US2329682A - Burner control apparatus - Google Patents

Description

Sept. 14, 1943. H. F. ALFER Y 2,329,682

BURNER CONTROL APPARATUS I Filed May 21, 1941 INVENTOR. BY H672??? FfiZfq/y 1m M fim 1612;

Patented Sept. 14, 1 943 UNITED STATES PATENT OFFICE BEJRNER CONTROL APPARATUS Henry F. Alfe ry, Milwaukee, Wis., assignor to Milwaukee Gas' Specialty Company, Milwaukee, Wis., a corporation of Wisconsin Application May 21, 1941, Serial No. 394,444

- 9 Claims. (cl. 236-1) room, space, or building, it may be assumed thatthe rate of heat loss from the room, space or building is a function of temperature difference between the prevailing outside temperature at any time and the predetermined inside temperature which it is desired to maintain.

Obviously, in the case of a building, the rate of loss varies with the type of building, but after that factor is once determined, it may be assumed to be substantially a constant, and the above principle is varied only by such factors as sun, wind, and the like.

The function of the heating system is to supply heat in just sufficient quantity to make up for the loss so as to maintain the inside temperature at a predetermined value or within a selected range. Eflicient use of the fuel is also desired.

If it is sought to accomplish the foregoing results merely by turning on and shutting down a burner adjusted, for example, for average requirements, the system will not follow as closely as desired the conditions as sensed by the thermostat. Overheating and ineflicient use of the fuel will frequently occur when the outside temperature rises sufliciently to reduce the temperature difference below the average temperature difference for which the apparatus is set, whereas, underheating will frequently occur when the outside temperature drops sufl'lciently to increase the temperature difference for which the system is set.

One of the main objects of the present invention, is to provide a high, low fire control which .is operative -not only to shutofl and turn on the burner, but also to regulate the fire to suit the conditions as sensed, for example, by the room thermostat. v

Another object of the invention i to provide,

in conjunction with the burner control apparatus of the character described, means which is opera tive to enrich the fuel mixture, and particularly the gas-air mixture for the burner upon ignition of the burner.

Another object of the invention is to provide scribed which is of simple character and eifective in operation.

While the particular features by which I provide a system of the character set, forth are important features within the more specific aspects of the invention, it is to be understood that the precise features shown and described may be varied within the broader aspects of the invention.

In order to acquaint those slgilled in the art with the manner of constructing and operating burner control apparatus in'accordance with the present invention, I will ndw describe one preferred embodiment of the invention in connection with the accompanying drawing, in which the single figure is a diagrammatic view showing burner control apparatus embodying the invention.

The invention can be embodied in a wide variety of forms for use with a wide variety of sys-.

tems, but for. purposes of illustration the invention has been shown as embodied in a thermofor delivering gas or other fuel to the burner 10' through onebranch pipe line I 2 of the system for low fire at the burner l0 and, as will presently appear, through another branch pipe line I3 of the system simultaneously with the delivery of fuel through the branch l2 for high fire at the burner I0.

The low fire branch pipe line l2 has a low fire valve l4 connected between contiguous sections thereof, and the high fire branch pipe line l3 has a high fire valve l5 connected between contiguous sections thereof. Each of the low and high fire valves [4 and I5 is of any desired type capable not only of being held open, but of being actually actuated to open position by the relatively minute thermoelectric current generated by the heat of a pilot flame on the hot junction or junctions of a thermocouple, thermopile, or other thermoelectric generator. moelectric valve more fully disclosed and claimed in the copending application of Lourdes V. McCarty, Serial No. 390,247, filed April 25, 1941, is illustrative of one suitable automatic valve adapted to be employed as the low and high fire valves I 4 and I5 of the present invention. The automatic thermoelectric valve of the diaphragm The automatic ther-' known forms of valves .illg chamber or less diagrammatically as a type more fully disclosed and claimed in the Patent No. 2,291,567, issued July 28, 1942, to Guido Wunsch and Josef Schupp ert, is illustrative of another suitable automatic valve adapted to be employed as the low and high fire valves i4 and E5 of the present apparatus.

It is to be understood that any other suitable may be employed as the low and high fire valves I4 and I5 'of the present invention.

The low fire branch pipe line l2 leads to the burner IQ for the delivery of the ga or other fuel thereto-for example, through an outlet or delivery o-rifice i8 into a mixing chamber in which the fuel is mixed with air which enters the mixing chamber 20 through one or more ports usually provided at the outer end 2| of the mix- 20, as well understood in the art. The combustible mixture of gas and air passes out from the mixing chamber 20 through a conduit 22 to the burner it where it is delivered through the ports of the burner and ignited by a pilot burner 24.

The high fire branch pipe line 13 also leads to the burner ill for the delivery of gas or other fuel thereto through the outlet or delivery orifice 53 into the mixing chamber 20 in which this fuel, with the fuel supplied through the branch pipe line 92, is mixed with air which enters the mixing chamber through the port or ports previously referred to, the mixture passing out from the mixing chamber 20 through the conduit 22 to the burner. 1

The pilot burner 26,,

W to maintain a. pilot fiame 25 for igniting the main burner, issupplied with gaseous fuel by a pilot supply pipe 25 shown fragmentarily and more or less diagrammatically. The pilot burner 25 may be a continuously burning pilot burner, or the system may be arranged to shut off the supply of fuel to the pilot burner which is located in juxtaposition to the main burner upon extinguishment of the pilot light, within the scope of the present invention.

In the case of a room, space, or building heater,

the thermostat indicated in its entirety at 30 may i be in the form of a room thermostat mounted in appropriate position within the room or other space heated b the main burner, or it may be subject to the temperature of any other medium, the temperature of which it is desired to control.

The thermostat 3B is shown as comprising a bimetallic spiral having a resilient arm 32 carrying a contact 33, and a second arm 34 carrying a contact 35. Instead of being in the form shown, the room thermostat 30 may consist of two separate thermostat with individual adjustments.

The cont-act 33 on the resilient arm 32 cooperates with a relatively fixed contact 38 which is connected by a conductor 39 to one terminal 40 for the coil of the electromagnet (not shown) within the body of the low fire valve IA. The contact 35 on the second arm 34 of the thermostat 30 cooperates with a relatively fixed contact 42 which is connected by a conductor 43 with one terminal 44 for the coil of the electromagnet (not shown) within the body of the high fire valve l5. For purposes of illustration, the thermoelectric generator which is energized by the heat of the pilot flame 25 for supplying thermoelectric 'current for energizing the electromagnet of the low fire and high fire valves l4 and I5, is shown more prising a pluralit of thermocouples connected in series. This, of course, may vary within the scope of the present invention, a thermocouple or any other form of thermoelectric generator which will generate the required thermoelectric current being contemplated within the scope of the appended claims.

One terminal of the thermoelectric-generator is connected by a conductor 52 to the other terminal 53 for the coil of the electromagnet for The conductor 52 is con- 54 to the other terminal 55 for the coil of the electromagnet for the high flame valve I5. The inner end of the bimetallic spiral of the thermostat 30 is supported by a member 58, and a conductor connected between this member 58 and the other terminal of the thermoelectric generator 50 connects the contacts 33 and 35 in circuit with thethermoelectric generator through the arms 32 and 34, respectively, and the bimetallic spiral.

The operation of the device, as thus far described, is as follows:

As the room or space, for example, cools, the thermostat first closes its contact 33 into contact with the contact 38. This closes the thermoelectric circuit for the electromagnet of the low fire valve 54, and, assuming that the pilot burner 24 is ignited and that the the hot junction or junctions of the thermoelectric generator 50, the resulting energization of the electromagnet for the low fire valve i4 actuates this valve to open position and maintains the same in open position as long as the contacts 33, 38 are closed and the pilot flame is ignited. Fuel then flow through the branch pipe line i2 to the mixing chamber 25 where it is mixed with air for supporting combustion, and the combustible mixture passes to the burner H! where it is ignited by the pilot burner 25 to provide the low fire main burner. flame.

The branch pipe line 12 is preferably provided with a low fire adjusting valve 55 for adjusting the low fire fuel supply to provide, for example, the desired relation between the pressure of the fuel and the orifice i8 to maintain a satisfactory low fire fiame.

If theroom continues to cool, or if the cooling is greater than that which will be taken care of by the low fire valve, the further cooling of the thermostat 30 closes the contact 35 into contact with the contact 42. The resilient character of the arm 32 permits this action while maintaining the contact between contacts 33 and 38. The closing of the contacts 35,42 closes the thermoelectric circuit for the electromagnet of the high fire valve 15, and assuming that the pilot burner is ignited and heating the hot junction or junctions of the thermoelectric generator 50, the resulting energization of the electromagnet for the high fire valve l5 actuates this valve to open position and maintains the same in open position the low fire valve I4. nected by a conductor as long as the contacts 35, 42 are closed and the burner flame at said burner.

thermopile 50 com- Heating of the room to the temperature at which the contacts 35, 42 open, causes these contacts to separate, thereby opening the thermoelectric circuit for the, high fire control valve l5 and causing this valve to close. Further heating of the room, or a sufficientrise in temperature to cause separation of the contact 33 from the contact 38, opens the thermoelectric circuit for flame thereof is heating I the low fire control valve I 4, whereupon this valve closes to shut off the fuel supply to the main burner through the branchpipe line l2.

In order to overcome any possibility of ignition failure when the low fire control valve l4 opens first, I'provide, in conjunction with the apparatus of the present invention, means for supplying excess gas to enrich the gas-air mixture upon starting or ignition with the low fire valve l4 opening first.

This excess gas supply or enriching means for operation where the low fire valve opens first comprises. a diaphragm valve indicated in its entirety at 10. This valve has a valve body H having its inlet chamber 12 connected by a pipe 13 to th branch pipe line l2 ahead of the low fire adjustment valve 65, and an outlet chamber 14 connected by a pipe 15 to the branch pipe line Communication between the inlet and outlet chambers 12 and 14 is effected through a passage 16 having'at one end a valve .seat 11 for avalve disc member 18. The valve disc member 18 is carried by a stem 19 connected at 88 to a flexible diaphragm 82. The periphery of the diaphragm 82 is clamped between the valve means for the high fire control valve, thermostat means in said condition responsive circuit and having a pair of contacts one cooperable with the bodypart H and a hood or cover 83 which may be secured in place to the valve body part II by screws or other. suitable means. A diaphragm chamber 85 is provided between the hood or cover 83 and the diaphragm 82. v

For the purpose of bleeding the head pressure gradually from the chamber 85 as the pressure of the gas ahead of the diaphragm acts on the diaphragm, a bleed tube connection 88 is provided between the chamber 85 and the low pressure pipe l5. A bleed tube adjustment may be provided at 90 for adjusting the action of the valve disc member I8 into closed position engaging the valve seat 11.

A the low fire valve [4 opensassuming that the high fire control valve l5 remains closed-gas fiows through the low fire adjustment to the burner as previously described. Gas is by-passed at this time from the branch pipe line l2 through the diaphragm valve to the burner orifice l8 to provide a full or enriched gas supply on starting or ignition. As the pressure ahead of the diaphragm 82 acts on the diaphragm, the gas in the head chamber 85 of the valve is bled off through 'the bleed tube 88 tothe low pressure side of the valve, and the valve disc member 18 gradually closes into engagement with the valve seat 11 to shut off the by-pass supply of fuel so that the proportioning of the fuel and air will thereafter be such as to give satisfactory results during continuous low fire operation of the burner.

It will be understood that the low fire control valve I4 is preferably of suflicient size to provide excess gas on the initial opening of the valve M, as described. It will also be understood that the gas or fuel supply line I l supplies sufficient gas to provide an increased amount of fuel to the burner when the high fire control valve 15 is opened.

The embodiment of the invention shown in the drawing is for illustrative purposes only, and it is to be expressly understood that said drawing and the accompanying specification are not to be construed as a definition of the limits or scope of the invention, reference being had to the appended claims for that purpose.

I claim: I

1. A burner control apparatus comprising, in combination, a main burner, a pilot burner in juxtaposition to said main burner, a fuel supply contact means for the low fire control valve and the other cooperable with the contact means for the high'fire control valve, a thermoelectric generator responsive to the heat of the pilot burner and connected into said condition responsive circult, a low fire adjustment means in said low fire fuel supply pipe, and a fuel supply pipe connected between said low fire fuel supply pipe and said high fire fuel supply pipe ahead of said low fire adjustment means and beyond said high fire valve for supplying excess fuel tolenrich the fuel-air mixture for the burner upon starting the burner with the low fire supply of fuel supplied by said low fire control valve.

2. A burner control apparatus comprising, in combination, a main burner,,a pilot burner in juxtaposition to said main burner, a fuel supply pipe for supplying fuel to maintain a relatively low fire at the main burner, an electroresponsive low fire contro1 valve in said pipe, a fuel supply. a

means forthe low fire control valve and contact v means for the high fire control valve, thermostat means in said condition responsive circuit and having a pair of contacts one cooperable with the contact means for the low fire control valve and the other cooperable with the contact means for.

the high fire control valve, a thermoelectric generator responsive to the heat of the pilot burner and connected into said condition responsive circuit, .a low fire adjustment means in aid low fire fuel supply pipe, a fuel supply pipe connected between said low fire fuel supply pipe and said high fire fuel supply pipe ahead of said low fire ad justment means and beyond said high fire valve for supplying excess fuel to enrich the fuel-air mixture for the burner upon starting the burner with the low fire supply of fuel supplied by said low fire control valve, and a valve in said last mentioned pipe having a valve member which is open when said burner is started with the low fire fuel supply and operative to closed position by the pressure of the fuel in said low fire fuel supply pipe.

3. A burner control apparatus comprising, in combination, a main burner, a pilot burner in juxtaposition to said main burner, a fuel supply pipe for supplying fuel to maintain a relatively low fire at the main burner, an electroresponsive pipe for supplying fuel to maintain a relatively high fire at the main burner, an electroresponsive high fire control valve in said last mentioned pipe, a condition responsive circuit having contact means for the low fire control valve and contact means for the high fire control valve, thermostat means in said condition responsive circuit and having a pair of contacts one cooperable with the contact means for the low fire control valve and the other cooperable with the contact means for the high fire control valva'a thermoelectric low fire control valve in said tact means for the low fire generator responsive to the heat of the pilot burner and connected into said condition responsive circuit, a low fire adjustment means in said low fire fuel supply pipe, a fuel supply pipe connected between said low fire fuel suppl pipe and said high fire fuel supply pipe ahead of said low fire adjustment means and beyond said high fire valve for supplying excess fuel to enrich the fuelair mixture for the burner upon starting the burner with the low fire supply of fuel supplied by said low fire control valve, a valve in said last mentioned pipe having a valve member which is open when said burner is started ,with the .low fire fuel supply and operative to closed position by the pressure of the fuel in said low fire fuel supply pipe, said head pressure chamber, and means for bleeding the head pressure from said chamber to the low pressure side of the system.

4. A burner control apparatus comprising in combination, a main burner, a pilot burner in juxtaposition to saidmain burner, a fuel supply pipe for supplying fuel to maintain a relatively low fire at the main burner, an electroresponsive pipe, a fuel supply pipe for supplying fuel to maintain a relatively high fire at the main burner; an electroresponsive high fire control valve in said last mentioned pipe, a condition responsive circuit having concontact means for the high fire control valve, thermostat means in said condition responsive circuit and having a pair of contacts one cooperable with the contact means for the low fire control valve and contact means for the high fire control valve, a thermoelectric generator responsive to the heat of the pilot burner and connected into said condition responsive circuit, a low fire adjustment means in said low fire fuel supply pipe, 8. fuel supply pipe connected between said low fire fuel supply pipe and said high fire fuel supply pipe ahead of said low fire adjustment means and beyond said high fire valve for supplying excess fuel to enrich the fuel-air mixture for the burner upon starting the burner with the low fire supply of fuel supplied by said low fire control valve, a

valve in said last mentioned pipe having a valve member which is open when said burner is star-ted with the low fire fuel supply and operative to closed position by the pressure of the fuel in said low fire fuel supply pipe, said last mentioned valve having a head pressure chamber, means for bleeding the head pressure from said chamber to the low pressure side of the system, and means for adjusting said bleeding action to control the closing of said last mentioned valve.

5. A burner control apparatus comprising, in

-' combination, a burner, a fuel pipe for supplying fuel to said burner, adjustment means in'said pipe capable of restricting the fiow of fuel to said burner to an amount less than full fiow control valve and the other cooperable with the last mentioned valve having a fuel to said burner, adjustment means in fuel to said burner, adjustment means in said pipe capable of restricting the flow of fuel to said burner to an amount less than full flow through said pipe, an on" and off valve in said pipe ahead of said adjustment means, means operative only upon starting the burner for supplying excess fuel to the burner from said pipe ahead of said adjustment means and beyond said on and oif" valve, and means independent of said last means for supplying fuel to the burner in conjunction with the supply through said adjustment means to provide a high fire at the burner.

'7. A burner control apparatus comprising, in combination, aburner, a fuel pipe for supplying said pipe capable of restricting the fiow of fuel to said burner to an amount less than full flow through said pipe, an on and off valve in said pipe ahead of said adjustment means, and means operative only upon starting the burner for supplying excess fuel to the burner from said pipe ahead of said adjustment means and beyond said on and off valve, said last means being normally open and operable to-closed position by the pressure of the fuel in said fuel supply pipe.

8.- A burner control apparatus comprising, in combination, a burner, low fire and high fire pipes for supplying fuel to said burner, a control valve in each of said pipes, condition responsive means controlling said valves, and means actu ated by the pressure in said low fire pipe for supplying excess fuel therefrom to said burner independently of said high fire control valveupon starting of said burner and shutting off the supply of excess fuel to said burner after starting thereof.

9. A burner control apparatus comprising, in

combination, a burner, low fire and high fire pipes for and off supplying fuel to saidburner, an on' control valve in each of said pipes,

temperature responsive means effective to open said low fire valve and said high fire valve successively upon successive drops in temperature and to close said high fire valve and said low fire valve successively upon successive increases in temperature, and means connected to said pipes beyond said valves actuated by the pressure in said low fire pipe for supplying excess fuel from the latter to said burner independently of said high fire control valve upon starting of said burner and shutting off the supply of excess fuel to said burner after starting thereof.

' HENRY F; ALFERY.

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