The Client

The plenum was used in the process of deodorising waste gases generated by the water treatment process.

Challenges

• The floor and walls of the plenum were heavily coated with a residue left by the deodorising process.
• The plenum had proved difficult to clean due to small “blow holes” left on the surface of the concrete during the original construction process.
• We had a narrow window of opportunity during which the plenum could be offline to enable the work to be carried out.

Before Treatment

Solution

As all the interior of the plenum had “blow holes” in the surface of the concrete, some of which were quite large and most were filled with the residue created by the deodorising process, we cleaned the whole of the plenum manually by brush and an industrial vacuum.

Once cleaned, we applied a coat of solvent-free epoxy resin primer and two coats of hot spray chemically resistant high-build tank lining grade epoxy resin using our specialised plural component hot spray machine. The coverage and cross-linking properties of the resin were excellent. A light-coloured resin was chosen for the lining of the plenum, as this will aid future inspection.

After Treatment

The Results

We completed the project in a single working day and the plenum was returned to active use one hour following the final coat of resin treatment. As warm, dry air was blowing into the concrete chamber, this accelerated the hardening process of the resin.