FAQ CATEGORY: Fire Safety

Fire Safety

What are my options for a fire suppression system in my dust collector?

Without an effective fire suppression system, a dust collector could become a meeting point for the three components of any fire: a fuel source, oxygen and an ignition source. Fortunately, effective systems exist to protect both workers and equipment.

The best fire suppression system is an internal one, rather than simply relying on a facility’s sprinklers and fire extinguishers. The latter create a lot of mess and do little to prevent damage to a dust collector itself. Integrated fire suppression devices protect equipment, workers and production lines much more effectively than other measures.

A fire suppression system is able to dispense a gas, such as FM-200 gas, or other agent to kill a fire quickly and cleanly. This should be a last resort, however. A well-designed system will be able to use other fire-fighting measures before deploying gas.

RoboVent’s Supprex-200 is a dual-stage system that is activated by smoke or heat. Sensors within the Supprex-200 can detect these factors and trigger a damper to shut off airflow to the dangerous areas. The system can also automatically turn off the blower. These actions cut off the flow of oxygen and kill a fire before it spreads. The FM-200 gas is only deployed if needed.

What is a spark arrestor?

A spark arrestor is a device that kills sparks before they can cause problems in a dust collector or other piece of equipment. Sparks are a common cause of fires in ductwork and dust collectors—providing one of the three necessary components of a fire: a fuel source, oxygen and an ignition source. If sparks are not stopped, they can ignite dusty filters or dust that is present in ductwork.

Sparks are a common feature of welding, grinding and metal cutting, so it is imperative that an active approach is taken to stopping them. A spark arrestor, such as RoboVent’s Delta3™ Spark Arrestor, catches and kills sparks before they can hit a filter. The Delta3™ does this by using centrifugal force to fling sparks and embers against the outer wall of the device, pulling of their thermal envelop so that they are rapidly cooled and extinguished. Testing has shown that this device kills 99.9% of sparks.

Using a spark arrestor can prevent catastrophic fires that might start in your dust collector and spread throughout your facility, as well as smaller fires that might put your dust collector out of commission for a day or two. These fires could shut down production lines that depend on the dust collectors. Cleaning up after fires is also a major burden for maintenance staff. A spark arrestor can avoid these problems, ensuring worker safety and saving money.

How do I reduce the risks of a dust collector fire?

There are several methods available to reduce the risk of a dust collector fire. The most effective measure for reducing your fire risk is to add a spark arrestor to your dust collector.

Most of the traditional spark arrestance methods rely on physical interventions to prevent sparks from entering the dust collector. Sometimes baffles or metal meshes are used to interrupt a spark’s trip into the collector. The hope is that bouncing off of these surfaces causes a spark to lose its thermal energy. Another method is to create an area of turbulence within the ducts before a spark can reach the filter. This turbulence can kill sparks, at least in theory.

Unfortunately, these methods have serious drawbacks, including a high failure rate. If a spark is large, it might have too much thermal energy to be dissipated by these measures. Or the spark might fly past the devices altogether. These methods carry other negatives, as well, including a loss in efficiency. For example, installing meshes in your ductwork often forces you to increase your airflow, which is an added expense.

The RoboVent’s Delta3™ Spark Arrestor has been designed to kill sparks rather than mitigate them. In comparative studies, it killed 99.9% of sparks, a far higher number than other types of spark arrestors. The Delta3 achieves this by creating centrifugal force to fling sparks against the wall of the device, quickly extinguishing them. RoboVent’s engineers used Computational Fluid Dynamics software to design this device to kill sparks while keeping airflow smooth and uninterrupted.

How do dust collector fires start?

fire_triangle

The causes of dust collector fires are summarized nicely by the “fire triangle.” This graphic includes the three primary components of a fire: a fuel source, oxygen and heat.

Unfortunately, a dust collector brings two of these elements together very efficiently: fuel and oxygen. Many dusts and fumes found in manufacturing facilities are combustible. If air quality is being properly controlled, these substances are likely being pulled into dust collectors. This, along with the filter media itself, is the fuel. A steady airflow through the dust collector ensures that oxygen is always present, as well. All that is left to produce a fire is a heat or ignition source.

Ignition sources are usually not hard to find in manufacturing facilities. Processes such as welding, grinding and metal cutting produce a steady stream of sparks, any one of which could start a fire. If these sparks are not extinguished before they hit the filter media, a fire could result.