| 摘要 |
<p>The waste gas quality of a tunnel furnace is improved by the waste gas (13) being carried off from the furnace at high temperature in a first outlet (14) from the firing zone (D). The furnace gas, which moves in countercurrent in relation to the articles being heat-treated and is enriched with gasifiable and combustible constituents as it flows over the articles being heat-treated, is removed from the warming-up zone (A) in a second outlet (110) and reintroduced in the cooling zone (E), i.e. before the high-temperature zone (D), - or directly into the high-temperature zone. On passing through the high-temperature zone (D), the combustible constituents of the returned waste gas are burned and in this manner no longer pollute the waste gas. <IMAGE></p> |
