Blast prevention techniques

Emission levels from the exhaust gas of shot blasting have been eollected in an Italian foundry survey. The results are displayed in Table 3.54. All techniques reach maximum dust emission levels below 30 mg/Nm. The average value is below 15 mg/Nm. The wet Venturi system is the least effeetive system, leaving an emission factor well above those for the other techniques. On the other hand, it also acts as is a safety device to prevent an aluminium-dust-explosion [225, TWO, 2003]. 

Another reason for strengthening masonry walls is non-structural. A wide spread use of natural gas in buildings and numerous terrorist activities that have surfaced in recent years have created a due concern that non-structural masonry walls in structures must be strengthened against blast effects of explosions to prevent injuries by wall debris. Conventional techniques of retrofit often add significant mass to the structure and... 

Dense phase transport lines should have gradual curvatures to prevent rough operation. Aeration should be provided to ease the flow of solids in dense phase transport lines and in risers. Blast connections should be available to clear them in case of plugging. Technique should be developed to weld patches on eroded lines during operation. 

This technique is effective at removing paint but cannot remove mill scale and heavy corrosion. In addition, the quality of the cleaning may not be suitable for some paint systems, unless the surface had been previously blast-cleaned. If bare steel is exposed, inhibitors may be necessary to prevent flash rusting. 

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