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Explosion Isolation

In the event of an explosion, it is imperative that the event is isolated from the rest of the process system network to prevent secondary explosions.

When we propose explosion isolation we mean encapsulating an explosion within a process vessel, perhaps a dust collector, and preventing a fireball from exiting that vessel or isolating it from the associated process equipment and duct.

Complete explosion isolation systems are comprised of components that are designed to detect a combustible dust explosion as soon as it occurs and to instantly isolate or contain the deflagration and prevent it from spreading back through the duct system into the facility.

Explosion Isolation on Dust Collector

Explosion Isolation on dust collector
Explosion Isolation on dust collector

Explosion Isolation on Dust Collector

Explosion Isolation on Cartridge Dust Collector - IEP Technologies Pistonfire II Chemical Suppressor as an Active Isolation component on duct from the process

Explosion Isolation of Combustible Dust

Explosion isolation of combustible dust with an IEP Technolgies Flap Valve
Explosion isolation of combustible dust with an IEP Technolgies Flap Valve

Explosion Isolation of Combustible Dust

Explosion Isolation Valve – Dust collection system for combustible dust with IEP Technologies Flap valve on duct system.

Explosion Isolation on Exhaust Duct

Explosion Isolation on Exhaust Duct
Explosion Isolation on Exhaust Duct

Explosion Isolation on Exhaust Duct

Explosion Isolation on exhaust duct – Twenty-two (22) inch IEP Technologies Flap Valve on dust collection system capturing combustible dust.

IEP Flap Valve

IEP Technologies Isolation Flap Valve
IEP Technologies Isolation Flap Valve

IEP Flap Valve

IEP Technologies Isolation valve

Passive Explosion Protection Systems

Passive Explosion Protection Systems
Passive Explosion Protection Systems

Passive Explosion Protection Systems

Explosion Isolation on a totally Passive Explosion Protection System - Isolation utilizes the ProFlapPlus III Isolation Flap Valve and VENTEX Valve on the recirculation duct.

Airlock Explosion Isolation

Airlock Explosion Isolation on Hopper
Airlock Explosion Isolation on Hopper

Airlock Explosion Isolation

8x8 HDX airlock for hopper isolation

Donaldson Torit TD 573 with Explosion Protection

Donaldson Torit TD 573 with Explosion Protection
Donaldson Torit TD 573 with Explosion Protection

Donaldson Torit TD 573 with Explosion Protection

Explosion Isolation - Passive Explosion Protection System on Sugar Dust handling included Ventex Clean Air Isolation valve, Pro Flap Plus III Dirty Air Isolation on Inlet, Hoerbiger Flameless Vent on Vessel, Rotary Airlock (8 Vane) and a Torit TD 573.

IEP Explosion Isolation Valve

IEP Explosion Isolation Valve
IEP Explosion Isolation Valve

IEP Explosion Isolation Valve

Explosion Isolation Flap Valve

Explosion Flap Valve

Explosion Flap Valve
Explosion Flap Valve

Explosion Flap Valve

EXP Isolation Flap Valve on Pharma application

High Kst Explosion Active Chemical Isolation

High Kst explosion active chemical isolation
High Kst explosion active chemical isolation

High Kst Explosion Active Chemical Isolation

Explosion Isolation - High Kst inlet explosion active chemical isolation

Explosion Isolation Flap Valve on Donaldson PowerCore Dust Collector

Explosion Isolation Flap Valve
Explosion Isolation Flap Valve

Explosion Isolation Flap Valve on Donaldson PowerCore Dust Collector

Explosion Isolation on Donaldson PowerCore® dust collector with IEP Technologies Pistonfire II Suppressors and NFPA 69 certified rotary airlocks.

XP Products Hopper Isolation

XP Products hopper isolation
XP Products hopper isolation

XP Products Hopper Isolation

XP Products hopper isolation on a Donaldson Torit DFE 2-8

Combustible dust explosions are classified as primary and secondary.  Initially, we apply various means of explosion protection for process equipment, the known combustible dust generators, but secondary explosions potentially have a more dangerous result when the deflagration fireball migrates back thru the exhaust duct to interconnected process equipment and igniting accumulated dust off horizontal surfaces or secondary “dust clouds” created by the initial explosion.  Because secondary dust sources are not containable and if your dust has been tested and poses a risk, isolation is mandatory to include in your explosion protection program.  That said, good housekeeping along with knowledge of and removal of accumulated dust will significantly mitigate this potential problem. If you have an explosion component on your process equipment, don’t misunderstand the risks of not having isolation on that same system, i.e. an explosion vent on your dust collector does not protect you against a possible secondary dust explosion catastrophe.

Explosion isolation is mandated by NFPA Standard 654: Standard for the Prevention of Fire and Explosion from the Manufacturing, Processing, and Handling of Combustible Particulate Solids.

Explosion isolation devices are defined as active or passive. Active devices need a detection device to sense pressure increase and signal the isolation device to actuate. Passive isolation devices or flap valves are fully operational with airflow and close shut in reaction to a deflagration pressure increase. There are four types of explosion isolation devices IEP Technologies and SysTech offer based on the Kst and Pmax of the dust:

Explosion Isolation Flap Valves


IEP Technologies Inc. (IEP) offers several models of explosion isolation devices, including an IsoFlap™-M flap valve and the Ventex isolation flap valve.

The IsoFlap™-M valve, a passive isolation flap device, is a reliable explosion isolation solution that mitigates explosion propagation risks to upstream equipment. The IsoFlap™M by IEP Technologies Inc. is available from 4 to 28 inches diameter and meets the requirements of OSHA Combustible Directive and NFPA 654, 69 latest edition, and EU ATEX directive compliant.

If returning the cleaned exhaust airstream to the facility, an IEP Technologies “VENTEX” passive isolation valve may be applied, depending upon your system design. Ventex valves are available for applications in dust transport systems for dust explosion Classes ST-1 and ST-2.

Explosion Isolation Flap Valve on a dust collection system

IsoFlap™-M Isolation Flap valve

Chemical Explosion Isolation


A bottle charged with sodium bicarbonate discharges an explosion suppressant into the duct to suppress a fireball, preventing it from reaching inter-connected equipment or plant areas.  As an active device, it is activated by a signal from a Dynamic Rate of Rise pressure detector through a control and monitor panel.  They are applied where Kst dust values are very high, or duct diameters are very large or as part of a complete dust collector suppression package.

Explosion Suppression System on dust collection system

Chemical Explosion Isolation Bottle

High-Speed Explosion Isolation Valve


High-pressure explosion isolation valves are activated when a pressure detector senses the pressure wave from the deflagration and triggers the release of a high-speed knife gate to close, forming a mechanical barrier in the pipeline.  The barrier prevents propagation of the fireball back into the interconnecting duct and processes; isolating and protecting the return air duct from a secondary explosion. High-speed valves are an active device, and a control panel and pressure detector are required as part of the package.

Mechanical valve for explosion isolation.

Mechanical “Knife Gate” Isolation Valve

Hopper Explosion Isolation


Dust collector designs typically incorporate a Rotary Airlock Valve at the hopper outlet to provide an air seal as the collected particulate is discharged into a dumpster or another collection device.  When handling potentially explosive materials, isolation at the outlet of the discharge hopper of a dust collector requires an isolation flame barrier to meet NFPA Code.  If a rotary airlock is used, it must be designed for the pressures associated with a deflagration.  SysTech installs rotary airlock valves that are tested and certified to comply with NFPA 69.

 

A second outlet option is a Drum Kit.  The XP Products drum kit is attached to the hopper outlet, it acts as an extension of the dust collector hopper. The drum kit, which is a passive solution to combustible dust protection,  includes a spool piece that bolts to the hopper outlet, a hydraulic lift rated to 800 pounds, and a drum band clamp.  The hydraulic lift makes moving of the filled drum much easier and less strenuous on the operator. The kit meets NFPA compliant 3rd party testing to 14 psi. A dust level sensor is available as an option.

Donaldson Torit offers an SDK option that is a tested and NFPA compliant connector piece between the hopper outlet and a 55-gallon drum.

 

Whichever explosion protection components are installed it is important to remember periodic inspections are required per NFPA Code.  Refer to the applicable NFPA Code or ask us at SysTech and we’ll give you the information you need to be sure you’re covered.

All IEP explosion isolation systems and components are highly effective in preventing explosions from igniting and creating secondary explosions in associated equipment or adjacent work areas.  SysTech, with IEP’s engineering knowledge, will assist you in designing and installing explosion isolation components as part of your complete explosion protection system.

Hopper outlet explosion isolation with a rotary airlock

Rotary Airlock Valve

Hopper outlet explosion isolation

XP Products Hopper Isolation

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