US2411230A

US2411230A - Burner control system

Info

Publication number: US2411230A
Application number: US574987A
Authority: US
Inventors: William A Ray
Original assignee: General Controls Co
Current assignee: General Controls Co
Priority date: 1945-01-29
Filing date: 1945-01-29
Publication date: 1946-11-19
Anticipated expiration: 1963-11-19

Description

NOV. 19, w A, RAY

BURNER CONTROL SYSTEM Filed Jan. 29, 1945 3nventor: 'WILL'IAM A. RAY,

(Itiorneg.

Patented .Nov. 19, 1946 UNITED STATES PATENT OFFICE BURNER CONTROL SYSTEM William A. Ray, Los Angeles, Call1'., assignor to General Controls 00., a corporation Application January 29, 1945, Serial No. 574,987

7 Claims.

My present invention relates to means ior controlling the operation of a fluid-fuel burner system of the type which includes a main burner, a pilot burner for the main burner, an electric igniter for the pilot burner, and an electrically operated valve for controlling supply of fuel to the main burner.

' flame, for effecting the delay referred to in the preceding objects.

Another object is to provide, for eifecting the delay, a motor, operated by the pressure of the fuel in the system, for actuating switching means controlling energizatlon of the igniting means and the main-burner valve; the motor being so constructed that its operation in alternate directions is relatively slow. p

Another object is to provide means responsive to the condition of the main-burner valv for controlling energlzation of the igniting means.

Other objects and advantages of the invention will be found inthe description, the drawing, and the claims; and, for full understanding of the invention, reference is to be had to the followin detailed description and accompanying drawing, the single figure of which is a view, mainly in end of the lower section 20 is closed by another flexible diaphragm 22 to form a pressure chamber 23 below the main diaphragm 2i; another pressure chamber 24, above the main diaphragm, being formed by the upper section ill, the aper tured top end of which is closed by a housing 25. While the valve I is open, the lower pressure chamber 23 is constantly subjected to the gas pressure through a horizontal inlet passage 26 in the section a flow-restricting or oriflce mmeber Zl being provided at the inner end of this passage. Controlling fluid pressure in the upper chamber 24 is a three-way pilot valve comprising a pair of jets 28 and 29 with which a movable blade-like closure 30' cooperates. The

jet 28 is fitted in a horizontal passage ill in the upper section it, which passage is in communicadiagram, of a gas-burner control system embody-=- ing the invention.

In the drawing, the numeral l l indicates a conduit through which gas from a source (not shown) is supplied to a main burner l2 under the control of an electromagnetically-operated main valve l3. Branching from conduit ll, ahead of the main valve i3, is a pipe it to the end of which is connected a pilot burner it for igniting the main burner. Controlling flow through pipe it is a. valve l5 comprising a manually-rotatable plug it having a passage l l.

Connected to pipe it at the outlet side of valve l5, by another pipe M, is a fluid-pressure-operated switch generally indicated at l8 and comprising a pair of

hollow casing sections

19 and 20 between. which is clamped at its margin a main flexible diaphragm 2i. The open bottom tion with the inlet passage 26 through aligned vertical passages .32 and 33 in sections l9 and 20, respectively. Cooperating with a reduced section of passage 3i is a sonically-pointed screw 34,

whereby the rate of flow of gas to the jet 28 can be adjusted. The jet 29 fits in another horizontal passage 35 which leads through a pipe 36, in series with a flow-restricting member 31, to the atmosphere; the pipe 36, in practice, being extended to a point adjacent the main burner it.

The pilot closure 30 is of magnetizable material and is fulcrumed on the lower arm of a U-shaped electromagnet core 38 mounted on the top surface of section i9; a compression spring 38 biasing the closure-armature 30 away from the upper arm of the core and into engagement with jet 29. Around the upper arm of core 38 is an energizing coil ill which is connected by wires 4!, sealingly and insulatingly extending through the top wall of housing 25, to a thermoelectric generating device generally indicated at 2 and comprising one or more thermocouples, contained within a shell 13, having hot Junctions adapted to be heated'by the flame 44 of pilot burner I 2'. Thermoelectric generating devices of the type commonly employed in gas-burner control systems may be so constructed that their heating and cooling (and the resultant growth and decay of generated current) are either relatively slow or fast. Examples of such thermoelectric generating devices are disclosed in the Ray Patent No. 2,340,899. In the device of Fig. 1 of that patent, the elements are relatively light and their hot junctions (enclosed in thin stainless steel protective sleeves) are exposed to the flame or to the atmosphere and therefore heat or cool rapidly; whereas as shown in Fig. 6, the elements are relativel massive, and are surrounded by insulating material and a relatively-thick meta1 jacket, so that they heat or cool slowly. To

efiect delay of operation of the system herein disclosed (in addition to such delay as may be produced by the operation of the fluid-pressure motor of switch l8) the thermoelectric generating device 42 may be so constructed that it heats .and cools relatively slowly.

Connected, by a link 45, to stiffening plates arranged on opposite sides of the main diais a switch member 45 rockably mounted on a pin 41 secured to a housing 48 which is attached to the lower section 2|) below diaphragm 22; the member 46 being in two sec tions joined together with diaphragm 22 there-,

' between. Carried by the switch member 45 is a contact arm 49 which cooperates with a pair of a of diaphragm 2| occurs and the position of switch arm 49 is unaltered; this arm being biased to its shown position mainly by the weight of the stiffening plates on opposite sides of main diaphragm 2|. The flow-restricting member 21 prevents the possibility of upward surge of the diaphragm 2| upon initial application of gas pressure. The pressure of the gas acting on the lower diaphragm 22 is ineffective to move the switch member 46 due to the pivotal arrangement of the same.

After a predetermined interval, determined by the specific construction of thermoelectric generating device 42, the same becomes heated to a degree such that electricity is thereby generated in-an amount suilicient to so energize the core 38 that the armature-closure 30 is attracted out contact blades 50 and 5| insulatingly mounted energization of two electrical circuits. With arm 49 in engagement with blade 5|, as shown, a first circuit is completed which, comprises the secondary 55 of a conventional A. C. service transformer 5B, the primary 51 of an ignition transformer 58, a thermal'cut-out 59, and'a switch 50 operated by the valve l3; the circuit being traced from the righbhand side of the transformer secondary 55 through wire 6|, switch arm 53, fixed contact 54, wire 62 and .fiexible extension 63,

switch arm 49, contact blade 5|, wire 64, primary 51 of ignition transformer 58, wire 55, thermal cut-out 59, wire 65, movable arm 61 and fixed contact 68 or switch 59, and wire 69 back to the other side of transformer secondary 55.

When, as will be described hereinafter, the switch arm 49 is moved into engagement with contact blade 5|], a second electrical circuit is completed which comprises a thermostat 10, the electrically-operated valve l3, transformer secondary 55 and switch 52this circuit being traced from contact blade 59, through wire 1|, thermostat 10, wire 12, energizing coil 13 of solenoid valve I3, and wire 69 back to the lefthand side of transformer secondary 55; the portionof the second circuit from the right-hand side of the I transformer secondary to contact arm 49 being common with that of the first circuit. The secondary 14 of the ignition transformer 53 is connected by wires 15 to a heating coil 16 for igniting gas at the pilot burner I2.

extinguishment of the pilot-burner were due to In describing the operation of the system it will be assumed that the main burner I2 is arranged to supply heat to aroom or space wherein the thermostat 10 is located. With the parts in the, positions shown in the drawing the system is out of operation, as during a period when no heating is required. To initiate operation of the system, the plug I6 of valve l5 is manually rotated to open position so that gas issues from the pilot burner. Since by the opening movement of valve l5 the switch 52 is closed, the "flrst or igniting circuit is completed as described above and, normally, after a brief interval the gas issuing from the pilot burner is ignited.

With the opening'otvalve IS the pressure of the gas is applied tdjpoth of the chambers 23 and 24 of the pressure-operated switch l8 (the pilot jet 28-being uncovered) so that no movement of engagement with jet 29 and into engagement with the other jet 28. When this occurs, the gas compressed in the upper chamber 24 is slowly vented to the atmosphere, through jet 29, restriction 31 and pipe 36;, the pressure in the lower chamber then being effective to raise the main diaphragm 2| and thereby rock the I contact arm 49 into'engagement with the upper blade 50. In this position of arm 49 the second circuit, including winding 13, is completed,

contact 68 so that the igniting circuit is additionally interrupted at this point. During existence of flame .at the pilot burner, the pressureoperated switch is maintained in its second" circuit-connecting position; the main-burner valve |3 then being opened and closed in accordance with the demand of thermostat 1|].

If the pilot-burner flame is extinguished accidentally, or by closing of manual valve i5, upon resultant cooling of the thermoelectric generating device the electromagnet core 38 is deenergized so that the armature-closure 30 is released and assumes the position shown in the drawing. Gas can then pass through the open jet 28 into chamber 24 and, since this chamber is now closed ,with respect to the atmosphere, the fluid pressure therein gradually becomes the same as that in chamber 23 below the main diaphragm so that that diaphragm falls under the force of gravity, and the switch arm 49 is brought into engagement with the lower contact blade 5| to reestablish the first electrical circuit. If the accidental causes, (other than .failure of gas or electric supply), the pilot burner would be immediately reignitedsince switch 52 is still in closed condition. It follows that after a temporary interruption of electrical service the burner system would automatically become operative.

Obviously, if extinguishment of the pilot burner were due to the closing of valve l5 (and resultant opening of switch 52), the system would remain inoperative until valve l5 were again closed.

Due to .the flow restrictions provided by are spaced apart by a distance such that there is an appreciable interval between the disengage ment ofarm 4s from one of the blades and its I engagement with the other.

The thermal cut-out Ed is of conventional design and operates to open the ignition circuit only in the event of failure foffignition due to a defect in the transformer 58 or heating coil l6, or in the event that the proper amount of gas fails to issue from the pilot burner when valve i5 is opened.

The manual valve or 'g'asscock i5 is preferably located at a point remote from, the burner or funace to avoid the possibility of injury of the person operating it if an explosion should occur. It

i 'will be observed that, to place the burner system 1. In a gas-burner control system: a main burner; a pilot burner for said main burner; a manually operable valve for controlling supply of fuel to said pilot burner; a first electrical circuit; electrical means in said first circuit for igniting the fuel at said pilot burner; a second electrical, circuit; an electrically operated valve in said sec ond circuit for controlling supply of fuel to said main burner and biased to closed position; a first switch adapted to control a source of electrical energy for said circuits and actuated to circuitclosing position by movement of said manually operated valve to open position; a second switch in circuit with said first switch and adapted, when the first switch is closed, to connect said circuits 3. In a gas-burner control system: a main burner; a pilot burner for said main. burner; a manually operable valve for controlling supply of fuel to said pilot burner; a first electrical circuit; electrical means in said first circuit for igniting the fuel at said pilot burner; a second electrical circuit; an electrically operated valve in said second circuit for controlling supply of fuel to said main burner and biased to closed position; a first switch adapted to control a source of electrical energy for said circuits and actuated to circuit-closing position by movement of said manually operated valve to open position; a second switch in circuit with said first switch and adapted when the first switch is closed, to connect said circuits individually to said source, the second switch having two circuit-connecting positions and being biased to first-circuit-connecting position; a motor, operable by the pressure of the fuel, for actuating said second switch between said two positions; a pilot valve for controlling operation of said motor; means responsive to the flame of the pilot burner for operating said pilot valve upon establishment of the flame to a position such that the second switch is actuated to secondcircuit-connecting position by the motor; and means operatively associated with said-motor for ,so restricting fiow of fuel with respect thereto that actuation of the second switch is delayed for a predetermined interval following the establish ment and the extinction of the flame.

4. In a gas-burner control system: a main burner? a pilot burner for said main burner; a manually operable valve for controlling supply of r fuel to said pilot burner; a first electrical circuit;

- electrical means in said first circuit for. igniting individually to said source, the second switch having two circuit-connecting positions and being biased to first-circuit-connecting position; a motor, operable slowly in opposite directions by the pressure of the fuel, for acutating said second switch between said two positions; valve means for controlling the operation of said motor; and means responsive to the flame of the pilot burner for controlling the operation of said valve means.

2. In a gas-burner control system: a main burner; a pilot burner for said, main burner; a

manually operable valve for controlling supply of fuel to said pilot burner; a first electrical circuit; electrical means in said first circuit for igniting the fuel at said pilot burner; a second electrical circuit; an electrically operated valve in said second circuit for controlling supply of fuel to said main burner and biased to closed position; a first switch adapted to control a source of electrical energy for said circuits and actuated to circuitclosing position by movement of said manually operated valve to open position; a second switch in circuit with said first switch and adapted, when the first switch is closed, to connect said circuits individually to said source, the second switch having two circuit-connecting, positions and being biased to first-circuit-connecting position; a motor, operable slowly in opposite directions by the pressure of the fuel, for actuating said second switch between said two positions; a pilot valve for controlling operation of said motor; and means, responsive to the flame of the pilot burner, effective only after a predetermined interval following establishment of the flame to operate said pilot valve to a position such that the second switch is actuated to second-circult-connecting position by the motor.

the fuel at said pilot burner; a second electrical circuit; an electrically operated valve in said second circuit for controlling supply of fuel to said main burner and biased to closed position; a first switch adapted to control a source of electrical energy for said circuits and actuated to circuitclosin position by movement of said manually ble partition; mean operatively connecting said partition to said second switch; means under the control of said manually operated valve for subjecting both of said chambers to the pressure of the fuel when the manually operated valve is opened so that the second switch remains ternporarily in its biased position; a pilot valve for venting one of the chambers so that the pressure of the fuel in the other of the chambers is effective to move the partition slowly in a direction such that the second switch is actuated to secondcircuit-connecting position; and means responsive to the flame of the pilot burner for operating said pilot valve.

5. A system, as defined in claim 4, including means for so restricting flow of fuel with respect to the motor that actuation of the second switch is delayed for a predetermined interval following the establishment and the extinction of the pilotburner flame 6. In a gas-burner control system: a main burner; a pilot burner for said main burner; a manually operable valve for controlling supply to circuit-closing position by movement of said manually operated valve to open position; a second switch in circuit with said first switch and burner; a first electrical a first switch adapted to control a source of electrical energy for said circuits and actuated to adapted, when the first switch is closed, to corn I nect said circuits individually to said source, the second switch having two circuit-connecting positions and being biased to first-circuit-connecting position; a motor, operable slowly in opposite directions by the pressure of the fuel, for actuating said second switch between said .two positions; a pilot valve for controlling operation of said motor; an electromagnetic device for operating said pilot valv; and a thermoelectric generating device, arranged for heating by the flame of the pilot burner, for energizing said electromagnetic device, the thermoelectric generating device being so constructed that it heats and cools circuit-closing position by movement of said manually operated valve to open position; a second switch in circuit with said first switch and adapted, when the first switch is closed, to connect said circuits individually to said source, the second switch having two circuit-connecting positions and being biased to first-circuit-connectingposltion; a motor for actuating said second switch between said two positions and comprising means forming a pair of pressure chambers separated by a movable partition; means operatively connecting saidpart-ition to said second switch; means under the control of said manually operated valve for subjecting both of said chambers to the pressure of the fuel when the manually operated valve is opened so that the second switch remains temporarily in its biased position; a pilot valve for controlling fuel pressure in one of the chambers; an electromagnetic device for operating said pilot valve and efiective when energized to operate the pilot valve to a position wherein said one of the chambers is vented, so that the pressure of the fuel in the a other of the chambers can move the partition manually operable valve for controlling supply A of fuel to said pilot burner; a first electrical circuit; electrical means in said first circuit for isniting the fuel at said pilot burner; a second electrical circuit; an electrically operated valve in said second circuit for controlling supply of fuel to said main burner and biased to closed position;

pilot valve 7 interval following the establishment and .the

slowly in a direction to actuate said second switch to second-circuit-connecting position; and a thermoelectric generating device for energizing said electromagnetic device, the thermoelec- "trlc generating device being so constructed that it heats and cools slowly so that operation of the is delayed for a predetermined extinction of the flame.

- WILLIAM A. RAY.