| 摘要 |
<p>A primary filter (1) is placed in a primary filtration circuit (C1). A secondary filter (5) is placed in a bypass in a secondary circuit (C2) so the secondary filter is representative of the state of the primary filter and responds to immediate control. Tracer gases are injected (by 3) upstream of the secondary filter and detected downstream, with the detector (6) activating an alarm (7). The injector of tracer gases is fed from a reservoir (4) of tracer gases. A primary ventilator (2) and a secondary ventilator (8) are placed respectively upstream or downstream of the principal and secondary filters. The secondary filter is smaller than the primary filter and is identical to the primary filter with respect to the filtered product, contact time, speed of passage and geometry. The tracer gases injected upstream of the secondary filter are representative of the filtered gases.</p> |
