| 摘要 |
<p>The heater runs on natural gas, and has a tubular outer casing with an axial-flow fan in the rear end, while a burner clear of the fan has a gas pipe union outside the casing. The burner is pot-shaped (8) with a closed base surface (18) and one or more rows of outlets (17) in a ring extending round the sidewall (19). It is connected to a coaxial supply pipe (16) to whose open end (24) part of the air current from the fan is delivered. A pipe (20) from the gas union (21) extends into the supply pipe, its mouth being situated at a predetermined distance from the burner pot.</p> |
