Abstract: An object of the present invention is to provide a filler metal for an aluminum brazing sheet for heat exchangers capable of preventing or controlling occurrence of a melting hole during heating for brazing, and a method of manufacturing the same. In an Al—Si alloy filler metal which is clad on the aluminum brazing sheet and melted during heating for brazing, the maximum particle diameter of a coarse Si particle crystallized in the eutectic structure of the filler metal is 20 ?m or less. Provided that an average value and a standard deviation in a normal distribution of the particle diameter of the coarse Si particle in the filler metal are respectively ? and ?, (?+3?) is preferably 10 ?m or less. This brazing sheet is obtained by a method of adding a specific amount of Na, Sr, or Sb to the filler metal, a method of limiting the amount of impurities in the filler metal within a specific range, a method of specifying a cooling rate during the casting of the filler metal, or the like.

Abstract: An object of the present invention is to provide a filler metal for an aluminum brazing sheet for heat exchangers capable of preventing or controlling occurrence of a melting hole during heating for brazing, and a method of manufacturing the same. In an Al—Si alloy filler metal which is clad on the aluminum brazing sheet and melted during heating for brazing, the maximum particle diameter of a coarse Si particle crystallized in the eutectic structure of the filler metal is 20 &mgr;m or less. Provided that an average value and a standard deviation in a normal distribution of the particle diameter of the coarse Si particle in the filler metal are respectively &mgr; and &sgr;, (&mgr;+3&sgr;) is preferably 10 &mgr;m or less.

Abstract: A combustion apparatus comprises a pair or more than two pairs of burner groups. Each burner group comprises one regenerator per a plurality of burners. In each pair of burner groups, a first burner group and a second burner group are fired alternately and waste heat produced when the first burner group is fired is stored in a regenerator of the second burner group. The stored waste heat is utilized to preheat the combustion air of the second burner group when the second burner group is fired. Similarly, waste heat produced when the second burner group is fired is stored in a regenerator of the first burner group, and the stored waste heat is utilized to preheat the combustion air of the first burner group when the first burner group is fired.