US2331570A - Burner control system - Google Patents

Description

Ot. 12, 1943. w. A. RAY 2,331,570

BURNER CONTROL SYSTEM Filed July 19, 1940 INVENTOR, I/VI/L .ZA/VA. HAY

AT TOIZQNEY Patented Oct. 12, 1943 UNITED STATES PATENT OFFICE BURNER CONTROL SYSTEM WilliamV A. Ray, Glendale, Calif. Application July 19, 1940, Serial No. 346,363

Claims.` (Cl. 236-1) This invention relates to a system for controllingA the operation of a uid fuel burner, such as a gas burner utilized to heat an oven in a range.

In the systems of this character, it has been proposed heretofore to provide an arrangement whereby the temperature of the oven or other space to be heated may be maintained by a presetting mechanism, such as a. dial. These systems however are apt to be inaccurate; and it is not easy to provide highly important safeguards to ensure closing of the valve controlling the ow of fuel upon the burner failing to light or when the ame for any other reason is extinguished.

It is one of the objects of this invention to provide a system that is simple and reliable in operation, and that can maintain the temperature of the range within quite close limits.

It has been common to provide the gas cock controlling the oven burner on the nfront of the range, and often a thermostatic control unit is combined with this cock. This type of installation requires a, considerable amount of piping for the gas up to the front of the range where the gas cock is located for accessibility. This piping introduces additional leak hazards at the pipe joints and at the cock. This is highly disadvantageous, because the pipe must often be brought to places where quite high temperatures exist. The gas cock also, is apt to stick or leak as a result of it being subjected to these temperatures. By the aid of this invention, the objectionable piping is obviated; and instead resort is had to electric wiring. The gas valve is conveniently located in a safe place, and remotely controlled by the aid of electrical energy.

These results are obtained by the aid of an automatically operated safety valve, arranged to have a low fire as well as a high re position, and that may be operated to close completely upon failure of the pilot llame or when it is desired to discontinue the oven heat. Such a Valve is described in a prior application, Serial No. 335.085, filed on May 14, 1940, in the name of William A. Ray, and entitled Fluid control valve. It is another object of this invention to make it possible to utilize a valve of this character in an elective and simple manner for the controll of temperature in an oven.

This invention-possesses many other advantages, and has other objects which may be made more easily apparent from a consideration of one embodiment of the invention. For this purpose there is shown a form in the drawing accompanying and forming part of the present specication. This form will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description isnot to be taken in a limiting sense, since the scope of this invention is best defined by the appended claims.

Referring to the drawing:

Figure l is a diagrammatic representation of a system embodying the invention; and

Figs. 2 and 3 are diagrammatic sectional views ofthe valve structure utilized in the system, respectively showing low re and high fire positions.

In the present instance there is shown a gas burner I adapted to be supplied with fuel through a conduit leading from a control valve structure 3. This valve structure 3 is described and claimed in the previously filed application Serial No. 335,085 hereinbefore referred to. This valve structure is intended to have three positions. The closed position is illustrated in Fig. 1. A low fire position is shown in Fig. 2 .and a, high fire position is shown in Fig. 3. While the manner in which these three positions may be obtained by a unitary valve or a number of valve structures is not important so far as the system is concerned, a short description of the Valve structure illustrated may be included for the sake of completeness.

The valve structure 3 may be provided with a valve body 4 having an inlet chamber 5 and an outlet chamber 6. Separating the two chambers is a wall or partition 1, through which extends a port opening 8.

A valve closure structure is adapted to co- V operate with the port 8. 'I'his valve closure structure may include a disk-like member 9 adapted to be seated on the tapered annular valve seat I0, surrounding port 8. In this way communication between the inlet chamber 5 and outlet chamber 6 is interrupted.

The closure structure is shown as carried by a flexible diaphragm I I. The upper surface of the diaphragm is subjected in the position shown in Fig. l to the inlet pressure, whereby the closure 9 is urged to the closed position. For this .purpose a casing I 2 forming a chamber I3 is provided above the valve body 4. The diaphragm I I forms a flexible wall of thev chamber. Inlet pressure'in the chamber I3 is provided by the conduit I4 leading from the inlet chamber 5 directly into the pressure chamber I3.

Provisions are made to reduce the pressure in chamber I 3 by closing conduit I4 and by opening chamber I3 to atmosphere. For example, this may be accomplished by the aid of an electromagnet I5 shown in this instance as located within the chamber I3. This electromagnet when energized operates to rotate a pivoted armature I5 against the force of a spring I1. The upper end of the amature when the electromagnet I5 is deenergized, serves to close the jet opening of a conduit I3. This conduit I8 would otherwise permit venting of the chamber I3 to atmosphere; for example through another chamber I9 and a vent 20, leading from that chamber.

The armature'li when the electromagnetIS' is energized will be rotated in a clockwise direction to close the jet opening of the conduit I4.

'In this way passage of uid under pressure of this chamber I3 is stopped. At the same time conduit I8 is opened and the iiuid pressure in chamber I3 is reduced through passage of the fluid into chamber I 9 and to atmosphere through vent 20.

The position assumed by the valve parts when the electromagnet I5 isenergized is illustrated in Fig. 2. The pressure in the chamber I3 is re- -duced to a minimum, and therefore the valve closure 9 is moved upwardly by the inlet pressure in chamber 5 operating on the lower surface of diaphragm Il. For this position (corresponding to the low fire), the fuel in passing to the outlet chamber G-is confined to a restricted passageway 2| formed in wall 1 and opening in the wall of port 3. This restriction is accomplished by the upward movement of a supplemental closure 22 joined to the main closure 9 by the intermediate rod 23. This supplemental closure-22 rises and seats against the tapered valve seat 24 formed around the bottom of theY port 3. Accordingly fuel is not permitted to passdirectly through the port 8. The fuel from inlet chamber 5 ows as indicated by the arrows, downwardly into the port 3 and thence through the restricted passage 2l in to the outlet chamber 3. Accordingly a restricted flow of fuel corresponding to low nre is permitted for this position of the valve.

Inorder to pass to high iire position, the clo-` for the energized condition. From chamber I9 fluid pressure may flow through the conduit I8 rinto the chamber I3. Since the fuel encounters restricted passageways in passing from the port 8 through passageway 2,0, conduit 29, chamber I9 and conduit I8, the pressure in chamber I3 remains always somewhat less than in chamber 5, and accordingly the valve closure structure is not urged to the position of Fig. l but assumes the intermediate position of Fig. 3. In this intermediate position the closure 22 is freed from its seat 24 and the valve structure assumes the high fire position.

The control of the valve structure to render it completely inactive or fully closed as in Fig. 1 is effected by the control of the electromagnet I5. If the electromagnet I5 is deenergized as in Fig. l, the valve structure 3 is surely closed, whether or not the electromagnet 25 be energized. Accordingly the electromagnet I5 is the cdominant control for causing the valve to close completely. When the electromagnet I5 on the other hand is energized, the condition of energization of magnet 25 is determinative of the amount of fuel which passes to the outlet cham'- ber 5 and burner I. With the electromagnet 25 deenergized, the passage of fuel is restricted corresponding to the low re position of Fig. 2.

When the electromagnet 25 is energized as in The electrornagriets I5 and 25 are arrangedl in control circuits, as for example for controlling the temperature attained in an oven of a range. The temperature control may be effected sure structure 9-23-22, is moved to the position illustrated in Fig. 3; that is, both of the closure members 9 and 22 are open. Therefore fuel may pass from chamber 5 entirely through the port 3, past the closure 22 into the outlet I chamber 5.

In order to obtain this intermediate position of the valve closure structure, the pressure lin chamber I3 is raised above atmosphere but of such a value as not to cause the valve closure structure to assume the closedposition of Fig. 1. This increase in pressure is obtained by' energization of an electromagnet 25 located in the chamber I9. This electromagnet operates upon a pivoted armature 29'.' A spring 21 urges the armature 23 to the position shown in Figs. 1 and 2 when the electromagnet 25 is deenergized.V In this unattracted position, the vent 20 is opened to atmosphere. However, when the electromagnet 25 is energized, the armature 25 assumes the position of Fig. 3. The vent 25 is now closed. At the same time, in spite of the closing of conduit` I4, some fluid is permitted to pass into chamber I3. This is accomplished through the passageway 23 in wall 1 and opening in port 8; and through conduit 29 to chamber I9. This conduit 29 is closed by the armature 25 while the electromagnet 25 is deenergized, but is open for example by the aid of an extensible bellows 3l! connected to a pressure cell 3|. This pressure cell `3I may be located so that the vapor pressure therein is a function of the temperature to be controlled. Cell 3l usuallyencloses, for this purpose, a readily volatilizable liquid. The pressure attained in the bellows structure 33 accordingly depends upon the temperature to which the cell 3l is subjected. The member 30 isV shown as operating a contact arm 32 carrying the contact point 33. This arm 32 is urged toward the right as by a spring 34, so as to tend to bring the contact 33 into engagement with the stationary contact 35. If the temperature is suiiicie'ntly low, the sprlng 34 causes the contacts 33 and 35 to close and the electromagnet. 25 is energized.

The source of electrical energy for the circuit is shown in this instance as provided by a thermopile structure 39 adapted to be influenced by the main burner flame. Accordingly no current ows in the circuit of electromagnetl 25, since the burner is inactive. The complete circuit for the electromagnet 25 may be traced from thermopile 35, arm V32, contacts 33 and 35, coil of electromagnet 25, clock control switch 31, back to the thermopile 36. The clock control switch 31 may be arranged as to cause deenergization-of electromagnets after4 a predetermined period of activity of the oven, irrespective of the position of the circuit controller 33-35.

The control circuit for electromagnet I5 includes the contact points 38 and 39. Contact point 38 is carried on a movable arm 40, and contact point 39 is stationary. In the position shown these contacts 38 and 39 are open, whereby it islassured that the electromagnet I5 is the inactive position of Fig. 1.

deenergized. The source of electrical energy for this control circuit. is a pilot generator or thermopile 4|. This pilot' generator is subjected to the flame 42 of the pilot burner 43. 'I'his pilot burner is connected as lby conduit 44 to the inlet chamber 5 of the valve structure 3. Accordingly should the pilot flame 42 be extinguished for any reason, the electromagnet I5 will be deenergized and the valve structure will be caused to assume l Thus the ow of fuel to main burner is stopped.

The complete circuit forthe electromagnet I5 may be traced as follows: from pilot generator 4|, arm 40, contacts 38 and 39, the coil of electromagnet I5, clock control switch 31, back to the pilot generator 4I I In order that the valve be rendered active so las to place the thermal responsive control of electromagnet 25 into operation, the contacts 38 and 39 mustv be closed and the pilot 43 must be lit. Also, the clock control switch 31 must be' in closed position. With all of these three conditions present, the valve first passes to the low re position of Fig. 2. 'I'he high fire position is not attained, because the thermopile generator 36 is not active, and the control circuit for electromagnet 25 is unenergized. However, as soon as a low fire position is reached, the llame of burner I soon causes the generator 36 to be active, and-the circuit for electromagnet 25 is energized. The valve then can pass to the high fire position of Fig. 3 if contacts 33, 35 are closed and this continues until the temperature attained is suiicient to separate contacts 33 and 35. Thereafter the closing and opening of the contacts 33 and 35, under the control of the temperature responsive pressure cell 3|, is accomplished as required by the temperature obtaining in the oven.

Upon the elapsingy of a. predetermined time, the

clock control switch 31 is opened and 'the system is shut down, as represented in Fig. 1.

Control of the closing and opening of the contacts 38 and 39 is shown in this instance as accomplished by manual rotation of a shaft 55. This shaft has a manually controlled handwheel 45 by the aid of which it may be rotated. Shaft 55 carries a cam 46 having a high point adapted to cooperate with the arm 44. When the high point 41 is in the position of Fig. 1, the arm 49 is urged toward the left, and the contacts 39 and 38 are opened. Just as soon as shaft 44 is rotated in a clockwise direction, the contacts 38 and 39 are permitted to close,` and the valve structure 3 is thus permitted to be placed under the independent control of the temperature lresponsive device 3 I.

Rotation of the shaft 55 also serves to adjust .the temperature of response of circuit controller 33-35. For this purpose the shaft 55 is provided with another cam 48. This caml 48 operates upon the right hand end projection 49 of the bellows 38. The position of the right hand end of the bellows 30 as determined by cam 48 obvi- .ously adjusts the degree of expansion required of bellows 30 to open the contacts 33, 35. Accordingly'the cam 48, in adjusting the position of the left hand end of the bellows 30, simultaneously adjusts the temperature at which the vapor pressure is suiiicient to expand the bellows 30,.to open the contacts 33 and 35. Cam 48 has a high point 50, corresponding to inactiveposition, in which the contacts 33 and 35 must remain open irrespective of the temperature attained by pressure cell 3|. As shaft 55 is turned in a clockwise direction to close contacts 38 and 39, the temperature at which contacts 33 and 35 open is increased, since the right hand end of the bellows 30 is permitted to move toward the right, under the iniiuence of spring 34.

The setting of the temperature at which the contacts 33 and 35 will open is thus determined by the angular position of the cam 48.' Accordingly it is possible to indicate the averagetemperature to be attained in the oven by the aid of the dial 5I fastened to the shaft 55. This dial 5I may carryappropriate scale marks 52 adapted to cooperate with a stationary index point.

A limiting stop 53 may be provided for counterclockwise rotation of shaft 55, and to ensure that the cam 46 will not pass beyond the position illustrated in Fig. 1.

By appropriate rotation of the dial 5I, -therefore,.from the inactive position of Fig.v 1, two main effects are attained. One is theY immediate engagement of contacts 38 and 39. This renders the valve structure 3 responsive to the control provided by contacts 33 and 35. The other main effect is the adjustment, by continued rotation of shaft 44 through a required angle, of the temperature at which contacts 33 and 35 will open. This is accomplished by of the cam 48 with`the bellows 30.

'I'he dominant control is lodged in the clock control switch 31. When this switch opens both of the electromagnets I5 and 25 are' deenergized and the valve closes. While the clock control switch 31 is closed, the dominant control of valve 3 is effected by contacts 38 d 39. However, in the event of pilot flame fai ure this control is nulliiied and the valve structure 3 is closed.

Assuming that the pilot burner 43 is not extinguished, and that contacts 38 and 39 are closed by a rotation of shaft 44, then by alternate opening and closing of contacts 33 and 35, the valve structure 3 assumes alternately the low fire and high iire positions. This opening and closing of thesecontacts is dependent upon the temperature control sure cell 3|.

What is claimed is:

1. In a temperature controlledl fuel burner system, means for causing the burner to assume only a. high nre or a low re condition, means responsive to temperature for controlling the burner optionally to assume either the high provided by the presre orthe'low nre condition, and a common means for adjusting the temperature at which the temperature responsive means operates, and for causing the burner to assume an active condition. l

, 2. In a temperature controlled fuel burner system, means for causing the burner to assume only a high lre or a low re condition, means responsive to temperature for controlling the burner optionally to assume either the high fire or the low fire condition, means for adjusting the temperature at which the temperature responsive means operates',l means 'for causing the burner to assume an inactive condition, and

f means cooperating with the temperature adjusting means and the means for causing the burner to assume an inactive condition, to ensure that the burner remains ininactive condition when the temperature is adjusted to a limiting value.

3. In a temperature controlled fuel burner the cooperation i electrically controlled to cause the valve to close. or to cause the burner to burn with high-fire; or to cause the burner to burn with low lire, a circuit controller adapted to control the valve to cause it to be placed either in high nre or low rire position, a circuit controller adapted to cause the valve to be placed in inactive or active position, means responsive to attainment of low and high temperature limits for operating the circuit controller respectively for high ilre or low lire valve position, and a common means independent of temperature, for adjusting one of said limits of the temperature of response of the circuit controller for high or low ilre valve position, and for operating the circuit controller to cause the valve to be placed in active position.

4. In a temperature controlled fuel burner system having a valve structure adapted to be electrically controlled to cause the valve to close, or

to cause the bu'rner to burnY with high fire, or to cause the burner to burn with lowA fire, a circuit controller adapted to control the valve to cause it to be placed either in high fire or low fire position, a circuit controller adapted to cause the valve to be placed in active or inactive position, temperature responsive means for operating the circuit controller for high fire or low re valve position, a pair of rotary members respectively for adjusting the temperature response of the rst circuit controller, and for operating the second circuit controller, and a common operator for both said rotary members.

5. In a temperature controlled fuel burner system having a valve structure adapted to be electrically controlled to cause the valve toclose, or to cause the burner tonburn with high re, or to causethe burner to burn with low fire, a circuit controller adapted to control the valve to cause it to be place'd either in high fire or low fire position, a circuit controller adapted to cause the valve to be placed in inactive or active position, temperature responsive means for operating the circuit controller for high fire or low re valve position,-and thermopiles operated by consmption of fuel by the burner for supplying energy controlled by said circuit controllers.

6. In a temperature controlled fuel burner system having a valve structure adapted to be electrically controlled to cause the valve to close, or to cause the bumerto burn with high fire, or to cause the burner to burn with low re, a circuit both said circuit controllers, for causing the temperature responsive controller to become active and for setting the valve structure so that it may respond to said temperature responsive control.

8. In a temperature controlled fuel burner system having a valve structure with a closure mem-` ber adapted to assume a valve closing position, a low iire position and a high ilre position, electrical control means which when unenergized causes the closure to remain at all times in closing position, separate electrical control means for causing the closure to assume either a highnre or a low-fire position in accordance with the energization or deenergization of said separate control means, means responsive to attainment of low and high temperature limits for energizing or ldeenergizing said separate control means, and means independent of temperature, for energizing or deenergizing the control means that when unenergized, causes the closure to assume closing position.

9. In a temperature controlled fuel burner system having a valve structure with a closure member adapted to assume a valve closing position, a low-re position and a high fire position, electrical control means which when unenergized causes the .closure to remain at all times in closing position, separate electrical control means y for causing the closure to ssume either a highcontroller adapted to control the valve to cause t ittobeplacedeitherinhighfireorlowiirep' sition, a circuit controller adapted to cause the valve to-be placed in inactive or active position,

temperature responsive means for operating the circuit controller for high re or low iire valve position, a common means independent of temperature, for adjusting the temperature of response of the circuitcontroiler for high or low fire valve position. 'and for operating the circuit controller to cause the valve to be placed in active position, thermopiles operated by consumption of fuel by the burner for supplying energy controlled by saidcircuit controllers. 4

'1. In a temperature controlled fuel burner system having a valve structure adapted to be electrically controlled to cause the valve to close, or to cause the burner to burn with high fire, or to cause the burner to burn with low ilre, a circuit re or a low-fire position in accordance with the energization or deenergization of said separate control means, temperature responsive means for energizingior deenergizing said separate control means, means independent of temperature, for

`energizing or deenergizing the control means that when unenergized causes the closure to assume closing position, and a common means for optionally rendering both of said control means active or inactive.

10. In a temperature controlled fuel burner system having a valve structure with a closure member adapted to assume a valve closing position, a low fire position, and a high iire position. electrical control means which whenpun'energized causes the closure to remain at all times'in closing position, separate electrical control means for causing the closure to assumeeither a high-nre or a low-re position in accordance with the energization or deenergization of said separate control means, temperature responsive means for energizing or deenergizing said separate control means, means independent of temperature, for energizing or deenergizing the control means that when unenergized causes the closure to assume closing position, means for adjusting the temperature of response of .the temperature responsive means, and means whereby the control means for causing the closure to remain in closing position, is rendered effective when the adjusting means is adjusted below a limiting temperature.

WILLIAM A. RAY.

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