Fouling Removal

During normal everyday use many processes can become contaminated or fouled by bacteria or sea life. However, this is normally controlled by continuous dosing of biocide such as copper/chlorine from an electro chlorination unit for seawater cooling or regular planned treatments such as glutaraldehyde or THPS. Over time electro chlorination units can fail or resistance to regularly used biocides can build up and bacteria and sea life can take hold and foul the system.

Fouling can cause a range of issues from corrosion which can cause a localised failure of a pipe wall to loss of flow from sea life completely blocking a cooling water flow path.

Fouling removal is needed to de contaminate the affected system and allow a restart and the steps can vary depending on the fouling to be removed.

SANCCUS SOLUTIONS

Bacterial fouling

Bacterial fouling is treated by application of an approved broad-spectrum biocide at a shock dose rate designed to target and eliminate the bacteria efficiently and swiftly. Ideally the biocide should be different from the biocide typically used to treat the system being decontaminated as bacteria present may have become resistant to this.

The biocide should be added at the specified dose and left to contact for the specified time targeting the bacteria. The system should then be drained and flushed if possible to chemically clean the internal surfaces before returning to service.

Sulphate type

Macrofouling is treated in several steps and is similar to Bacterial fouling in that the first step is to treat with an approved biocide at high dose. The biocide should be approved for use to target the sea life present and should be left to act for the proscribed time.

Once treated with biocide the sea life shells may need to be targeted by an acid based dissolver designed to target the spots where the shells have cemented/ adhered to internal surfaces as this is essentially carbonate based material. The system should then be flushed at as high a velocity as possible to remove the freed shells. Should high velocity flushing with water not be effective then it may possible to flush with a lower viscosity debris pick up gel. The system should then be chemically cleaned as normal before returning to service.

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