting the outer chamber slowly upon movement of the diaphragm in a direction to open the valve. Rapid return of the valve to its maximum closed position is achieved by providing a check valve which permits rapid supply of air to the outer chamber in response to movements of the diaphragm in a direction to close the valve.

A preferred embodiment of this invention will become apparent by reference to the attached drawings wherein:

FIGURE 1 is a schematic illustration of a gas burner system embodying this invention; and

FIGURE 2 is a cross-sectional view of an improved valve construction adapted for use in the gas burner system of FIGURE 1.

Referring now to FIGURE 1, a gas line 10 supplies gas to burner 11 in a furnace or other gas fired apparatus 12. Gas line 10 is provided with a main shutoff valve 13 and an improved burner regulator valve 14 for the purpose of controlling the rate of flow of gas to burner 11.

Burner regulator valve 14 shown in FIGURE 2, comprises a body 20 divided into an outer section 21 and inner section 22 by a diaphragm 24. Outer section 21 forms a substantially closed first or outer chamber 25 with diaphragm 24 and inner section 22 forms a second or inner chamber 26 with diaphragm 24.

First or outer chamber 25 and second or inner chamber 26 are both internal of valve 14. As used herein, the expression outer chamber refers to first chamber 25 whichis outer in the sense that it is in communication with the exterior of the valve through vent device 45. Likewise, the expression inner chamber is used to denote second chamber 26 which is an inner chamber in the sense that it is in communication with the interior of valve 14. In the same sense, inward movement of diaphragm 24 refers to movement of diaphragm 24 towards the interior or inner chamber 26 of valve 14 and outward movement of diaphragm 24 refers to movement of the diaphragm toward outer chamber 26.

An inlet port 28 and an outlet port 29 both having means to attach portions of a gas line thereto are provided in inner section 22 and communicate with inner chamber 26. A partition 30 having valve orifice 31 divides inlet port 28 from outlet port 29 by dividing inner chamber 26 into inlet and outlet sections.

A valve plug 32 is movable with diaphragm 24 and in the illustrated embodiment is secured thereto. Both valve orifice 31 and valve plug 32 are generally cylindrical in shape and the inner diameter of valve orifice 31 is greater than the outer diameter of valve plug 32 thereby forming a restricted opening therebetween communicating inlet port 28 with outlet port 29. In the illustrated embodiment annular sheet metal cupped rings 33, 34, 35 surround valve plug 32 on both sides of diaphragm 24 and therein.

serve to seal outer chamber 25 from inner chamber 26 as well as to give the desired shape to the diaphragm. In addition, annular rings 33, 34, 35 are provided with lips 36, 37, 38 respectively which serve as stop members pre venting overflexure of diaphragm 24 by engagement with a portion of the valve body.

A resilient spring 50 disposed in a portion of outer section 21 biases diaphragm 24 to a normal inward position such that valve plug 32 is within valve orifice 31 thereby biasing the valve to its maximum closed position. An adjustment screw 41 is provided for varying the spring compression force on diaphragm 24. Spring 40 engages annular ring 33 which serves to protect diaphragm 24 from the thrust of the spring. By varying the position of adjustment screw 41, the valve may be caused to open at any downstream pressure within the range of the adjustment provided. It will be observed that outlet port 29 is in substanially unrestricted communication with diaphragm 24 so that the valve is essentially responsive to downstream pressure only and is substantially unresponsive to upstream pressure present at inlet port 28.

Outer chamber 25 is substantially closed to the atmosphere except for vent device 45 which is threaded in vent opening 46. Vent device 45 has a vent limiting port 47 in communication with outer chamber 25 through bore 44. Vent limiting port 47 may be formed by a cup shaped sheet metal member inserted Within an opening in vent device 45 and having an appropriately restricted opening By this .means, various sizes of vent limiting ports may be supplied using a single vent limiting device 45.

A recycle port 48, of similar construction to vent limiting port 47, but having a less restricted opening is likewise normally in communication with bore 44. A ball check valve 49 is provided to close recycle port 48 upon the presence of a slightly higher pressure in outer chamber 25 than theat external of valve 14 such as would be occasioned upon outward movement of diaphragm 24. It will be observed that vent limiting port 47 is at all times in communication with outer chamber 25 but that recycle port 48 is only in communication with outer chamber 25 when the pressure surrounding valve 14 is substantially equal to or greater than that within the outer chamber.

In operation, valve 14 is inserted in gas line between main shutoff valve 13 and gas burner 11. As main shutoff valve 13 is opened, gas is supplied to inlet port 28 of valve 14. Because of the clearance existing between valve plug 32 and valve orifice 31, a controlled amount of leakage of gas exists between inlet 28 and outlet 29. Initially,

substantially only gas leaking through this clearance is supplied to burner 11 through outlet 29. After a controlled interval of time, a sufiicient gas pressure has built up at outlet 29 so that the pressure of gas acting outwardly on diaphragm 24 begins to open the valve. By this time, burner 11 has been ignited fully by pilot 50. As the gas pressure builds up, valve plug 32 is completely withdrawn from valve orifice 31 by outward movement of diaphragm 24 and substantially full gas pressure is supplied to the gas burner from gas line 10.

Opening of valve 14 is inhibited by both spring 40 and restricted vent limiting port 47. Spring 40 tends to bias valve14 to its normal maximum closed position and the force of the spring which is controlled by adjustment screw 41 must be overcome before the diaphragm may move outwardly sufiiciently for valve plug 32 to clear valve orifice 31. In addition, as diaphragm 24 is forced When main shutofi? valve 13 is closed and no gas pressure is supplied to inlet port 28, Spring 40 biases diaphragm 24 and valve plug 32 to the maximum closed position of valve 14. Return or inward motion of diaphragm 24 is not restricted by the size of vent limiting port 47 because as the pressure in outer chamber 25 is reduced below that which is outside valve 14, check valve 49 opens thereby permitting venting of chamber 25 to the atmosphere through the less restricted recycle port 48.

In the event of failure of valve 14 such as by rupture of diaphragm 24, it will be observed that the pressure of gas issuing from inlet port 28 through the diaphragm into outer chamber 25 will cause check valve 49 to close recycle port 48 and the only path of escape of such gas from the valve is through restricted vent limiting port 47 Since only a small amount of gas in the atmosphere can be easily detected, a vent limiting port serves as a satisfactory means of detecting a ruptured diaphragm without significant danger of explosion external of the gas fired device. Consequently vent limiting port 47 together with check valve 49 and recycle port 48 comprises an effective safety device in the event of failure of valve 14.

It will be observed that because valve 14 is responsive to downstream pressure at gas burner 11 rather than to upstream pressure issuing from main shutofif valve 13, variation in supply pressure or modulation of valve 13 will not have a deleterious effect on the operation of the valve and that in all cases an intially small quantity of gas is supplied to burner 11 for ignition which gradually increases before the full main gas pressure can be supplied to the burner.

While I have described a preferred embodiment of the present invention, it will be appreciated that other modifications and embodiments thereof may be constructed within the scope of the following claims.

We claim:

1. In a burner lighting system, a gas burner, a main shutoff gas valve, and a burner regulator valve interposed in a gas line between said shutoff valve and said gas burner, said burner regulator valve comprising a valve body divided by a diaphragm into a first chamber and a second chamber, said first chamber being substantially closed and having means to slowly vent said chamber upon application of a force to said diaphragm tending to move it in a valve opening direction, means to quickly vent said first chamber upon application of a force to said diaphragm tending to move it in a valve closing direction, an inlet port and an outlet port communicating with said second chamber, said outlet port being in substantially unrestricted communication with said diaphragm, partition means between said inlet and outlet ports, a valve orifice in said partition means, a valve plug movable with said diaphragm and positioned for movement into said valve orifice upon one direction of movement of said diaphragm and away from said orifice upon another direction of movement of said diaphragm, said valve orifice having a larger internal dimension than a corresponding external dimension of said valve plug so that a restricted clearance exist between said plug and said orifice, means comprising a portion of said gas line connecting said outlet port to said gas burner and means comprising another portion of said gas line connecting said inlet port to said main shutoff valve so that said burner regulator valve slowly opens in response to a rise in pressure at said burner downstream thereof.

2. A burner lighting system as defined in claim 1 wherein said burner regulator valve includes resilient means biasing said diaphragm in an inward direction to reduce the flow through said burner regulator valve to burner, said burner regulator valve comprising a valve body divided by a diaphragm into a first chamber and a second chamber, vent means associated with said first chamber, said first chamber being in communication with ambient atmosphere through said vent means, a gas inlet port in said valve body, a gas outlet port in said valve body, said second chamber being in substantially unrestricted communiction with said outlet port whereby said diaphragm is enabled to sense the outlet pressure of said valve, partition means in said valve body between said inlet port and said outlet port, a valve orifice in said partition means, a valve plug movable in response to said diaphragm, said valve orifice having a larger internal dimension than a correspondingly located external dimension of said valve plug when said valve plug is in a predetermined maximum closed operating postion, biasing means to return said valve plug to said maximum closed operating position in the absence of outlet pressure being sensed by said diaphragm, said vent means governing the rate of change of pressure in said first chamber to thereby limit the rate of movement of said diaphragm and said valve plug, said vent means slowly venting excess pressure in said first chamber to the atmosphere when said diaphragm is urged by outlet gas pressure in a direction to open said valve, said vent means further serving to quickly admit ambient atmosphere into said first chamber when said diaphragm moves in a direction to close said valve, means comprising a portion of said gas line connecting said outlet port to said gas burner and means comprising another portion of said gas line connecting said inlet port to said main shutoff valve so that said burner regulator valve slowly opens in response to a rise in pressure at said burner downstream thereof.

4. A burner lighter system comprising a gas burner, a main shutoff gas valve, and a burner regulator valve interposed in a line between said shutoff valve and said gas burner, said burner regulator valve comprising a valve body, a diaphragm in said valve body, an internal chamber in said valve body sealed from communication with ambient atmosphere by said diaphragm, a gas inlet port in said valve body, a gas outlet port in said valve body in communication with said internal chamber, partition means in said valve body between said gas inlet port and said gas outlet port, said gas outlet port being in substantially unrestricted communication with said diaphragm whereby said diaphragm is exposed to the outlet pressure of said valve, a valve orifice in said partition means, a valve plug movable in response to said diaphragm, means providing restricted communication between said inlet port and said outlet port throughout said partition means when said valve plug is in a predetermined maximum closed operating position, biasing means to return said valve plug to said maximum closed operating position in the absence of outlet gas pressure being exerted on said diaphragm, means associated with said valve plug to limit the rate of opening of said valve by controlling the rate of movement of said valve plug in a valve opening direction, said means associated with said valve plug permitting relatively rapid rate of movement of said valve plug in a valve closing direction, means comprising a portion of said gas line connecting said outlet port to said gas burner and means comprising another portion of said gas line connecting said inlet port to said main shutoif valve so that said burner regulator valve slowly opens in response to a rise in pressure at said burner downstream thereof.

References Cited in the file of this patent UNITED STATES PATENTS 959,397 Simmons May 24, 1910 2,135,585 Long Nov. 8, 1938 2,174,515 Hughes Oct. 3, 1939 2,302,284 Abbott Nov. 17, 1942 2,871,879 Downe et al. Feb. 3, 1959 UNITED STATES PATENT OFFIC CERTIFICATE OF CORRECTION Patent No. 3,053,315 I September 11, 1962 Frederick W. Deady, Jr, et alo It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 22, for "he read the column 3, line 7, for "50" read 4O line l8, for "substan ially" read substantially line 3'1, for theat read that same column 3, line 69, for "limitng" read limiting column 6, line 12, for "throughout" read through vSigned and sealed this 26th day of March 1963.

(SEAL) Attest:

ESTON G JOHNSON DAVID L. LADD Attesting Officer Commissioner of Patents

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