Device for the Multifunctional Control of the Supply of a Combustible Gas to a Burner Apparatus

Abstract

A device for the multifunctional control of the supply of a combustible gas to a burner apparatus is disclosed and comprises, in a main gas supply duct, an electromagnetically controlled electrovalve with an on/off function, a flow regulator downstream of this electrovalve and comprising a valve seat, a respective shutter associated therewith and controlled by a reversible electric motor, such as a step-by-step motor, for the control of the displacement of the shutter with respect to the valve seat. In the device the intercepted condition of the valve seat is detected and a signal correlated with the detected intercepted condition of the valve seat is generated this signal being adapted to supply the corresponding consent for the control to open or close the electrovalve, in order to enable or prevent the passage of gas through this duct in the phases of ignition and extinction of the burner respectively.

1 . A device for the multifunctional control of the supply of a combustible gas to a burner apparatus, comprising, in a main gas supply duct:
 an electromagnetically controlled electrovalve with an on/off function,   a flow regulator downstream of the electrovalve and comprising a valve seat, a respective shutter associated therewith and controlled by a reversible electric motor for the control of the displacement of the shutter with respect to the valve seat,   means for detecting the intercepted condition of the valve seat,   means for generating a signal correlated with the detected intercepted condition of the valve seat, said signal being adapted to supply the corresponding consent for the control to open or close the electrovalve, in order to enable or prevent the passage of gas through the duct in the phases of ignition and extinction of the burner respectively.   
   
   
       2 . A device according to  claim 1 , wherein the means for detecting the intercepted condition of the valve seat associated with the shutter comprise sensor members of the mechanically, electrically or optically actuated type. 
   
   
       3 . A device according to  claim 1 , comprising additional energy storage means adapted temporarily to supply said device, and in particular the electrovalve in the event of a power cut in the electricity mains. 
   
   
       4 . A device according to  claim 3 , wherein the energy storage means comprise at least one buffer battery. 
   
   
       5 . A device according to  claim 4 , wherein the buffer battery is of rechargeable type. 
   
   
       6 . A device according to  claim 4 , wherein the buffer battery is located in a position remote from the burner apparatus. 
   
   
       7 . A device according to  claim 1 , comprising respective means for detecting a flame at the main burner and at the pilot burner associated therewith. 
   
   
       8 . A device according to  claim 7 , wherein means are provided for comparing the consent signal with the signal from the flame detection means at the main burner so as to enable the device to operate only if these signals accord, so as to ensure that there is no flame at the main burner with the electrovalve in the condition intercepting the gas passage and vice versa, i.e. there continues to be a flame with the electrovalve open. 
   
   
       9 . A device according to  claim 2 , wherein the sensors of mechanical type comprise proximity sensors adapted to detect that the shutter has reached a position in its control stroke. 
   
   
       10 . A device according to  claim 2 , wherein the means for detecting the intercepted condition of the valve seat comprise means for verifying that electrical current is circulating in the control circuits of the electrically supplied members of said device. 
   
   
       11 . A device according to  claim 1 , comprising a pressure regulator integrated in the flow regulator and comprising a control diaphragm of the shutter acting on the actuator rod of the shutter so that the modulation and on/off functions are integrated in the regulator. 
   
   
       12 . A device according to  claim 1 , , wherein the electrovalve comprises an electromagnetic operator acting directly on the corresponding valve seat. 
   
   
       13 . A device according to  claim 1 , wherein the electrovalve comprises a servo-valve with an electromagnetic control operator. 
   
   
       14 . A device according to  claim 13 , comprising a pressure regulator operationally associated with the servo-valve. 
   
   
       15 . A device according to  claim 13 , wherein the servo-valve comprises a respective valve seat associated with a respective shutter with a diaphragm control, for the opening of the seat in opposition to a resilient recall, one side of the diaphragm being subject to a pilot pressure existing in a pilot chamber which communicates with the main duct via a pilot duct, the electromagnetic operator being adapted to act to close or open the pilot duct so as indirectly to control, via the diaphragm control, the respective shutter of the servo-valve. 
   
   
       16 . A device according to  claim 15 , in which a second communication duct is provided between the pilot chamber of the servo-valve and a section of the main duct downstream of the servo-valve, the pressure regulator with diaphragm control being disposed in this the duct. 
   
   
       17 . A device according to  claim 2 , comprising additional energy storage means adapted temporarily to supply said device, and in particular the electrovalve in the event of a power cut in the electricity mains. 
   
   
       18 . A device according to  claim 5 , wherein the buffer battery is located in a position remote from the burner apparatus. 
   
   
       19 . A device according to  claim 14 , wherein the servo-valve comprises a respective valve seat associated with a respective shutter with a diaphragm control, for the opening of the seat in opposition to a resilient recall , one side of the diaphragm being subject to a pilot pressure existing in a pilot chamber which communicates with the main duct via a pilot duct, the electromagnetic operator being adapted to act to close or open the pilot duct so as indirectly to control, via the diaphragm control, the respective shutter of the servo-valve.