Rich-lean combustion burner

Abstract

A row of rich-side flame holes of a combustion burner is arranged in center. Two rows of lean-side flame holes are arranged respectively on sides of the rich-side flame hole row. Two rows of rich-side flame holes are arranged respectively on the outsides of the two lean-side flame hole rows. Supply of lean-side mixture is provided to the lean-side flame hole rows from a tubular part. A lower end part of a central rich-side burner part is projected into a tubular part, into which the rich-side mixture is introduced, to establish lateral fluid communication, with its lower end edge placed in a state of non-contact with the inner surface of the tubular part. First communication holes in fluid communication with an internal space are opened in the lower end part. Communication holes in fluid communication with the outer rich-side flame holes are opened in the inside of the tubular part.

1 . A rich-lean combustion burner in which two rows of lean-side flame holes are disposed so as to sandwich, therebetween and from both lateral sides, one row of central rich-side flame holes disposed so as to longitudinally extend in a central position and two rows of outer rich-side flame holes are disposed so as to sandwich, therebetween and from outside, both said two rows of lean-side flame holes,
 wherein it is arranged that the flow of a rich-side mixture introduced into a single rich-side mixture introduction channel whose downstream end is a closed end is diverged so that said rich-side mixture is distributed to said one row of central rich-side flame holes and to said two rows of outer rich-side flame holes,   wherein a first rich-side mixture supply channel for supply of said rich-side mixture to said one row of central rich-side flame holes, a second and a third rich-side mixture supply channel for individual supply of said rich-side mixture to each of said two rows of outer rich-side flame holes and said rich-side mixture introduction channel are partitioned from one another,   wherein a portion of a formation member for partition formation of said first rich-side mixture supply channel is disposed so as to project into said rich-side mixture introduction channel and wherein a first communication hole in fluid communication with said first rich-side mixture supply channel is formed in said projecting portion of said formation member so as to open facing towards the inside of said rich-side mixture introduction channel,   wherein a second communication hole in fluid communication with said second rich-side mixture supply channel and a third communication hole in fluid communication with said third rich-side mixture supply channel are formed in a formation member for partition formation of said rich-side mixture introduction channel such that said second and said third communication holes each open facing towards the inside of said rich-side mixture introduction channel, and   wherein said projecting portion is disposed such that its end edge and an inner surface of said rich-side mixture introduction channel are placed in a state of non-contact with each other.   
     
     
         2 . The rich-lean combustion burner as set forth in  claim 1 , wherein said projecting portion is disposed such that its lower end edge extending in the upstream and downstream direction of said rich-side mixture introduction channel and an inner bottom surface of said rich-side mixture introduction channel are placed in a state of non-contact with each other, thereby bringing a space portion in the inside of said rich-side mixture introduction channel, which space portion is defined between said lower end edge and said inner bottom surface which are in opposing relationship in vertical direction, into lateral fluid communication. 
     
     
         3 . The rich-lean combustion burner as set forth in  claim 1 , wherein said projecting portion is disposed such that its end edge facing towards said closed end of said rich-side mixture introduction channel and an inner surface of said closed end are placed in a state of non-contact with each other, thereby bringing a space portion in the inside of said rich-side mixture introduction channel, which space portion is defined between said end edge and said inner surface which are in opposing relationship in upstream and downstream direction, into lateral fluid communication. 
     
     
         4 . The rich-lean combustion burner as set forth in  claim 1 , wherein in the inside of said projecting portion, said first rich-side mixture supply channel is partition-formed between one pair of walls situated facing each other in lateral direction, with a predetermined lateral inner width spaced therebetween, and wherein said first communication hole is formed in each of said wall pair and wherein both said first communication holes are formed so as to pass through in alignment with each other in lateral direction. 
     
     
         5 . The rich-lean combustion burner as set forth in  claim 4 , wherein said first communication hole is formed so as to have an opening the size of which is equal to or in excess of said inner width between said wall pair at a location where said first communication hole is formed. 
     
     
         6 . The rich-lean combustion burner as set forth in  claim 1 , wherein said first communication hole is formed at a position in said projecting portion which position is situated nearer to the upstream of said rich-side mixture introduction channel, thereby leaving an internal space on the side nearer to the closed end of said rich-side mixture introduction channel than said first communication hole formation location. 
     
     
         7 . The rich-lean combustion burner as set forth in  claim 1 , wherein said first communication hole is formed at an upper part of said projecting portion in said rich-side mixture introduction channel. 
     
     
         8 . The rich-lean combustion burner as set forth in  claim 1 , wherein pluralities of communication holes are provided, in the upstream and downstream direction of said rich-side mixture introduction channel, respectively as said second communication hole and as said third communication hole, and wherein of said pluralities of communication holes, ones situated on the upstream side are formed so as to have a larger diameter than the others situated on the downstream side. 
     
     
         9 . The rich-lean combustion burner as set forth in  claim 1 , wherein a plurality of communication holes are provided, in the upstream and downstream direction of said rich-side mixture introduction channel, as said first communication hole, and wherein of said plurality of communication holes, one situated on the upstream side is formed so as to have a larger diameter than the other situated on the downstream side. 
     
     
         10 . The rich-lean combustion burner as set forth in  claim 1 , wherein said first communication hole is formed in the shape of a long hole which is elongated in a direction in which said rich-side mixture introduction channel extends. 
     
     
         11 . A combustion apparatus equipped with a rich-lean combustion burner as set forth in any one of  claims 1 - 10 .