| 摘要 |
<p>1526478 Treating furnace exhaust gas S A DES ANCIENS ETABS PAUL WURTH 1 Nov 1976 [6 Nov 1975] 45351/76 Heading B1W [Also in Divisions F3 and F4] Gas exhausted from the top of a blast furnace 1 is cleaned by a dust bag and cyclone 14, first and second washing stages 18 and 20 and drying stage 22 before passing to distribution conduit 25, a proportion of the gas being bled off from the main path at a point upstream of stage 20, where the gas loses much of its pressure, and being recycled to the furnace via auxiliary washing stage 24, compressors 28, 30 and conduits 9 and 11 to cool and keep free of dust the equipment 2-8 by which ore is delivered to the furnace. Compressors 28 and 30 operate in parallel, compressor 30 being normally in reverse and being switched on automatically if temperature sensors 122, 124 detect an unacceptable rise. The gas passes from the compressors through cooler 108 and dryer 110, and flow through conduits 9, 11 is monitored and recorded by means 114 - 120. Washing stages 20 and 24 may both involve annular passage 'Venturis', and the width of the passage in stage 24 may be automatically varied to maintain a constant pressure drop and degree of gas-purification, the variation being controlled by temperature sensors 122, 124 or flowmeters 114, 116. The recycled gas could be bled off upstream of stage 14 if desired, the object being to minimise the power requirements of the compressors by bleeding the gas off before it has lost much pressure. The hoppers 4, 4' deliver ore to furnace 1 through valves in channels 8, 8' and a spout 2, which is moved by a drive mechanism in chamber 5.</p> |
