US2812807A - Gas burner control means - Google Patents

Description

Nov. 12, 1957 W. D. ANTRIM GAS BURNER CONTROL MEANS 2 Sheets-Sheet 1 Filed D66. 18. 1953 INVENTOR. Will/AM D. ANT'R/M Nov. 12, 1957 w. o. ANTRIM GAS BURNER CONTROL MEANS 2 Sheets-Sheet 2 Filed D60. 18. 1953 INVENTOR. Will/44M D. ANTR/M United States Patent GAS BURNER CONTROL NIEANS William D. Antrim, Cleveland Heights, Ohio, assignor, by

mesne assignments, to Carrier Corporation, a corporation of Delaware Application December 18, 1953, Serial No. 399,087

2 Claims. (Cl. 158133) This invention relates to a gas burner control means in which a pilot burner is employed, together with an element thermally responsive thereto and means controlled by such element by change in condition thereof between hot and cold, dependent upon operation or nonoperation of the pilot burner.

Various types of thermally responsive element are known to the art in such applications, but almost each of them requires a substantial period of time following outage of the burner to which it is responsive, before cooling by dissipation of its residual heat sufficiently to accomplish its purpose in such phase of its cycle.

Usually, the means to be controlled by such element includes a gas valve, which is in many applications the safety shut-off valve of a main burner served by the pilot burner, admission of gas to which main burner in the absence of a pilot flame for immediate ignition thereof, would be dangerous. At any rate any redemand for pilot burner operation should be met as immediately as possible.

Therefore, it is known in the art to provide a standby pilot burner in igniting relation to the main pilot burner above described, but out of controlling relation to the described thermal element, to have standby operation immediately following such outage and during cooling of the element to its cold condition of operation in its cycle.

Thus, where the main pilot burner is subject to an electrically operated valve, which might be closed and shortly reopened, as by an instantaneous power failure, or other redemand, an immediate reignition of the main pilot will occur.

Similarly where the main pilot burner is subject to a manual valve which might be reopened soon after closing, as by an operators change of mind, immediate reignition of the main pilot will likewise follow.

Objects of this invention are to provide means for suitably prolonging the operation of the standby pilot burner, following outage of the main pilot burner, which means act automatically and independently of the element which is thermally responsive to the main pilot burner, and also which may be located wherever convenient and remotely from the element.

Another object is to accomplish these purposes without the necessity of employment of the usual standby pilot burner valve, or of any valve which need either operate in a high temperature or maintain a perfect seal during long periods of idleness.

As another object, the invention is capable of employment in association with all known types of slow acting thermally responsive devices regardless of the specific nature thereof, and particularly whether or not mechanical motion is available therefrom.

Moreover, and as other objects, the invention is generally less expensive to manufacture and to install, and more reliable in operation than the art has heretofore known.

More detailed objectives are that the invention provides instant oncoming of the standby pilot burner and prolonged operation thereof as desired, and regardless of the on and/ or off timing period required by the thermally responsive element.

It also permits incorporation as a unit therewith of an electric switch for an electric ignition device for the main pilot burner which it serves, if desired, with all of the advantages above recited.

Further objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings, which are diagrammatic and conventionalizcd, as for example indicating valves as closed but nevertheless flames at pilot burner ports; and wherein Figure 1 illustrates an embodiment of the invention as applied to a range oven ignition system employing a constant pilot burner for ignition, and

Figure 2 illustrates an embodiment applied to a system employing electric ignition.

In the drawings common parts bear common reference characters.

With reference now to the drawings, and first to Fig. 1 thereof, A is a source of fuel gas supply such as the manifold of a gas cooking range, and B is a burner to be operated from such gas supply, and here indicated as the oven burner of the range, which burner may hereinafter be referred to as the main burner. Gas supply to the main burner B is had from the manifold A through the line 1 sequentially by way of a manual shut-off valve 2 and safety valve 3, and such line may also include a timer operable solenoid valve 4 located after the manual valve 2 and ahead of the safety valve 3. The safety valve 3 is arranged to be controlled by a thermal element 5, which element is thermally responsive to a safety pilot burner 6, which may be hereinafter referred to as a main pilot burner.

The main pilot burner 6 receives its gas supply from a line 7 which is subject to the manual valve 2 and solenoid valve 4 but ahead, and therefore independent, of the safety valve 3. The pilot burner 6 is ported to provide a flame portion 6a eifective on the thermal element 5, the flame portion 6b in igniting relation to the main burner B and a flame portion 60 from which it receives ignition as will be described. The porting arrangement is such that all the described flame portions act as one, in that they are in igniting relation with each other and all come on or go off together substantially simultaneous- 1y.

For ignition of the main pilot burner 6, a constant pilot burner 70 is provided, as at the top of the range and having its own gas supply from the manfold A independent of the other burners of the range. A flash tube 8 leads between the constant pilot burner 70 and the main pilot burner 6, and may be interrupted as at 8a to receive a sub-burner 9, the function of which will hereinaftcr appear. The sub-burner 9 receives gas supply through a line 10 subject to the manual valve 2 and solenoid valve 4 where provided, and is also subject to a valve 11 controlled by the thermally responsive element 5. The arrangement is such that the valve 11 is open when the thermal element 5 is in cold condition, and automatically closes when the thermal element is in hot condition, which conditioning, of course, is determined by the main pilot burner 6.

What has thus far been referred to in the drawing is generally known in the art; and its operation is as follows, commencing with flame only at the constant pilot burner 70, the manual valve 2 closed, the thermal element in cold condition, and neglecting the solenoid valve 4, which may be presumed as open.

Opening the manual valve, upon desire to operate the main burner B, admits gas to the line I but, the safety valve 3 being closed, no gas as yet is passed to the burner B. Gas is however admitted to the main or safety pilot burner 6, and also to the sub-burner 9 since its valve 11 is open. The flash tube 8 is charged with gas both from the sub-burner 9 and the main pilot 6 so that the gas emerging from the port 60, as well as the sub-burner 9, is ignited from the constant pilot 70 by fiash in the tube 8. Thus, the pilot burner 6 has operation at all of its ports.

Operation at the port 6a heats the thermally responsive elements 5, which moves from cold to hot position. This causes the safety valve 3 to open, admitting gas to the main burner B, which has ignition from the flame at 6b of the main pilot. It also causes the valve 11 to close, thus cutting off gas from the sub-burner 9.

Upon outage of the main pilot burner 6 and consequent cooling of the thermal element 5, the main burner B will automatically be shut down by closing of its safety valve 3, and the lighting cycle will be automatically repeated and operation of the burner B resumed provided the manual valve 2 remains open meanwhile.

Closing of the manual valve 2 for desired termination of operation of the main burner B at any time, will cut off main burner gas in the line 1, main pilot gas in the line 7 and sub-burner gas in the line 10, leaving only the constant pilot burner 70 in operation. It will be seen that the main pilot burner 6, thermal element 5, and main burner valve 3, comprise an arrangement wherein the main pilot burner 6 is a safety pilot and the main burner valve 3 is an automatic safety shut-off valve, as they are known in the art, whereby gas cannot be admitted to the main burner B unless and until the main pilot burner 6 is in operation to ignite such gas by way of its ignition flame 6b.

In practice, however, since the thermal element may require substantial cooling time to resume its cold condition following outage of the main pilot burner 6, it is possible that the operator might during such period reopen the manual valve 2 before closing of the safety valve 3 and thereby admit gas to the main burner B, with the main pilot burner 6 not in operation.

For such reason a standby pilot burner 12 is provided, arranged in igniting relation to the main pilot burner 6 and particularly its port at 6b, out of controlling relation with the thermally responsive element 5, and preferably in igniting relation to the main burner B. The standby pilot burner 12 is arranged to remain in operation after outage of the main pilot burner at least sufficiently to permit attainment by the thermally responsive element 5 of its cold condition.

According to this invention, the standby pilot 12 is served by a line 13 so related to the line 7 of the main pilot burner 6 that both are similarly affected by the manual valve 2.

Arranged in this line 13 is a storage, gas holder, reservoir or receiver, generally indicated at 14, and ahead of such reservoir is a check valve 15, so that the reservoir has an inlet connection by way of the check valve and an outlet connection leading to the standby pilot burner 12. in which outlet connection there may be arranged an adjustment valve or limit orifice 16.

As here shown, the reservoir is of diaphragm type, wherein a horizontally disposed diaphragm 17, weighted as at 18, is enclosed within the housing 19, the arrange ment being such that an expansible gas-receiving chamber is provided beneath the diaphragm with a covered chamber thcreabove. The cover over the diaphragm is provided with a small vent 21 to relieve pressure in the latter upper chamber.

The capacity of the reservoir, the mass of the weight 18 of the diaphragm l7, and the size of the vent 21 are such that operation will be as follows:

Upon opening of the manual valve 2, gas will be admitted to the standby pilot burner 12 simultaneously with gas to the main pilot burner 6.

Such gas will flow to the standby pilot burner 12, through its line 13 by way of the check valve 15 and reservoir chamber 20 so that the diaphragm 17 will raise the weight 18 and the reservoir will be charged to capacity.

Upon closing of the manual valve 2, gas will be immediately cut off from the line 17 leading to the main pilot burner 6, and simultaneously to the line 13 leading to the reservoir so that the check valve 15 will seat. Thereafter, although the main pilot burner be out of operation, the standby pilot burner 12 will be maintained in operation until the capacity of the reservoir is exhausted. The pressure of this standby gas will remain substantially constant by the action of the weight 18 on the diaphragm 17 during this period and until the thermal element 5 has attained its cold condition and closed the safety shut-off valve 3.

Where the solenoid valve 4 is included, remote timed control may be had by employment of a time switch to operate the solenoid valve, as will be well understood by one familiar with the art.

Briefly, to preset the control for subsequent commencement and/or termination of the operation of the burner B, the operator suitably presets the time switch to which the solenoid valve is subject, and opens the manual valve 2. Thereafter, operation will be generally as above described except under the immediate overall control of the solenoid valve 4 instead of the manual valve 2. The location of the solenoid valve is such that it simultaneously and similarly controls the lines 7, 10 and 13 of the main pilot burner 6, sub-burner 9 and standby pilot burner 12 respectively. It will be apparent that when the solenoid valve is in control and there be an instantaneous interruption of the electric power, the standby pilot burner 12 will have safety operation for service. of the main pilot burner 6 as described.

With reference now to Fig. 2 of the drawings, a system is disclosed wherein electric ignition is provided for the main pilot burner 6, instead of the flash tube type of ignition disclosed in Fig. 1. Here an electric ignition element 22 is arranged in igniting relation to the port 6c of the main pilot burner 6, the thermal element 5 arranged to operate a switch 23 and a suitable source of electric power 24 provided for energization of the ignition element 22.

Also, a switch 25 is arranged to be actuated by the diaphragm 17 of the reservoir 14 and preferably within the chamber above the diaphragm, as indicated.

These electrical parts are interconnected in a circuit wherein the arrangement is such that contact is made with the switch 23 only when the thermal element 5 is in cold condition and contact is broken at the switch 25, when the reservoir 14 is fully discharged.

Thus, to commence operation of the main oven burner B, the operator opens the manual valve 2. This admits gas to the main pilot burner 6 and also to the line 13 of the standby pilot burner 12. Charging of the reservoir 14 closes the switch 25 and, the switch 23 being closed, the ignition element 22 is energized to ignite the main pilot burner 6. Operation of this burner heats the thermal element 5, to break contact at the switch 23 and deenergize the ignition element 22, as well as opening the safety shut-oil valve 3. Upon closing of the manual valve 2, prolonged operation of the standby pilot burner 12 will be had as before, until the thermal element 5 has cooled to close the safety valve 3 and remake contact at the switch 23. Upon exhaustion of the reservoir 14, contact will be broken at the switch.

Should the manual valve be reopened during standby operation of the pilot burner 12, the main pilot 6 will have immediate reignition therefrom.

A spring 26 may be provided in connection with the switch 25 to insure its closing immediately upon admission of gas to the reservoir chamber.

The solenoid valve 4 may be employed in the circuit of Fig. 2 for the same general purposes and results as described in connection with Fig. 1. In some installations, the manual valve 2 might be dispensed with and all control had, and remotely, by employment of the solenoid valve, responsive either to timer or thermostatic means, as known in the art.

Given the switch 25 of Fig. 2, should a signal device be desired, to indicate operation of the main burner B, a light 260, or equivalent, may be provided in the circuit. Similarly, in the arrangement of Fig. 1, were a switch such as the switch 25 provided, responsive to the diaphragm 17, an equivalent signal device could be arranged for similar purpose.

I claim:

1. In combination with a main gas burner, a main safety pilot burner arranged in ignition relation therewith, gas supply means for said main gas burner and including a safety valve and a shut off valve upstream thereof, means thermally responsive to said safety pilot burner for control of said safety valve, and gas supply means for said safety pilot burner communicating with said main gas burner supply means between said shut off valve and said safety valve; a standby pilot burner artanged in igniting relation to said main gas burner and said gas main safety pilot burner, and gas supply means for said standby pilot burner including reservoir means, means providing an inlet connection to said reservoir means effectively from said main burner gas supply means between said shut off valve and said safety valve, and check valve means arranged to prevent reverse flow in said inlet connection, the capacity of said reservoir being suflicient that said standby pilot burner may have a period of gas supply therefrom following outage of said safety pilot burner, until after closing of said safety valve.

2. In apparatus as set forth in claim 1 ignition means for said safety pilot burner, switch means responsive to pressure within said reservoir means, and means providing a circuit for control of said ignition means, whereby energization of said ignition means is initiated by said switch means responsive to charging of said reservoir.

References Cited in the file of this patent UNITED STATES PATENTS 726,490 Yerrington Apr. 28, 1903 2,346,704 Ray Apr. 18, 1944 2,449,185 Unger Sept. 14, 1948 2,635,683 Klein Apr. 21, 1953 2,652,109 Ray Sept. 15, 1953

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