Explosion-Proof Dustremoval Equipment

There are many industrial processes that produce harmful dust that needs to be safely removed from the air. Unfortunately, many industrial vacuums and air cleaning units are not designed to remove flammable or explosive dust that can combust and cause severe damage.

The best way to ensure safety is by using a safe dust collector, preferably one connected to an efficient source capture extraction system. These systems extract the dust in immediate proximity to where it’s produced.

Vents

The most effective way to minimize the potential for dust explosions in your facility is to design and install explosion-proof equipment. The primary purpose of these systems is to control the concentration of combustible materials, but in addition, they are designed to protect people and property from an explosion should one occur.

Explosions are caused by a combination of two factors: flammable dust, and a suitable source of ignition. Preventative measures aim to avoid the presence of combustible dust, but they often do not prevent these explosions from occurring.

Venting is one of the most common methods of mitigating the risk of a dust explosion. The concept is simple: put controlled weak spots on the vessel wall of the dust collector that will open once predetermined pressures have been reached, allowing the overpressure to be relieved and flame fronts to exit safely to a designated release area.

There are several options for venting in a dust collector, including flameless and traditional vents. In addition, the ATEX and NFPA standards recommend venting to the outside of your building, where it is safest.

Camfil APC offers a number of standard vent models for use in explosion-proof dustremoval applications. They are ATEX and NFPA certified, and can be adapted to fit a variety of different types of dust collectors.

Typical vents for cyclones and baghouses include the KER model, which opens at pressures ranging from -0.725 PSIG to +0.5 PSIG and is perfect for static over/under pressure conditions up to 50% of the rated rupture pressure. The KER also includes integrated flange gaskets, cross rib and folded edges as standard design features to ensure long durability and aerodynamic advantages compared to a domed vent.

A secondary protection option is a self-actuating flap valve on the inlet duct to your dust collector. This will extinguish any flame front that has been ignited by a deflagration within the dust collector, and it also helps prevent a secondary explosion that can travel back into the space where it was initially ignited.

In many instances, the distance between the inlet duct and the release area is too great for explosion venting to be considered safe. If this is the case, it is best to install a suppression or suppression-isolation system. Suppression systems are covered in NFPA 69, which also includes inlet and outlet ducting, spark-extinguishing systems and methods for preventing an explosion from traveling back into the building.

Latches

Dust accumulation is a problem in virtually every industry. Whether it’s metal working, furniture making or 3D printing, dust can be a fire hazard, especially if the dust is confined within ductwork or other confined spaces where it could be exposed to an ignition source such as a spark from faulty machinery or static electricity.

Thankfully, explosion-proof dustremoval equipment can reduce these risks by incorporating the most effective features. These include vents, high-speed abort gates, pressure sensors, and explosion relief elements that work in tandem with each other to protect employees from the dangers of dust-related fires and explosions.

Vents: The National Fire Protection Association (NFPA) has specific standards for ventilation systems designed to prevent dust explosions and combustible material igniting in the ductwork. They recommend venting to a higher point than the dust collector to prevent it from becoming over pressurized and causing an explosion.

Latches: A good pressure release safety latch will keep a door or vent cover from opening under a set predetermined pressure. It will also release the cover when an internal explosion occurs and maintain a seal.

The best explosion-proof pressure release safety latches are durable, reliable and provide a good return on investment. They have adjustable strike points and a release force that can be adjusted to match the application.

They are available in standard and compact sizes. They can be configured to handle high or low pressures and are suitable for dust collectors, rotary airlocks, isolation valves, and screw conveyors.

Latches are a small component of the overall process, but they can make a big difference. A well-designed explosion-proof dustremoval equipment and implemented system can help to minimize the risk of dust explosions and fires, while reducing production downtime. Using the right equipment to prevent a dust explosion can save companies time, money, and most importantly, lives. It’s important to partner with an experienced professional engineer to design and implement a safe and reliable dust collection system. Ensure that the equipment meets the required certifications and comply with local and federal fire code requirements.

Chemical Isolation

Dust explosions are a common risk in industrial processes. They can cause fires and other damage, endanger people, and even destroy equipment. There are several ways to reduce the hazards of dust explosions, including ventilation, isolation, and chemical suppression.

In addition to preventing dust explosions from occurring, these safety measures are essential for reducing the amount of debris and dust that ends up in the environment and spreading throughout your facility. These measures also help you comply with NFPA standards.

Isolation is a key safety feature for dustremoval equipment and prevents combustible material from spreading through the ducting in the event of an explosion. Isolation systems are designed to react within milliseconds of detecting an explosion and release a suppressant that extinguishes the flame before it can spread or increase pressure in connected process equipment.

This type of explosion protection is most commonly used in ducting and piping that connects equipment to each other. When an explosion occurs, a chemical is injected into this ducting to interrupt the transport of flame fronts and a suppressant to quench the flame.

There are several types of chemical isolation that can be applied to ducting in dustremoval equipment. They can include a pressure-driven detection system that activates the injection of a chemical agent into the ducting if an explosion is detected.

Alternatively, a system that uses a mechanical barrier can be installed in the ducting to isolate pressure and flame fronts caused by an explosion. This valve is designed to react within milliseconds of an explosion and can be triggered by a sensor mounted in the ducting itself or by a control panel.

These pressure-driven systems are typically more expensive than passive devices, but they can offer greater explosion protection. They also require recertification on a regular basis.

If your company works with combustible dust, you may want to conduct a Dust Hazard Analysis (DHA). This evaluation will determine what the risks are and how to best manage them. It can also help you identify potential sources of ignition that could lead to an explosion.

The most common combustible dusts are coal and grain, which can easily ignite when they’re in contact with oxygen or when they’re in contact with a fire. They can also ignite when they’re in a confined space and when they are airborne. There are also many other combustible materials that can create an explosion, such as wood chips, paper, and plastics.

Pressure Sensors

A wide variety of pressure sensors are available for use in explosion-proof dustremoval equipment. These can be used to monitor the performance of different components and systems. In addition, they can be used to notify a user if a particular element or system within an explosion-proof enclosure needs maintenance or repair.

The type of sensor used will depend on the combustible material being collected. For example, if the dust is flammable, explosion-proof dustremoval equipment it may require an explosion-proof sensor to detect a pressure differential between the collector’s inlet and outlet ports.

Some of the most common explosion-proof sensors include ATEX compliance pressure sensors and flame-isolation valves. These devices are designed to prevent overpressure or a flame front from propagating through the inlet duct of the collector and into a building, which can cause catastrophic damage and injuries.

Another common type of pressure sensor in an explosion-proof dustremoval system is a monitoring filter. This device is affixed to the top of a dust collector and acts as a flame front barrier, preventing the explosive dust that is being collected from traveling through the ducting to a building where it can ignite.

As with many other aspects of dust hazards, it is important to conduct a thorough analysis and identify all the potential ignition sources present in a specific location. This will help you determine the exact type of explosion-proof auxiliary equipment that you will need to keep your employees safe.

It is also necessary to assess the production process and housekeeping procedures at each facility to determine where nuisance dusts are being generated, released, or tend to accumulate. These can include intake and mixing locations, bag dumps, and welding or cutting stations.

Once you have a clear picture of your combustible dust problem, you can make recommendations for explosion-proof ventilation, latches, and chemical isolation systems. Nederman’s safety experts can guide you through this entire process, from beginning to end.

The risk of a dust explosion depends on three factors: the source of the ignition, the combustible fine dust, and the concentration of the dust in the air. To lower the risk, you should consider reducing or eliminating the source of the nuisance dusts. It can also be a good idea to improve the processes that generate or release these dusts.