Sugar Producer

Avoiding the BANG Protecting facilities from sugar dust explosions S ugar presents a combustion hazard in its dry, dusty form. A fine sugar dust explosion can generate a pressure in excess of 100 PSI within enclosed process equipment in less than one-tenth of a second. Where sugar dust and air are mixed together in a confined space, the consequences of a dust explosion are the greatest. Filtration equipment handling a combustible dust almost certainly contains a hazardous concentration of material under normal operating conditions. Other items of equipment may only temporarily carry a "combustible load" of hazardous material, perhaps during start up, shut down, loading or unloading. However, while that combustible load is present, the risk is no less severe. If the potential for a combustible load cannot be eliminated, protection measures are required. However, when this is the case, many operators of sugar dust processing or handling facilities may not fully understand the steps that must be taken to mitigate those risks. Because these safety precautions typically represent some capital expenditure, many owners and operators are seeking information regarding available technologies on the market. Explosion Protection Devices To protect process equipment and personnel, a hybrid of technical measures is often required. Among the options are passive devices like vents or containment systems along with active devices such as explosion suppression or spark detection and extinguishing systems. Chemical or mechanical isolation devices are required to protect connected equipment and piping from propagating to a secondary event, which can often be more dangerous and destructive than the initial event. Explosion Vents During the early stages of a sugar dust or gas explosion, explosion vents open rapidly at a predetermined burst pressure, allowing the combustion process to escape to the atmosphere and limiting the pressure generated inside the process equipment to calculated safe limits. Venting is the most popular and widely adopted protection mechanism, in part because it is economical and requires little attention or maintenance once installed. For decades, explosion vents have traditionally been designed using a "composite" approach that sandwiches plastic film between more resistant stainless steel sheets with holes or slots cut into it. These vents are designed to "open" at typically 1 to 1.5 PSI set pressure, a result of the hole pattern cut into the sheet metal. Over time, however, this type of vent is prone to tears in the plastic film, which is the seal between the process conditions and the atmosphere. With this type of technology, the holes and slots in the stainless steel sheets can admit particulates and debris over time. In addition to being unsanitary, particularly for food processors, the buildup can eventually affect the functionality of the vent. "A vent that becomes heavier in weight due to buildup will open slowly and less efficiently," says Geof Brazier, president of BS&B Pressure Safety Management, a manufacturer of a broad range of dust explosion

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