The Importance of Explosion-Proof Dust Removal Equipment
All industries that create combustible dust are at risk of a dangerous dust explosion. This type of industrial accident can destroy an entire factory.
To prevent these explosions, all operations with combustible dust must use explosion-proof dust removal equipment. This equipment includes ductwork, filtration, and cleaning systems. Explosion proof vacuums are the best choice for companies that follow an ongoing program of inspections, testing, safe housekeeping, and control initiatives.
Combustible dust is a serious danger in many industries and can quickly cause fires and explosions in the workplace. It’s a result of many materials being processed into fine particulates that can ignite and burn, and it can be found in wood, grain, many chemicals and light metals. The risk of combustible dust explosions can damage facilities and injure employees.
Using the wrong equipment or failing to follow proper procedures can be the reason behind a dust explosion. To ensure safety, facilities need to be aware of the risks and take steps to protect their employees.
In addition to regular monitoring, a facility should invest in high reach ATEX cleaning equipment to remove any dust build up from hard-to-reach areas like air vents, lighting and inside equipment. Additionally, all workers who are responsible for removing combustible dust should be trained to do so to the appropriate standard.
The National Fire Protection Association (NFPA) defines combustible dust as a solid material that poses a fire or deflagration hazard when suspended in the air or another oxidizing medium in heavy concentrations. This includes a wide range of materials used in factories, processing plants and warehouses including food and textiles (e.g. sugar, spice, flour), wood and paper products (e.g. cardboard, jute, paper pulp), tobacco products, coal, fossil fuel power generation, chemical manufacturing and pharmaceuticals as well as metal working and processing such as 3D printing and additive manufacturing.
To create a combustible dust explosion, there are five conditions that must be met:
1. The combustible dust must be fine enough to ignite and burn in the presence of an ignition source.
2. The combustible dust must be in heavy concentrations, causing a fire to spread rapidly.
3. The combustible dust must be exposed to an oxygen rich environment, enabling the fire to continue spreading and exploding.
4. The combustible dust must be contained in a limited space that allows pressure to build.
5. The combustible dust must be ignited and explode. Once an explosion occurs, it can start a chain reaction that can destroy the entire facility. It can also kill explosion-proof dustremoval equipment employees and injure others nearby. Investigations into incidents involving combustible dust have shown that multiple inadequacies such as poor housekeeping practices, lack of employee training and incorrect use or maintenance of equipment are often to blame.
Flammable liquids are a common part of many laboratory and industrial environments. These volatile substances are used as fuels, solvents and cleaners, but they pose a significant risk of fire when they’re not stored safely. The two primary hazards associated with flammable and combustible liquids are explosion and fire. They can produce toxic vapors and gases that are harmful to workers’ respiratory systems and burn the skin if they come into contact with them. Inhalation of these vapors and gases can also cause fainting and suffocation. The most serious hazard is that they can ignite and explode when they’re heated above their flash point.
The flash point is the lowest temperature at which a liquid gives off enough vapor to ignite an explosive mixture with air near its surface. OSHA defines flammable and combustible chemicals into different categories based on their flash points. Class I liquids have a flash point of 100 degrees F or below, while class II and III liquids have a flash point of 200 degrees F or above.
Storage cabinets for flammable and combustible fluids are an essential part of any workplace that uses hazardous chemicals. These safety-rated containers help to reduce the risks of fire and explosion that are associated with these liquids by containing them in an enclosed, isolated area. The cabinet’s doors must remain closed at all times and the container should be locked to prevent accidental dispensing. The storage cabinet should be located away from open flames and ignition sources, and it should be clearly labeled to identify the contents of the cabinet.
It’s important to segregate flammable and combustible materials from other chemicals, including corrosives and oxidizers. This helps to minimise the risk of accidents and ensures that all workers are aware of potential risks when working with these materials. The Globally Harmonized System (GHS) hazard pictogram should be displayed at the entrance to areas that contain these chemicals, and flammable and combustible storage containers should be labeled with this symbol.
In addition to storing flammable and combustible material safely, it’s crucial that your organisation follows all applicable safety guidelines when transferring these liquids from container to container. This includes ensuring that the correct chemical is dispensed and never mixing chemicals together. The GHS hazard symbols for these substances should also be displayed on the outside of each container.
The recent rash of grain explosions across the nation should serve as a wake-up call to companies still using old equipment with ductwork, pipes and other infrastructure that can easily become overburdened by explosive combustible dust. Though each incident may have had its own unique circumstances, the one thing all of them shared was a lack of proper housekeeping practices and cleaning of surrounding areas that should be protected by explosion proof vacuum cleaners and immersion separators.
Designed for use with any central vacuum system, Ruwac USA’s NA35 Series explosion-proof dust-removal systems offer a simple solution to cut risk while keeping work spaces clean. The system safely collects explosive or glowing media particles entering the vacuum and immediately mixes them in a turbulent liquid bath. Moving air and liquid are rapidly forced onto the materials to submerge them and neutralize them in the process. This stops the already contained particles from finding any possible ignition source introduced to the vacuum and eliminates the potential for an explosion.
Another safety feature of the NA35 is its thermal fuse performances that are characterized by discontinuous impedance increases that shut down an electrical circuit in case of overcharging runaway reactions. The impedance changes are exhibited on Nyquist plots of P-class (before pore closure) and D-class membranes sandwiched between blocking stainless steel plate electrodes. The plots exhibit suppressed semicircle responses at high frequencies, but are linearly increased at lower frequencies.
Metal dusts such as aluminum, magnesium and their commercial alloys require specialized extraction methods. Nilfisk’s explosion/dust ignition proof vacuum line includes a variety of models that are certified for use in NFPA 484 (Class II, Group E) hazardous locations to provide a safe and effective method of metal dust recovery. The immersion separators collect and render inert the dangerous metal dusts in an inert liquid immersion bath water or oil.
The resulting water or oil-based material can then be collected in the conductive recovery bags and stored in a corrosive resistant metal tank or disposed of in an inert gas atmosphere. These industrial-grade systems meet the same strict ATEX standards that are associated with all Nilfisk explosion/dust ignition proof vacuums, so users can be confident that they are protecting their employees, equipment and facility.
The equipment you use to handle combustible dust and flammable liquids should have safety features that prevent fire, explosions, and other damage. This includes the machines you buy and the way you use them. It is essential to do your research before purchasing any NFPA-classified piece of machinery or equipment. This includes a certified explosion-proof vacuum approved for use in the hazardous work environment.
Explosion-proof vacuums are typically large air-powered filtration systems with high-quality filtering that can remove combustible dust and volatile liquids from the atmosphere in commercial or industrial settings. They have filters, separators, and a system that purifies and separates dust from the air before it exits through a vent.
These vacuums are available in different classes, divisions, and power ratings with special products developed for unique work areas. A typical combustible dust vacuum will have a metal drum that collects the waste and keeps it confined to avoid potential explosions. They also have a pressure switch and filters that are checked to ensure they are working properly.
An air-powered explosion-proof vacuum can also have a single, dual, or quad Venturi tube that creates the vacuum using explosion-proof dustremoval equipment compressed air. They do not directly use electricity or electrical motors that could potentially generate static electricity, making them safe for Class 1, Division 1 environments.
A cyclone explosion-proof vacuum separates dust from the vacuum stream to force it downward while collecting it into a collection drum. This process increases operating time and reduces maintenance requirements. These vacuums often have a digital display to show when the filters need cleaning or when the machine needs servicing.
Many industries produce materials of a fine particle size that are combustible. These include industries that work with wood, food, metal, and plastic processing. These industries are at risk for a secondary dust explosion, which can be much more devastating than the primary dust explosion that occurs when the initial ignition ignites the combustible dust cloud. These second explosions occur when the pressure wave from the initial explosion dislodges additional dust that had been settled on other surfaces in the facility, such as on top of machinery or ledges, on structural elements like beams and columns, in ceiling ducting, or inside suspended ceilings.