Combustion system for a gas combustion apparatus

Abstract

Combustion system for a gas combustion apparatus adapted for being powered by an electrical supply network (9), comprising a thermoelectric circuit (1) comprising a thermocouple (2), a solenoid valve (3), and a timer device (4,6) configured to keep a burner (8) lit for a preset cooking time. The thermoelectric circuit (1) comprises a switch (5) in parallel with the solenoid valve (3), the switch (5) being enabled by the timer device (4,6) so that the timer device (4,6) causes the switch (5) to be energised and to close said switch when the preset cooking time has elapsed, short-circuiting the thermoelectric circuit (1) and preventing the circulation of electric current to the solenoid valve (3), and permits the circulation of electric current generated by the thermocouple (2) to the solenoid valve (3) in the event of a failure in the supply of electric current from the supply network (9).

Description

TECHNICAL FIELD

[0001] The present invention relates to a combustion system for a gas combustion apparatus.PRIOR ART

[0002] Safety thermoelectric circuits are known in the state of the art for gas combustion apparatus comprising burners such that the thermoelectric circuits cause the gas flow to the burner to be cut off when no flame is detected in the burner. Each thermoelectric circuit comprises a thermocouple and a solenoid valve, the thermocouple generating a thermoelectric current when heated by the burner flame, the generated current being capable of keeping the solenoid valve energised to allow gas to flow to the burner.

[0003] EP0288390A1 describes a thermoelectric circuit further comprising a MOSFET in series between the thermocouple and the solenoid valve with the MOSFET acting as a switch. The MOSFET is powered by an external supply to enable it to operate as a closed switch to allow current to flow from the thermocouple to the solenoid valve. Even in the presence of flame in the burner, the MOSFET can open the thermoelectric circuit when required by the control, preventing the passage of current to the solenoid valve, and therefore causing the solenoid valve to close the gas flow to the burner.

[0004] EP3534069A1 discloses a flame monitoring system for a burner comprising a thermocouple, a solenoid valve, a voltage meter for measuring the voltage of the thermocouple, and interrupting means configured to interrupt the circulation between the thermocouple and the solenoid valve for a time for the voltage meter to measure the voltage of the vacuum thermocouple, said time being such that the gas solenoid valve keeps the gas passage open during the interruption by the own inertia of the gas solenoid valve. The interruption means are configured to be in the open position in the absence of power supply.DISCLOSURE OF THE INVENTION

[0005] The object of the invention is to provide a combustion system for a gas combustion apparatus, as defined in the claims.

[0006] The combustion system according to the invention comprises a thermoelectric circuit comprising a thermocouple configured to detect a flame in the burner, and a solenoid valve electrically connected to the thermocouple, and configured to allow gas to flow to the burner when energised by the thermocouple. The combustion system is configured for being powered by an electrical supply network.

[0007] The combustion system further comprises a timer device configured for keeping the burner lit for a preset cooking time. The thermoelectric circuit comprises a switch in parallel with the solenoid valve, the switch being enabled by the timer device, so that the timer device causes the switch to be energised and to close said switch when the preset cooking time has elapsed, short-circuiting the thermoelectric circuit and preventing the circulation of electric current to the solenoid valve, and permits the circulation of electric current generated by the thermocouple to the solenoid valve in the event of a failure in the supply of electric current from the electrical supply network.

[0008] This results in a combustion system with an optimized timer function that continues to operate despite possible power cuts in the electrical supply network, allowing the use of combustion systems with this function in places where the electrical supply network is subject to constant power cuts.

[0009] These and other advantages and features of the invention will become apparent from the figures and the detailed description of the invention.DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 shows an electrical diagram of a combustion system for gas combustion apparatus according to the invention.DETAILED DISCLOSURE OF THE INVENTION

[0011] Figure 1 shows an electrical diagram of an embodiment of a combustion system according to the invention adapted to a gas combustion apparatus comprising at least a burner 8. The combustion system is adapted to combustion apparatus that include a timer function for the cooking of food. The combustion system is preferably adapted to ovens with the timer function, although it could also be used in cookers with gas burners in their cooking tops that integrate such a function.

[0012] "Timer function" means a function where the user first selects a preset cooking time for the food to be cooked, where the gas burner is lit for a period of time up to the preset cooking time, and the corresponding burner 8 of the oven or cooker is switched off when the preset time has elapsed.

[0013] The combustion system comprises a thermoelectric circuit 1 comprising a thermocouple 2 configured to detect the flame in the burner 8, a solenoid valve 3 electrically connected to the thermocouple 2 and configured to allow gas to flow into the burner 8 when energised by the thermocouple 2, and a switch 5 connected in parallel with the solenoid valve 3, the combustion system being configured for being powered by an electrical supply network 9.

[0014] On the other hand, the combustion system also comprises a timer device configured to keep the corresponding burner 8 lit for the preset cooking time. In order to prevent the burner 8 of the cooking apparatus from being switched off during the operation of the timer function as a result of micropower cuts or power cuts of any duration in the electrical supply network 9, the timer device cooperates with the switch 5 of the thermoelectric circuit 1 to ensure that the ignition of the burner 8 is maintained during the timer function, and to interrupt the circulation of electrical current between the thermocouple 2 and the electromagnetic valve 3 when the cooking time previously set by the user is reached. The timer device is not a safety device, it does not perform a safety function but is an additional and optional feature of the gas cooking apparatus.

[0015] The timer device comprises a switch 4 and a timer 6 (shown schematically) configured to actuate the switch 4 when the preset cooking time is reached. Since the power supply network 9 is preferably an AC network, the combustion system 10 further comprises an AC / DC power supply 7 fed by the power supply network 9, the switch 5 of the thermoelectric circuit 1 being connected to the AC / DC power supply 7. Timer devices are known in the state of the art so that a more detailed description thereof is not considered necessary.

[0016] The timer device enables the switch 5 of the thermoelectric circuit 1, so that it causes said switch 5 to be energised and to close the switch 5 of the thermoelectric circuit 1 when the preset cooking time has elapsed, by connecting it to the AC / DC power supply 7 thereby short-circuiting the thermoelectric circuit 1 so that the current generated by the thermocouple 2 flows through the switch 5 and the solenoid valve 3 is de-energised.

[0017] In particular, the switch 4 of the timer device is electrically connected to the switch 5 of the thermoelectric circuit 1 and to the AC / DC power supply 7, so that, during the period of time up to the preset cooking time, the switch 4 of the timer device prevents the AC / DC power supply 7 from energising the switch 5 of the thermoelectric circuit 1, whereby said switch 5 of the thermoelectric circuit 1 is disabled for the purposes of the thermoelectric circuit 1.

[0018] In the event of a failure in the supply of electric current by the power supply network 9 during the period of time up to the preset cooking time, the timer device does not act on the thermoelectric circuit 1, so that the switch 5 of the thermoelectric circuit 1 is not powered, and is therefore also disabled for the purposes of the thermoelectric circuit 1. The electric current generated by the thermocouple 2 flows to the solenoid valve 3, keeping the solenoid valve 3 energised, and keeping the gas passage continuously open.

[0019] If the electrical power supply is restored before the preset cooking time has elapsed, the solenoid valve 3 remains energised until the preset cooking time has elapsed, at which time the switch 4 of the timer device would cause the switch 5 of the thermoelectric circuit 1 to be energised by the AC / DC power supply 7.

[0020] If the power supply does not return before the preset cooking time is elapsed, preferably the user should shut off the gas supply to the burner 2.

[0021] Preferably, the switch 4 of the timer device is an electromechanical switch. More preferably, the electromechanical switch is a relay type switch.

[0022] Preferably, the switch 5 of the thermoelectric circuit 1 is a transistor. More preferably, it is a MOSFET type transistor. The switch 5 of the thermoelectric circuit 1 comprises a gate terminal 5a, a drain terminal 5b and a source terminal 5c wherein one end of the thermocouple 2 connected to the source terminal 5c and the other end of the thermocouple 2 connected to the drain terminal 5b of the switch 5. The gate terminal 5a is connected to the switch 4 of the timer device and to the AC / DC power supply 7.

[0023] In one embodiment, the switch 5 of the thermoelectric circuit 1 is embedded in the thermocouple 2. In a more preferred embodiment, the AC / DC power supply 7 is also embedded in the thermocouple 2 together with the switch 5 of the thermoelectric circuit 1.

Examples

Embodiment Construction

[0011]Figure 1 shows an electrical diagram of an embodiment of a combustion system according to the invention adapted to a gas combustion apparatus comprising at least a burner 8. The combustion system is adapted to combustion apparatus that include a timer function for the cooking of food. The combustion system is preferably adapted to ovens with the timer function, although it could also be used in cookers with gas burners in their cooking tops that integrate such a function.

[0012]"Timer function" means a function where the user first selects a preset cooking time for the food to be cooked, where the gas burner is lit for a period of time up to the preset cooking time, and the corresponding burner 8 of the oven or cooker is switched off when the preset time has elapsed.

[0013]The combustion system comprises a thermoelectric circuit 1 comprising a thermocouple 2 configured to detect the flame in the burner 8, a solenoid valve 3 electrically connected to the thermocouple 2 and config...

TECHNICAL FIELD

[0001] The present invention relates to a combustion system for a gas combustion apparatus.PRIOR ART

[0002] Safety thermoelectric circuits are known in the state of the art for gas combustion apparatus comprising burners such that the thermoelectric circuits cause the gas flow to the burner to be cut off when no flame is detected in the burner. Each thermoelectric circuit comprises a thermocouple and a solenoid valve, the thermocouple generating a thermoelectric current when heated by the burner flame, the generated current being capable of keeping the solenoid valve energised to allow gas to flow to the burner.

[0003] EP0288390A1 describes a thermoelectric circuit further comprising a MOSFET in series between the thermocouple and the solenoid valve with the MOSFET acting as a switch. The MOSFET is powered by an external supply to enable it to operate as a closed switch to allow current to flow from the thermocouple to the solenoid valve. Even in the presence of flame in the burner, the MOSFET can open the thermoelectric circuit when required by the control, preventing the passage of current to the solenoid valve, and therefore causing the solenoid valve to close the gas flow to the burner.

[0004] EP3534069A1 discloses a flame monitoring system for a burner comprising a thermocouple, a solenoid valve, a voltage meter for measuring the voltage of the thermocouple, and interrupting means configured to interrupt the circulation between the thermocouple and the solenoid valve for a time for the voltage meter to measure the voltage of the vacuum thermocouple, said time being such that the gas solenoid valve keeps the gas passage open during the interruption by the own inertia of the gas solenoid valve. The interruption means are configured to be in the open position in the absence of power supply.DISCLOSURE OF THE INVENTION

[0005] The object of the invention is to provide a combustion system for a gas combustion apparatus, as defined in the claims.

[0006] The combustion system according to the invention comprises a thermoelectric circuit comprising a thermocouple configured to detect a flame in the burner, and a solenoid valve electrically connected to the thermocouple, and configured to allow gas to flow to the burner when energised by the thermocouple. The combustion system is configured for being powered by an electrical supply network.

[0007] The combustion system further comprises a timer device configured for keeping the burner lit for a preset cooking time. The thermoelectric circuit comprises a switch in parallel with the solenoid valve, the switch being enabled by the timer device, so that the timer device causes the switch to be energised and to close said switch when the preset cooking time has elapsed, short-circuiting the thermoelectric circuit and preventing the circulation of electric current to the solenoid valve, and permits the circulation of electric current generated by the thermocouple to the solenoid valve in the event of a failure in the supply of electric current from the electrical supply network.

[0008] This results in a combustion system with an optimized timer function that continues to operate despite possible power cuts in the electrical supply network, allowing the use of combustion systems with this function in places where the electrical supply network is subject to constant power cuts.

[0009] These and other advantages and features of the invention will become apparent from the figures and the detailed description of the invention.DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 shows an electrical diagram of a combustion system for gas combustion apparatus according to the invention.DETAILED DISCLOSURE OF THE INVENTION

[0011] Figure 1 shows an electrical diagram of an embodiment of a combustion system according to the invention adapted to a gas combustion apparatus comprising at least a burner 8. The combustion system is adapted to combustion apparatus that include a timer function for the cooking of food. The combustion system is preferably adapted to ovens with the timer function, although it could also be used in cookers with gas burners in their cooking tops that integrate such a function.

[0012] "Timer function" means a function where the user first selects a preset cooking time for the food to be cooked, where the gas burner is lit for a period of time up to the preset cooking time, and the corresponding burner 8 of the oven or cooker is switched off when the preset time has elapsed.

[0013] The combustion system comprises a thermoelectric circuit 1 comprising a thermocouple 2 configured to detect the flame in the burner 8, a solenoid valve 3 electrically connected to the thermocouple 2 and configured to allow gas to flow into the burner 8 when energised by the thermocouple 2, and a switch 5 connected in parallel with the solenoid valve 3, the combustion system being configured for being powered by an electrical supply network 9.

[0014] On the other hand, the combustion system also comprises a timer device configured to keep the corresponding burner 8 lit for the preset cooking time. In order to prevent the burner 8 of the cooking apparatus from being switched off during the operation of the timer function as a result of micropower cuts or power cuts of any duration in the electrical supply network 9, the timer device cooperates with the switch 5 of the thermoelectric circuit 1 to ensure that the ignition of the burner 8 is maintained during the timer function, and to interrupt the circulation of electrical current between the thermocouple 2 and the electromagnetic valve 3 when the cooking time previously set by the user is reached. The timer device is not a safety device, it does not perform a safety function but is an additional and optional feature of the gas cooking apparatus.

[0015] The timer device comprises a switch 4 and a timer 6 (shown schematically) configured to actuate the switch 4 when the preset cooking time is reached. Since the power supply network 9 is preferably an AC network, the combustion system 10 further comprises an AC / DC power supply 7 fed by the power supply network 9, the switch 5 of the thermoelectric circuit 1 being connected to the AC / DC power supply 7. Timer devices are known in the state of the art so that a more detailed description thereof is not considered necessary.

[0016] The timer device enables the switch 5 of the thermoelectric circuit 1, so that it causes said switch 5 to be energised and to close the switch 5 of the thermoelectric circuit 1 when the preset cooking time has elapsed, by connecting it to the AC / DC power supply 7 thereby short-circuiting the thermoelectric circuit 1 so that the current generated by the thermocouple 2 flows through the switch 5 and the solenoid valve 3 is de-energised.

[0017] In particular, the switch 4 of the timer device is electrically connected to the switch 5 of the thermoelectric circuit 1 and to the AC / DC power supply 7, so that, during the period of time up to the preset cooking time, the switch 4 of the timer device prevents the AC / DC power supply 7 from energising the switch 5 of the thermoelectric circuit 1, whereby said switch 5 of the thermoelectric circuit 1 is disabled for the purposes of the thermoelectric circuit 1.

[0018] In the event of a failure in the supply of electric current by the power supply network 9 during the period of time up to the preset cooking time, the timer device does not act on the thermoelectric circuit 1, so that the switch 5 of the thermoelectric circuit 1 is not powered, and is therefore also disabled for the purposes of the thermoelectric circuit 1. The electric current generated by the thermocouple 2 flows to the solenoid valve 3, keeping the solenoid valve 3 energised, and keeping the gas passage continuously open.

[0019] If the electrical power supply is restored before the preset cooking time has elapsed, the solenoid valve 3 remains energised until the preset cooking time has elapsed, at which time the switch 4 of the timer device would cause the switch 5 of the thermoelectric circuit 1 to be energised by the AC / DC power supply 7.

[0020] If the power supply does not return before the preset cooking time is elapsed, preferably the user should shut off the gas supply to the burner 2.

[0021] Preferably, the switch 4 of the timer device is an electromechanical switch. More preferably, the electromechanical switch is a relay type switch.

[0022] Preferably, the switch 5 of the thermoelectric circuit 1 is a transistor. More preferably, it is a MOSFET type transistor. The switch 5 of the thermoelectric circuit 1 comprises a gate terminal 5a, a drain terminal 5b and a source terminal 5c wherein one end of the thermocouple 2 connected to the source terminal 5c and the other end of the thermocouple 2 connected to the drain terminal 5b of the switch 5. The gate terminal 5a is connected to the switch 4 of the timer device and to the AC / DC power supply 7.

[0023] In one embodiment, the switch 5 of the thermoelectric circuit 1 is embedded in the thermocouple 2. In a more preferred embodiment, the AC / DC power supply 7 is also embedded in the thermocouple 2 together with the switch 5 of the thermoelectric circuit 1.

Examples

Embodiment Construction

[0011]Figure 1 shows an electrical diagram of an embodiment of a combustion system according to the invention adapted to a gas combustion apparatus comprising at least a burner 8. The combustion system is adapted to combustion apparatus that include a timer function for the cooking of food. The combustion system is preferably adapted to ovens with the timer function, although it could also be used in cookers with gas burners in their cooking tops that integrate such a function.

[0012]"Timer function" means a function where the user first selects a preset cooking time for the food to be cooked, where the gas burner is lit for a period of time up to the preset cooking time, and the corresponding burner 8 of the oven or cooker is switched off when the preset time has elapsed.

[0013]The combustion system comprises a thermoelectric circuit 1 comprising a thermocouple 2 configured to detect the flame in the burner 8, a solenoid valve 3 electrically connected to the thermocouple 2 and config...

Claims

1. Combustion system for a gas combustion apparatus comprising at least one burner (8), the combustion system comprising a thermoelectric circuit (1) comprising a thermocouple (2) configured to detect flame in the burner (8), and a solenoid valve (3) electrically connected to the thermocouple (2), and configured to allow the passage of gas to the burner (8) when energised by the thermocouple (2), the combustion system being configured for being powered by an electrical supply network (9), characterised in that it further comprises a timer device (4,6) configured to keep the burner (8) lit for a preset cooking time, the thermoelectric circuit (1) comprising a switch (5) in parallel with the solenoid valve (3), the switch (5) being enabled by the timer device (4,6) so that the timer device (4,6) causes the switch (5) to be energised and to close said switch (5) when the preset cooking time has elapsed, short-circuiting the thermoelectric circuit (1) and preventing the circulation of electric current to the solenoid valve (3), and permits the circulation of electric current generated by the thermocouple (2) to the solenoid valve (3) in the event of a failure in the supply of electric current from the electrical supply network (9).

2. Combustion system according to the preceding claim, comprising an AC / DC power supply (7) connectable to the electrical supply network (9), the timer device (4,6) being connected to the switch (5) and to the AC / DC power supply (7), so that the timer device (4,6) closes the switch (5) by connecting it to the AC / DC power supply (7).

3. Combustion system according to the preceding claim, wherein the timer device (4,6) comprises a switch (4) and a timer (6) configured to actuate the switch (4), said switch (4) being electrically connected to the switch (5) of the thermoelectric circuit (1) and to the AC / DC power supply (7), such that, during the period of time up to the preset cooking time, the switch (4) of the timer device (4,6) prevents the power supply to the switch (5) of the thermoelectric circuit (1) by the AC / DC power supply (7), when the preset cooking time is reached the timer device (4,6) enables the switch (5) of the thermoelectric circuit to be powered by the AC / DC power supply (7) and, in the event of a power failure during the period of time up to the preset cooking time, the switch (5) of the thermoelectric circuit (1) is not powered.

4. Combustion system according to the preceding claim, wherein the switch (4) of the timer device is an electromechanical switch.

5. Combustion system according to any of claims 2 to 4, wherein the switch (5) of the thermoelectric circuit (1) is a transistor, preferably a MOSFET.

6. Combustion system according to the preceding claim, wherein a drain terminal (5b) and a source terminal (5c) of the switch (5) are each connected to a respective terminal of the thermocouple (2), and a gate terminal (5a) of the switch (5) is connected to the switch (4) of the timer device and to the AC / DC power supply (7)7. Combustion system according to any of claims 2 to 6, wherein the switch (5) of the thermoelectric circuit (1) is embedded in the thermocouple (2).

8. Combustion system according to the preceding claim, wherein the AC / DC power supply (7) is embedded in the thermocouple (2).

9. Gas combustion apparatus comprising at least one burner (8) and a combustion system (10) according to any of the preceding claims associated with the corresponding burner (8).

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