TPT September 2024

TUBE WELDING MACHINES & TECHNOLOGY

Advantages of upgrading to Mosweld SiC tube welding FOLLOWING the introduction of SiC technology in its induction generators EMMEDI is offering new compact SIC models (S, S-S and XS) that offer a high power to volume ratio. These models are equipped with features that offer high efficiency, making them ideal for both new lines and the modernisation of existing lines. Some time ago EMMEDI decided to introduce the new silicon carbide transistor technology in its tube welding generators. It has now been seven years since its first SIC welder was launched. Its SIC welder was the original product, and due to its pioneering nature, initially prompted some reservations. However, customers soon recognised the advantages of the change and embraced it. This technological breakthrough has now established a new trend. EMMEDI also collaborates closely with its customers to enhance the performance of its equipment and adapt to their evolving needs. Welding equipment is the core component of an induction brazed tube manufacturing line. It is a relatively modest element in terms of the line’s overall features and cost. However, ensuring efficient operation is crucial for boosting the line’s overall productivity and the quality of the fabricated pipe. It is important to define what is meant by efficiency in an induction tube welding equipment. In the context of EMMEDI generators, efficiency is defined as the power delivered to the tube, specifically at the output power terminals of the generator, inductor and tube set (in accordance with standard 61922:2002). Its efficiency in SIC equipment is approximately 92 per cent. It is not uncommon for industry professionals to confuse the real efficiency (in accordance with the standard) with the efficiency offered by the generator’s internal transistors and inverters. The latter is consistently higher because it does not factor in the losses associated with the remaining system components. In the case of EMMEDI, the efficiency is 98.7 per cent, with the welder utilising most of the consumed power. The challenge of replacing welders in tube factories with old lines is becoming increasingly common. These factories must increase production while also reducing energy consumption and increasing welding speed. While the mechanical components of these lines can be refurbished, the welding

generator itself cannot. In most cases, the solution is to replace the generator with one that is more modern and offers better performance (not higher power) while also requiring the same or less space than the existing generator. Features to facilitate deployment and production include: versatility and flexibility; EMMEDI adapts to any situation and space in the plant, especially in the replacement of valve equipment; low volume, at equal power; welding process quality control and fabrication traceability; and adjustable short circuit sensitivity. Features that impact quality improvement include: the Clean Motion system, which includes an internal motorised XYZ regulation-type table. This avoids the accumulation of dirt on guides and other mechanical elements of this type of system, allowing precise adjustment of the inductor position through the control panel and the reduction of stops. The autotransformer and input transformer have been eliminated from the design. This configuration allows for direct connection to the grid, which ultimately results in reduced costs and a more compact footprint within the plant. Power factor > 0.95 for the whole power range of the equipment. Electric companies anywhere in the world penalise values below 0.95 and this means having to include a filtering system (or reactive power compensator) that prevents the equipment from going below this 0.95. At this point it is essential to explain what the power factor is, what is the reactive energy and how they are measured – reactive energy is a type of energy generated by the operation of some electrical devices, such as motors or transformers, which use coils to transform energy into electromagnetic fields. This type of energy is not consumed or used for heating and is measured in kilo volt-reactive ampere hour (kVarh). The sum of active energy and reactive energy is called apparent energy and is what we consume daily as electrical energy. The amount of reactive power per total energy is measured with the Power Factor (Cosϕ). To offset reactive energy, it is

essential to install capacitor banks, which represents a substantial capital investment and ongoing maintenance expense. After seven years, EMMEDI Mosweld SiC family technology continues to evolve to meet new customer requirements. With an energy efficiency of over 92 per cent and the versatility to customise equipment, these welders improve end-product quality. Customers are already experiencing significant energy savings. Mosweld SiC enables manufacturers to modernise lines and respond to market demands. EMMEDI www.saetemmedi.com

The presence of dirt inside the welder cabinet is due to an external system that is responsible for moving the generator and positioning the inductor with precision

The Clean Motion system features an axis table in the cabinet for inductor adjustment on the line, which eliminates the risk of stoppages due to dirt accumulation

42

www.read-tpt.com

SEPTEMBER 2024