Premixing device and combustion device equipped with the same

Abstract

To provide a premixing device comprising a flapper of excellent responsiveness, capable of making its performance of maintaining an air-fuel mixture at a suitable air / fuel ratio an excellent one and of making its ignition performance an excellent one.SOLUTION: A premixing device A comprising a gas flow path 30 for allowing air to flow therethrough, a gas outflow port 31a allowing fuel gas to flow out into the gas flow path 30 by making use of a negative pressure, and a flapper 5 disposed in the gas flow path 30, further comprises flapper-action regulating means 6, 7 of allowing the opening of the flapper 5 to change in response to an air flowrate when it is in a range of not higher than the upper limit position, while preventing the flapper 5 from turning beyond the specified upper limit position toward the opening direction, which action regulating means 6,7 can select and set either of the first upper limit position P1 for normal combustion, and the second upper limit position P2 for igniting fuel with a smaller opening of the flapper 5 relative to the first upper limit position P1.SELECTED DRAWING: Figure 3

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