Page 556 - APPLIED PROCESS DESIGN FOR CHEMICAL AND PETROCHEMICAL PLANTS, Volume 1, 3rd Edition

522 Applied Process Design for Chemical and Petrochemical Plants

Table 7-30
Hazard Classes and "Kst Values for Selected Types of Dusts
(A) Agricultural Products (B) Chemical Dusts

Median Minimum Median Minimum
particle explosive Ks, Dust particle explosive Ks, Dust
size, concentration P max> (dP/dt)m •• , bar-m Hazard size, concentration P max• (dP/dt>mn• bar-m Hazard
Material µm �� �rp �d� � �� Material µm g/m' bar ga bar/sec sec Class
Cellulose 33 60 9.7 229 229 Adi pie <10 60 8.0 97 97
Cellulose, 42 30 9.9 62 62 Acid
pulp Anthr a- <JO 10.6 364 36�
Cork 42 30 9.6 202 202 qui none
Corn 28 60 9.4 75 75 Ascorbic 39 60 9.0 111 111
Egg White 17 125 8.3 38 38 Acid
Mill:. 83 60 5.8 28 28 Calcium 92 500 5.2
powdered Acetate
Milk. non· 60 8.8 125 125 Calcium 85 250 6.5 21 21
fat. dry Acetate
Soy Flour 20 200 9.2 110 110 Calcium 12 30 9.1 132 132
Starch. 10.3 202 202 Stearate
corn 125 9.2 136 136
Starch. 18 60 9.2 101 101 Carboxy- 24
methyl·
rice cellulose
Starch. 22 30 9.9 115 115 Ocxtrin 41 60 8.8 106 106
wheat Lactose 23 60 7. 7 81 81
Sugar 30 200 8.5 138 138 Lead 12 30 9.2 152 152
Sugar. 27 60 8.3 82 82 Srearare
milk Methyl- 75 60 9.5 134 134
Sugar. 29 60 8.2 59 59 cellulose
bee, Paraform- 23 60 9.9 178 178
Tapioca 22 125 9.4 62 62 aldehyde
Whey 41 125 9.8 140 140 Sodium 23 60 8.4 119 119
Wood 29 10.5 205 205 2 Ascorbate
Flour Sodium 22 30 8.8 123 123
Stearare
Sulfur _:2:.:.0 30c.:_ 6c..._ 8 15_ 1 15_1 _
(C) Carbonaceous Dusts
Median Minimum (D) Metal Dusts
particle explosive Ks, Dust
size, concentration P max• (dP/dt)max• bar-m Hazard Median Minimum
Material µm g/m' bar ga bar/sec sec Class particle explosive K5, Dust
size, concentration P max• (dP/dt)mn• bar-m Hazard
Charcoal 28 60 7. 7 44 Material µm g/m' bar ga bar/sec sec Cl.ass
activated
Charcoal. 14 60 9.0 10 10 Aluminum 29 30 12.4 415 415
wood Bronze 18 750 4.1 31 31
Coal. 24 60 9.2 129 129 Iron <10 125 6.1 111 111
bituminous Carbonyl
Coke. 15 125 7.6 47 47 Magnesium 28 30 17.5 508 508
petroleum Zinc 10 250 6.7 125 125
Lampblack <IO 60 8.4 121 121 Zinc <10 125 7.3 176 176
Lignite 32 60 10.0 151 151
Peat. 15% 58 60 I0.9 157
H,O
Peat, 22% 46 125 8.4 69
H,O
Soot. pine <IO 7.9 26 26

To obtain updated listing of the published information when related to liquid flashing in a vessel as it discharges
on this research, contact the AIChE office in New York. on pressure relief. It cannot be adequately covered by
The work is original and conducted by thoroughly quali- conventional fluid two-phase flow.
fied researchers/ engineers. The work on runaway reac- Articles describing procedures related to the DIERS
tions is the first systematized examination of the subject
and is really the only design approach available, but it development of this entire subject have been published by
some members of the DIERS group. These are referenced
requires careful study and is not just dropping numbers in here, but to adequately describe the methodology
equations.
requires more space than is suitable for this chapter. The
Two-phase flow is an important aspect of venting relief detailed descriptions and illustrations in the noted arti-
as well as of runaway reactions, and is a complicated topic cles can be most helpful to the potential user.