Bulk Powder Electrostatics Hazards Evaluation
Author | : |
Publisher | : |
Total Pages | : 23 |
Release | : 1994 |
ISBN-10 | : OCLC:495785310 |
ISBN-13 | : |
Rating | : 4/5 (10 Downloads) |
Book excerpt: As process sizing increases, larger quantities of powders are handled at any location in the process. In the gun propellant manufacturing processes, large blend batch sizes produce more uniform gun ballistic output. In a few facilities, up to 100,000 pounds of propellant is blended in a single batch. Other facilities blend anywhere from 200 pounds to 5,000 pounds. Flare and pyrotechnic composition bulk powder operations have been scaled up to 1,000 pound blending batch sizes. In explosive manufacturing operations, several thousand pounds of ingredients can be stored and transported at one time. It is not uncommon to handle 2,000 pounds of dynamite powder mixtures. From an electrostatic safety standpoint, one must question what quantity of bulk powder can be handled at any one time (e.g., blending, mixing, etc.) without potential electrostatic discharge (ESD) ignition. Powder handling electrostatic (ES) charging transfer of large quantities of powder (more than 100 pounds) to hoppers or process bins can generate very high ES charges. In this paper, evaluation methods will be presented to determine ES process safety in bulk powder operations.