Abstract: A device for controlling a fuel-oxidizer mixture for a premix gas burner, comprises: an intake duct for admitting the mixture into the burner; an injection duct, connected to the intake duct to supply the fuel; a monitoring device for checking the state of combustion in the burner; a gas regulating valve; a fan located in the intake duct; a control unit for controlling the speed of rotation of the fan between a first and a second rotation speed, corresponding to a minimum flow rate of oxidizer (Qmin) and a maximum flow rate of oxidizer (Qmax), respectively; a regulator coupled to the intake duct and having a first aperture, adjustable through a first shutter, and a second aperture, adjustable through a second shutter. The control unit is configured to drive the gas regulating valve in real time.

Abstract: Described is a device for controlling a fuel-oxidizer mixture for a premix gas burner, comprising an intake duct, which defines a cross section for the passage of a fluid inside the duct and includes an inlet, a mixing zone and an outlet, an injection duct, connected to the intake duct in the mixing zone, a monitoring device, configured for generating a control signal, representing a combustion state in the burner, a gas regulating valve, positioned along the injection duct, a fan, positioned in the intake duct for generating therein an operating flow in an inflow direction, a control unit, configured to control the rotation speed of the fan, a regulator, coupled with the intake duct for varying the cross section. The control unit is configured for controlling the gas regulating valve in real time.

Abstract: A method for reducing harmful gas emissions from a gas-fired boiler including a sealed forced-draught combustion chamber in which there is a burner to which there leads a first conduit for drawing in combustion air and from which there departs a second conduit for the discharge of combustion flue gases. Provision is made for drawing off a portion of the flue gases or exhaust gases from the second conduit and injecting it into the combustion air to reduce the percentage of atmospheric oxygen present in that combustion air and consequently reduce the production of harmful gases in the combustion flue gases. A boiler operating according to the aforesaid method is also disclosed.

Abstract: A method for reducing harmful gas emissions from a gas-fired boiler including a sealed forced-draught combustion chamber in which there is a burner to which there leads a first conduit for drawing in combustion air and from which there departs a second conduit for the discharge of combustion flue gases. Provision is made for drawing off a portion of the flue gases or exhaust gases from the second conduit and injecting it into the combustion air to reduce the percentage of atmospheric oxygen present in that combustion air and consequently reduce the production of harmful gases in the combustion flue gases. A boiler operating according to the aforesaid method is also disclosed.

Abstract: A method for regulating the combustible mixture such as air/gas, air/methane gas or the like fed to a burner, the method including measuring a flame signal correlated with the composition of the mixture fed by feed members controlled by a combustion controller arranged to regulate the combustion on the basis of the flame signal. During burner operation the mixture feed conditions are modified within a narrow time interval to obtain a flame signal variation; a ratio between values of this the flame signal at the end and at the beginning of the interval is compared with a predetermined reference value; and, on the basis of the deviation of this ratio from the reference value, the flame set point is regulated, as consequently is the air or gas of the mixture if this is rendered necessary.

Abstract: A method and device for verifying the integrity of each operator of a gas valve including two operators disposed in succession on a passage path for the gas directed to a burner; the operator being subjected to command action by a corresponding actuator controlled by a command and control unit adapted to sense the presence of the flame in the burner, which is correlated with the gas flow rate reaching this burner. Each operator is made to close alternately, with corresponding cessation of gas feed to the burner and successive sensing of the extinguishing of the flame at the burner within a predefined time period, power to these operators being completely interrupted if it is sensed after said time period that the flame is extinguished.

Abstract: A method for flame sensing in a solid, liquid or gaseous fuel burner, the flame generated at an ionization electrode, the flame presence resulting in an ionizing effect on the electrode. The electrode is powered by an alternating voltage signal. The ionization phenomenon generates in the electrode a direct current. The current being sensed by a suitable sensing circuit including a control unit. This signal generator being of relatively low internal impedance to enable the measured generated current to have a high value compared with that normally used and of waveform to tend to limit the value of the direct current flowing through the electrode. The sensing and control circuit being such as to enable the presence of a parasitic current on the flame sensing electrode to be measured. A device for implementing the method is also disclosed.

Abstract: A gas burner for premixed combustion is positioned in a combustion chamber and comprises two components, a first defined by a distributor for a gas and air mixture and the second defining the burner shell. The components being close together but spaced apart. The distributor has a perforated distribution surface through which the gas-air mixture passes directed towards the burner shell, which also has a perforated burning surface on which the flame caused by the combustion of said mixture is generated, to create a thermal load within the combustion chamber. The thermal load in this latter is disuniformly distributed.

Abstract: Multifunctional safety valve device with proportional pressure regulator, for line feeding aeriform fluid to a user, including a body defining a fluid or gas conduit connected to a gas feed line and a gas delivering line. The conduit has first and second passages intercepted by respective first and second valving elements. The second element downstream of the first for gas pressure regulating and modulating. The valving elements operated by electromagnetic actuators and urged closed at least by a spring. The second element cooperating with a membrane subjected to gas pressure to urge the second element closed. The membrane has, subjected to gas pressure, a surface larger than that of the second element subjected to the same pressure, to maintain the second element closed. The second element presenting, downstream of the second passage, a portion with a flexible rim arranged to seal the second passage when intercepted by the second element.

Abstract: A method for flame sensing in a solid, liquid or gaseous fuel burner, the flame generated at an ionization electrode, the flame presence resulting in an ionizing effect on the electrode. The electrode is powered by an alternating voltage signal. The ionization phenomenon generates in the electrode a direct current. The current being sensed by a suitable sensing circuit including a control unit. This signal generator being of relatively low internal impedance to enable the measured generated current to have a high value compared with that normally used and of waveform to tend to limit the value of the direct current flowing through the electrode. The sensing and control circuit being such as to enable the presence of a parasitic current on the flame sensing electrode to be measured. A device for implementing the method is also disclosed.

Abstract: Multifunctional safety valve device with proportional pressure regulator, for line feeding aeriform fluid to a user, including a body defining a fluid or gas conduit connected to a gas feed line and a gas delivering line. The conduit has first and second passages intercepted by respective first and second valving elements. The second element downstream of the first for gas pressure regulating and modulating. The valving elements operated by electromagnetic actuators and urged closed at least by a spring. The second element cooperating with a membrane subjected to gas pressure to urge the second element closed. The membrane has, subjected to gas pressure, a surface larger than that of the second element subjected to the same pressure, to maintain the second element closed. The second element presenting, downstream of the second passage, a portion with a flexible rim arranged to seal the second passage when intercepted by the second element.