US2300146A

US2300146A - Gas burner control

Info

Publication number: US2300146A
Authority: US
Publication date: 1942-10-27
Anticipated expiration: 1959-10-27

Description

Patented Oct. 27, 1942 s PATENT OFFICE ass BURNER common Edward 3. Done, Shaker Heights, Ohio, assignor to The Bryant Heater Company, Cleveland,

Ohio, a corporation of Ohio Application July 2, 1940, Serial No. 343,611

Claim. (Cl- 158- 117.1)

This invention relates to improvements in gas burner controls, and to do primarily with a methodand means'for providing automatic burner ignition] wherein one pilot maintains an 18- niting flame during or! periods of the burner only; while a second pilot operating during the on periods of the burner only performs the usual functions of a safety pilot and serves also to reignite the flrst' pilot at the conclusion of an on period.

I The two pilots therefore operate alternately and never simultaneously except for a slight overlap sumcient to pass igniting flame from oneto the other.

One oi the objects of the invention is the provision of a system providing flame'lgnition wherein the lighting pilot is extinguished during the on periods of the burner, this feature being especially important in lighters for small capacity or broiler burners whereby the eflective burner pattern may be aflected to a minimum extent by the lighting apparatus.

Another object is the elimination of waste, the lighting pilot flame being of little value during the operation of the burner.

Other objects and features of novelty will appear as I proceed with the description of that embodiment of the invention which, for the purposes of the present application, I have illustrated in the accompanying drawing, in which Figs. 1 and 2 are diagrammatic illustrations of a burner control embodying the invention, Fig. 1 showing the same in the burner on position, and Fig. 2 in the burner of! position.

In the drawing Ill represents a gas burner of conventional character fed by a gas line H in which there may be a shut-of! valve l2, ordinarily maintained in the open position. A diaphragm valve I3 is interposed in the line between the valve i2 and the burner, this valve comprising a diaphragm ll forming one side of a pressure chamber i5. When there is line pressure in the chamber the valve is closed, as in Fig. 2, because the area exposed to line pressure on the upper side of the diaphragm is greater than that on the lower side. On the other hand when the pressure above the diaphragm is atmospheric line pressure below the diaphragm raises it and opens the valve, this being a conventional construction.

it is a conductor which is continuously in communication with line H so long as the valve i 2 remains'open. I1 is a conductor which is continuously in communication with .pressure chamber l5. Conductor I1 is in constant communication with a branch ll leading to a lighting pilot 20' leads to a control pilot 2|. Pilots i9 and 2| are close enough together to enable either one to be ignited by a flame from the other, while pilot 2| at least is mounted in igniting relation withmain burner l0. Between

conductors

20 and 20 there is a valve of any desired character for controlling the flow of gas to pilot 2|. In some cases, as in that herein illustrated, this valve maybe an electric valve 22 which may be operated thermostatically, as where the burner is a furnace burner controlled from the premises to be heated. In other cases the valve 22 may be a manual valve, as forexample in the case 01' an oven or broiler burner.

On a bracket 23 in which the pilot 2! is sup- Ported there is mounted one leg of a thermal element 2| of horseshoe shape, disclosed and claimed in Hahn Patent 2,064,909, which is so disposed as to be heated by flames emerging from holes 25 in the lower portion of the pilot 2|. The expansion of element 24 when heated causes the free leg thereof to press against a longitudinally slidable rod 28 that acts upon a ball valve 21 working against a spring 28 that tends to hold the valve away from its seat 29 which is located at the end of a conductor 30 that is in communication with a conductor it. When valve 2.! is open conductor 30 is in free communication through a passage 3i with conductor l8 and thence with conductor ll, as well as with lighting pilot l9.

Diaphragm I4 is held down against its seat during oil. periods of the burner by line pressure in chamber l5, supplied through conductors I6 and 30, open valve 21, passage II and conductors l8 and".

19. From conductor ii to branch conductor 20,

Means may be provided additionally for supplying pressure to chamber II to close the diaphragm valve in the event that some condition in the system calls for the closing of the valve as a safety measure. As illustrative of means for effecting this result I have shown a normally closed valve 32 which, when opened, provides communication between conductors I6 and I! and thus supplies the necessary gas pressure to chamber i5 for closing the diaphragm valve. The valve 32 may be opened when steam pressure in a steam heating system reaches a predetermined height, when the temperature in a flue reaches a predetermined height, when the temperature of water in a hot water system reaches a predetermined height, etc. When the valve 32 is open the diaphragm valve cannot open, or if it is already open it will thenimmediately close. Safety devices of this nature are well known in the art.

Fig. 2 of the drawing shows the apparatus in the normal or oiI condition. Pressure is built up in pressure chamber I5 by gas flowing through conductors l6 and 30 and open valve 21 into conductors l8 and I1. Valve 21 also admits gas .to the lighting pilot l9, which is burning. Now if valve 22 is opened flow of gas to control pilot 2| is initiated. This pilot is then ignited from pilot [9 and the flame travels down pilot 2| tothe holes 25, the flame from which plays upon the horseshoe 24 and causes it to expand. This expansion moves rod 26 longitudinally to close valve burner, a lighting pilot and a control pilot ar- 21 against its seat 29, after which the pressure in chamber l5 and in the conductors I1 and I8 dissipates itself through the lighting pilot l9.

ranged in interigniting relation, a valve for the main burner, means enabling pressure in the gas line to close said valve, said means also providing flow of gas to said lighting pilot, valve controlled means for feeding gas to said control pilot, and

, means responsive to the flame from. said control Diaphragm valve I 3 therefore opens and gas flows to the burner which is ignited by the flame from pilot 2 I.

When after a period of burner operation the valve 22 is closed, cutting off gas to the pilot 2|, thermal element 24 contracts and permits spring .28 to open valve 21, which lets gas into the conductors l8 and I1 and thence into the chamber 15, resulting in the closing of the diaphragm valve l3. Pilot I9 is then relighted by the lime from the residual gas in pilot 2| and conductor after which the latter pilot goes out.

Having thus described my invention, I claim:

1. In apparatus of the class described, a gas supply, a main burner, a main valve adapted to be closed by gas pressure, a lighting pilot and a control pilot arranged in interigniting relation and in igniting relation with the main burner, means for maintaining gas fiow to said lighting pilot during off periods of the main burner, means for feeding gas to the control pilot at the beginning of an ignition cycle, and means responsive to the control pilot for relieving the pressure on said main valve and cutting of! gas to the lighting pilot, whereby-the main burner goes on and the lighting pilot goes off after the control pilot is lighted.

2. .In apparatus ofthe classv described, a main burner, a lighting pilot and a control pilot arrangedin interigniting relation and in igniting relation with the main burner, means for maintaining gas flow to said lighting pilot during the off periods of the main burner, means for feeding gas to the control pilot at the beginning of an ignition cycle, and means responsive to the control pilot for admitting gas to the main burner filled with gas under line pressure to hold the pilot for relieving the pressure at said valve to open the same and for cutting off the supply of gas to said lighting pilot.

4. In a gas'burner control system, a main burner, a valve therefor, a lighting pilot and a control pilot arranged in interigniting relation, said control pilot beingarranged in igniting relation with said main burner, said main burner valve having a pressure chamber adapted when valve closed,-said pressure chamber being normally in communication with the gas line and with the said lighting pilot, means for feeding gas from the line to said control pilot, a valve for said last na'med means, and means responsive to the flame from said control pilot for exhausting gas from said pressure chamber and said lighting pilot.

5. In mechanism of the character described, a main burner," a pressure i'ctuated main valve, a lighting pilot,*a control pilot, means functioning during'th'e oft periods of the main burner to supply gas to the lighting pilot, means for causing gas to flow to the control pilot at the beginning of a lighting cycle, thermal means functioning in response to the operation of the control pilot to relieve pressure on the main valve for opening the same and at the same time to interrupt the flow of gas to the lighting pilot, whereupon the main burner goes on and the lighting-pilot goes off, said thermal means functioning when the supply of gas to the control pilot is. interrupted to again admit gas to the lighting pilot and to applygas pressure to close the main valve.

EDWARD R. DOWNE.