GB1309699A - Device for sampling and or eliminating dust and like solid particles from a polluted atmosphere - Google Patents

Abstract

1309699 Rotary air filter; cyclone separator CHARBONNAGES DE FRANCE 1 April 1970 [4 April 1969 (2) 5 March 1970] 15456/70 Headings BIT and B2P [Also in Divisions F1 F4 and G1] A device for sampling and/or separating polluting agents, e.g. dust, from the atmosphere comprises a rotor which acts both as a particle collecting member and also as a radial delivery fan. The rotor may comprise a vane fan 12 (Fig. 1) on top of which is afixed a filter 4 of the membrane type, or the rotor may comprise a relatively thick permeable disc 16 (Fig. 3) e.g. of polyurethane foam, mounted on an impermeable base 17 and carrying the filter membrane 4, or the permeable disc may itself constitute both the fan and the filter (Fig. 8). The rotor is mounted in a chamber 1 having an axial inlet 8 and radial evacuation orifices 9, the diameter of the inlet and outlets being chosen so as to provide a flow-rate through the chamber very much less than the actual flow rate of the fan when the rotor is rotated at constant speed by motor 6. Polluted air is sucked in through 8 (arrows Fa) and forced out through 9 (arrow Fe) after passing through the filter element, the majority of the air recirculating several times (arrows Fr). Dust is deposited on the filter disc, first on the central zone 10 (Fig. 2) then outwardly to zone 14. The amount of dust deposited may be observed by drawing concentric circles 15 on the face of the disc. The disc may have its centre slightly hollowed (Fig. 7 not shown) or be replaced with an annulus (Figs. 4 and 9 not shown). The rotary filter may be combined in series with a cyclone (Fig. 13 not shown) for removal of larger particles before passing to the rotor and the filter disc may be impregnated with coloured reagents for the detection of particular gases or with activated carbon for removal of noxious gases. The top of the casing 1 is suitably transparent.