| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce Helmholtz resonance noise in addition to fan noise in a combustion device which includes a combustion chassis with a built-in burner, a fan supplying combustion air into the combustion chassis, a heat exchanger disposed above the combustion chassis, and an exhaust hood disposed above the heat exchanger to discharge combustion exhaust air through a cylindrical exhaust port extending upward from an upper wall portion of the exhaust hood, and further includes an exhaust limiting cylinder inserted to the exhaust port from under. <P>SOLUTION: A cylindrical portion 65 raised upward is formed on the outer periphery of an annular flange 64 extended radially outside from the lower end of the exhaust limiting cylinder 63, and the upper end of the cylindrical portion 65 is fixed to the opening edge of the exhaust port 61 in the upper wall portion of the exhaust hood 6. The cylindrical portion 65 includes a plurality of ventilation holes 66 for passing the combustion exhaust air which are formed therein at circumferential intervals. <P>COPYRIGHT: (C)2013,JPO&INPIT |
