US 12,264,818 B2
Premixing device and combustion device including the premixing device
Kyohei Ogawa, Hyogo (JP); and Shigeo Sugie, Hyogo (JP)
Assigned to NORITZ CORPORATION, Hyogo (JP)
Filed by NORITZ CORPORATION, Hyogo (JP)
Filed on Sep. 11, 2022, as Appl. No. 17/942,171.
Claims priority of application No. 2021-157500 (JP), filed on Sep. 28, 2021.
Prior Publication US 2023/0102736 A1, Mar. 30, 2023
Int. Cl. F23D 14/60 (2006.01); F23D 14/02 (2006.01); F23D 14/62 (2006.01); F23D 14/70 (2006.01)
CPC F23D 14/62 (2013.01) [F23D 14/02 (2013.01); F23D 14/60 (2013.01); F23D 14/70 (2013.01); F23D 2203/007 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A premixing device comprising:
a gas flow path for allowing air to flow in a predetermined direction;
at least one gas outlet that allows fuel gas to flow out into the gas flow path by utilizing a negative pressure generated in the gas flow path; and
a flapper disposed in the gas flow path, being rotatable around an axis extending in a direction intersecting a flow direction of the air, and changing an opening degree according to an air flow rate so that when the air flow rate in the gas flow path is small, the opening degree is smaller than when the air flow rate is large,
the premixing device further comprising:
an operation regulating part for the flapper which allows the opening degree of the flapper to change according to the air flow rate in a range below a predetermined upper limit position while preventing the flapper from rotating in an opening direction beyond the upper limit position,
wherein the operation regulating part is capable of selectively switching and setting one of a first upper limit position for normal combustion and a second upper limit position for fuel ignition as the upper limit position of the flapper, and the opening degree of the flapper at the second upper limit position is smaller than the opening degree of the flapper at the first upper limit position.