thermal treatments -high purity gases

Idroenergy designs, manufactures, sells and installs on-site high-purity hydrogen and nitrogen generation systems, which are widely used in metallurgy, where the use of high purity atmospheres that keep a consistent quality over time is essential. Thanks to Idroenergy on-site nitrogen and hydrogen production systems, that are able to produce gases with any degree of purity, any kind of steel thermal treatment can be done.

When we speak about thermal treatment of metals we mean the heating thermal cycle able to confer to the treated metal a crystalline structure which complies with precise mechanical and / or technological specifications. During the thermal treatment of steel, implemented under precise physical conditions, it is important to follow the heating phase with a variably slow cooling phase, which is precisely the condition that grants the steel crystalline structure that allows it to be processed.

The cooling and heating rate applied to the metal during the heat treatment is very important since it influences the transition temperatures as well as the nature of the structure obtained. The speed applied to the heating and cooling phases cause different results on the thermal treatment of steel. Particularly, the application of nitrogen to the thermal treatment of steel allows obtaining very hard nitrides, the nature of which varies depending on the composition of steel, the treatment temperature and the percentage of nitrogen diffused.

Instead, hydrogen is widely used in annealing furnaces for steel production, thanks to its combustion properties which make it an alternative material free of toxic emissions. Hydrogen is used as thermal treatment to adhere the ceramic insulator to the metal in the production of spark plugs, which this way become cleaner and brighter. The use of hydrogen as a clean fuel is increasingly becoming a possible source of energy for the future.

Idroenergy designs, manufactures, sells and installs throughout Italy and abroad nitrogen generators and hydrogen generators of any size, able to produce gases with different degrees of purity. Particularly, Idroenergy designs nitrogen and hydrogen treatment systems at high-purity atmospheres, which find wide application in the thermal treatment of metals.

Among the metallurgical applications of high-purity hydrogen and nitrogen produced on-site through Idroenergy generators we can find continuous thermal treatment of wires, pipes, profiles and sheet metal, static thermal treatments in bell furnaces, annealing treatments, flexibilisation, solubilisation, galvanising treatments, sintering, brazing in furnace, treatment of steel, bronze, brass, gold, silver, copper and other metals. Hydrogen and nitrogen have different chemical characteristics that make them indispensable, but also suitable for various applications in the field of thermal treatment of metals.

Thanks to their special technology Idroenergy hydrogen generators are able to produce continuous high purity hydrogen, without any trace of electrolyte or other impurities resulting from the process. Similarly, Idroenergy nitrogen generators with low energy consumption, made with the application of PSA technology, produce nitrogen (N2) continuously, always ensuring maximum reliability (24h/24) and efficiency improving the company productivity.
In this regard, and to increase user safety, please note that Idroenergy applies a strict policy of control of its on-site nitrogen and hydrogen production systems, which are remotely controlled through the exclusive technology ICS – Idroenergy Communication System, which allows to remotely monitor the operation of generators to intervene if necessary, and in person, over the strict and meticulous ordinary and extraordinary maintenance schedules agreed with the companies.

On-site nitrogen and hydrogen production systems manufactured and installed by Idroenergy are highly safe and ensure uninterrupted productivity at high purity atmospheres even for very long periods of operation at high flow rate. Using Idroenergy nitrogen and hydrogen generators you can significantly save on gas supply costs and increase the workplace safety. With the nitrogen and hydrogen generators, in fact, only the amount of gas necessary for the required applications is produced, thus avoiding dangerous accumulations of high pressure gases.

The gas purity is very important for all applications of nitrogen and hydrogen to metallurgy. On-site nitrogen and hydrogen generation systems produced and sold by Idroenergy allow a special gas purification treatment. Thanks to the passage within the special purification systems PF, gases produced by nitrogen and hydrogen generators are purified three times. The PF-gas purification systems able to obtain:

o  purification of nitrogen and hydrogen from every oxygen molecule through catalytic process (up to 1 ppm of O2 residue),
o  elimination of any trace of humidity from the gases thanks to the automatic inversion drying towers,
o  if required, the mixture of  purified H2 and N2 gases, with the possibility to singularly adjust the components for the specific treatment.

The thermal treatment of metals in electrically heated or combustion furnaces is an industrial process able to induce structural, mechanical and technological changes in the metal composition due to temperature variations. The alternation between heating, cooling and constant temperature phases and the speed and duration of the different phases, are able to produce different effects and structural changes that allow metal processing to obtain the required products and compositions.

Any metal oxidation that may occur during the heating phases may compromise the brightness and the mechanical characteristics of the finished pieces; therefore, in the thermal processing of metals, and especially of steel, it is essential to properly handle heating and cooling time, to avoid the occurrence of problems related to oxidation.
On-site nitrogen and hydrogen production systems designed, sold and installed by Idroenergy throughout Italy and abroad are able to protect metals during the thermal processing. In fact, nitrogen and hydrogen react in contact with steel and thanks to the so-called redox process, are able to remove any oxidations found on the metal bringing it back to its original splendour.

In contact with the steel to be treated, nitrogen and hydrogen are transformed into water vapour that eliminates the oxidation and is afterwards removed with the gas. This way, the metal pieces produced are distinguished by superior characteristics of brightness and mechanical performativity. On-site nitrogen and hydrogen generators produced by Idroenergy are able to produce high-purity nitrogen and hydrogen which guarantee high quality that remains constant in time and are therefore ideal for the application to steel thermal processing.
Particularly, the application of nitrogen and hydrogen to the industry of metal thermal processing requires high purity atmospheres:

o  Purity: > 99.9995% and over
o  Dew point: better than -70° C
o  Contents of O2 up to 1 ppm

o  HYDROGEN: from 1 to 80 m3/h
o  NITROGEN: from 1 to 400 m3/h
o  NITROGEN-HYDROGEN MIXTURE:  from 1 to 500 m3/h

The different on-site nitrogen and hydrogen production systems can be installed in parallel reaching gas flow rates of several hundreds of m3/h with the maximum reliability even in long term and on small areas.
Summarising, Idroenergy technology for on site nitrogen and hydrogen production is applied in metallurgy to steel thermal treatment, and especially in the following fields:


Thanks to their excellent characteristics in terms of purity, to the constant monitoring of quality and to the remarkable safety of gas and nitrogen generators, Idroenergy on-site purified gas production systems provide excellent achievements in the field of thermal treatment of metals, with maximum efficiency and cleanliness of treatment furnaces. Idroenergy nitrogen and hydrogen gas generators have wide production versatility, high-capacity corresponding to high rates of reliability. Moreover, Idroenergy systems use exclusive technologies, for both, reliability of operation and processes obtainment.

With no oversized plants, Idroenergy enables its customers to produce nitrogen and hydrogen on-site, greatly reducing the cost of gas supply and minimising risks, reaching excellent results in terms of purity, which is essential for the thermal processing of metals. Below, we briefly summarise the benefits of nitrogen and hydrogen produced through Idroenergy generators and characteristics that make them perfectly suitable for the application to thermal processing of steel and other metals.


– High Purity
– Constant and controlled quality
– No CO2 emission to the environment
– Free of impurity derived from carbon residues
– Absence of humidity (constant on time)
– Bright results on production
– Maximum efficiency and cleanliness of treatment furnaces (belts, chambers, muffles)


– Wide range of product capacities
– High system reliability
– Exclusive “Splitting tower system” technology
– Extended system modularity
– Possibility to generate high purity without oversized systems
– Greater convenience and enhanced process productivity