1Indirect Gas HeatersForain’s indirect gas heater consists mainly of firetubes enclosing burners and a coil containing gas to be heated. They are called ‘indirect heaters’ because a medium (water-glycol mixture or oil) is used to transmit heat (thermic exchange) generated by the burner and received by the gas.
The safety system, which is part of every Forain’s heater, can detect all operating defects and controls independently the unit under each operating condition, in order to guarantee the correct outlet gas temperature.
The heaters can be supplied with regulation and safety systems either of electric or pneumatic type, wherever electric power is not available. In fact, they are installed mainly in remote areas because of their reliability, high performance and low maintenance cost.
Principle of operation
Forain indirect gas heater working operation is due to the circulation of hot water or oil into the shell. The firetube is installed in the lower part of the shell, while the coil to be heated is placed above it.
The burning fuel transmits heat to the firetubes and through these to the water or oil bath; hot water or oil heat the coil walls and consequently the cold gas inside.
2ELECTRICAL HEATERSFor applications where high duty is not needed, electric heaters can be used.