US 3247886 A
Description (OCR text may contain errors)
April 26, 1966 K. G. MITCHELL PILOT LIGHT IGNITER Filed May z5. 1962 MIN United States Patent O 3,247,886 lPlLQT LlGHT lGNlTER Kenneth G. Mitchell, @lrlahoma City, Okla., assignor to Black, Sivalls dz Bryson, Inc., Kansas City, Mo., a corporation of Delaware Filed May 25, 1962, Ser. No. 197,636 3 Claims. (Cl. 158-125) The present invention relates generally to a burner pilot light igniter. More specifically, the present invention relates to a pneumatically controlled device and system for the ignition, monitoring and re-ignition of a burner pilot light.
Prior to the present invention, most ignition systems for burners have been electrical. In many applications in the petroleum industry this has been a distinct disadvantage. Often burner applications in the petroleum industry are in remote locations where electricity is either not available or is not dependable. vIn such locations, however, gas such as methane gas is readily available. This gas is now used at such locations both as a fuel and as a medium for pneumatic controls, An ignition system for a burner should be reliable and have provision for automatically restarting the pilot light if it is accidentally extinguished. The ideal ignition system should also provide a time delay after sensing that the pilot light is out during which all fuel to the burner and to the pilot light is shut off to allow purging of the combustion chamber. Therefore, it is the primary object of the present invention to provide a pneumatic device and a pneumatic system igniting a pilot light of a burner. Another object of the present invention is to provide a pneumatic device and system for igniting a burner pilot light having a delay prior to ignition or re-ignition during which the pilot gas supply and the main burner fuel are shut off to avoid ignition of gases which may have collected in the combustion chamber. A further object of the present invention is to provide a pneumatic ignition and control system for a burner which will shut off the main fuel supplying the burner when the pilot light is extinguished and will initiate the restarting of the pilot light and when it is burning will open the main fuel valve to the burner.
These and other objects of the present invention will be readily apparent from the following specification and drawing wherein FIGURE l is a diagrammatic representation of the components of the system of the present invention, and FIGURE'Z is an enlarged cross-sectional view of the bleed type check valve 16 of FIGURE l.
With reference to the drawing, gas supply line 1 extends through valve 2 which is pneumatically actuated and valve 3 into pilot light device 4. Valve 3 i-s provided to maintain a pressure in gas supply line 1. Thermopile 5 is positioned adjacent the combustion end of pilot light device 4 to sense the temperature of the pilot light within pilot light device 4. Line 6 connects from gas supply line 1 ahead of valve 2 through valve 7 into pneumatic motor 8. Valve 7 is pneumatically actuated. Line 9 extends from gas supply line 1 ahead of valve 2 to solenoid valve 1lb. Branch 11 of line 9 connects into the lower chamber of diaphragm actuator 12 -of valve 2. Solenoid valve 10 is connected to thermopile 5 and is a three-way valve with one port connected to line 9, one port connected to line 13 and the other port connected to exhaust. When thermopile 5 is cold, the valve 1t) will be positioned to connect device 23 which will be positioned in relatively close upper diaphragm chamber of diaphragm actuator 12. Branch 15 of line'13 connects through bleed type check valve 16 into tank 17 Check valve 16 is set for restricted flow toward tank 17 and to allow full flow back from tank 17. Tank 17 is connected through line 18 to diaphragm actuator 19 of valve 7. Branch 20 of line 13 rice connects to the main burner fuel shut-off valve (not shown). Diaphragm actuator 12 of valve 2 is spring loaded to close valve 2. Diaphragm actuator 19 is spring loaded to close valve 7.
Pneumatic motor 8 is mechanically connected to transducer 21 which is designed to supply an electrical potential resulting from mechanical movement or bearing pressure. Piezoelectric crystal devices of this type are readily available which will produce a high voltage potential as a result of an imposed force of as little as 40 pounds. Wire 22 connects from transducer 21 to spark device 23 which will be positioned in relatively close proximity with the combustion end of pilot light device 4.
.Wire 24 connects from thermopile 5 to solenoid 25 of solenoid valve 11i.
lt should be noted that valves 2 and 7 are positioned with relation to each other in the manner shown in the drawing. Bot-h valves 2 and 7 are provided with a finger, 26 and 27 respectively, extending from their bodies. Finger 26 is connected to valve 2 and finger 27 is an extension of the valve stem of valve 7. With valves 2 and 7 positioned as shown, when valve 7 is actuated, nger 27 will extend, engaging finger 26 and causing valve 2 to be opened. Thus valve 2 will be held in this open position as long as valve 7 remains in the position with its nger 27 extended. Valve 28 in gas supply line 1 is provided to shut off the pilot light system of the present invention.
In operation, the -system of the present invention will keep the pilot light ignited at all times and if the pilot light should become extinguished it will be re-ignited only after a time delay to allow the purging of fuel from the combustion chamber. Assuming that it is desired that the pilot light device be lighted and that it is not lit, valve 28 will open and thermopile 5 will be cold causing Isolenoid 25 to be de-energized so that solenoid valve 10 will be positioned connecting line 9 with line 13. Since branch 11 is connected into the lower chamber below the diaphragm in diaphragm actuator 12 of valve 2, the pressure of the supply gas in gas supply line 1 will be exerted in this chamber at all times when valve 28 is open. With `solenoid valve 10 connecting line 9 to line 13, the upper chamber of diaphragm actuator 12 will also be exposed to the supply gas pressure through branch 14. With the same pressure being exerted on both sides of the diaphragm of diaphragm actuator 12, the :spring will close valve 2 shutting off the flow of gas through gas supply line 1 to pilot light device 4. The supply gas pressure will also be exerted through branch 20 to close the valve vin the main gas line to the burner thereby shutting olf the burner. Also, this supply gas pressure is delivered through branch 1S and check valve 16 into tank 17. Check valve 16 and tank 17 are selected to provide the desired time delay in the actuation of valve 7 after solenoid valve 10 is actuated. This time delay should be sufficient to allow complete purging of all of the fuel from the combustion chamber to avoid any explosions when igniting the pilot light.
When suicient pressure builds up in tank 17 and line 18, diaphragm actuator 19 will be actuated to open valve 7. With valve 7 open, supply gas from gas supply line 1 will tlow through line 6 and valve 7 into pneumatic motor 8. Pneumatic motor 8 is connected mechanically to transducer 21 which when actuated by motor 8 will emit a pulsating, high potential electric current which is carried to spark device 23 by wire 24.
The actuation of valve 7 will cause linger 27 to be extended into contact with finger 26 of valve 2. Diaphragm actuator 19 of valve 7 has sullicient diaphragm area that when it is exposed to supply gas pressure it will overcome the spring force of its own spring and also will overcome the force closing valve 2. Thus, the actuation of valve 7 into the open position will also open valve 2 allowing supply gas to flow through gas supply line 1 and valve 3 to pilot light device 4.
With gas flowing to pilot light device 4 and with spark device 23 putting out ignition sparks, the pilot light wll commence burning. When the pilot klight burning has been consistent, thermopile 5 will sense the burning and will energize solenoid 25 of solenoid valve 10 to reverse its position connecting line 13 to the exhaust port. This position of solenoid valve will exhaust the supply gas from branch 20 opening the main burner valve from the upper chamber of diaphragm actuator 12 through branch 14 opening valve 2; and from the chamber of diaphragm actuator 19 through line 18, tank 17, check valve 16 and branch closing valve 7. With valve 7 closed, motor 8 will stop and no further sparks will be given off by spark device 23. Valve 2 will remain open to supply gas to pilot light device 4 as long as it continues to burn. Solenoid valve 10 will remain in the position connecting line 13 to the exhaust port as long as thermopile 5 continues to sense that the pilot light is burning.
From the foregoing, it has been shown that the present invention provides a reliable ignition system which does not require a source of electrical current external of the system, which will provide a purging time prior to any re-ignition and which will also provide a continued series of sparks during ignition even after combustion has commenced in the pilot light device until combustion of the pilot light is sensed by the thermopile.
What 1 claim and desire to secure by Letters Patent 1. An automatic burner pilot light ignition system comprising,
a pilot light device,
vfirst valve means for supply fuel to said pilot light device,
means sensing combustion of fuel in said pilot light device and connected to and holding open said first valve means when said pilot light device is burning,
a gas motor,
spark creating means connected to and actuated by said motor and positioned adjacent the pilot light device for providing -a spark to ignite said pilot light device,
second valve means lfor supplying fuel to said motor, means interconnecting said -second valve means with said rst valve means for opening the first valve means upon opening of the second valve means,
a pneumatic time delay means connected to and actuating said second valve means after a time delay sufficient to allow purging of the fuel, and
said pneumatic time delay means connected to and actuated by said means sensing combustion of fuel when the pilot light device is unlit thereby automatically lighting said pilot light device by actuating said second valve means.
2. An automatic pneumatic burner pilot light ignition system comprising,
a pilot light device,
rst valve means for supplying fuel to said pilot light device,
thermopile means positioned adjacent the pilot light device for sensing the burning of fuel in said pilot 4 light device, said thermopile means actuating said first Valve means when the pilot light device is burning fuel,
pneumatic spark creating means positioned to provide a spark adjacent the pilot light device when actuated,
second valve means for suplying fuel to said pneumatic spark creating device when open, means interconnecting said second valve means with said first valve means for opening the first valve means upon opening of the second valve means,
a pneumatic time delay means connected to and actuating said second valve means'after a time delay sufficient to allow purging of the fuel,
said pneumatic time delay means opening said second valve means providingl fuel and a spark when the pilot light device is unlit but deactuating said second valve when the pilot light device is lit.
3. A pneumatic automatically actuated burner pilot light ignition system comprising,
a pilot light device,
first valve means for supplying fuel to said pilot light device,
a thermopile sensing the combustion of fuel positioned adjacent said pilot light device,
a solenoid valve connected to the thermopile and actuated thereby, said solenoid valve connected to said first valve means and causing the holding open of said first valve means when the thermopile senses combustion of fuel in said pilot light device,v
pneumatically actuated spark creating means positioned to provide a spark adjacent the pilot light device when actuated,
second valve means for supplying fuel to said spark creating means, means interconnecting said second valve means with said first valve means for opening the first valve means upon opening of the second valve means,
a pneumatic time delay means connected to and actuating said second valve means after a time delay sufficient to allow purging of the fuel,
said pneumatic time delay means connected to and actuated by the solenoid valve when the pilot light is unlit to automatically light said pilot light device by actuating said second valve means thereby providing fuel and a spark to said pilot light device.
References Cited by the Examiner UNITED STATES PATENTS 2,041,014 5/1936 Norton 158-28 2,125,473 8/1938 Vaughan 158-28 2,305,242 12/1942 English 158-125 X 2,346,704 4/ 1944 Ray 158-126 2,362,247 11/1944 Converse 158-125 2,707,518 5/1955 Ray 158-136 2,717,916 9/1955 Harkness 123-148 3,172,456 3/1965 Glasgow et al. 158-125 JAMES W. WESTHAVER, Primary Examiner.
FREDERICK L. MATTESON, IR., Examiner.
M. L. BATES, Assistant Examiner.