A dust collection system is an air quality improvement system used in industrial, commercial, and home production shops to improve breathable air quality and safety by removing

particulate matter Particulates – also known as atmospheric aerosol particles, atmospheric particulate matter, particulate matter (PM) or suspended particulate matter (SPM) – are microscopic particles of solid or liquid matter suspended in the air. The ter ...

from the air and environment. Dust collection systems work on the basic formula of ''capture'', ''convey'' and ''collect''. First, the

dust Dust is made of fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind (an aeolian process), volcanic eruptions, and pollution. Dust in homes ...

must be ''captured'' or ''extracted''. This is accomplished with devices such as capture hoods to catch dust at its source of origin. Many times, the machine producing the dust will have a port to which a duct can be directly attached. Second, the dust must be ''conveyed''. This is done via a ducting system, properly sized and manifolded to maintain a consistent minimum air velocity required to keep the dust in suspension for conveyance to the collection device. A duct of the wrong size can lead to material settling in the duct system and clogging it. Finally, the dust is ''collected''. This is done via a variety of means, depending on the application and the dust being handled. It can be as simple as a basic pass-through filter, a

cyclonic separator Cyclonic separation is a method of removing particulates from an air, gas or liquid stream, without the use of filters, through vortex separation. When removing particulate matter from liquid, a hydrocyclone is used; while from gas, a gas cyclone ...

, or an impingement baffle. It can also be as complex as an electrostatic precipitator, a multistage baghouse, or a chemically treated wet scrubber or stripping tower.

Types of systems

Smaller dust collection systems use a single-stage vacuum unit to create suction and perform air

filtration Filtration is a physical separation process that separates solid matter and fluid from a mixture using a ''filter medium'' that has a complex structure through which only the fluid can pass. Solid particles that cannot pass through the filter ...

, where the waste material is drawn into an impeller and deposited into a container such as a bag, barrel, or canister. Air is recirculated into the shop after passing through a filter to trap smaller particulate. Larger systems utilize a two-stage system, which separates larger particles from fine dust using a pre-collection device, such as a

cyclone In meteorology, a cyclone () is a large air mass that rotates around a strong center of low atmospheric pressure, counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere as viewed from above (opposite to an anti ...

or baffled canister, before drawing the air through the impeller. Air from these units can then be exhausted outdoors or filtered and recirculated back into the work space. Dust collection systems are often part of a larger air quality management program that also includes large airborne particle filtration units mounted to the ceiling of shop spaces and mask systems to be worn by workers. Air filtration units are designed to process large volumes of air to remove fine particles (2 to 10

micrometre The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

s) suspended in the air. Masks are available in a variety of forms, from simple cotton face masks to elaborate respirators with tanked air — the need for which is determined by the environment in which the worker is operating. In industry, round or rectangular ducts are used to prevent buildup of dust in processing equipment.

Dangers of neglect

Proper dust collection and air filtration is important in any work space. Repeated exposure to wood dust can cause chronic bronchitis,

emphysema Emphysema, or pulmonary emphysema, is a lower respiratory tract disease, characterised by air-filled spaces ( pneumatoses) in the lungs, that can vary in size and may be very large. The spaces are caused by the breakdown of the walls of the alve ...

, "

flu Influenza, commonly known as "the flu", is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptom ...

-like" symptoms, and

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

. Wood dust also frequently contains chemicals and

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

, which can become airborne and lodge deeply in the

lung The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of t ...

s, causing illness and damage.

References

External links

Center for Disease Control's National Institute for Health and Safety (CDC-NIOSH)
– (U.S.)
Rod Cole article, "Grounding PVC and Other Dust Collection Myths
- (U.S.) {{Woodworking Particulate control Waste treatment technology Woodworking Solid-gas separation