Allied Blower launches world’s largest back blast dampers

Until now, NFPA- and ATEX-certified Back Blast Dampers (BBD) have been limited in sizes of up to 40 in. (1016 mm) in diameter. With many wood processing facilities demanding larger system capabilities, Allied Blower & Sheet Metal, Surrey, BC, says it has successfully certified a line of BBDs with diameters up to 50 in. (1270 mm).

BBDs are designed to protect personnel and structures against overpressures resulting from an explosion. The blast dampers protect air inlets and exhaust penetrations in an otherwise hardened structure.

The Allied BBDs are designed for easy installation, inspection and maintenance. The instrumentation meets North American standards to easily integrate into a plant or mill PLC system and is available in Class 2 Div 2. The BBD can resist a vented dust collector explosion reaching a Pred of 5 psi (0.35 bar) for dusts with a Kst of up to 200 bar-m/sec. This range provides safe operation for a large range of deflagrable dusts used in industry.

When comparing the options of using a passive mechanical system or an active chemical suppression system, the mechanical systems are perceived to have lower maintenance costs because of their simplicity in function, design, training requirements and the low frequency of inspections.

With a mechanical BBD, mill staff do not need specialized training or tools when inspecting and keeping maintenance records for NFPA compliance, as they would with an active chemical system. This results in more up-time, allowing for more production.

A combination of Allied BDD and an Allied NFPA-certified rotary feeder can provide NFPA-compliant passive isolation for large sized deflagrable dust/fire suppression systems.

Allied is an owner-operated company, making for short lead times and easily available replacement components. Being familiar with North American and European standards and technologies, Allied can build solutions to deflagrable dust/fire suppression issues in compliance with industry regulations.

Allied Blower & Sheet Metal,

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