Abstract: Provided is a gas-air mixing device for a combustor which effectively controls the amount of gas and air supplied to a burner provided in a combustor, thus improving the turn-down ratio which leads to increased convenience for using hot water and heat and enhanced durability of the burner. The gas-air mixing device for a combustor comprises: a housing, connected on one side to a turbo fan; a discharge part disposed on one side of the housing and in contact with the turbo fan; first and second air supply parts, provided on the other side of the discharge part and separated by a first partition; first gas supply part, divided by a second partition, and a second gas supply part having a protruding part; and an opening/closing means for controlling the flow of gas and air by opening or closing the second air supply part and the second gas supply part.

Abstract: Provided is a gas-air mixing device for a combustor which effectively controls the amount of gas and air supplied to a burner provided in a combustor, thus improving the turn-down ratio which leads to increased convenience for using hot water and heat and enhanced durability of the burner. The gas-air mixing device for a combustor comprises: a housing, connected on one side to a turbo fan; a discharge part disposed on one side of the housing and in contact with the turbo fan; first and second air supply parts, provided on the other side of the discharge part and separated by a first partition; first gas supply part, divided by a second partition, and a second gas supply part having a protruding part; and an opening/closing means for controlling the flow of gas and air by opening or closing the second air supply part and the second gas supply part.