Sponge rubber ball
A sponge rubber ball is used to clean the pipes and to remove dirt from the pipes of tube bundle heat exchangers in general and from the cooling pipes of condensers in particular. For this purpose, depending on the application, it is used in quantities from 20 to a few thousand in the Taprogge process . The balls are added to the cooling water flow via a special ball inlet and are driven by the cooling water through the pipes to be cleaned and removed from the cooling water by means of a sieve at the other end of the condenser . The circulation is carried out by means of a centrifugal pump. Under normal conditions, the balls can remain in use for up to four weeks, but balls that have become smaller due to wear must be replaced.
Sponge rubber balls are produced with diameters from 10 mm to 45 mm. They consist of biodegradable natural rubber , which is processed in a vulcanization process. In the course of vulcanization, the balls acquire their diameter and other desired properties:
- the nature of the surface,
- the elasticity affects the contact pressure in the pipe.
- the density determines the lift .
Decisive for the effectiveness of the cleaning are a diameter that matches the pipe to be cleaned and the surface properties of the ball. The diameter of the balls is slightly larger than the nominal diameter of the condenser tubing. Due to their elasticity , they generate a contact pressure on their way through the condenser tubes, which reliably cleans the tubes. The buoyancy influences the distribution of the balls on the individual tubes of the tube bundle within the heat exchanger. During production, a dye is usually added that characterizes the properties of the balls.
To improve the cleaning effect, the balls can be provided with a coating. Corundum is used as a coating material to remove particularly hard deposits . Pumice is used as a further auxiliary material, which removes roughness from the interior of the pipes by polishing . Additional auxiliaries improve the temperature resistance of the balls so that they can be used, for example, in the heat exchangers of seawater desalination plants.
The determination of the dimensions of the sponge rubber ball and its other properties depends on a large number of parameters and should always be carried out by the manufacturing company.