by Marjorie Steele, Editor for IQS
When I first learned IQS® had a site solely devoted to “dust collectors”, I got a mental image I haven’t been able to shake: a bunch of big industrial machines sitting around, inanimate…collecting dust. Like the miniatures in my wall shadowbox, or the weird knickknacks my mom has been buying off EBay lately. Dust collectors.
Ok, so I have a degree in playing with words, not in Industrial Engineering. It turns out dust collectors perform, in many manufacturing plants, one of the most important steps in material processing; they are vital to worker and equipment safety and can often help recoup thousands of dollars of materials that are lost during manufacturing. So what is it dust collecting systems do exactly?
They sit around collecting dust.
Almost every type of manufacturing or material processing creates a release of foreign particles into the air – some more than others. Woodshops and lumber mills are classic examples; all that sawing, grinding and cutting creates not only the sawdust on the ground, but the much finer wood dust in the air. That’s why woodworkers often wear masks or handkerchiefs over their face: to protect their lungs from all those tiny, abrasive wood particles. Metal fabrication produces the same effect. As parts are cut, machined and polished, tiny metal particles are released into the air, not only posing a health risk to workers and clogging expensive equipment, but also wasting valuable metal material. A microscopic amount of titanium dust in the air might not seem like a large enough amount to make any significant financial difference to a company, but multiply those particles of titanium by 500 cubic feet produced 5 days a week, 52 weeks per year over the period of several years and you’ve got yourself a mountain of titanium dust.
Other processes release any number of contaminants into the air. A plastic siding manufacturer releases plastic dust each time extrusions are cut; pharmaceutical mixers spray a number of powdered chemicals into the plant atmosphere, and petrochemical processing plants are faced with a slew of wet and dry chemical air pollutants resulting from manufacturing processes.
Dust collectors are a fairly simple solution to this problem. They act as a kind of surrogate lung for a certain area or for an entire plant, sucking up contaminated air, collecting out particles and pushing contaminant-free air back out. There are many types of dust collectors and dust collecting systems designed for different applications, but the basic types are:
- baghouse units
- downdraft tables and booths
- portable units, and
- free-hanging ambient units
The most common and usually the most cost-efficient type of filtration is the fabric filter, commonly found in “baghouse” units. These are hopper-shaped units containing cloth or fiberglass filtering bags through which contaminated air is forced, leaving particles behind in the filter cloth while purified air moves on through and out. A fan creates suction at the end of the unit, drawing polluted air in through ductwork and “capture arms,” or “suction hoods” which reach down to contaminated areas. This handy little diagram is a great example of how a classic baghouse filter works:
Another type of dust collector is the portable unit, or the collection booth, which can be moved around to areas of concentrated contamination. Downdraft tables and booths provide vacuuming airflow for specific work areas. Not all dust collectors use fabric filters; some use specific airflow currents (“inertial separators”, or “cyclone” dust collectors), electrostatic precipitation or wet mist (“wet scrubbing”) to pull contaminating particles out of the air. These different types of dust collecting are effective in different applications, depending on the material, size, temperature, flammability and friability of the particles being collected.
If you’d like to learn more about the different types of dust collectors available for your facility, try browsing the companies listed in our Directory. While many small shops and hobbyists are able to fabricate their own small dust collectors, larger industrial processes require much higher volume, professionally fabricated systems.
Although the dust in my shadowbox may not be evidence of the greatest housekeeping, it’s not going to harm my respiratory system or clog up the furnace. The dust in a manufacturing facility, however, poses a much greater threat; so make sure your workers and equipment aren’t collecting all the dust in your facility – leave that to the real dust collectors.