Fume extraction technology improves welding shop air quality without hampering production

Situation

The quality of the hall air at Aebi Schmidt Nederland B.V. was already at an acceptable level, but that wasn’t good enough for the Holten, Netherlands, company. Increasing demand for its agricultural and municipal maintenance equipment had generated more welding work, but the manufacturer wanted to ensure a healthy environment for its workforce.

“One focus at Aebi Schmidt was clearly on improving working conditions,” said Facility Manager Steven Koenderink. “Air quality was one of the central issues here.”

The Netherlands already has one of the lowest workplace exposure limits for production plants—1 mg/m3— but the manufacturer was looking to improve the air quality even further, particularly in the welding shop. The company wanted to completely ban from production any hazardous substances with lung-damaging, toxic, or even carcinogenic effects—precisely those that arise in large quantities during its production of steel-heavy add-on parts using GMAW.

During Aebi Schmidt’s search for a supplier of extraction technology, the goal was clearly defined: the cleanest possible hall air in line with the needs of production. For example, the intake systems for the hazardous substances generated during welding had to effectively extract them while maintaining flexibility in production. A fixed budget defined the framework for the investment in protective welding equipment.

Resolution

Germany-based Kemper GmbH adhered to these specifications from the outset and put together a customized protective welding equipment concept for the manufacturer. To allow for possible adjustments to the welding shop layout, the manufacturer decided on mobile extraction units. Kemper recommended welding fume extraction by means of high-vacuum systems with connected extraction torches, which would capture welding fumes directly and immediately at the point of origin.

These systems have a reputation for being difficult to use, so Aebi Schmidt agreed to a comprehensive test of the VacuFil 250 system. After a few days, the system had extracted so much welding fume that the manufacturer ordered 13 units. Because each unit can be coupled with two extraction torches, employees can weld safely at 26 workplaces at the same time. The systems are matched to each other in terms of extraction capacity so that the welding fumes are optimally captured without destroying the protective gas envelope.

The welders automatically carry the extraction system integrated in the torch nozzle for removal of hazardous substances at the point of origin. This allows the manufacturer to achieve high production capacity as well as clean hall air for its employees. Even at high welding intensity, the units extract high levels of smoke and dust in continuous operation with a maximum output of 250 m³/hr. without any loss of quality, even when two employees are welding at the same time.

Using KemTex ePTFE filter cartridges with surface filtration, the systems permanently filter out more than 99.9% of the captured welding smoke particles. Even particles smaller than 0.1 µm have no chance of escaping back into the hall air after extraction. In addition, with automatic filter cleaning, welders do not have to interrupt their work. Instead, as the filter becomes saturated, the hazardous substances enter a disposable container that can be changed contamination-free.

For further employee safety at the Aebi Schmidt plant, Kemper also installed a push/pull general ventilation system in the welding robot gantry that captures rising welding smoke at a height of about 4 m above the equipment during automated welding processes. A ducting system transports the fumes to a central WeldFil filter system outside the hall, where hazardous particles are separated out, and purified air is returned to the outlets.

Thanks to the comprehensive protective welding equipment measures, the air in the hall has consistently improved. “The air pollution control technology at the workplaces and in the robot gantry clearly exceeds our expectations,” said Koenderink. “Our welders are very happy with the improved air quality.”