Handling Industrial Wood Dust
The key to preventing such incidents lies in how you manage wood dust. This can be broadly broken down into a three-step process:
1. Capture It
The initial step in safely managing wood dust involves capturing it at the source. This is typically achieved by designing an effective hood for each dust source. Each machine has specific requirements for suction, usually specified as a combination of drop diameter and air velocity. It's critical to maintain these air velocities while the machine is generating dust.
It's important to note that not all woodworking machine manufacturers thoroughly test their hood designs. Consequently, some machines may not collect all dust, even at the recommended air velocity. In such cases, you may need to redesign and adjust the machine hoods.
If the machine manufacturer's specifications are being met at the hood and dust is not reliably captured, adjustments are necessary.
2. Transport It
Once captured, the dust must be efficiently transported to the dust collector. The air velocities required for this vary depending on the type of contaminant.
The American Conference of Governmental Industrial Hygienists provides recommended design velocities for different contaminants:
Depending on the specifics of the materials and processes in each facility, the minimum transport velocity can range from 2000 to 4000 feet per minute.
A well-designed ducting system is crucial to maintain transport velocities. Ideally, the duct design should be as simple and short as possible to minimize pressure losses, have suitable hoods for all machines, minimize the number of elbows (none greater than 45 degrees), and limit the use of flexible ducts.
3. Process It
Finally, you need the right fan, motor, and dust collector. Factors that influence which fan, motor, and dust collector are right for your application would include:
Total air volume requirements
Type of dust
Production processes used
The fan installation should be error-free. The first elbow at the fan inlet should ideally be at least three times the diameter away from the fan inlet (preferably five times). This enhances fan efficiency. A stack should be utilized on the fan outlet.
Using a direct-driven fan motor ensures better energy efficiency. Optionally, the captured wood dust can be recycled into new material (like MDF board) or used to generate energy as biofuel. Additionally, sawdust can be turned into pellets, a practice employed by companies like Gildale Farms.
Ultimately, each situation is unique and should be prepared for each individual project together with a domain expert.
A good dust collection system will provide a reliably clean and safe working environment that is conducive to high productivity.
Well-maintained industrial dust collection systems should have a life cycle of 20 years. This longevity should be considered when selecting a dust collection solution, as investing in a superior solution today can yield significant returns over the system's life cycle.
Author, Krystof Litomisky