US3191661A - Electric ignition gas control system - Google Patents

Description

June 29, 1965 w. A. RAY 3,191,661

ELECTRIC IGNITION GAS CONTROL SYSTEM Filed April 11, 1963 2 Sheets-Sheet 1 INVENTOR. WILUAM A. RAY

ATTORNEYS.

June 29, 1965 w. A. RAY 3,191,661

ELECTRIC IGNITION GAS CONTROL SYSTEM Filed April 11, 1963 I Q 2 Sheets-Sheet 2- mic IZZB ran BI |2s no 1324 v FIC: 3. i l

1&5 $5? $3 INVENTOR. WILLIAM A. BAY

ATTORNEYS.

United States Patent ELEQTRIC IGNITION GAS CONTROL SYSTEM Wiiiiam A. Ray, North Hollywood, Calif., assignor, by

mesne assignments, to International Telephone and Telegraph Corporation, New York, N.Y., a corporation of Maryland Fiied Apr. 11, 1%3, Ser. No. 272,405

9 Claims. (Cl. 158-125) The present invention relates to gas control systems in which electrical ignition of gas is accomplished and to control apparatus useful in such systems.

Briefly, the system described herein, as exemplary of the present invention, involves a main burner, a pilot burner for igniting the main burner and electric igniting means for igniting gas flowing from the pilot burner to produce a pilot flame for ignition of the gas from said main burner, means being provided as exemplified in part by a thermocouple heatable by the pilot flame for assuring the presence of the pilot flame prior to escape of gas to the main burner. The system is interlocked both electrically and mechanically to assure this operation.

It is therefore a general object of the present invention to provide a system of this character as well as control apparatus useful therein.

A specific object of the present invention is to provide a system of this character in which a gas-burning system incorporating a pilot burner and a main burner may be set in operation by operation of a switch such that pilot gas is allowed to flow simultaneously with the production of an electric igniting spark to produce a pilot flame, after which, with some time :delay, gas is allowed to flow to the main burner for ignition by the pilot flame, this operation being accomplished by means which are interlocked so as to achieve safe operation.

Another specific object of the present invention is to provide a system of this character wherein the igniting spark and the flow of pilot burner gas are always accomplished substantially simultaneously, the system functioning to safely shut down in the event of failure of the ignition current source.

Another specific object of the present invention is to provide a system of this character which is entirely automatic in its operation Without the necessity of special programming equipment such as, for example, timing devices, electric switches and the like.

Another specific object of the present invention is to provide a system of this character which is simple, reliable and relatively inexpensive considering the functions it performs safely.

Another specific object of the present invention is to provide a system of this character which incorporates a pilot burner and means associated with the pilot burner for sensing the presence of a flame in the pilot burner and which does not require a special manual resetting operation to place the system in operation after, for example, a failure in the power source or in the gas supply source. 1

Another specific object of the present invention is to provide a system of this character in which proper and safe sequencing of events is accomplished in lighting a pilot burner, followed by a subsequent ignition of gas from a main burner by the pilot burner, such sequence of operations being accomplished by operation of an electric switch.

Another specific object of the present invention is to provide a system of this character featured by a unique interlocking of the gas control and ignition means.

Another specific object of the present invention is to provide a system of this character such that a restoration of the gas supply, assuming a previous interruption of "ice such supply, results automatically in a safe ignition of main burner gas.

Another specific object of the present invention is to provide a system of this character in which safe operation occurs under those conditions wherein there may be periodic failures in the electrical supply source.

Another specific object of the present invention is to provide control apparatus involving the use of two pilot valves for controlling the flow of gas to a pilot burner and a main burner, with the operation of one of such pilot valves being dependent upon the existence of a gas-igniting spark and the operation of the other pilot valve being dependent upon the presence of a suitable pilot flame.

Another specific object of the present invention is to provide a system of this character featured by both gas and electric interlocking for assuring proper and safe sequence of operations in the process of initially lighting a pilot burner and subsequently igniting gas from a main burner by the pilot flame.

Another specific object of the present invention is to provide an improved gas control system using electric ignition.

Another specific object of the present invention is to provide a system of this character involving two pilot valves, both of which are required to be operated in order for gas to flow to a burner such that failure in either one of the two pilot valves prevents escape of gas to the main burner.

Another specific object of the present invention is to provide a system of this character that allows manual override should there be a failure in that power source which normally is used to obtain electric ignition.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. This invention itself, both as to its organization and manner of operation, together with further objects and advantages thereof, may be best understood by reference to the following description taken in connection with the accompanying drawings in which:

FIGURE 1 illustrates a system embodying features of the present invention.

FIGURE 2 is generally a cross-sectional view through a modified control device for use in the system shown in FIGURE 1.

FIGURES 3 and 4 show another modified control device for use in the system shown in FIGURE 1, FIGURE 3 being generally a sectional view and FIGURE 4 being generally a sectional view taken in the direction indicated by the lines 4-4 in FIGURE 3.

In FIGURE 1, a gas supply is connected to the inlet 10 to a valve casing 12 having a movable diaphragm valve element 14 cooperating with an annular stationary valve port 16 for controlling gas fiow to the outlet 18 in communication with main burner 20. The valve 14, 16 in its normally closed position as shown defines an inlet chamber 15 and an outlet chamber 17 in casing 12.

The inlet chamber 15 is in communication with one end of a passageway 22 formed in the walls of casing 12, such passageway 22 being in communication with stationary ports 24 and 26 of three-way electrically operated valves 28 and 30, respectively, and also in communication with a metering orifice 32.

The valve 28 is disposed within a casing chamber 34 which is defined by the circular chamber wall 36, the upper side of diaphragm valve element 14 and partition 38 having an opening 49 therein communicated with the other stationary valve port 42 of valve 28 via passageway 44.

The valve 30 is disposed within a pilot valve chamber 46 which is defined by partition 38, the chamber Wall 36 and the top wall 48, the wall 36 being formed with a threaded opening which is in communication with the other stationary valve port 52 of valve 39 via passageway 54. This threaded opening 59 receives one end of a pilot burner condui having its other end in communication with pilot burner 53 mounted in close proximity to main burner 20 for ignition of gas escaping from main burner 20.

An electric igniter 6t), in the nature of a spark plug, is mounted in close proximity to the pilot burner 58 for igniting gas escaping therefrom and suchigniter is con- 'nected to a high tension shielded line or cable having its outer metal shield connected to one terminal of igniter so and also to the 'metal mounting for the pilot burner 53 which is at ground potential. The cable 62 has an inner conductor and an inner stabilizing resistance 64connected to one terminal of such conductor, the other terminal of resistance 64 being connected to the high potential electrode of igniter 60, such conductor being also connected to one terminal of a high voltage coil on wound on a ferrite core 68, the other terminal oi coil as being grounded.

A thermocouple 7 it is mounted'in close proximity to the pilot burner '58 for sensing the presence of the pilot flame at burner 53 and has one of its terminals grounded and the other one of its terminals connected to a terminal of the valve coil 72 wound on its U-shaped core 74, the other terminal'of coil '72 being grounded. An armature 76, which is also a valve member, is pivoted on one leg of the yoke or core 7 and is normally urged into engagement orifice 32, chamber 46, port 52, line 56 to the pilot burner 53. Some delay is now encountered in further operation occasioned by the requirement that the thermocouple 7i) requires some time for heating by the now present pilot flame in order for it to develop current to sufiiciently energize coil 2'2. Whenthis requirement is met, the valve 23 is operated by the current flowing in coil 72 such that the armature 7s closes port 24 and opens port 42. The closing of port 2 interrupts the previously described pressure communication from inlet chamber to chamber 34 and since chamber 34 is now vented to chamber as through port 42, the inlet pressure acting on the underside of diaphragm 14 causes the valve 1 16 to open slowly, with the gas displaced in resulting upward movement of the diaphragm exhausting through port 42 to chamber 46 which is now in communication with the pilot burner 53 through now open port 52. Chamber 46 at this time is not under full inlet pressure since there is a pressure drop across the metering orifice 32 which is of such size as to provide a controlled slow opening of the main valve 14, to. This metering orifice may either be fixed or be manually adjustable. The pilot burner is preferably either of with valve port 42 to close it by a compression spring 78.

The other valve in upper chamber 46 is actuable using :a construction like thatdescribed above and for this purpose there is provided a U-shaped core or yoke 86 with coil 82 wound thereon. An armature 84, which is also.

7 switch 96.

(Erie output terminal 9% of rectifier 94 is connected to the collector electrode of transistor Mil through a series circuit which includes coil 82 and coil 162, in that order, coil 162 being wound on coil 66. The base electrode of transistor 1% is connected to one terminal of coil 1%, wound on coil 162, the other terminal of coil lil ibeing connected not only to the other output terminal was of rectifier 74 but also to one terminal of capacitor 1&3 having its other terminal connected to the junction point of coils 82 and M2. is connected to the output terminal through resistance 11% which may have a value of 3 ohms. Capacitor 1318 may have a value of 25 microt'arads.

I The operation of the arrangement shown in FIGURE 1 The emitter electrode of the transistor is essentially as follows. Assuming the normal conditions shown therein, no gas flows to the main burner 2i since its control valve 14-, 16 is closed by the inlet gas pressure communicated to the topside of diaphragm '14 through passageway 22 and open port 24 to chamber 34, supplemented to a degree by the coil compression spring 19 act ing to close the valve 14, 16; and no gas flows to'the pilot burner 58 since valve 5'2, 84 is closed by spring as. The system is placed in operation by closure of switch 96 which causes the oscillator including transistor 1% to oscillate to produce a high frequency ignition spark at igniter es With unidirectional current flowing through coil 32 for operating the valve 3% i.e. to move the armature member '84- in engagement with valve port as to close it and open valve port 52. Under this condition gas flows to the pilot burner 58, for ignition by the now present spark, through the following path: from inlet chamber 15 which is still closed by diaphragm 14, through passageway 22, metering the nonaerated or low-pressure inspirated type. The gas now escaping from the main burner 20 is ignited by the pilot flame.

A continued closure of switch 96 keeps the pilot burner ON, continues to develop the spark at igniter tland continues to keep the main burner ON.

Upon subsequent failure of the power source 88 or opening of switch 96, the system shuts down. The ignition spark is no longer developed and coil 82 is de-ener gized to open port 26 and close port 52 to thereby allow the chamber 46 to assume the same pressure as the inlet pressure. The pressure in chamber 46 is communicated to chamber 34 through the now open port 4-2 to pressurize the topside of diaphragm ld'to close the main valve l4, 16. However, the closure of main valve 14, 16 is not dependent on the position of valve 28 since in one of its positions (port 42 open) it is closed by inlet pressure being applied through port 42 and in the other one of its positions (port 24- open) it is closed by inlet pressure being applied through port 24.

Also, it should be noted that upon failure of the thermocouple, the coil 72 is not energized or is energized insulticiently, in which case the spring 78 moves the armaturevalve member '76 to close port 42 and to open port 24 so that the gas inlet pressure then introduced through the open port 24 causes the mainvalve 14, 16 to close. 7 Should the gas supply be interrupted during normal operation of the system, the spring 17 is sufiicient in strength to close valve l4, l6, the-thermocouple is no longer heated and the valve port 42 is closed by'armature 76.

i It will be seen that in order to obtain gas flow to the main burner, both pilot valves 23 and 36 must be in their operated ON conditions, i.e. conditions corresponding to energization of their respective coils 72 and 82; and when either pilot valve is OFF, the main valve 14, 16 is either prevented from opening or, it previously opened, the valve 14, 16 will be closed.

Should the thermocouple it? fail to generate or pilot flame fail to ignite, electrical ignition continues as long as the switch .96 is closed and a limited but safe amount of gas flows to the pilot burner such that subsequent ignition of such pilot gas flow, limited by the metering orifice 32 is accomplished quietly and without explosion or hazard.

The system is adaptable for manual override when there is a power failure. In such case manually operable means may extend through the casing 36 for operating and releasably maintaining the armature 84 to its ON position wherein the armature 84 closes port 26. When the port 26' is thus closed and port 52 is opened, the operator may use a match to light the gas flowing from the pilot burner. The pilot flame then heats the thermocouple 7i toienergize coil '72 and to cause the main valve l4, l6

'63 to open. To avoid an overheated condition, normally closed safety limit switches responsive to such overheat condition may be connected in series with coil 72 and thermocouple 70.

By constructing the diaphragm valve 14, 16 such that there is some movement of the diaphragm before the main valve is opened, i.e. by incorporating some play between the diaphragm and the main valve, a time delay action is obtained which has the effect of extending thermoelectric generator response time on very short cycle operation.

If desired, the passageway 44 may be suitably orificed such that venting of the chamber 34 into chamber 46 during upward movement of the diaphragm does not produce too rapid enlargement of the pilot burner flame while at the sametim'e controlling the opening movement of the main valve 14, 16. For substantially the same results, the pilot burner line 56 may be suitably orificed.

The oscillator for producing the spark may operate in the audio frequency range and at frequencies as high as 20 kilocycles using a spark gap of to FIGURE 2 illustrates a control device which may be substituted for the one shown in FIGURE 1 and includes a chamber for a filter through which the gas to the pilot burner flows. Corresponding elements in FIGURES l and 2 have the same reference numerals for ease of comparison.

It will be seen that a general function of the metering orifice 32 in FIGURE 1 is now accomplished by the adjustable valve means 132 in FIGURE 2. The pilot gas now flows, in turn, from inlet chamber 15, passageway 122, filter chamber 122A, adjustable orifice 122B, fixed orifice 122C, port 52, when open, which is in communication with the pilot burner line connection. Also, the housing is provided with a chamber 136 and removable cover 131 for housing electrical components such as the full-wave bridge rectifier 94 as illustrated in the succeeding figures. Also in FIGURE 2 there is provided an adjustable valve element 150 in the passageway 151 which communicates port 42 with chamber 46 for achievinga controlled opening of valve'14, 16 and/or for preventing a large enlargement of the pilot gas flame, as described above, when the gas in chamber 34 is exhausted into the pilot burner line.

FIGURES 3 and 4 illustrate more constructional de tails of a contemplated commercial construction having the additional features of FIGURE 2 and show the rectifier 94 mounted in chamber 130 connected to terminals 160 on a terminal mounting plate 129 on cover 131, the cover being sealed by gasket 165 and mounting the pilot gas fiow control 132. Upon removal of the cover, occasioned by removing a' series of fastening bolts 170, access is had to the filter chamber 122A, rectifier chamber 130,

adjustable valve means 150 corresponding to the valve means 150 of FIGURE 2, and adjustable valve means 26A in the passageway 22 (FIGURE 2) leading to port 26 and pilot valve 30. Access may be had to the pilot valve 28 by disassembling the casing parts 170 and 171 between which the marginal edge of diaphragm 14 is clamped by fastening screws (not shown) joining these two casing parts.

The chamber 139 may be filled with a potting compound having good heat transfer properties for conducting heat from the rectifier to the surrounding metal casing.

While the particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

I claim:

1. In a fuel control system of the character described, a pilot burner, first means for igniting gas issuing from said pilot burner to produce a pilot flame, a main burner 6 having gas therefrom ignited by said pilot flame, second means sensing the presence of a pilot flame, third means for controlling the flow of gas to said pilot burner, fourth means for controlling the fiow of gas to said main burner, fifth common means jointly controlling said gas-igniting means and said pilot burner gas flow control means, and sixth means controlling said main burner gas flow control means in response to the condition of said pilot flame sensing means, said third means including a solenoid valve having an operating coil, said first means including an oscillator for producing an oscillatory discharge for ignition of gas from said pilot burner, and said fifth means including a voltage source and a switch, with said source and switch being connected in series with said coil and oscillator to supply current to said oscillator through said coil to maintain said third means effective to supply gas to said pilot flame.

2. In a control of the character described, a casing having an inlet chamber and a first opening connectable to a pilot burner and a second opening connectable' to a main burner, said casing having a first chamber and a second chamber, pressure-operated valve means defining a part of said inlet chamber and a part of said second chamber for controlling gas flow between said inlet chamber and said second opening, first pilot valve means for alternately communicating said first chamber either with said inlet chamber or said first opening, second pilot valve means for alternately communicating said second chamber either with said inlet chamber or to said first chamber.

3. A system including the control of claim 2 wherein there is provided a pilot burner connected to said first opening, a main burner connected to said second opening, gas ignition means for igniting gas from said pilot burner to produce a pilot flame used in ignition of gas from the main burner, common means for jointly operating said gas ignition means and said first pilot valve means, and means sensing the presence of the pilot flame and con trolling said second pilot valve means.

4. A control as set forth in claim 2 including a restricted metering orifice constantly communicating said inlet chamber with said first chamber.

5. A control as set forth in claim 2 in which said second pilot valve means communicates to said pilot burner through a path which includes said first chamber and said first opening.

6. A control as set forth in claim 2 in which said casing includes a pilot filter chamber having one end thereof in communication with said inlet chamber and the other end thereof in communication with said first chamber through a passageway having an adjustable. orifice.

7. A control as set forth in claim 6 including adjustable gas flow control means in a passageway extending from said second valve means to said first chamber.

3. In a fuel control system of the character described, a pilot burner, first means for igniting gas issuing from said pilot burner to produce a pilot flame, a main burner having gas therefrom ignited by said pilot flame, second means sensing the presence of a pilot flame, third means for controlling the flow of gas to said pilot burner, fourth means for controlling the flow of gas to said main burner, fifth common means jointly controlling said gas-igniting means and said pilot burner gas flow control means, and sixth means controlling said main burner gas flow control means in response to the condition of said pilot flame sensing means, a casing having a gas inlet chamber and a gas outlet connected to said main burner, pressure-responsive valve means controlling the flow of gas to said outlet, said casing having a first chamber and a second chamber, first electromagnetically operated valve means in said first chamber and having a first coil, second electromagnetically operated valve means in said second chamber and having a second coil, said first valve means being alternately effective to place said first chamber in communication either with said inlet or said pilot burner, said second valve means being alternately effective to place said sec- 0nd chamber in Communication either with said inlet or i said first chamber, said second chamber being defined in part by said pressure-responsive valve means, said gas inlet chamber being defined in part by said pressure-res onsive valve means whereby operation of said pressureresponsive valve means is controlled in accordance with pressure conditions in said inlet and second chambers, said first coil being controlled by said fifth common control means, and said second coil being energized by said second pilot'fiame sensing means.

9. In a gas control system of the character described, a pilot burner, gas ignition means for igniting gas from said pilot burner to produce a pilot flame, means sensing the presence of a pilot flame, a main burner, the gas from which is ignited by said pilot flame, means responsive to operation of said ignition means and controllng the flowof gas to said pilot burner, and means responsive to the condition of said sensing means and controlling the flow of gas to said main burner, a casing having a gas inlet chamber and a first and second chambers, said means controiling the flow of gas to said pilot burner including first pilot valve means in said first chamber for alternately communicating said first chamber to either said inlet chamber or .to said pilot burner, said inlet chamber and said second chamber each being defined in part by a pressure-responsive valve means controlling the now of gas second pilot valve means in said second chamber for alternately communicating said second chamber either with said inlet chamber or with said first chamber, said first pilot valve means being operated in response to operation of ignition means, said second pilot'valve means being operated in response tothe condition of said sensing means.

References Cited by the Examiner UNITED STATES PATENTS 2,268,959 1/42 Ray 158-131 2,406,185 8/46 Aubert 158-124 2,411,230 11/46 Ray 158-130 X 2,437,894 3/48 Ray 2 158-130 X 2,512,173 6/50 Ray 158-129 2,558,267 6/51 Ray 158-129 X 2,566,019 8/51 Dempsey 158-136 X 2,599,457 6/52 Jones 158-129 X 2,615,511 10/52 Ray 158-131 2,661,013 12/53 Eskin et al 158-130 X JAMES W. 'WESTHAVER, Primary Examiner. O MEYER PERLIN, Examiner.

Claims (1)

1. 2. IN A CONTROL OF THE CHARACTER DESCRIBED, A CASING HAVING AN INLET CHAMBER AND A FIRST OPENING CONNECTABLE TO A PILOT BURNER AND A SECOND OPENING CONNECTABLE TO A MAIN BURNER, SAID CASING HAVING A FIRST CHAMBER AND A SECOND CHAMBER, PRESSURE-OPERATED VALVE MEANS DEFINING A PART OF SAID INLET CHAMBER AND A PART OF SAID SECOND CHAMBER FOR CONTROLLING GAS FLOW BETWEEN SAID INLET CHAMBER AND SAID SECOND OPENING, FIRST PILOT VALVE MEANS FOR ALTERNATELY COMMUNICATING SAID FIRST CHAMBER EITHER WITH SAID INLET CHAMBER OR SAID FIRST OPENING, SECOND PILOT VALVE MEANS FOR ALTERNATELY COMMUNICATING SAID SECOND CHAMBER EITHER WITH SAID INLET CHAMBER OR TO SAID FIRST CHAMBER.

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