The techniques for rebuilding eroded-corroded condenser tube sheets have been covered in previous newsletters and can be found here:  

However, problems with condensers and other forms of heat exchangers are not confined only to the tube sheets.

The water flow is channeled from one bank of the tubes to another at each end of the heat exchanger by the division bars which are ribs within the end covers.  The covers and division bars are normally of cast iron or occasionally steel.  This deflection of the cooling water causes extreme turbulence within the covers which in turn corrodes and erodes the division bars.  Combined with this, graphitization of the cast iron up to a depth of ½” is not uncommon after relatively short periods in service.

The end result of this attack is that the division bars do not seal against the corresponding seals across the tube sheet.  This then allows the circulating water to escape across the cover plates at high velocity, via gaps in the division bars, rather than following the fixed line of flow through all the condenser tubes.  This leaves relatively stagnant pockets in some of the condenser tubes which, receiving an inadequate supply of water, overheat or allow the settlement of debris with consequential deposit attack.  Reduction of efficiency is the end result.

Now, complete and permanent repair and rebuilding of heat exchanger cover plates can be carried out with Belzona Ceramic Metals.  Such is its erosion-corrosion resistance, that reclaimed units have outlived completely new replacements while affording increased heat transfer efficiency as a result of better water flow.  We see customers coating their units new to stop any erosion-corrosion.

Tell us, how can we help repair, protect and improve your component equipment?

Stephanie Rumford
srumford@rumfordgroup.com
937-435-4650
RumfordGroup.com