SysTech includes cost effective and compliant fire protection & prevention solutions for the dust collection systems we provide. With a myriad of fire protection equipment available, from commercial office fire extinguishers hung on a nearby wall to automated spark detection and suppression systems in industrial applications, SysTech’s focus is fire mitigation specifically for dust collection systems. Because potential fire and explosion issues are not as clearly defined as we might like, we simply protect the systems we supply with the correct technology.
Fire prevention and protection for dust collection systems is what we do…
To better understand what we are dealing with, let’s define what a fire is.
There are three requirements to be met for a fire to occur, an ignition source (sparks, embers), fuel (dust, fumes, mist), and an oxidizer (oxygen within the air). Applied fire prevention and protection methods look to eliminate one or more of these components from the environment to remove the fire threat.
To further clarify terminology, let’s define the difference between prevention and protection.
Prevention aims to eliminate possible ignition sources from the environment. The most common ignition sources are sparks and embers. If your process is at risk of producing embers (slow to extinguish), then an active spark mitigation or a water quench strategy could be applied. If your possible ignition source is sparks (quick to extinguish), passive spark mitigation using separation technology may be a better approach. Both techniques essentially aim to cool the sparks or embers before they come into contact with any flammable or combustible material.
When prevention techniques are applied, we can significantly decrease the chance of a fire or explosion. However, we cannot predict everything. We recognize and understand that even if every precaution is taken to prevent a fire or explosion from occurring, life is unpredictable, and there is still a possibility of an event occurring. This is where fire protection comes into play.
Since it would be difficult to eliminate every possible ignition source, a protection plan must be implemented. Protection serves as a means to protect capital equipment (dust collectors), facilities and personnel in the case of a fire.
Typical fire protection applications would include (not an all-inclusive list):
- Wood Dust Collection
- Metal Grinding Applications
- Conveying Equipment
- Laser and Plasma Cutting
- Storage Vessels
Evaluating Fire Protection System Options
Fire protection systems address mitigation of potential fires through the following means:
- CO2 Fire Suppression System – CO2 or Carbon Dioxide Fire Suppression Systems include a heat sensor, control panel, extinguishing assembly and high (850 psi) or low (300 psi) pressure alloy tanks that store the carbon dioxide. The systems main responsibility is to remove the oxidizer portion of the fire triangle we referred to above. Within milliseconds of a sensor detecting heat, the control panel signals carbon dioxide release, typically from alloy cylinders. The introduction of the carbon dioxide into the fire zone displaces sufficient oxygen in the atmosphere to extinguish the open flame. An important advantage of CO2 systems is minimal clean-up after the event as opposed to water, resulting in less production interruption. High pressure CO2 systems are recommended where space is limited. All systems are in accordance with the current NFPA 12, Standard for Carbon Dioxide Extinguishing Systems.
- Fire Sprinkler Heads – A fire sprinkler system is an active fire protection method, consisting of a water supply system, which provides adequate pressure and flow rate to a water distribution piping system, onto which sprinkler heads positioned within the collector are connected. The sprinklers are designed in accordance with NFPA 13 and NFPA 15, which require a sprinkler discharge density of 25 gpm/ft2 for bag house collectors and 0.20 gpm/ft2 for ducts, hoppers and cyclones.
Selecting Fire Prevention System Options
Fire prevention systems attempt to decrease the amount of possible ignition sources through the following means:
- Spark Detection and Extinguishing Systems – Sensors are placed in the ductwork upstream of the collection equipment to sense a spark or burning material and extinguish it with a minimal amount of water before it becomes an ignition source. These systems consist of a control panel, a varying number of extremely sensitive spark detectors and an extinguishing assembly. When a spark is detected a signal is sent to the control panel, this signal causes the control panel to go into an alarm state and the extinguishing assembly to automatically be deployed. The extinguishing assembly is comprised of a solenoid valve and a varying number stainless steel nozzles. It sprays a minimal amount of water 180 degrees to effectively quench any spark within the cross section of the duct. The control panel serves as a communicator during emergencies between the spark detectors and and extinguishing assembly. While this is the control panels main function, it also serves as a monitoring device for employees to keep an eye on their airstream and for them to have the option of shutting the system down if production stops.
- Spark Traps – Sometimes referred to as a drop out box, spark traps are an in-line duct source-capture system that removes the spark before it reaches the main containment unit, where dust, mist or fumes may be present as fuel.
Fire Prevention Associated Equipment
Equipment associated with fires incorporated into a dust collection system include:
- Abort Dampers – When returning exhausted and cleaned air to the building, and there is a fire, abort dampers are used to divert and expel smoke.
- Static Grounding and Bonding – An important consideration to eliminate static electricity as an ignition source in potentially flammable and combustible atmospheres, e.g., powder processing operations can generate electrostatic charge as materials move through interconnecting duct and process vessels.
Should your responsible Authority Having Jurisdiction (AHJ) require additional documentation, SysTech can recommend a Risk Assessment Consultant to evaluate and document the existence or non-existence of fire hazards within your facility.
SysTech offers the most applicable fire protection systems and services for your application.