Welding Fume Extraction System in Confined Spaces
Welding Fume Extraction System in Confined Spaces
What is a confined space in an industrial setting and why is a fume extraction system a critical device?
Any space with constrained access with limited means of entry and exit are called confined spaces. Ventilation is normally poor or very limited, oxygen supply is low, air contaminants are present, and traces of toxic or flammable gases are found.
The dangers present in confined spaces can put any person in harm’s path. Oxygen shortage is a major problem. When there is limited access and oxygen supply is low, respiration increases while more carbon dioxide (CO2) is released. With more CO2 being released in the atmosphere, oxygen levels drop down. This endangers the life of the people within the confined space.
There is also a risk of explosion due to toxic or flammable gases stored in confined space. Lingering flammable vapors inside a tank truck or cargo or welding gases in a metalworking shop can cause fire or explosions triggered by faulty electrical wiring, faulty electrical equipment, or welding sparks.
These dangers are found in places such as tanks and wells, basement and lofts, tunnels, sewers, or excavations of more than 4 ft deep. Also, there are different occupations that must deal with these dangers, including:
repair service
cleaning services
painting contracts
building and renovation
rescue operations
Accidents have been rampant in areas with no necessary safety measures.
The Risks of Welding: Smoke Removal and Exhaust
Even with the most advanced gears and equipment, accidents can still happen, especially in confined spaces that do not follow strict safety guidelines wherein some are more commonplace where accidents originate.
The lack of proper ventilation.
In work areas such as metal fabrication buildings with confined spaces, fumes and toxic gases build up and displace oxygen. The displacement of oxygen already puts people in danger that is potentially fatal. Some toxic gases produced in welding, grinding, cutting, and reshaping materials, are odorless and colorless. People are unknowingly inhaling toxic gas that puts them in great danger.
A local exhaust system helps take out this danger by keeping toxic gases and contaminants out of the working space and for oxygen levels to remain in a safe percentage.
The presence of electrical hazards.
It isn’t just fumes and toxic gases that put people at risk. Electrical safety when welding in confined spaces can not be neglected. Anything made of metal such as a pipe or tank will be part of the welding circuit which means the worker can be unconsciously standing on a part of the project being worked on that is electrically hot. Electric shocks are uncommon, and it can happen anytime, in the most unexpected places.
To reduce this risk, the electric welding power source must be outside the confined space or far from it. The cables and wires supplying electricity must have proper insulation.
Types of Welding Smoke Ventilation to Remove Air Contaminants
In the early times where technology is young and unexplored, natural ventilation used to be the most common and most effective way of allowing fresh air into closed spaces and in homes. However, this is no longer a sufficient ventilation method especially for homes and buildings that are air-sealed for energy conservation and efficiency. Plus, it does little for moisture control.
There are three ventilation categories that are widely used in commercial and industrial workstations.
Natural Dilution Ventilation
Dilution ventilation is the simplest and cheapest way to ventilate a space. It is the natural way of allowing fresh air into a closed space by simply opening windows, doors, and other building openings to lower the concentration of air pollutants or significantly removing it.
It is deemed less effective in industrial and commercial settings because one has no control over the extraction of airborne contaminants. This isn’t a recommended ventilation strategy for confined spaces that have structural features obstructing natural airflow. It’s also not recommended in work areas where toxic gases and carcinogenic substances are present.
Mechanical Dilution Ventilation
Mechanical dilution uses the same concept as natural dilution: to dilute the concentration of airborne contaminants in a workspace. It is done by removing dirty air from the area and supplying it with clean air. If the air is stagnant and there is no movement, the highest concentration of contaminants will be near the source, thus, polluted air floats around within the worker’s breathing zone.
Wall fans, roof exhaust fans, HVAC systems, and other mechanical means to moved contaminants from endangering the workers are used for dilution.
Local Exhaust Ventilation
Local Exhaust Ventilation (LEV) is the most effective and preferred method of keeping airborne pollutants away from the workers. It is commonly used in welding areas to extract smoke and fumes with the assistance of a welding exhaust fan. Flammable gases, toxins, and other unwanted gases and vapors are collected before they become airborne and managed by local exhaust ventilation systems.
Aside from LEV, workers, especially welders, gear up with a high-quality welding helmet that limits the exposure to weld fumes preventing direct inhalation.
Here are some examples of LEV:
Downdraft Bench – From the open grip work surface, the air is drawn downward wherein the collected contaminants are passed in the exhaust ducting. For this to work, air speed must be high so contaminants going airborne and reaching the workers’ breathing zone don’t happen.
Fume Extraction Welding Guns – A hose is placed close to the source of contamination (or close to the welding spot). The extracted fumes are collected into the exhaust system. It’s an ideal and effective LEV on flat and vertical surfaces.
Read more about ventilation systems here.
The Risks of Welding: Smoke Removal and Exhaust
Ventilation of confined spaces is significant in the foundation of maintaining a healthier workspace for all workers in different industries, especially those processes that involve welding or production areas that are dependent on it. The system itself is simple but it is highly effective in keeping clean and breathable air.
A welding exhaust system, even with the presence of an indoor air quality measuring device, proves to be a worthy investment when:
Unexpected dangerous particles are hard to detect with a normal measuring device.
Measurement errors due to improper handling of measuring devices.
Environmental degeneration that remains undetected.
Arrow Industrial Air Filtration is a Mechanical and HVAC Contractor that has been in the heating, cooling and ventilation business for years.
Visit our page to know more about us and how our services can address your ventilation issues.
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