Group D materials

Kapoor, 1976 Kai and Furusaki, 1985 Yoshida et al., 1976). Although less information exists for larger particle sizes, bubble size appears to not change with temperature for Group B materials (Sishtla et al., 1986 Wittman et al., 1981), and to increase with temperature for Group D materials (Sittiphong et al. 1981). 

Increasing temperature has a large effect on h for small particles near and below the Group A/B boundary. Increasing temperature causes h to increase for these particles. The effect of temperature is less pronounced for Group B particles, and h decreases with temperature for Group D materials. 

However, this mode of flow usually is limited to conveying distances of L < 500 m. The Group D materials that possess wide size distributions (especially a considerable amount of fines) and/or unusual particle shape (e.g., crushed coal, petroleum coke, crushed bath, rice hulls) usually are not suited to low-velocity conveying. In these cases, the options are dilute-phase or single-slug dense-phase (i.e., these materials usually are too coarse for bypass conveying). However, when long distances are involved, dilute-phase may be the only practical option. 

Group D powders They are large particles that are distinguished by their ability to produce deep spouting beds (spurt or jet of gas through the bed). Roasted coffee beans, lead shot, and some roasted metal ores are examples of group D materials. 

Another way to examine scaleup of hydrodynamics is to build a cold or hot scale model of the commercial design. Validated scaling criteria have been developed and are particularly effec tive for group B and D materials [Gheksmau, Hyre and Woloshuu, Powder Tech., 177-199 (1993)]. 

Vapor is heavier than air and may travel considerable distance to source of ignition and flash back Ignition Temperature (deg. F) 824 Electrical Hazard Class I, Group D Burning Rate 4 mm/min. Chemical Reactivity - Reactivity with Water No reaction Reactivity with Common Materials No reactions Stability During Transport Stable Neutralizing Agerusfor Acids andCaustics Not pertinent Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

Divisions 1 and 2, Group D areas. (Courtesy of Crouse-Hinds Electrical Construction Materials, a division of Cooper Industries, Inc.)... 

Lohrmann,P. C., andMarcus,R. D., The Performance of a Bottom-Discharge Blow Vessel Pneumatically Conveying Three Group A Materials, Bulk Solids Handling, 4(2) 409-412 (1984)... 

Class D substances and with a 10 h half-time for Class W and Class Y substances. Absorption of material directly into blood is predicted to occur with a 15 min half-time for all compounds. Direct absorption is predicted for 0.5 of the Class D material, for 0.1 of the Class W material, and for 0.01 of the Class Y material. Cuddihy and Ozog (1973) studied direct absorption of 144CeCl3 solutions deposited in the nasal region of Syrian hamsters. About 0.04 of the deposited radiocerium was absorbed through the nasal membranes into the blood. This is about one-half of that predicted by the Task Group Model for nasal absorption of Class W compounds in humans. 

Peptone was used as a source of blood group A material by Goebel, who showed that the active substance it contained was principally carbohydrate and contained D-galactose and D-glucosamine. 

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