Report of Investigations 4904: A Study to Determine Factors Causing Pressure Piling in Testing Explosion-Proof Enclosures

Details

• Personal Author:
  Gleim, E. L. ; Marcy, J. F.
• Corporate Authors:
  United States. Bureau of Mines
• Description:
  An attempt has been made in this report to predict and evaluate the effect of pressure piling in any given explosion-proof compartment on the basis of its geometry. As a beginning, a simple type of rectangular box that could be divided easily into separate compartments was employed. By extending these tests to more closely represent the more-complicated commercial enclosures taken with their contents, prediction of pressure piling should be made with greater confidence than possible at present. With this in view, continuation of this investigation is planned. Higher-frequency gages will be used to insure greater reliability in the measurement of pressures. Possibility of cavity resonance should be eliminated by the use of flush-type diaphragms. These general deductions are made on the basis of the test results: 1. Pressures of about 125 pounds per square inch are obtainable with openings as large as 8 inches in diameter in a 12-inch-square plate. These pressures are due mainly to high-frequency vibrations. The 50-percent safety margin sometimes provided in commercial enclosures may be reached under these conditions. 2. There is a critical ratio between the size of the hole in the partition plate and the distance of the ignition point from the plate before a vibratory type of explosion can be generated. It would be of considerable interest to determine the extent to which this ratio is independent of the size of the box. 3. Pressure gages, such as those specially designed for detonation studies in gasoline engines, would be used in future explosion tests to insure adequate high-frequency response. A frequency response at least 10 times greater than that of the present gages would be desirable. This need is also indicated from the recent tests by Titman and Haig and Staples. [Description provided by NIOSH]
• Subjects:
  Coal Coal Mining Dust Electricity Explosions Mining Occupational Health Safety
• Keywords:
  Coal-mining Electrical-equipment Electrical-systems Explosion-prevention Explosion-protection Explosive-atmospheres Explosive-dusts Explosive-gases Mining-industry Underground-mining
• Series:
  Mining Publications
• Subseries:
  Report of Investigations
• ISSN:
  1066-5552 (print)
• Publisher:
  United States. Bureau of Mines
• Document Type:
  Text
• Genre:
  Case Report
• Place as Subject:
  OSHA Region 3 ; Pennsylvania
• Rights:
  Public Domain
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  PRC - Pittsburgh Research Center
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  17 pdf pages
• NIOSHTIC Number:
  nn:20036628
• Citation:
  Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 4904, 1952 Aug; :1-16
• Federal Fiscal Year:
  1952
• Peer Reviewed:
  False
• Source Full Name:
  Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 4904
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:a5ba32b6f4cc91b3f0e304810352aaa08f5311c847e73f0d8424b484892bf8547115e1f7df99088b91c55eadc7dff9aec2f3a42041d50f4b67e33158806ea7bc
• Download URL:
  https://stacks.cdc.gov/view/cdc/202002/cdc_202002_DS1.pdf
• File Type:
  [PDF - 3.81 MB ]