A new solution to impingment attack
of heat exchangers, condensers and reactors tubes
and Steam Condensers are liable to various forms of deterioration
and corrosion among which impingment Attack or Erosion-Corrosion
is a very damaging one due to the relatively high rate of attack
Erosion-Corrosion is essentially
due to removal of protective oxides or corrosion layers from
metal surfaces by turbulent flow of liquids or by high velocity drops
of condensing vapours or by suspended solid particles
carried over in the refrigerating fluid.
As mechanical forces,
necessary to remove oxides or corrosion products
from metal surfaces decrease drastically when flow
becomes laminar inside tubes Erosion-Corrosion is mostly limited to
the initial part of a tube (generally in a length
corresponding to µ-1° times the tube diameter and more rarely
to the final part of a tube.
As a result of Erosion-Corrosion
heat exchanger or condenser tubes tend to loose
their mechanical strength due to a severe thickness reduction
just next the tube plate and eventually to be perforated at the inlets
while the rest of surface might still be in good conditions.
To solve this problem of tube
deterioration either to repair damaged tubes or to protect
new ones Aetech have developed and tested Metallic Inserts
in different materials and a proprietary Hydraulic Expansion technique
for their installation.