Flaretec were commissioned for the thermal and mechanical design, detailed design, fabrication, assembly, control system and E&I installation works for an Indirect Gas Fired Heater Package.
The heater design was forced draft, natural circulation type and designed for outdoor operation to API 12K Standards.
Comprising of a single firetube assembly with a single forced draft burner, operation with a modulating fuel gas flow rate was possible over a turn down rate of at least 4:1. Process turndown was unlimited as the burner was able to cycle between low fire and “off” in the event of low heat demand.
The Bath Heater consisted of a horizontal cylindrical shell with a fire tube assembly in the lower part and a heat exchange coil in the upper part. A gas fired burner fires into the firetube assembly in the lower part of the vessel, and the heat is transferred to a glycol/water oil heating coil, arranged in three parallel flow paths in the upper part of the vessel by means of natural circulation of the glycol/water in the shell.
Expansion bellows in the main firetube absorbs movement due to differential thermal expansion.
The design basis for heater operation is that the glycol/water outlet temperature is maintained essentially constant by modulating the fuel gas rate to the burner.