Device for regulating the air/gas mixture supplied to burner appliances, in particular for burners of decorative fires

Abstract

A device for regulating the air/gas mixture supplied to a gas burner appliance of a decorative fire is provided. The device includes a duct for supplying the air/gas fuel mixture to the burner and a choke of the flow of primary air taken into the duct and adapted to be mixed with the flow of gas or the flow of the air/gas mixture, in which heat-sensitive actuator acting directly on the choke is provided so that the choking of the flow is regulated automatically as a function of the heat level reached in the heat-sensitive actuator.

1 . A device for regulating an air/gas mixture supplied to a gas burner appliance of a decorative fire, comprising a duct for supplying the air/gas fuel mixture to the burner and a choke of a flow of primary air taken into the duct and adapted to be mixed with a flow of gas or a flow of the air/gas mixture, the device comprising a heat-sensitive actuator acting directly on the choke so that the choking of the flow is regulated automatically as a function of a heat level reached in the heat-sensitive actuator. 
   
   
       2 . A device according to  claim 1 , wherein the heat-sensitive actuator is of the type with a bimetallic plate made from respective metals having different coefficients of thermal expansion. 
   
   
       3 . A device according to  claim 2 , wherein the choke comprises a choke member of the flow connected to the plate so as to be automatically displaced from and to a position choking the duct as a function of the temperature reached in the plate following ignition of the burner. 
   
   
       4 . A device according to  claim 2 , wherein the choke comprises at least one shutter member associated with at least one respective through opening through the duct adapted selectively to enable the intake of primary air into the duct, the shutter member being controlled in operation by the bimetallic plate actuator. 
   
   
       5 . A device according to  claim 2 , wherein the bimetallic plate forms the choke member of the flow. 
   
   
       6 . A device according to  claim 5 , wherein the plate is disposed inside the duct ( 3 ). 
   
   
       7 . A device according to  claim 5 , wherein the plate is connected at one end to the inner wall of the duct and can be displaced between a first position in which, at ambient temperature, it is disposed in the position of maximum choking of the flow supplied through the duct so as to reduce the quantity of primary air of the air/gas mixture, and a second position in which, at a predetermined temperature level, the plate is disposed in the position of minimum choking of the flow. 
   
   
       8 . A device according to  claim 7 , wherein the temperature level is selected to be equal to or more than 40° C.