A steelmaking company in Australia had been experiencing corrosion issues in one of their venturi scrubbers, requiring patch repairs every six months. In 1995, Corrocoat Engineering Victoria was contracted to repair and protect the scrubber internally. Over subsequent shutdowns until 2003, the entire internal lining of over 200m2 was replaced with Corrocoat's Polyglass VE/VEF coating system. This extended the working life of the critical scrubber and prevented the need for replacement. The success of this project led the customer to specify Corrocoat's coating systems for other areas of the plant.

1. Case study: VEF for venturi scrubbers
Extended life for venturi scrubbers.
Client
Steelmaking industry, Australia.
Application date
1995 - 2003.
Scope of work
Starting in 1995, the bottom of the scrubber was
repaired and protected. Subsequent shutdowns up to
2003 saw the entire internal lining replaced.
Products
Polyglass VE & VEF.
Corroglass 602 and Corroglass laminating resin.
Substrate
Carbon steel (20mm thick).
Coating system
• Grit blast internally to SA 3.
• Wash to reduce Metallic Salts.
• Pitfill with Corroglass 602 & repaired with 600g
quadriaxial glass fibre laminating fabric.
• Apply Polyglass VE/VEF to a minimum dft of 1.5mm.
• 100% Spark tested and thickness checked.
Coating credentials
Prior to Corrocoat Engineering Victoria’s involvement in
1995, this critical pressure vessel required patch weld
repairs every six months, necessitating regular scrubber
shutdown periods to combat corrosion which was
causing through-plate perforation and leaking.
Corrocoat Engineering Victoria first treated the vessel in
1995, and subsequent inspections have shown these
original areas of repair to be intact and corrosion-free.
Repairs carried out between 1995 and 2003 have now
resulted in the coating of the entire internals of the
pressure vessel – a total in excess of 200m2. Without
Corrocoat protection, it would by now have been
necessary to replace the entire base of the blast furnace
venturi scrubber. The effectiveness of the Corrocoat
methods and materials has negated the need for
replacement and extended the working life of the scrubber.
The success of this project has led to the customer
specifying Corrocoat systems to protect other areas of
plant including a further scrubber and other blast
furnace gas handling systems such as precipitators.
Photographs
Left: The scrubber prior to blasting and coating.
Middle: Visible perforations seen after initial blasting.
Right: A view of the externals of the venturi scrubber.
Corrocoat Ltd, Forster Street, Leeds LS10 1PW Tel +44 (0) 113 276 0760 Fax +44 (0) 113 276 0700 www.corrocoat.com