Article

Correlations for flame speed and explosion overpressure of dust clouds inside industrial enclosures

Direzione Centrale Emergenza, Corpo Nazionale dei Vigili del Fuoco, Via Cavour 5, 00184 Roma, Italy; Facoltà di Ingegneria, Università degli Studi di Roma “La Sapienza”, Via A. Scarpa 16, 00161 Roma, Italy
Journal of Loss Prevention in the Process Industries 01/2008; DOI: 10.1016/j.jlp.2008.01.004

ABSTRACT Explosion relief vents on enclosures in powder-handling plants are currently designed according to technical standards that in some situations may overestimate the required vent area significantly. These technical standards sometimes do not take into account the real work conditions of industrial plants (e.g. turbulence intensity) and therefore explosion worst cases are not always foreseeable. The availability of methods either for the evaluation of explosion overpressure or sizing of relief vents, with involvement of the pre-ignition turbulence, could be very useful for a better estimate of these quantities. In this work two empirical correlations are presented: the first one allows the calculation of the flame speed and the burning velocity starting from the explosion indices KSt and Pmax of the standardized 20-l sphere test. The second allows either the calculation of the explosion overpressure or the sizing of relief vents of an enclosure.

0 Bookmarks
 · 
189 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: We present a new technique to synthesize high throughput pipelined data paths for those algorithms containing nested loops. Given an initiation interval constraint, the objective is to synthesize a low cost data path for the problem in register transfer level (RTL). Mapping algorithms for processor array synthesis which do not take initiation interval into account cannot be applied to our case; while traditional pipeline synthesis techniques suffer from complex interconnection and high register cost. Our contributions include proposing (1) an approach which conserves the regularities of nested loops, and (2) an architecture which possesses the advantages of both the highly multiplexed and lowly multiplexed architecture styles. Experiments on several algorithms in the image and DSP applications show this approach is very efficient
    Proceedings of the 1993 IEEE/ACM International Conference on Computer-Aided Design, 1993, Santa Clara, California, USA, November 7-11, 1993; 01/1993
  • [Show abstract] [Hide abstract]
    ABSTRACT: Empirical correlations are often used to estimate safety distances in the event of dust explosions. In Europe, there are two main correlations available in VDI 3673 and EN 14491. Whereas the VDI 3673 correlation is based on experimental investigations of vented dust explosions using large vessels, and assumes an external explosion, the EN 14491 correlation is derived from SKJELTORP et al. internal explosion tests in ammunition storage facility. This paper provides an overview of the experimental studies of vented gas and dust explosion. It aims to highlight the main findings of such studies, while defining the conditions for a secondary explosion to occur and comparing experimental data with the application of standards, in order to propose elements to choose the more appropriate correlation.
    Journal of Loss Prevention in The Process Industries - J LOSS PREVENT PROC IND. 01/2010; 23(1):15-29.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The on-way peak overpressure and flame propagation speed of gas deflagration in the tube with obstacles are important data for process safety. Based on carbon monoxide deflagration experiments, the paper presents a multi-zone integration model for calculation of on-way peak overpressure, in which the tube with obstacles is considered as a series of venting explosion enclosures which link each others. The analysis of experimental data indicates that the on-way peak overpressure of gas deflagration can be correlated as an empirical formula with equivalence ratio of carbon monoxide oxidation, expansion ratio, flame path length, etc., and that the on-way peak overpressure exhibits a linear relationship with turbulence factor and flame propagation speed. An empirical formula of flame propagation speed is given.
    Science China Technological Sciences 53(7). · 1.19 Impact Factor