It The Kanthal® Flow Heater.delivers a compact electric heating system that can reach outlet temperatures up to 1,100°C (2,012°F), with high power density and flexible operation for both continuous and cyclic processes. For customers, this creates new opportunities to electrify high-temperature process-gas applications while improving efficiency, control, product quality, safety, emissions performance, and lifecycle value.

Primary aluminum is a good example. Across the production process, heating requirements vary significantly depending on the job that needs to be done —from drying and preheating to shortening start-up times and supplying very high-temperature process air.Markus Mann, Technology & Innovation Manager, Kanthal.

“Aluminum production remains one of the most energy- and carbon-intensive industrial processes, driving a global push toward electrification and lower-carbon technologies. The challenge is clear: accelerate the green transition while maintaining, and ideally improving, productivity and process performance,” says Rishiraj Mukherjee, Global Product Manager at Kanthal.

Markus Mann, Technology & Innovation Manager at Kanthal, explains, “Flow Heater's temperature capability is a significant leverage.” He adds, “Achieving 1,100°C (2,012°F) with electric air heating enables us to perform process tasks that typically depend on combustion, offering comparable or superior performance and lower risk.”

So, can one electric heating technology adapt to and improve these very different applications? Let’s find out.

Smelting: ladle drying and preheating with dry air

During anode assembly, molten cast iron is handled in ladles that must be completely dry and preheated before use. The conventional direct-flame approach creates a challenge: combustion produces moisture in a process that requires moisture removal.

The Flow Heater can be integrated directly into the casting station, avoiding the need for a separate radiant heating set-up, which is an advantage where space is a constraint.  

For ladle pre-heating, open-flame burners emit moisture and pollutants and typically cannot modulate power output, increasing high-temperature stresses in the refractory lining. Convective electric air heating generally provides more homogeneous heating, faster dry-out, and better refractory life, making it the preferred technology when the objective is controlled, repeatable ladle conditioning before service.

The result is high-efficiency, clean, and silent heating with precise temperature ramping. “For ladle preheating, the advantage is straightforward: we can remove moisture without reintroducing it through combustion, while efficiently and precisely controlling the heating cycle,” says Mann.

Cast house: Degasser pre-heater

Aluminum degassing removes dissolved hydrogen and other impurities from molten metal, reducing porosity and improving mechanical properties, surface finish, and pressure tightness. Before the degasser goes into operation, its refractory lining needs to be preheated to remove moisture, avoid thermal shock, and prevent melt cooling at start-up.

The Flow Heater is used specifically for this preparation step. A suitably sized Flow Heater can heat the degasser lining to 450°C (842°F) in 20 minutes, compared with 48-72 minutes for a conventional electric heating solution operating at the same power, resulting in more than 70% lower energy use.

“Because preheating is only required at start-up, the heating system does not need to be part of the continuous degassing process,” says Mann. “It can be configured as a mobile or permanent installation, depending on how the customer wants to integrate it into the cast house.”

Cast house: Ceramic Foam Filter (CFF) box filter dryer & pre-heater

Before casting, molten aluminum passes through a Ceramic Foam Filter (CFF) box to remove inclusions and impurities. The refractory-lined box and filter material need to reach 700–750°C (1,292–1,382°F) beforehand to prevent the metal from freezing as it passes through the filter.

For this application, the Flow Heater supplies high-temperature dry air. The primary configurations used are 40 kW and 60 kW standard series Flow Heater systems, delivering air above 1,000°C (1,832°F). Performance test data show around 40 minutes from ambient and 12 minutes when reheating from 300°C (572°F).

The heater is switched off once molten aluminum starts flowing, since additional air could disturb the metal and increase oxide formation.

“High outlet temperature allows us to bring the CFF box to operating condition quickly, while electric heating avoids the moisture produced by combustion,” says Mann.

The primary benefits are efficient heating with dry air vs. a gas burner (CH4 + O2 -> CO2 + H2O), plus better reliability and efficiency than other air-heating systems because of protection against overheating, higher outlet temperatures, and shorter Flow Heater cycle times.

One technology, endless possibilities

Rishiraj Mukherjee, Global Product Manager, Kanthal.Whether for primary aluminum or other high-temperature industries, the Kanthal® Flow Heater is not a one-size-fits-all product. Kanthal offers standard systems from 3.5 kW to 60 kW, as well as custom-engineered solutions for higher power requirements, supported by control systems, blowers, and related accessories.

“The starting point is always the customer’s process,” says Mukherjee. “Once we understand the process operating window, we can determine and offer the right solution, whether that is a standard Flow Heater, multiple units, or a custom-engineered system.”

Looking to electrify high-temperature process heating, replace combustion-based heating, or improve an existing system? Talk to us about your process, and we can help determine how to configure a Kanthal® Flow Heater to fit it.