A typical example of heat recovery steam generation is installed in Slovenjia, near the capital Ljubljana.

The appliance consists in a horizontal steam evaporator, smoke tube type, designed for the production of 430kg/h of steam at 3barg, equipped with control and regulation systems suitable for continuous operation without supervision for 72h.

There is also a system to divert the flue gas and bypass the boiler, used both for regulation and for safety. The diverter is equipped with a pneumatic modulating actuator that regulates the passage of the flue gas in the boiler to keep the pressure stable. The actuator is single-acting and includes a spring which, in the event of an emergency or even a power failure, quickly brings it to a safe position, discharging the entire flue gas flow rate into the bypass duct.

A compact and efficient solution that, working 8,000 hours a year, can save the equivalent of 265,800 Nm3 of natural gas and avoid the emission of 511 tons of CO2/year.