Metal Dust Collection Systems
Metal dust collection is very different from wood dust collection. It requires extra attention since the particles can be very hazardous to the body and the workplace. Muza Sheet Metal Co., LLC. has also been designing, fabricating and installing metal dust collection systems since 1928. Below are some important reasons to have an efficient dust collection system.
Elements of a Dust Explosion
Elements Needed for a Fire (the familiar "Fire Triangle"):
- Combustible dust (fuel)
- Ignition source (heat)
- Oxygen in air (oxidizer)
Additional Elements Needed for a Combustible Dust Explosion:
- Dispersion of dust particles in sufficient quantity and concentration
- Confinement of the dust cloud
The addition of the latter two elements to the fire triangle creates what is known as the "explosion pentagon". If a dust cloud (diffused fuel) is ignited within a confined or semi-confined vessel, area, or building, it burns very rapidly and may explode. The safety of employees is threatened by the ensuing fires, additional explosions, flying debris, and collapsing building components.
An initial (primary) explosion in processing equipment or in an area were fugitive dust has accumulated may shake loose more accumulated dust, or damage a containment system (such as a duct, vessel, or collector). As a result, if ignited, the additional dust dispersed into the air may cause one or more secondary explosions. These can be far more destructive than a primary explosion due to the increased quantity and concentration of dispersed combustible dust.
If one of the elements of the explosion pentagon is missing, a catastrophic explosion can not occur. Two of the elements in the explosion pentagon are difficult to eliminate: oxygen (within air), and confinement of the dust cloud (within processes or buildings). However, the other three elements of the pentagon can be controlled to a significant extent, and will be discussed further in this document.
Facility Dust Hazard Assessment
A combustible dust explosion hazard may exist in a variety of industries, including: food (e.g., candy, starch, flour, feed), plastics, wood, rubber, furniture, textiles, pesticides, pharmaceuticals, dyes, coal, metals (e.g., aluminum, chromium, iron, magnesium, and zinc), and fossil fuel power generation. The vast majority of natural and synthetic organic materials, as well as some metals, can form combustible dust. NFPA’s Industrial Fire Hazards Handbook5 states that "any industrial process that reduces a combustible material and some normally noncombustible materials to a finely divided state presents a potential for a serious fire or explosion."
Research identifies the health consequences of long-term exposure to metal working dust. The Occupational Safety and Health Administration (OSHA) has used warnings similar to wood dust exposure to explain the adverse health effects.
"Exposure to metal dust has long been associated with a variety of adverse health effects, including dermatitis, allergic respiratory effects, mucosal and non-allergic respiratory effects and some forms of cancer."