Document LKaE5Jp2xZLjB1Zn6jyp05EVd

SAFETY ENGINEERING TABLES Spray coating Tanks, open surface Tumbling mills Hollow trunnion type Tumbling mills, drums, cages, barrels Welding Woodworking Miscellaneous Packaging machines, granulators, enclosed dust producing units. Packag ing, weighing, container Slung, inspection Type of Hood Booth--operator in* side Booth--operator out side Booth--downdraft (See Table 45-L) Exhaust connection by manufacturer Enclosure Local hood with flange Downdraft bench Booth (See Table 43-JC) Complete enclosure Booth Downdraft Ventilation Air Flow 100-200 fpm at booth cross section Um&1 Transport Velocity (fpm> 1,500-2,000 Remarks and References Ref 15 150-200 fpm at booth cross section 100-200 fpm downdraft 1.500-2,000 1.500-2,000 Use higher ventilation rote for small booths 4 sq ft or less Ref 36, 37, 38. 39 Use branch diameter same size as 3,500-5,000 Ref 14 exhaust outlet For round mills branch diam should be % diam of mill, for square mills branch diam should be I in. plus % side dimension of mill. 400 fpm through openings but not less than 75 cfm sq ft plan area 3400 Where equipment is enclosed and dust tight during rotation, en closure may not be needed if feed and discharge operations can be otherwise controlled. 6 in. from arc--150 cfm B-9 in. from arc-273 cfm 8-10 in. from arc--423 cfm 10-12 in. from arc--600 cfm 150-250 cfm per sq ft grille area 100 fpm at booth face 2,000-4,000 Ref 40 2,000 2,009 Ref. 22, 41 100-400 fpm indraft through in spection or working openings, but not less than 23 cfm per sq ft of enclosed plan area 50-150 cfm per sq ft of open face area 75-150 cfm per sq ft of dust pro ducing plan area 3,000 3,000 3,500 Ref. 19 Proa ABHRAE Gottis g4 Ooio Book, 1999, CbapWr Si Used bp permission