Blast Parameter Calculations for BLEVEs and Pressure Vessel Bursts

BLAST PARAMETER CALCULATIONS FOR BLEVEs AND PRESSURE VESSEL BURSTS 

In this section, three examples of blast calculations of BLEVEs and pressure vessel bursts will be given. The first example is designed to illustrate the use of all three methods described in Section 6.3.2. The second is a continuation of sample problem 9.1.5, the BLEVE of a tank truck. A variation in the calculation method is presented instead of determination of the blast parameters at a given distance from the explosion, the distance is calculated at which a given overpressure is reached. The third example is a case study of a BLEVE in San Juan Ixhuatepec (Mexico City). 

The nondimensional range R is checked to determine whether the basic method may be followed or the refined method must be used. The control building lies at a nondimensional range of 6.9, so the basic method may be followed. The range of the large storage tank is less than 2, so the refined method must be used to obtain an accurate result. This will be done in Section 9.2.1.3. 

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This section first presents literature review on pressure vessel bursts and BLEVEs. Evaluation of energy from BLEVE explosions and pressure vessel bursts is emphasized because this value is the most important parameter in determining blast strength. Next, practical methods for estimating blast strength and duration are presented, followed by a discussion of the accuracy of each method. Example calculations are given in Chapter 9. 

In this section, three methods for calculating the blast parameters of pressure vessel bursts and BLEVEs will be presented. All methods are related that is, one basic method and two variations are presented. The choice of method depends upon phase of the vessel s contents and distance to the blast wave s target, as illustrated in Figure 6.19. 

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