US1933318A - Safety gas burner - Google Patents

Description

Oct- 31, 1933- L. F. Dol-:N 1,933,318

SAFETY GAS BURNER Filed April 15, 1927 HIIIIIII- InuenZar Patented Oct. 31, 1933 UNITED STATES 1,933,318 SAFETY GAS nomma Loran F. Doen, Cleveland, Ohio, asslgnor to The Cleveland Heater Company, Cleveland, Ohio,

a corporation of Ohio Application April 15, 1327. serial No. 184,085

2 Claims. '(Cl. 15S-117.1)

This invention relates to gas burning appliances and in particular the gas burners used in connection therewith.

'It has for its main object to provide a pilot- 5 less, non-flash, safety gas burner.

Another object of this invention is to provide a gaseous fuel burner that combines in a relatively simple and inexpensive unit, thermostatic control means to prevent the escape of l unburned gas, which means is integral with the burner and responsive to the heat of the dames of the-burner.

Another object of this invention is to makea gaseous fuel burner in which the individual l burners can act at times as their own pilot lights, burning with a tiny flame that is not apt to be extinguished by sudden drafts and other causes of pilot light extinguishment.

A further object of this invention is to provide a gaseous fuel burner that will function properly under a wide range of gas pressures and draft conditions.

My improved burner was invented particularly for use in automatically controlled gas burning appliances.

Appliances of the above referred type in general require and are dependent upon a pilot light for ignition. Disas'trous and even fatal results have often occurred from accidental extinguishment of pilot lights and subsequent turning on of the main gas supply in automatically controlled gas burning appliances.

Efforts to obviate this hazardous condition have been in two directions, one, by use of safety pilots and the other by using the burner itself as a pilot burner.

The objections to use of safety pilots are the added initial expense and the cost of servicing or keeping the automatic safety pilot in operating condition when in the hands of the user. Dispensing with the single independent pilot light by allowing a restricted flow of gas to the main burner so that a small fiame is maintained at each of the burner orifices may result in a reduction of cost, but it is still a moot ques\` tion as to whether or not the same set of conditions that would cause the extinguishment of a single pilot light would not also operate to extinguish a larger number of smaller lights or flames.

Furthermore, burners of the type referred to must be so constructed that reduced gas pressure will not cause the fiame to fiash back and burn in the primary air mixing tube. This necessary condition has resulted in the development of gas burners that have none or very little primary air mixed with the gas before combustion takes place, spreading of ame in Yat each burner orifice. These pilot flames burn in relatively large, open, primary air mixing tubes, having a shield or deflector plate above their top open end. This arrangement has the advantage of protecting and shielding the pilot flame from being blown out or extinguished and at the same time permits a maximum amount of air to be mixed with the gas before combustion takes place when an unrestricted flow of gas is admitted to the burner. v

The advantages and protective features of the safety pilot are achieved'by building into the burner itself a thermostatic valve, that positively cuts off all gas to the burner orifices upon extinguishment of the pilot flames by accident or otherwise, and that thermostatically controls the f'low of gas to the burners when full capacity operation of the burner is desired.

The accompanying drawing is a central sectional elevation of a gas burner illustrating my invention.

As exemplified in the drawing, my improved burner consists of a burner body having radially arranged conduits 1 which are adapted to support individual burners at their outer ends and adapted to be placed in communication at their inner ends with the central chamber 2. This chamber has an opening 3 adapted to be placed in communication with the main gas supply line. A thermostatic valve 28 or any other suitable valve may be used to control the supply of gas to the opening 3 of the burner body. Another inlet 4 is provided in the central chamber to provide at all times a restricted flow of gas to the burners. This gas is under control of a needle valve 5 of conventional design, not shown in detail, which is connected to the source of gas supply.

A valve seat 6 is formed in the central chamber 2 and cooperates with a valve head '7, slidably mounted upon the valve stem 8 to control the iiow of gas to the burner orifices. A spring 9 supported between the valve head 7 and the abutment 10 is adjustably mounted on the valve stem by means of lock nuts 11. A small bypass 110 12 is formed in the valve stem and is adapted to allow communication between the central chamber 2 and the conduits 1. The purpose of this bypass will be explained presently. A flexible diaphragm 13 such as leather is secured to the valve stem by the sleeve 14 and nut 15 and at its outer edge to the burner body by means of a centrally bored plug 16. The diaphragm 13 provides a leakproof valve stem packing without hampering the movement of the valve.

A strip of thermostatic metal 17 is secured to the upper end of the valve stem by means of nuts 18 and has slotted ends slidably mounted in annular grooves 19 of the burner mixing tubes 20. The thermostatic metal is of the ordinary and well known type, in which a composite strip is formed of two of the metals having dissimilar thermal characteristics so that with a change in'temperature of the strip there is a corresponding change in its shape or radius of curvature. The burner mixing tubes 20 have primary air inlet openings 21 and a gas orifice 22. A shield or deflector plate 23 is mounted upon the top of the mixing tube by a ring 24 that is secured and fitted in the top of the mixing tube.

In the position of the 'valve shown in the drawing and assuming that no gas is being admitted to the opening 3 it will be seen that a restricted ow of gas is entering the burner by way of the needle valve 5 bypass 12 and thence to the burner orifices 22. Under these conditions a small yellow flame pilot light such as 25 burns in each of the mixing tubes. If it is desired to operate the burner at full capacity, the opening 3 is placed in communication with a source of gas supply by an automatic valve or other means. This increases the-height of the flame 25 to approximately the size of the flame 26 shown in dotted lines. The additional heat given off by the enlarged flame increases the temperature of the thermostatic strip 17 causing it to move the valve stem 8 downward bringing the shoulder 27 of this valve stem into engagement with the valve head 7, if it is not already in contact therewith, and then opening the valve by continued movement of the valve stem 8. The iiames from the individual burners are now spread out in a relatively flat fan shaped blue flame by reason of the gas stream from the orifices 22 impinging upon the deflector plates 23.

On cutting oi' the supply of gas to the opening 3 the flame changes from a large fan shaped blue flame to the small cone shaped yellow flame 25. The thermostatic strip 17 now cools changing its shape and at the same time raising the valve stem and associated parts until the valve head 7 is in engagement with its seat 6. It will be noted that the pilot flames 25 are burning entirely within the mixing tube and are well protected against drafts or other conditions which might tend to extinguish them. However, in the event that the pilot lights should become extinguished, accidentally or otherwise, the thermostatic strip 17 will cool and raise the Valve stem 8 from the position shown in the drawing compressing the spring 9 and causing the inlet openings of the bypass 12 to be covered by the downwardly extending portion of the valve head 7, so that the gas supply to the burner orifices is completely cut oi.

Under the preceding conditions where the valve in the chamber 2 and the by-pass 12 are closed, it will be impossible to get gas to the burner orifices until the pilot lights or burners are relighted. This necessitates manually pushing down the valve stem 8 and holding it down until the thermostatic strip 17 is again Warm.

The production of carbon monoxide is avoided in this burner by using a relatively large open ended air mixing tube with a deflector plate positioned at a distance above the open end. of the mixing tube. By this construction when gas is burning in the tube it is not chilled before complete combustion takes place as it would be in a longer and narrower tube as ordinarily used in burners having primary air mixing tubes. Furthermore, by deecting and not impeding the flow of gas after it once leaves the oriice 22 it is possible to have the flame within or outside the mixing tube by merely changing the gas pressure.

The deflector plate supporting rings 24 are set loosely in the mixing tubes so that the fan shaped flame from each burner may be pointed in any direction desired from each burner by turning the deector plate. In this way, the ames may be directed to concentrate the heat at a point above the center of the burner or spread them out over an area considerably greater than that covered by the burner itself.

Furthermore, it is to be understood that the particular forms of apparatus shown and described, and the particular procedure set forth, are presented for purposes of explanation and illustration and that Various modifications of said apparatus and procedure can be made without departing from my invention as deiined in the appended claims.

What I regard as my invention and desire to claim, is:

1. A gas burner for heating purposes adapted to produce complete combustion uniformly with various kinds of gases under varying or iiuctuating gas pressures comprising gas distributing conduits, a flared mixing tube secured at the outlet end of each of said conduits, lateral air inlet openings and a central gas orifice in said mixing tube the size of said orifice and the diameter of said mixing tube being so proportioned with respect to each other that a gas flame may be maintained wholly within said mixing tube without impinging or contacting with the walls of said mixing tube, and a deiiector plate positioned above the burner body to spread a sheet of gas obliquely to the stream from said gas oriiice.

2. A valve comprising, a valve housing having inlet and outlet openings, a valve seat formed therein, a valve stem having a centrally arranged passage adapted to provide communication between the inlet and outlet sides of said valve housing, a valve head slidably mounted upon said valve stem adapted to cooperate with said Valve seat and said centrally arranged passage to completely or partially cut off communication between the inlet and outlet sides of the valve, resilient means to secure said valve head on said valve stem and thermally controlled means to operate the valve head.

LORAN F. DOEN.

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