EEI has designed, manufactured and supplied Economisers with heat duty upto 3,000, 000 kcal/hr.

Economisers are basically tubular heat transfer surfaces used to preheat the boiler feed water before it enters the drum or furnace surfaces. An economiser reduces the potential of thermal shock and strong water temperature fluctuation as the feed water enters the boiler drum.

It is the last water cooled heat trap, upstream of the air heater.

Plain tube

The most common and reliable economizer design is plain or bare tube. When coal is fired, the fly ash creates a highly fouled and erosive environment. The plain tube, inline arrangement minimizes the likelihood of erosion and trapping the ash as compared to a staggered arrangement.

These benefits have to be evaluated against larger heat transfer area and volume. with the following details for techno- commercial offer
Plain tube/ finned tube
Hot gas flow, pressure, temperature and nature of gas
Feed water, temperature, pressure and flow