Extracting harmful welding fumes should be standard in every manufacturing company for health reasons. Many rely on large extraction systems for extraction, which completely exchange all of the hall air within a very short time. More efficient and far cheaper than such large air filtration systems are extraction devices where appropriate fume extraction torches can be connected for source capture. With the fume extraction torches RAB GRIP and RAB GRIP HE 2 from ABICOR BINZEL, fume extraction is easy.
However, mistakes can be made when using a welding torch for source capture. We have put together the 5 most common mistakes when using a fume extraction torch.
Mistake #1: Incorrect extraction torch position
For purely physical reasons, welding smoke always ascends. Therefore, the openings of the extraction nozzle should be positioned right above the process to take up the weld fume right after its formation.
Left: RAB 36 KD – very good welding fume intake with the slim fume extraction nozzle / Right: RAB 36 HE – HE (High Efficiency) fume extraction nozzle allows broader intake of welding fume
For this reason, torch neck bend angles of 45 degrees and 60 degrees are ideal for this type of welding torch. If the welding position for the extraction is relatively vertical above the process, the welder not only captures the fume optimally, but also welds ergonomically. Handling becomes easier overall and the body does not tire as quickly.
Mistake #2: Not optimal extraction nozzle
For a fume extraction torch, the extraction nozzle is the only additional wear part. The fact that some welders still hesitate at the thought of using an extraction torch as a welding torch for MIG/MAG welding is mostly due to the extraction nozzle, because in some cases it restricts the view of the welding process. However, for special cases, where the view of the weld seam from the component is not limited, extraction nozzles with special sizes are also obtainable – and these make life a lot easier for the welder. The available extraction nozzles shown in catalogs are suitable for many applications – but special fume extraction nozzles are required for exceptional cases. Of course, a professional supplier also has special fume extraction nozzles for extraction torches in their portfolio.
Mistake #3: Cable assembly is too long
Optimal fume extraction performance is always related to the length of the cable assembly. The longer the cable assembly, the lower the static pressure and the lower the extraction capacity. With a mobile fume extraction system, the optimal static pressure ranges from 100–170 m3/h. Often, a cable assembly that is too long is selected for the fume extraction torch, although the application, for example, does not require a 5-meter cable assembly and the component can also be easily reached with a 4-meter cable assembly. Every meter too much and every loop in the cable assembly reduces the extraction result. A fume extraction cable assembly laid out without a tight radius, on the other hand, provides the required performance.
Although good fume extraction devices realise the required performance, the goal should always be a synchronised system. With fume extraction torches, the following rule always applies to the length of the cable assembly: as short as possible and as long as necessary.
Mistake #4: Interior of the torch is not cleaned regularly
A fume extraction torch for extraction at the source is ideally positioned directly above the process, but during its extraction work it not only captures the welding fume, but also the anti spatter agent applied for pretreatment of the components, as these evaporate during welding through and are also sucked in. All these dirt particles can get stuck in the extraction nozzle as well as in the inside of the torch head and the inside of the cable assembly. Trapped particles act like an obstacle in the suction flow and reduce the vacuum pressure of the extraction. The more debris the worse the general extraction performance.
Check and clean the fume extraction nozzle, torch neck and cable assembly regularly. If the debris cannot be removed by blowing out with compressed air, it is best to replace the corresponding fume extraction torch components.
Mistake #5: Bad service of fume extraction unit
The so-called dust box of the extraction device reveals how many dirt particles produced during welding and picked up by the fume extraction torch, get into the extraction device and are then filtered and collected in the dust box.
This dust box must of course also be emptied regularly. How often the dust box should be cleaned depends on the preparation of the material to be welded, the material to be welded itself, the welding time and the welding parameters. If a fume extraction torch is used a lot, the extraction device should have a cleanable filter, with automated or manual cleaning. So it is difficult to say in general that the filter has to be cleaned and the dust box emptied every other day. Even cleanable filters can no longer be used at some point and have to be replaced. Good fume extraction devices indicate when the filter needs to be cleaned, changed or that the dust box should be emptied. Please ask your supplier or manufacturer for fume extraction torches and fume extraction devices, if you are unsure about this.
You can find an overview of the fume extraction torches from ABICOR BINZEL here. If you are interested in user reports, please read more about the use of fume extraction torches and mobile fume extraction devices from ABICOR BINZEL at a Swedish manufacturer of spreaders for container loading.