Superconducting high magnetic field and ultra-low frequency induction heating technology originated in the pioneering research and development of electric heating equipment in the large and heavy metal rolling forming industry.With the merits of low loss characteristics of superconducting materials in DC applications and the advantages of electromagnetic induction heating technology, and by organic combination of the two techniques above, we realize a new heat treatment technology of low energy consumption and high quality for non-magnetic metal extrusion process. Compared with traditional electric heating technology, it gains huge and competitive advantage in terms of efficiency and performance.
Traditional electric heating technology uses an AC magnetic field to generate eddy currents in a static billet to heat. When heating nonferromagnetic materials such as aluminum and copper, the heating efficiency is less than 50%. More importantly, there exists several defects such as uneven heating, long penetration time, and low heating quality. Superconducting DC induction heating technology rotates the billet in a static magnetic field to generate an induction eddy current to heat, whose efficiency is lifted to 80-85%. A megawatt-class superconducting DC induction heater can save 6.4 million kWh per year and can reduce the heating cost of aluminum extrusion from 260 yuan/ton to 130 yuan/ton (7 RMB yuan≈1 US dollar). At present, China's aluminum production capacity accounts for half of total in the world and the domestic aluminum companies have more than 10,000 heating devices. If this breakthrough technology could be popularized and then the cost recovery cycle would be cut to 2-3 years. This technology deserve a huge potential market for energy-saving transformation of metal heating industry.
Due to its ultra low heating frequency (4-10 Hz), superconducting induction heating technology has excellent performance of temperature uniformity, heating quality, operation safety, and power grid compatibility, which makes it exceptional for rolling molding process of nonferromagnetic metals. This heating technology is the only method in the world up to now that can heat large diameter (more than 400 mm) metal workpieces on the core surface simultaneously and evenly. The principle prototype based on this method has been developed and certified in Nanchang. Its high penetration depth and ultra uniformity makes it suitable for military grade alloy molding processes, which can solve the crack problem of materials due to uneven heating effectively. It also can solve the bottleneck conundrum of nonuniformity of traditional heating equipment in large size nonferromagnetic metal workpieces such as ship main shafts. This technology can apply to poorly conductive titanium alloys to achieve rapid, uniform and high power heating. These outstanding advantages would boost the metal heating treatment quality overally.This technology is mastered only by Germany, South Korea and China (Liannovation is unique). Our technology is completely domestic based from basic superconducting tapes to constitutional components. Moreover, the German and Korean based technology could only heat small-sized workpieces (Dia. < 240 mm). The priciple prototype equipment in Nanchang, China is unique for large-sized metal workpieces (Dia.> 400mm). The Liannovation superconducting induction heater has the highest power capacity and the lowest frequency in the world.