Page 186 - Electrical Installation in Hazardous Area

Table 6.2 Properties of Combustible dusts (part from BS 6467, Part 2 (1988))

Dust Particle size distribution Ignition temperature Cloud Min
.e500 <125 t71 <32 t20 Median of cloud of layer Ign. Explosive
energy conc.
Percentage by mass

CUn "C "C
Natural Products
wood, Flour 55 23 65 490 340
Cork 83 19 7 42 470 300
Cellulose 75 31 45 520 410
Grain, mixed dust from filter 63 48 40 37 510 300
cocoa/sugar, mixture of milkshak e, 53 20 500 580 460
most of oil mnoved
Milk powder, skimmed, spray dried 35 18 11 90 540 340
Soya meal 85 63 50 20 620 280 100 -
Starch, Cornstarch 99 85 65 15 460 435 - 0.15
Tea, black, from dust separator 64 48 26 16 76 510 300 - -
Sugar, Milk 98 64 32 27 490 460 48 0.045
-
caramel, dried 93 46 16 75 490 455 -
Cocoa Powder 500 200 120
Organic products
Activated charcoal 86 56 29 660 400 -
Lignite 76 50 29 32 380 225 -
Bituminous coal medium-volatile 99 84 60 17 550 260 -
Phenolic resin 98 93 80 11 530 No glowing 0.015
to 450 "C
Synthetic rubber 66 46 18 9 80 450 240
Polyacrylonitrile 99 66 38 25 540 No glowing
to 450°C