Welding Fume Behavior and Hall Ventilation

BEHAVIOR OF WELDING FUME AND HARMFUL EFFECTS OF WELDING FUME

Fume is a dense collection of particles that are invisible to the naked eye and appear as a thin layer. Fume generated during welding contains contaminant particles with an average diameter of 0.05 to 20 micrometers. The amount and type of welding fume produced depends on the welding parameters and the base materials.

As soon as welding fumes are formed, they are rapidly directed upward due to the high temperature. The heat-losing smoke remains suspended at a height of 2.5 to 5 meters, depending on the conditions. As it cools, the smoke, freed from harmful and heavy particles, continues its slow upward movement. Internal air currents can disperse the particles up to 40 meters away and, driven downward by gravity, they rise back into the breathing zone with every movement and air current in the environment, where they are inhaled by all workers. These particles also settle in workers' eye sockets, skin, and hair follicles.

Harm of welding fumes

EFFECTS OF WELDING FUMES ON HUMAN HEALTH

In welded manufacturing plants, gases, dust, and fumes generated by the production process and released into the work environment enter the body through the respiratory tract. Some of these air pollutants can cause chronic (long-term) diseases, but depending on the level of exposure, they can also cause acute (sudden onset) illnesses. For example, metal fume fever, frequently seen in welders, is generally a temporary ailment but can also contribute to the development of chronic diseases. If the concentration of pollutants exceeds the permitted concentration in the work environment of welded manufacturing plants and this air is inhaled, depending on the duration and intensity of exposure, respiratory distress, blood disorders, cancer, chronic bronchitis, headaches, pulmonary edema, metal fume fever, and irritation of the oral and nasal mucosa can occur. Damage to the central nervous system, kidneys, liver, blood-forming system, and bone structure can also occur, and related diseases can occur. Occupational diseases called pneumoconiosis occur when metal-containing dust, gases, and fumes are inhaled for long periods and accumulate in the lungs. While carbon, tin, iron, and aluminum pose a low-level risk to workers in welded fabrication shops due to their exposure to dust, gases, fumes, and oxides, cadmium, chromium, lead, vanadium, manganese, mercury, molybdenum, nickel, titanium, and zinc pose a significant irritant and toxic effect, leading to much greater health problems and permanent illnesses. In summary, the dust, fumes, gases, and vapors frequently encountered in welded fabrication shops and inhaled through the body contain the chemicals listed above, causing respiratory irritation and permanent illness if inhaled in high concentrations for extended periods. Similar effects are also observed in the eyes, leading to health problems such as eye irritation, conjunctivitis, keratitis, and allergies.

EFFECTS OF WELDING FUMES ON THE ENVIRONMENT

The harmful effects of welding fumes arise from the emission of all these harmful substances from chimneys: they can reach distant areas through the wind. It has been observed that plants fail to grow in gardens and fields where these particles are dispersed. These particles also affect water resources. Animals in areas exposed to these particles are also affected, and their meat and milk can reach humans. Their effects on the atmosphere have also been proven through detailed research.

For all these reasons, if welding fumes cannot be locally absorbed and filtered in welded manufacturing facilities, an ambient ventilation system must be installed.

Since these systems do not take in air from outside, they also provide savings of up to 70% on heating costs, especially in winter.

Solutions such as push-pull and layered ventilation have been developed for many years. The common disadvantages of these two systems are that they are piped systems and have high investment and operating costs. Push-pull systems are not recommended for spaces with ceiling heights greater than 7.5 meters. Push-pull systems can be used in production areas with low thermal loads (annual MIG/MAG wire consumption less than 10 tons). These systems lose their functionality if not calculated and installed by professionals. Layered ventilation systems are very useful because they use the displacement ventilation principle. However, these systems have a high investment cost and maintenance costs. Another solution, filter towers, is produced by many companies. Because these systems do not require piping, they are much more practical and economical. After observing the advantages and disadvantages of all these systems over the years, our team designed a highly innovative system:

HIVENT / HiS:

R&D work has been conducted entirely within our company. The system filters all volatile particles formed in production areas to prevent them from being re-sprayed, ensuring that the ambient air reaches a breathable level.

HiVent HiS

Each HiS unit has a 1.3 kW EC motor. It features a composite fan that produces a maximum flow rate of 5,000 m³/h. The nanofiber-coated cartridge filters are at least class F9. The filter cleaning system is fully automatic.

CFD analysis of HiS system layout

The HiS absorbs and filters polluted air, returning some of the cleaned air to the environment at very low speeds at ground level, thus complying with the principle of displacement ventilation. Some of the cleaned air is blown through jet nozzles to the other HiS unit, ensuring continuous movement of volatile particles.