Boiler operation market heating boiler air preheater aph in boiler
Air Preheater Pros
- 2 pass design to extract maximum waste heat from flue gases leaving
- It is used to extract waste heat from the flue gases leaving the
boiler exhaust thereby increasing the efficiency of a boiler by 2-3
- It is used to preheat the fuel which further increases the boiler
- Payback time is less.
Air Preheater Cons
- Adding and equipment or accessory in the path of flue gases
increases flue gas pressure drop down the line, so the size of
Induced Draft Fan increases.
Working of Air Preheaters(APH)
1. Air Preheaters have a shell and tube type construction where
exhaust heat from the flue gases is transferred to the air when
they come in indirect contact with each other.
2. Air Preheaters consist of a shell where tubes are arranged in a
square or triangular pitch and are welded to a tube plate.
Depending upon the type of operation and ease of cleaning, flue
gases & air can be allowed to travel either shell side or tube
Air Preheaters(APH) Brief Introduction
1. Air Preheaters (APH) is the Shell and tube type Heat Exchangers
used for preheating the air which is fed to the boiler or
furnaces/kilns for combustion of fuels. Its primary objective is to
extract the waste heat from the flue gases leaving the boiler.
2. Dehai Boiler Company manufacture Air Preheaters and are given as
a standard side accessory along with the main equipment – Boiler,
in a Packaged Type Boiler, Combi Boilers.
Tubular type Air Preheater
1. Tubular preheaters consist of straight tube bundles which pass
through the outlet ducting of the boiler and open at each end
outside of the ducting.
2. Inside the ducting, the hot furnace gases pass around the
preheater tubes, transferring heat from the exhaust gas to the air
inside the preheater.
3. Ambient air is forced by a fan through ducting at one end of the
preheater tubes and at other end the heated air from inside of the
tubes emerges into another set of ducting, which carries it to the
boiler furnace for combustion.
|Layout item||Horizontal layout||Vertical layout|
|Tube arrangement||staggered arrangement /in-line arrangement||staggered arrangement /|
|Sealing of pipe and plate||Packing heat- resistant material/|
|Anti-wearing||a,when gas scours external tube, welcoming smoke tubes have
b,when gas scours inside tube,wear casing pipes are installed in