Air Preheater dun advanced0 pages

STEAM PRODUCT SOLUTIONS

Air Preheater

DUN™ Advanced Heating Surface

The outstanding
advantages of Alstom’s
DUN™ surface have
been demonstrated
in more than
1000 installations.

Proven state-of-the-art technology
Alstom’s patented DUN™ heating element profile is an optimised surface providing
a uniform outlet mass-flow velocity distribution and superior cleanability. It has
been developed as direct replacement for the DU profile.
The most noticeable differences in the DUN™ heating element compared to the
outdated DU family of heating elements are that each sheet has notches to create
channels, and the undulations on each adjacent sheet are crossed. The revolutionary
design of DUN™ profile interrupts the SkewFlow path and guides the flow directly
through the element pack. However, it should be noted that SkewFlow is not simply
prevented by crossing the undulations of DU, as the undulated sheet still represents
a clear continuous path for flow to follow to one side of the basket, but rather it is
prevented by our combination of crossed undulations and notches on every sheet.
Engineered to provide the highest levels of thermal performance, the DUN™ represents
the best available technology by providing heat recovery similar to the FNC surface,
with a lower pressure drop, superior cleanability, and better fuel flexibility.

Customer benefits
PROVEN TECHNOLOGY
Established surface with a large
installed base.
SUPERIOR CLEANABILITY
Significant reduction in fouling potential.
LEADING DESIGN
Uniform mass flow distribution and higher
heat transfer.
LOWER RUNNING COSTS
Reduced pressure loss requires less fan
power.
Less fouling potential increases element
life, reduces replacement costs.
Basket of DUN™ elements

TPW/BPROS/DUNAHS/eng/THP/02.13/CH/7867 © ALSTOM 2013. All rights reserved. Information contained in this document is indicative only. No
representation or warranty is given or should be relied on that it is complete or correct or will apply to any particular project. This will depend on the technical and
commercial circumstances. It is provided without liability and is subject to change without notice. Reproduction, use or disclosure to third parties, without express
written authority, is strictly prohibited. Alstom contributes to the protection of the environment. This leaflet is printed on environmentally-friendly paper.