Technical information
Abrasive Balls - Type „RA / RAT / RTA / RTAT“
Abrasive Balls - Type RA (up to 80°C - ring coated)
Abrasive Balls – Type RAT (up to 80°C - fully coated)
Abrasive Balls - Type RTA (up to 140°C - high temperature ring coated)
Abrasive Balls - Type RTAT (up to 140°C - high temperature fully coated)
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).
Abrasive Balls should be used with care, so as to avoid the risk of enhanced corrosion, especially in brackish, sea or other highchloride cooling waters.
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 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.
The coating used consists of fine particles of carborundum (aluminium oxide) bonded to the sponge ball using a specially selected adhesive.
Immediately prior to use, the balls are watered by squeezing them under water in the ball vessel once or twice to expel air.
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.
Number of abrasive balls required:
Smoothing rough tube surfaces: 0,2 n
Elimination of corrosion due to shutdown: 0,3 n
More adherent layers (e.g. iron rich films or manganese-rich deposits): 0,5 - 1,0 n
Hard crystalline scales varies widely; usually balls/tube.
Ball life is strongly dependent on the surface condition of the tubes to be cleaned. Hard scales and corroded surfaces have a particularly detrimental effect on ball life. In relatively smooth tubes, the abrasive ball life is of the order of 2000 tube passes.