Centralized extraction plant for welding fumes

Customer request

Extraction of fumes and powders produced during metal welding activities has to happen as close as possible to the polluting source, as required by EU legislation and for the safety of the operators.
The customer requires a great work flexibility, since the welding workstations can work at only 30% of its overall capacity in some periods. In operational terms, this means to design a plant capable to operate in efficiency in a capacity range from 9,000 to 40,000 m³/h with no electric power waste.

Solution

Customized design and installation of a centralized pinpointed extraction plant on each workstation, carried out through 160 mm diameter articulated suction arms equipped with extenders to increase their working range. Extraction workstations are connected between them by a circular section galvanized piping network and with a centrifugal simple extraction fan located outside the production area. An inverter system with reading of pressure inside the ducts adjusts the extraction capacity and consequently the fan power consumption for the maximum energy saving.

Design and development

After a careful analysis of the customer’s production needs and layout, our Technical Department developed a customized centralized plant:

• sizing of the exact speeds of air flow in extraction and discharge ducts, with consequent calculation of the overall load losses depending on the path of the tubes
• selection of extraction arms and extenders, so as to ease welder’s job and, at the same time, capture fumes as close as possible to the source
• use of different types of extraction hoods on the articulated arms, depending on the work to carry out and therefore on the capacity needs
• selection of fixing points of pipes and arms in the production room, with subsequent design and manufacture of special customized brackets
• selection of a simple extraction centrifugal fan, considering the overall plant capacity and load losses of the connected systems
• design of the electrical panel for plant control, including the automatic adjustment of fan revolutions with inverter system that changes in real time the work capacity depending on the number of workstations employed for the maximum energy saving