Case Study: VEF for venturi scrubbers

Extended life for venturi scrubbers.

Client

Steelmaking industry.

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.