JPS627448B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention, in a pot-type burner having an ignition tray and a combustion tray, prevents excess fuel from being supplied to the ignition tray when starting the burner, thereby ensuring stable combustion from the time of ignition. The present invention relates to a safety control device for ensuring safety during a state.

For pot-type burners used in grain dryers, etc., if the fuel supply pump is equipped with an automatic temperature control device to keep the burner temperature constant, the burner temperature will change immediately after ignition when starting the burner. is still low, so the amount of fuel supplied by the fuel supply pump is still large. For this reason, at the time of ignition, fuel tends to be supplied in excess of the amount necessary for ignition and stable combustion, and this excess supply may leak from the ignition pan and cause a fire. It was dangerous.

By the way, even in the conventional pot burner,
It is known that a solenoid valve is provided in the middle of an oil pipe that supplies fuel to a burner, and a small diameter pipe that supplies a small amount of fuel is connected to the oil pipe as a bypass of the solenoid valve. Even with such a configuration, it is possible to maintain safety by preventing excess fuel from being supplied when the burner is ignited.

However, since the above-mentioned bypass is for gradually supplying a small amount of fuel during ignition, its pipe diameter must be extremely small, and when the fuel oil temperature is low and its viscosity is high, such as during cold seasons, If the fuel oil contains even a small amount of impurities, the bypass may become clogged and the required amount of fuel may not be supplied at the time of ignition, resulting in ignition failure or failure.

Therefore, in view of the above problems, the present invention opens a solenoid valve interposed in the fuel supply path to the ignition pan when starting the burner, and supplies the appropriate amount of fuel for ignition after a certain short period of time elapses. By configuring an ignition fuel supply control circuit that closes later, it is possible to ensure ignition when starting the burner and ensure safety, as well as to ensure combustion after a certain short period of time for the flame to stabilize after confirming the ignition flame. By configuring a combustion fuel supply control circuit that opens the dish-side solenoid valve and self-maintains that state, it is possible to improve the transition to main combustion and to ensure safety by preventing fuel from leaking during that time. The present invention aims to provide a safety control device for burners.

Next, the configuration of the present invention will be described with reference to a preferred embodiment shown in the drawings.

In FIG. 1, 1 is a pot-type burner, and this burner 1 is equipped with an ignition plate 2 and a combustion plate 3.
Fuel supply pipes 5 and 6 are connected from the fuel supply pump 4, respectively.
Electromagnetic valves 7 and 8 are interposed in the middle, respectively. 9 is a flame detection element (flame eye, flame rod, etc.), 10 is a thermostat for overheat detection, 1
1 is an ignition heater, and 12 is a fuel tank. Note that this burner 1 has a blower (not shown) and blows hot air.

FIG. 2 shows a safety control device for the pot-type burner 1, in which the fuel supply pump 4 is connected to the power source E through the opening/closing contacts of a relay _R3 (described later) in series.
The solenoid valve 7 on the ignition plate 2 side is connected to the relay R ₄
The electromagnetic valve 8 and the ignition heater 11 on the combustion dish 3 side are connected to the same point as the fuel supply pump 4 through the switching contacts of the relay _R5 in series. The opening/closing contacts of relays R ₃ and R ₄ are open in the de-energized state and closed in the energized state.
The switching contact of relay _R5 switches to the ignition heater 11 side in a non-energized state and to the solenoid valve 8 side in an energized state.

On the other hand, E′ is a power supply, SW is a power switch, WS is a wind pressure switch operated by the air blowing from the blower, R ₁ to _{R 5} are relays, Bz is an alarm (buzzer, etc.), and AND ₁ is an AND circuit. One input terminal of this AND circuit AND ₁ is connected to the wind pressure switch WS.
and the other input terminal is connected to the power supply E' side through the switching contact of relay R ₂ (the side that closes in the de-energized state), and the output of the AND circuit AND _1. Relay _R3 is connected to the side. Alarm Bz is connected to the switching contact of relay _R2 (the side that closes in the energized state).
TS ₁ to TS ₄ are timer circuits. Timer circuit TS ₁
defines the time for supplying an appropriate amount of fuel to the ignition pan 2 for ignition when starting the burner, and
It operates only for a certain short time T ₁ (approximately 10 to 20 seconds). Relay R ₄ is connected to power supply E' via this timer circuit TS ₁ . In addition, the timer circuit TS ₃ is set to a time T ₃ commensurate with the stabilization time of the ignition flame.
(approximately 10 seconds), and relay _R5 is connected to the power source E' with the contacts of timer _TS3 and relay _R1 connected in series. A is a self-holding circuit, and one input terminal of this self-holding circuit A is connected to the timer _TS3 , and the other input terminal is connected to the power source E' via the timer _TS2 . TS ₂ specifies a preparation time T ₂ (approximately 2 minutes) for issuing an alarm if ignition does not occur within a series of ignition times. B is a flame detection circuit, and this flame detection circuit B receives the signal from the flame detection element 9 and operates the built-in relay _R1 , and the detection output signal of the flame detection circuit B is , the timer circuit TS ₄ and the inverting circuit C as one input of the AND circuit AND ₂ . The output of the self-holding circuit A is introduced into the other input terminal of the AND circuit AND ₂ , and the output of the AND circuit AND ₂ becomes one input of the self-holding circuit D. is connected to the thermostat 10. Relay _R2 is controlled by the output of the self-holding circuit.

Next, the operation of the present invention will be explained.

When starting the burner, turn on the power switch SW, and if the blower is operating normally, the wind pressure switch WS is closed, so both inputs of the AND circuit AND ₁ become H, and its output becomes H, so relay R ₃ is excited. For this reason, the contacts of relay _R3 are closed, fuel supply pump 4 is operated, and at the same time, ignition heater 11 is heated to red. Also, at the same time as the power switch SW is turned on, the timer TS ₁ starts operating, so the relay R ₄ is energized, its contacts close, the solenoid valve 7 opens, and fuel is supplied to the ignition pan 2.
It is ignited by the ignition heater 11. The timer TS ₁ is turned off after a certain short time T ₁ (approximately 10 to 20 seconds), so after that time T ₁ has elapsed, the solenoid valve 7 closes, a predetermined amount of fuel is supplied to the ignition pan 2, and the fuel is turned off. is never in excess supply. In addition, since the amount of fuel supplied at the time of ignition is controlled by the solenoid valve 7, there is no need to make the fuel supply pipe 5 thinner, which may prevent the fuel oil from increasing in viscosity or containing impurities. However, a predetermined amount of fuel is supplied at the time of ignition.

On the other hand, when an ignition flame is generated in the ignition pan 2, it is detected by the flame detection element 9, and the relay _R1 provided in the flame detection circuit B is energized, its contacts are closed and the timer _TS3 is activated. However, this timer TS ₃ is turned on after a certain short time T ₃ (approximately 10 seconds), relay R ₅ is energized, its switching contact is switched to the solenoid valve 8 side, and the flow to the combustion plate 3 is switched on. Since the supply of fuel is started, main combustion begins in the combustion dish 3. Then, the solenoid valve 8 is opened by the timer TS ₃ after the time required for the ignition flame to stabilize in the ignition tray 2, and fuel is supplied to the combustion tray 3, so that the ignition combustion state changes to the main combustion state. The transition takes place well, and no fuel leakage occurs during this period.

Note that if the ignition does not occur within the above series of ignition times, no signal will be sent from the flame detection element 9, so if this state exceeds the set time of the timer _TS4 , an AND signal will be sent through the inverting circuit C. One input of the circuit AND ₂ becomes H, and when the preparation time T ₂ of the timer TS ₂ has elapsed, the output of the self-holding circuit A becomes H. Therefore, the other input of the AND circuit AND ₂ becomes H, so the output of the self-holding circuit D becomes H.
As a result, relay _R2 is energized, its contact is switched to the alarm Bz side, and an alarm is issued. At the same time, one input of the AND circuit AND ₁ becomes L, and the relay R ₃ is de-energized, its contacts open, and the operation of the fuel supply pump 4 is immediately stopped, cutting off the fuel supply and ensuring the safety of the burner. is ensured. When the burner becomes overheated, the thermostat 10 sends an H signal to the self-holding circuit D, so the operation of the fuel supply pump 4 is immediately stopped in the same way as above, and the safety of the burner is maintained. Become.

In short, the present invention forms a fuel supply path from a fuel supply pump to the ignition pan and combustion pan of a pot-type burner, and interposes a solenoid valve in each fuel supply path, so that when the burner is started, the ignition pan side solenoid valve The ignition fuel supply control circuit opens and closes after a certain short period of time that supplies an appropriate amount of fuel for ignition, and after the ignition flame is confirmed, the above-mentioned combustion Since the combustion fuel supply control circuit is configured to open the dish-side solenoid valve and self-maintain that state, the amount of fuel supplied to the ignition dish when starting the burner can be controlled to prevent changes in the viscosity of the fuel oil and the contamination of impurities. In addition to being able to maintain a constant and appropriate amount of fuel regardless of whether it is present or not, it is also possible to start supplying fuel to the combustion dish after the flame has stabilized after ignition. Therefore, according to the present invention, it is possible to ensure ignition at the time of starting the burner and to ensure safety, as well as to ensure a good transition to main combustion and to prevent leakage of fuel during that time, thereby ensuring safety. It produces the effect that can be achieved.

[Brief explanation of the drawing]

The drawings show one embodiment of the device of the present invention, in which FIG. 1 is an explanatory diagram showing the configuration of a burner, and FIG. 2 is a circuit diagram of a safety control device. 1...Pot type burner, 2...Ignition plate, 3...
Combustion dish, 4...Fuel supply pump, 5, 6...Fuel supply pipe, 7, 8...Solenoid valve, 9...Flame detection element, 10...Thermostat for overheat detection, 11...
...Ignition heater, 12...Fuel tank, _R1 to _R5 ...
...Relay, SW...Power switch, WS...Wind pressure switch, Bz...Alarm, TS ₁ ~ TS ₂ ...Timer circuit, A...Self-holding circuit, B...Flame detection circuit,
D... Self-holding circuit, E, E'... Power supply.

Claims (1)

[Claims] 1 Form a fuel supply path from the fuel supply pump to the ignition pan and combustion pan of the pot burner, respectively,
An ignition fuel supply control circuit is provided in which a solenoid valve is interposed in each fuel supply path, and the solenoid valve on the ignition plate side is opened when the burner is started, and closed after a certain short period of time to supply an appropriate amount of fuel for ignition. and a combustion fuel supply control circuit that opens the combustion dish side electromagnetic valve and self-maintains this state after a certain short time period during which the flame is stabilized after the ignition flame is confirmed. safety control device.