Duct system, explosion

Illustrate the layered accident investigation process, using Example 13-1 as a guide, to develop the underlying causes of the duct system explosion described in section 13-1. 13-2. Repeat Problem 13-1 for the bottle of isopropyl ether accident described in section 13-2. 13-3. Repeat Problem 13-1 for the nitrobenzene sulfonic acid decomposition accident described in section 13-2. 

Ignition sources in the cupboard and duct system should be avoided. Plastic fans, electrical sockets external to the cupboard, and explosion-proof light fittings reduce the likelihood of ignitions. 

The reported experiments were conducted with a fixed chamber, but with various sizes of vents apertures and duct lengths. For comparison purposes, explosions occurring in the vented chamber or duct alone were also studied in the same conditions as in the chamber-duct system. 

Open fluid bed units are not capable of mamtainmg environmental protection demands when materials to be dried are moistened by organic solvents. Fluidized bed units are therefore equipped with closed duct systems as well as solvent recovery systems (Scheme 13.2). Due to safety regulations (solvent vapour and dust explosion) the entire apparatus needs to be filled with inert gas prior to process... 

Venting The term venting is popularly associated with pressure relief systems and devices, which are installed on enclosed conveyors (pneumatic, air gravity, screw etc.) and silos to prevent pressure buildup and potential explosions. However, sometimes dust is directly vented to either the atmosphere or to a ducting system with or without dilution with air. In this case venting may be classified as a method for non-fugitive dust control by ventilation or Di-Pution. 

Cylinders within workplaces should be restricted to those gases in use. Specially designed compartments with partitions may be required to protect people in the event of explosion. Take into account emergency exits, steam or hot water systems, the proximity of other processes etc. Consider the possibility of dense gases accumulating in drains, basements, cable ducts, lift shafts etc. 

If Uvo or more systems are connected together (such as a pipe length with an orifice plate, two or more vessels connected with pipe or duct, or a compartmented vessel) and an explosion develops in No. 1 area, which generally may be at equilibrium pressure with compartments No. 2 and 3 in equilibrium with No. 2, it can cause a pressure rise in front of the dame front in the unburnt gases in the interconnecting spaces (pipe, compartment). The increased pressure in compartment or area No. 1 becomes the starting pressure for an explosion in com-... 

On October 30, 1998, a flammable gas release led to gas migration to a non-electrically classified Electrical and Instrumentation (E l) Room. The flammable gas was ingested into the exterior heating and ventilation inlet duct. When the 480 volt primary power switch, within the E l room was remotely shut off, an explosion resulted. The E l module explosion led to a subsequent fire in adjacent production buildings. There were no injuries to personnel. The root cause of the incident was determined to be the failure of management systems... 

Monitor the various streams for impurities. Install explosion suppressors in potentially explosive spaces for dusts, such as the exit ducts from grinders. Dump cold liquid or inert solids into systems on the verge of temperatme runaway. Add an inhibitor to neutralize the catalyst for a potential temperature runaway (for example, add gaseous ammonia to neutralize the Lewis acid catalyst BF3... 

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