On-line tube cleaning systems operating at temperatures up to 80°C/140°C (e.g. steam condensers and heat exchangers in conventional and nuclear power- and MSF-Desalt plants) for removing more adherent deposits which can not be removed using sponge balls or to smooth out rough tube surfaces (e.g. roughness resulting from acid cleaning or due to corrosion).
Typical examples are:
- to remove corrosion products (e.g. due to shutdown) and fouled layers (slime, silt etc.) in retordit applications
- to remove layers, such as bio-fouling or manganese-rich deposits, which resist complete removal by sponge balls
- to remove hard crystalline scales (usually rich in calcium carbonate), especially in recirculated, open evaporative c. w. systems (cooling towers and cooling ponds)
- to remove damaged, artificial protective films (e.g. with ferrous sulphate treatments).
It should be noted that the nominal diameter of an abrasive ball, ring coated, is the diameter of the uncoated ball. (For further details of the uncoated balls see our Technical Information “Sponge Balls Type “RS”/”RT”).
Our Types RA – (RAT = fully coating) – RTA -(RTAT=fully coating) Abrasive Balls are available in a range of standard sizes from 15 to 45 mm diameter, in 1 mm steps, each in a standard medium grade of hardness.
Non-standard sizes or harnesses are available on request.
Immediately prior to use, the balls are watered by squeezing them under water in the ball vessel once or twice to expel air.
Resistance to cooling water:
Our sponge ball and coating adhesive have both been specially chosen for service in power plants and similar applications. The abrasive balls are thus resistant to virtually all types of cooling water.
The effectiveness of abrasive balls is strongly dependent on the nature of the fouled layer to be removed. In addition, the number of abrasive balls needed to clean a giver heat exchanger or steam condenser depends on the total number of tubes (n). The following figures can be used as a rule of thumb guide: