Premixing device and combustion device including the same

Abstract

A premixing device A includes: a premixing flow path 3 including first and second flow paths 3a, 3b a extending in an upper-lower height direction in parallel arrangement in a horizontal direction; and first and second fuel gas outlets 80a, 80b; and a flapper 5. The flapper 5 is provided to be able to swing in the upper-lower height direction on an upper side of a predetermined plate part 41a and a specific flow path region 3a′, swings by using self-eight as a downward force and an air flow from below the specific flow path region 3a upward as an upward force, and is able to simultaneously open and close both the first fuel gas outlet 80a and the specific flow path region 3a in accordance with a flow rate of the premixing flow path 3.

What is claimed is: 
     
         1 . A premixing device, comprising:
 a premixing flow path, extending in an upper-lower height direction, so that air supplied from outside is able to flow from a lower side toward an upper side, and provided for mixing a fuel gas with the air to generate a gas mixture;   a partition wall part, partitioning the premixing flow path into a first flow path and a second flow path in parallel arrangement in a horizontal direction;   a first fuel gas outlet and a second fuel gas outlet, through which the fuel gas is able to flow out to the first flow path and the second flow path by using a negative pressure generated due to air flows in the first flow path and the second flow path; and   a flapper, provided in the first flow path,   wherein the premixing device comprises:   a blade part, located at an intermediate position on the first flow path in the upper-lower height direction, wherein the first fuel gas outlet is provided to be open toward an upper side that is a downstream side in an air flow direction;   a specific flow path region, which serves as a portion of the first flow path in which an upper part and a lower part are open by using an arrangement adjacent to both sides or a single side of the blade part in a horizontal direction,   wherein the flapper is provided on an upper side of the blade part and the specific flow path region to be able to swing in the upper-lower height direction, and is configured to be able to simultaneously open and close both of the first fuel gas outlet and the specific flow path region in accordance with an air flow rate of the premixing flow path.   
     
     
         2 . The premixing device as claimed in  claim 1 ,
 wherein the flapper is able to swing in the upper-lower height direction by using a support part as a fulcrum, the support part supporting a proximal end of the flapper, and   the support part is provided at a position avoiding a directly above region of the first fuel gas outlet and the specific flow path region and above the first fuel gas outlet and the specific flow path region.   
     
     
         3 . The premixing device as claimed in  claim 1 , comprising:
 a seat part, having an upward-facing surface shape, and comprising an opening periphery part of the first fuel gas outlet and an opening periphery part on a downstream side of the specific flow path region in the air flow direction,   the flapper comprises a flapper body part and a connection part and is able to swing by using a support part as a fulcrum, the flapper body part has a plate shape and is opposite to and in contact with the seat part when the flapper is in a closed state, the connection part is in connection with the flapper body part, and the support part supports the connection part, and   when the flapper is in a fully open state, the flapper body part is configured to assume a posture upright in the upper-lower height direction by being located close to a side part of the first flow path.   
     
     
         4 . The premixing device as claimed in  claim 3 ,
 wherein the flapper is configured so that, in the fully open state, a center of gravity of the flapper is located closer to a center of the first flow path than a position directly above a swing center of the flapper, and a rotation force that lowers the flapper in a closing direction is generated.   
     
     
         5 . The premixing device as claimed in  claim 1 ,
 wherein the bladed part is provided in an arrangement of bridging between two opposite positions on an inner peripheral wall part of the first flow path, and, as the specific flow path region, a pair of specific flow path regions located on two sides of the blade part in the horizontal direction to sandwich the blade part.   
     
     
         6 . A combustion device, comprising:
 a premixing device, generating a gas mixture mixing air and a fuel gas; and   a burner part, receiving supply of the gas mixture from the premixing device to cause combustion of the fuel gas,   wherein the premixing device as claimed in  claim 1  is used as the premixing device.