| 摘要 |
PURPOSE: To effectually prevent a wall surface of a combustion chamber from being burned by disposing a blowoff outlet on a front surface of a casing and an axial flow fan on the back surface, disposing a combustion chamber at the center between the blowoff outlet and the axial fin for accommodating a flame of a burner, and protruding a plurality of secondary air holes in a combustion chamber wall surface corresponding to a strong air fan region of the axial flow fan. CONSTITUTION: A warm air heater includes an axial flow fan 6 composed of a motor 4 and a propeller fan 5 provided on the back surface of a casing 1. With rotation of the axial flow fan 6 air is sucked into the casing 1 from an air intake port 12, and part of the sucked air is fed to a burner 8 as primary air, and is supplied as secondary air from a secondary air hole 11 formed in a wall surface 10 of a combustion chamber 7 into the combustion chamber 7. Hot air produced by combustion on the burner 8 is mixed with fan air from the axial flow fan 6 at an opening 9 and is blown off from a blowoff outlet 3. By forming the secondary air hole 11 in the wall surface 10 of the combustion chamber 7 same height flames can be formed and hence combustion chamber wall surface is prevented from being burned. |
