Page 559 - APPLIED PROCESS DESIGN FOR CHEMICAL AND PETROCHEMICAL PLANTS, Volume 1, 3rd Edition

Applied Process Design 525

Table 7-31
Explosion Characteristics of Various Dusts (Cont.)

Max Rate Ignition Min Limiting
Maximum of Temperature Cloud Min Oxygen
Explosi- Ignition Explo- Explosion Pressure Ignition Explosion Percentage•
bility Sensi- sion Pressure Rise Cloud Layer Energy Cone (Spark
Type of Dust lndex tivity Severity psig psi/sec oc oc joules oz/cu ft Ignition)
Naphthvl-N -rnethvlcar-
bamate ("Sevin'') 1 5%
(85% Inert) >10 18.0 1.6 90 5,000 560 140 0.010 0.020
3. 4. 5. 6-tetrahydro-3. 5,-
dimethyl-2H-1. 3. 5
thiadeazine 2 thione.
("Crag" No. 974) 5%
(95% Inert) >10 8.7 2.0 97 6.000 310 330 0.030 0.025
a. a' Trithiobis (N. N-
dimethyl-thioformamide) 8.9 3.4 2.6 96 7,000 280 230 0.035 0.060
Thermoplastic Resins and
Molding Compounds
Group I. Acetal Resins
Acetal. linear (Polyformalde-
hyde) >10 6.5 1.9 113 4,100 440 0.020 0.035 C11
Group II. Acrylic Resins
Methy! methacrylate polymer 6.3 7.0 0.9 84 2,000 480 0.020 0.030 C11
Methyl methacrylate-ethyl
acrylate copolymer >10 14.0 2.7 85 6.000 480 0.010 0.030 C11
Methyl methacrylate-ethyl
acrylate-styrene copolymer >10 9.2 1.7 90 4.400 440 0.020 0.025
Methyl methacrylate-styrene-
butadiene-acrylonitrile
copolymer >10 8.4 1.4 87 4,700 480 0.020 0.025 C11
Methacrylic acid polymer,
modified 0.6 1.0 0.6 97 1,800 450 290 0.100 0.045
Acrylamide polymer 2.5 4.1 0.6 85 2,500 410 240 0.030 0.040
Acrylonitrile polymer >10 8.1 2.3 89 11.000 500 460 0.020 0.025 C13
Acrylonitrile-vinyl pyridine
copolymer >10 7.9 2.4 85 6.000 510 240 0.025 0.020
Acrylonitrile-vinyl chloride-
vinylidene chloride
copolymer (70-20-1 0) >10 5.9 3.0 87 15.000 650 210 0.015 0.035
Group Ill. Cellulosic Resins
Cellulose acetate >10 8.0 1.6 85 3,600 420 0.015 0.040 C14
Cellulose triacetate 7.4 3.9 1.9 107 4,300 430 0.030 0.040 C12
Cellulose acetate butyrate 5.6 4.7 1.2 85 2.700 410 0.030 0.035 C14
Cellulose propionate, 0.3%
free hydroxyl 7.5 2.9 2.6 107 4.700 460 0.060 0.025
Ethyl cellulose 5-10 micron
dust >10 21.8 3.4 120 6.500 370 350§ 0.010 0.025 C12
Methyl cellulose >10 9.3 3.1 133 6.000 360 340 0.020 0.030 C13
Carboxy methyl cellulose. low
viscosity, 0.3 to 0.4%
substitution, acid product 1.4 0.5 2.7 130 5,000 460 310 0.140 0.060
Hydroxyethyl cellulose-mono
sodium phosphate sizing
compound 1.7 2.1 0.8 110 4,000 390 340 0.035 0.070
Group IV. Chlorinated
Polyether Resins
Chlorinated polyether alcohol 0.2 0.6 0.3 88 1,900 460 0.160 0.045
Group V. Fluorocarbon
Resins
Tetrafluorcethylene polymer
(micronized) 0.1t 0.1 t § 670 570t §
Monochlorotrifluoroethylene
polymer 0.1: 0.1t § 600 720t §
Group VI. Nylon (Polyamide)
Resins
Nylon (polyhexamethylene
adiparnide) polymer >10 6.7 1.8 95 4.000 500 430 0.020 0.030 C13
Group VII. Polycarbonate
Resins
Polycarbonate 8.6 4.5 1.9 96 4.700 710 0.025 0.025 C15
• Numbers in this column indicate oxygen percentage while the letter prefix indicates the diluent gas. For example, the entry "C13" means dilution
to an oxygen content of 13 percent with carbon dioxide as the diluent gas. The letter prefixes are: C = Carbon Dioxide: N = Nitrogen: A = Argon:
and H = Helium.
t Ignition denoted by flame. all others not so marked (t) denoted by a glow.
t 0.1 designates materials presenting primarily a fire hazard as ignition of the dust cloud is not obtained by the spark of flame source but only by the
intense heated surface source.
§ No ignition to 8.32 joules, the highest tried.
II No ignition to 2 oz per cu ft, the highest tried.
Reprinted by permission, Fire Protection Handbook, 17th Ed. ( 1991), pp. 4-85, National Fire Protection Association [34].