We breathe every four seconds, about 22,000 times a day. In urban areas where air pollution is of greater concern, each of those breaths contains more than 25 million particles. On the other hand, indoor air may be 50 times more polluted than outdoor air. In commercial offices, schools, retail environments, and even our own homes, we breathe fine dust, harmful gases, viruses, and bacteria. In material and metalworking manufacturing facilities, we breathe all those plus other health-threatening particles and pollutants generated by various manufacturing processes.
The particles responsible for air pollution come from two main sources; natural or anthropogenic, aka human activity. Particles produced naturally come from wildfires, sand storms or volcanoes for example. Other natural particles include mold, pollen or other plant matter. Naturally occurring particles are generally larger in size than those produced by human activity. One of the most common sources of particles from human activity come from the combustion process that occurs in vehicles and power plants. Other particles can originate from gases used for cooking for example. Farming, textile production, paints, rubber worn off of vehicle tires and various metal processing techniques are other common sources.
CONTAMINANTS |
SOURCES |
EFFECTS |
Nitrogen Dioxide |
Combustion processes, e.g. welding and cutting |
Bronchial inflammatory symptoms in people and lowered lung function |
Ground Level Ozone |
Industrial emissions, particularly in welding, exhaust gases, petrol vapors, and chemical solvents | Chest pain, cough, throat irritation, and stuffiness, worsened asthma and other lung diseases |
Sulphur Dioxide |
Combustion of fossil fuels | Respiratory tract and asthma increase, headache and generally poor health |
Heavy metals - arsenic, chromium, cadmium, lead, mercury, and nickel |
Combustion processes, e.g. welding and cutting | Damage to blood, heart, liver, kidneys, and other organs, as well as reproductive and respiratory organs, slowing mental development, allergic skin reactions |
In most cases, dust and small particles can be extracted directly from the source by using accessories like extraction arms, canopy hoods, suction panels, etc. Because the dust load is large, the filter unit itself must have an automatic filter cleaning system that pulses the collected dust layer off the filter surface and into the collection bin below the unit. Camfil has the widest selection of units in the market such the popular Camfil APC Gold Series which can also cover NFPA and ATEX requirements in explosive dust applications.
When welding large components in the middle of the floor, direct source extraction is not always possible. In those situations, welding fumes can be handled by a system called Push/Pull. There is one ducting on the wall which draws dirty air (Pull) into the filter unit. An efficient filtration stage with HEPA H13-rated air filters separates the small particles and clean air is blown back to the hall (Push). Because air is recirculated, there is no problem with air pressure balance and the system saves a lot of energy required for heat as well.
If fume or dust load in production is not very high, then one solution is the CamCleaner, a standalone air cleaner. It uses multiple stages of air filters selected based on the particular contaminant load and can be designed to target particulate and/or gaseous contaminants. At a much lower cost than a dust collection system, multiple units can be installed to cover large areas. Camfil provides solutions for both ventilation filtration and industrial contaminant management, as well as measurement services for air quality monitoring.
*Report references, links, and additional information and figures are available here.
USA
