Choosing the right dust collection solution requires careful evaluation of the specific application.

The first step in choosing a dust collection solution is classifying the specific dust involved and the exhaust stream in which it’s entrained. Next, determine whether the collector should be a wet type (that is, one that uses water) or a dry type. These questions can guide you toward choosing the right type of dust collector:

• Is the dust being collected going to be reclaimed/reused in some way or will it be waste that requires safe disposal?
  • If it’s used in the process, can it be used wet?
  • If it’s waste, how expensive will it be to treat the waste stream and/or dispose of the slurry?
• Are there any fume pollutants in the air stream? If so, are they water soluble?
• What is the temperature of the air stream? Will the air stream quench?
• Is the dust explosive? If so, will a wet system mitigate or exacerbate the problem?

Once you have determined if a wet system or a dry one is a better solution, you’re ready to pick your dust collector. Baghouses and cartridge collectors are dry dust collectors, which don’t employ any liquids.  A cyclone can be either a wet or a dry dust collector; a wet scrubber is, as the name implies, strictly wet.

Dry dust collectors

The following table can help you weigh the advantages and disadvantages of the various dry dust collector options.  A cyclone is an inexpensive mechanical separator that is very good at separating larger dust particles from an airstream.  They require very little maintenance and can handle high dust loading easily.  Cyclones are often installed ahead of a baghouse or cartridge collector in the dust collection process when those types of collectors cannot handle the full dust load.

A baghouse provides high removal efficiency for small dust particles. It can handle moderate dust loadings but can become plugged if the loading gets too high.  Sticky dust (from materials such as boron oxide, products containing sugars, and many others) will cause high pressure drops; the bag filter limits the temperature of the airstream.  Compressed air can be used to clean the bags, but cleaning and changing bags is a very dirty and time consuming process.

A cartridge collector is less expensive and easier to maintain than a baghouse.  It uses cartridges instead of bags, making the collector more susceptible to plugging in high dust applications.  Much like a baghouse, sticky dust and high temperatures will cause issues with the filters and will require compressed air for cleaning.

Wet scrubbers

A variety of wet scrubber options are available, including wet cyclones, packed towers, Venturi scrubbers, wet electrostatic precipitators (ESPs) and spray chambers. All wet scrubbers involve the use of water to trap dust. A wet cyclone is similar to a dry cyclone, in that it provides very good removal efficiency for larger dusts and droplets.  A packed tower is best for fume removal. The tower can remove particulates, but the packing will clog if the particulates are not water soluble.  A Venturi scrubber can remove small particulates, but requires large amounts of energy to operate.  A packed bed is often located after the Venturi scrubber to help collect any dust or fumes. Wet ESPs and spray chambers offer very good dust collection, but they can be expensive to operate.

For more information on the variety of applications for which cyclones offer important advantages, refer to our Solutions Sourcebook, which demonstrates cyclone uses in a variety of industries, or contact us, via phone at (440) 543-7400 or by e-mail at dc@dustcollectorhq.com/.