Economizer
The economizer is the heat exchanger that raises the temperature of the water leaving the highest-pressure feed-water heater to the saturation temperature corresponding to the boiler pressure, which is done by the gases leaving the last super-heater or re-heater that still have enough heat to transfer before it leaves to the stack, that is why it is called economizer.
Types
Spiral finned tube economizer
The economizer is newly type heat transfer equipment, consists of spiral fin tubes to overcome the inferior heat efficiency and serious abrasion and short life than the bare economizer.
Material structure
Consists of a series of spiral fin tubes, the headers of inlet and outlet, bend, frame and other auxiliaries
Structural arrangement
In line/staggered arrangement
Characteristics
1). This type of economizer can largely develop the heat exchanging area than the bare economizer to add the heat transfer area, reduce the volume, compact structure and reduce the number of elbow and welding to make less leakage and add the heat transfer efficiency.
2). Not easy to collect dust and the fume pass through the fin tube to form the boundary layer to occur the vortex to make less chance for the fly ash particle to touch the tube wall.
3). Widely temperature range, high pressure limit.
4). Durable strong impact, reliable operation.
5). Less fume resistance, reduced abrasion and long working life.