A new retractable spray ball system for tank cleaning in CIP processes has been engineered by Tank Cleaning Developments to be fully self-draining, preventing trapping of fluid, which is a potential source of contamination. In most Cleaning In Place (CIP) systems standard retractable spray balls are pushed into the area to be cleaned by the force of cleaning fluid put through them. This has the disadvantage that once the liquid stops flowing through the system, the spray stem is closed by a return spring, potentially trapping fluid within it. This can be a possible source of contamination.
The Retract-A-Ball system from Tank Cleaning Developments operates pneumatically and is fully self-draining. With pneumatics, the spray stem can be held in the open position while the cleaning media drains both backwards and forwards. If necessary, a further air purge can take place to ensure no media remains.
When the system requires cleaning, the spray ball is operated pneumatically. A telescopic mechanism extends the spray ball into the area to be cleaned. It has between a 60mm (2.4in) and 120mm (4.7in) stroke. This can be adjusted in 10mm (0.4in) increments to position the head exactly in the target area for optimum cleaning.
Cleaning media then passes through the relatively small central telescopic system into the spray ball. This design ensures most of the internal mechanism of the Retract-A-Ball remains dry, making complete draining easier. After operation, the spray ball returns to its covered housing.
The system has achieved ATEX category 1 and is the first retractable spray ball compliant with this standard. A sealing configuration from Trelleborg Sealing Solutions has also proved itself in stringent performance tests. The design of the seals presented a number of challenges and the final sealing configuration in the Retract-A-Ball consists of specially designed spring-energised Turcon PTFE based lip seals along with O-Rings in EPDM and Isolast perfluoroelastomer.