Product Details
Tubular Type Air Preheater APH Boiler Industry Waste to Energy
Environmental friendly
What is Air Preheater (APH)
- An air preheater (APH) is a general term to describe any device
designed to heat air before another process (for example,
combustion in a boiler) with the primary objective of increasing
the thermal efficiency of the process.
- They may be used alone or to replace a recuperative heat system or
to replace a steam coil.
- In particular, this article describes the combustion air preheaters
used in large boilers found in thermal power stations producing
electric power from e.g. fossil fuels, biomasses or waste.
Purpose of Air Preheaters(APH)
- The purpose of the air preheater is to recover the heat from the
boiler flue gas which increases the thermal efficiency of the
boiler by reducing the useful heat lost in the flue gas.
- As a consequence, the flue gases are also conveyed to the flue gas
stack (or chimney) at a lower temperature, allowing simplified
design of the conveyance system and the flue gas stack.
- It also allows control over the temperature of gases leaving the
stack (to meet emissions regulations, for example).
Types of Air Preheaters
There are two types of air preheaters for use in steam generators
in thermal power stations: One is a tubular type built into the
boiler flue gas ducting, and the other is a regenerative air
preheater. These may be arranged so the gas flows horizontally or
vertically across the axis of rotation.
1. Tubular Type Air Preheater
- 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.
- Inside the ducting, the hot furnace gases pass around the preheater
tubes, transferring heat from the exhaust gas to the air inside the
preheater.
- 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.
2. Rotating-Plate Regenerative Air Preheater
- The rotating-plate design (RAPH) consists of a central
rotating-plate element installed within a casing that is divided
into two (bi-sector type), three (tri-sector type) or four
(quad-sector type) sectors containing seals around the element.
- The seals allow the element to rotate through all the sectors, but
keep gas leakage between sectors to a minimum while providing
separate gas air and flue gas paths through each sector.
Details
Layout item | Horizontal layout | Vertical layout |
Tube arrangement | staggered arrangement /in-line arrangement | staggered arrangement / in-line arrangement |
Sealing of pipe and plate | Packing heat- resistant material/
welding | welding |
Anti-wearing | a,when gas scours external tube, welcoming smoke tubes have
protective tile b,when gas scours inside tube,wear casing pipes are installed in
gas inlet |
Hydraulic Test
Detailed Drawing
Company Profile
Dehai Boiler is a manufacturer of A-class boiler(Power station
boiler,industrial boiler,HRSG,waste-to-energy boiler,biomass
boiler) and correlated A-class pressure parts intergrating the
design,fabrication,installation,repair and mainteance.

Dehai has ISO9001:2008 certificate issued by France AFAQ-EAQA
Ltd,A-class boiler manufacturing license,ASME S Stamp and U Stamp
authorized certificate.

Through effective management system and high quality products,Dehai
became the qualified supplier of many famous boiler factories and
energy companies and has won a lot of stable customers both
domestic and abroad ,such as :Amec Foster Wheeler,Alstom,Dongfang
Boiler,Harbin Boiler,Hangzhou Boiler,etc.

Based on the business idea of "High quality for survival and
perfect service for development",we shall care for customers'
demand and keep improving our work permanently. To create Dehai
brand,is to serve clients with our improved products and better
performance.

Dehai is located in Economic and Technological Development
Zone,Zhangjiagang City,Jiangsu Province. S38 highway Zhangjiagang
exit is about 1.5 kilometers to the north of our company and the
traffic is very convenient.