Legnano (MI) Italy
+39 0331 926600

Steel mill

Project Description








Steam In/Out


HP145 & HP204

132 & 200 kW

16/5,0 barg



Steel mill Acciai Speciali Terni (AST), founded in 1884, is one of the largest steel manufacturers in the world with a core business in stainless steel flat products. With the initiative to expand the main facility at Terni in Umbria, the company had begun a series of innovative projects to improve energy efficiency and reduce factory emissions.



The project,focused on increasing the efficiency of the Auxiliary Service department. The objective of the department was to generate steam with three steam boilers producing a total of 24t/h to be used for production processes. SON proposed the introduction of a HELIEX POWER screw expander with the capacity to generate electrical energy, exploiting the difference in pressure between the steam generated in the boilers and the steam pressure required by the production process.



The solution chosen by the client included the technology of HELIEX POWER, supplied by SON Srl in two steps. The first being the installation of the HP145 132kW. This installation was the beta test for HELIEX POWER technology. The machine was installed in parallel to the principal reduction valve, processing around 3 t/h of steam. This flow of wet steam, generated by the boiler at high pressure (16 barg), is elaborated by the Gen Set HP145, reducing the pressure to the needed pressure of 5,0 barg while generating power at the same time.
In light of positive results relative to the application of the HP145, the client decided to enter the next phase with the installation of a second HELIEX POWER Screw Expander, the larger HP 204 unit, equipped with an alternator of 200 kW. The combination of the two machines have the capacity to supply the facility with 332 kW, along with a reduction of TPES by circa 10% and a payback within 48 months.

Project Details