| 摘要 |
PURPOSE:To eliminate exhaust fan for high temperature while improving durability by connecting an air supply pipe and a venturi part by a piece of venturi piping, forming so that the diameter of a branch pipe is suddenly widened larger than that of an air introducing pipe and setting a switching mechanism. CONSTITUTION:Combustion air is introduced from an air introducing pipe 8 to reach a branch pipe 3. Since the diameter of the branch pipe is formed to suddenly widen larger than that of the air introducing pipe 8, a vortex is produced at the pipe wall part thereof and it is in a negative pressure state. When a change valve 12 is closed and another change valve 12' is opened, the vortex produced at the side of the change valve 12' is eliminated and negative pressure is not produced at the side of the change valve 12'. Therefore, air flow is sucked to the side of the change valve 12 by Coanda effect, flowed only at the side of an air supply pipe 4 and reaches a burner part 10 through an accumulator 11. Since part of the combustion air blows through a piece of venturi piping 7' at a venturi part 5', exhaust gas is effectively sucked and discharged from an exhaust part 16 by the combustion air. |
