JPH0160736B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a combustion control circuit for a combustor.

Conventionally, a combustion control circuit for a combustor includes a manually operated member that can be switched between a closed position, an open position, and an ignition position, and an electromagnetic safety valve and a cutoff valve connected in series with the safety valve are interposed in the gas passage leading to the burner unit. and by operating the member from the closed position to the ignition position beyond the open position, the safety valve and the shutoff valve are pressed open and the burner unit is ignited, and the first
As shown in the figure, the changeover switch a is switched from the charging circuit c of the capacitor b to the discharging circuit d, and by operating the member from the ignition position to the open position, the pressure on the safety valve is released, and the safety valve is connected to the solenoid e of the capacitor b. The valve is maintained in an open state by applying a discharge current of 1 and an electromotive force of a thermocouple f provided in the burner unit, and further, by operating the member from the open position to the closed position, the shutoff valve is closed and the burner unit is closed. Types with valves are known. In addition, in Fig. 1, g
is a switch that is closed when the above-mentioned member is operated to the ignition position, h is an igniter, and i is a power source.

However, after the combustor is used, while the safety valve is held open by the electromotive force of the thermocouple due to residual heat, the manually operated member is pressed by a small amount of pressure so that the igniter does not operate. When the safety valve is opened, raw gas is released until the thermocouple cools down and the safety valve closes, causing an inconvenience. The present invention aims to provide a combustion control circuit for a combustor that is free from such inconveniences, and includes a manually operated member that can be freely switched between a closed position, an open position, and an ignition position, and a gas passage connected to a burner unit. An electromagnetic safety valve and a shutoff valve connected in series with the safety valve are interposed, and when the manual operating member is operated from a closed position to an ignition position exceeding an open position, the safety valve and the shutoff valve are pressed open and the burner unit is ignited. and release the pressure on the safety valve by operating the manual operating member from the ignition position to the open position, and maintain the safety valve in the open state by the discharge current of the capacitor and the electromotive force of the thermocouple provided in the burner unit. Further, in the burner unit which extinguishes the burner unit by closing the cutoff valve by operating the manual operation member from the open position to the closed position, the shutoff valve may be closed by operating the manual operation member from the open position to the closed position. The present invention is characterized in that a circuit is provided in conjunction with the valve to cause a reverse current to flow through the solenoid of the safety valve to cancel the current generated by the electromotive force of the thermocouple, thereby closing the safety valve.

Embodiments of the present invention will be described below with reference to the drawings.

In Fig. 2, 1 indicates a burner unit;
The burner unit 1 consists of a main burner 1a and a pilot burner 1b.

Reference numeral 2 denotes a gas passage that supplies fuel gas to the burner unit 1, and the gas passage 2 has an electromagnetic safety valve 3 and a cutoff valve 4 interposed therebetween, and these valves 3 and 4 can be set in a closed position and an open position. The valve is opened by pressing a manual operating member 5 which can be switched between the ignition position and the ignition position.To explain this in detail, the operating member 5 is a push button 5a provided on the operating panel 6 on the front side of the combustor. It is composed of an operating rod 5b, a valve rod 5c coaxially extending rearward and inserted into the gas passage 2, and a lever 5d at the rear end, and the valve rod 5c includes:
In addition to supporting the shutoff valve 4, an ignition valve 7 consisting of a small diameter portion formed in the valve rod 5c is provided, and when the operation rod 5b is pushed against the return spring 8 from the illustrated closed position, After passing through an intermediate open position in which the cutoff valve 4 is opened, the cutoff valve 4 and the ignition valve 7 are opened, and the safety valve 3 is pushed open via the lever 5d. According to the switching operation to the ignition position and the release of the push operation at the ignition position,
A stopper 10 that engages with a protrusion 9 on the outer periphery of the operating rod 5b when the operating rod 5b is returned by a return spring 8.
The stopper 10 is stopped at the open position by pressing the fire extinguishing button 11 arranged side by side with the push button 5a.
When it is removed from the protrusion 9, it is returned to the closed position.

The present invention relates to a control circuit for the safety valve 3 interposed in the gas supply path 2 of the combustor. Solenoid 3 of safety valve 3
The circuit shown in FIG. 3 includes a capacitor 13 which energizes the safety valve 3 to keep the safety valve 3 open and keeps the safety valve 3 open by a discharge current until the valve is kept open. Now, by pressing the manual operation member 5, the charging circuit 16 of the capacitor 13 is connected to the power source 15 through one fixed contact 14a of the changeover switch 14, and the capacitor is connected to the power supply 15 through the other fixed contact 14b of the changeover switch 14. 13
and a discharge circuit 17 connected to the discharge circuit 1.
A normally open switch 18 which is closed when the manual operating member 5 is in the ignition position and opened when the manually operated member 5 returns to the open position, and a resistor 19 in parallel with the normally open switch 18 are interposed at 7.

The aforementioned changeover switch 14 has its movable contact 14.
When the manual operating member 5 is in the closed position, the fixed contact 14a that connects the capacitor 13 to the charging circuit 16 side is selected, and the fixed contact 14a that connects the discharging circuit 17 and the capacitor 13 is selected when the manual operation member 5 is pressed from the closed position. The state changes to a state in which the contact 14b is selected.

Furthermore, in the figure, the igniter 21 facing the pilot burner 1b is an ignition switch that intervenes in the igniter 20, and the ignition switch 21 is connected to the manual operation member 5.
Close by pressing the button to the ignition position.

When the manual operating member 5 is pushed and operated from the starting position to the final position, the selector switch 14 is first switched to the side that selects the discharge circuit 17, then the shutoff valve 4 is opened at the open position, and the switch 21 is opened at the ignition position. is closed to operate the igniter 20, and at the same time as the electromagnetic safety valve 3 is pushed open, the switch 18 intervening in the discharge circuit 17 is closed. Therefore, the charge stored in the capacitor 13 is discharged relatively quickly through the switch 18 of the discharge circuit 17 as shown by A in FIG. Keep the valve open. Therefore, fuel gas is supplied to the burner unit 1, and is ignited by a spark from the igniter 20.

When the manual operation member 5 is subsequently released from the push operation and returned to the open position, the normally open switch 18 is opened. Therefore, the discharge of the capacitor 13 is caused by the resistance 19
As a result, the current value rapidly decreases as shown by B in FIG. 4, and reaches the withdrawal current value a at which the electromagnetic safety valve 3 closes in a short time.

Therefore, if the burner unit 1 is switched to the open position while it is not ignited, the electromagnetic safety valve 3
The valve can be closed relatively quickly.

Also, burner unit 1 is ignited, but thermocouple 1
When the electromotive force of capacitor 13 has not reached a predetermined value and the capacitor 13 is returned to the open position, the discharge current value of capacitor 13 drops rapidly as described above, but the discharge occurs gradually, and the remaining Thermocouple 12
The current due to the electromotive force of is added,
This makes it possible to keep the withdrawal current value a or higher, and after that, the valve can be kept open by the electromotive force of the thermocouple 12 heated by the combustion heat of the burner unit 1, so once the burner unit 1 is ignited, the electromagnetic safety valve 3 is activated. The valve is never closed.

To extinguish the fire, press the fire extinguishing push button 11 to disengage the stopper 10 from the protrusion 9 and release the operating member 5.
During this operation, the shutoff valve 4 is closed to cut off the supply of combustion gas to the burner unit 1 to extinguish the fire, and the return operation of the operating member 5 causes the changeover switch 14 to close the charging circuit 16. Switch to the side that creates.

Thus, the charging current of the capacitor 13 flows through the solenoid 3a of the safety valve 3. This charging current is a reverse current that cancels the current flowing through the solenoid 3a due to the electromotive force of the thermocouple 12, and
Since a is demagnetized, the holding of the open state of the safety valve 3 by the electromotive force of the thermocouple 12 is released, and the valve is closed.

Therefore, after using the combustor, while the safety valve 3 is in the open state due to the electromotive force of the thermocouple 12 generated due to residual heat, the push button 5a is pressed again and the manual operation member 5 is activated so that the igniter 20 is activated. Even if the cutoff valve 4 is opened by pressing only a small amount of pressure so that it does not operate, raw gas will not be released.

Incidentally, in the above embodiment, the burner unit 1 is of a type equipped with a main burner 1a and an ignition burner 1b, but it can also be of a type equipped with a starter burner for constant flame in addition to these burners. Also, in the above embodiment, the ignition circuit is used as the igniter to ignite the igniter, but a piezoelectric igniter may also be used to ignite the igniter.

As described above, according to the present invention, an electromagnetic safety valve and a cutoff valve connected in series with the safety valve are interposed in the gas passage connected to the burner unit, and the above-mentioned operation is performed by operating the manually operated valve from the closed position to the ignition position beyond the open position. The safety valve and the shutoff valve are pressed open and the burner unit is ignited, and the pressure on the safety valve is released by operating the member from the ignition position to the open position. The burner unit is extinguished by holding the valve in the open state by a pair of electromotive forces, and then closing the shutoff valve by operating the member from the open position to the closed position, in which the burner unit is extinguished by operating the member from the open position to the closed position. A circuit is provided to close the safety valve by passing a reverse current through the solenoid of the safety valve to cancel the current generated by the electromotive force of the thermocouple in conjunction with the closing of the shutoff valve by the operation of the combustor. Even if the shutoff valve is opened by pressing the manual operating member to the extent that the igniter does not activate while the valve is held open by the electromotive force of the thermocouple due to residual heat, the thermocouple will cool and the safety valve will open. This has the effect of preventing raw gas from being released until the valve closes.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a combustion control circuit of a conventional combustor, FIG. 2 is a partially cutaway side view of a device according to an embodiment of the present invention, and FIG. 3 is a circuit diagram of an embodiment of the present invention. Figure 4 shows an explanatory diagram of its operation. 1...burner unit, 2...gas passage, 3...
... Solenoid safety valve, 5 ... Manual operation member, 11 ... Fire extinguishing push button, 12 ... Thermocouple, 13 ... Capacitor, 14 ... Selector switch, 15 ... Power supply, 16
...charging circuit, 17...discharging circuit, 18...normally open switch, 19...resistor, 20...igniter.

Claims (1)

[Claims] 1. A manual operation member that can be freely switched between a closed position, an open position, and an ignition position is provided, and an electromagnetic safety valve and a shutoff valve connected in series with the safety valve are interposed in the gas passage connected to the burner unit, and the manual operation member is closed. When the manual operation member is operated from the ignition position to the ignition position beyond the open position, the safety valve and the shutoff valve are pressed open and the burner unit is ignited, and when the manual operation member is operated from the ignition position to the open position, the safety valve is pressed. is released, and the safety valve is held open by the discharge current of the capacitor and the electromotive force of the thermocouple provided in the burner unit,
Furthermore, in the burner unit which extinguishes the burner unit by closing the shutoff valve by operating the manual operating member from the open position to the closed position, the shutoff valve may be closed by operating the manual operating member from the open position to the closed position. A combustion control circuit for a combustor, characterized in that a circuit is provided in which a reverse current is passed through the solenoid of the safety valve to cancel the current generated by the electromotive force of the thermocouple, thereby closing the safety valve.