Washing by HPM – cleaning the holds and hatch covers by using the special high-pressure machines (output pressure 300-500 Bar). Hold cleaning process with HP machine washing.
High-pressure hoses are connected to the HPM, providing a distance of 30 m to 80 m from the machine to the point of use. The machine must be fitted with a special turbo-nozzle (rotary) to increase the impact force of the flow on the heavily contaminated surface. Portable HPM, installed on the tank top or on the main deck of the vessel, allows water under the pressure to be transferred through high-pressure hoses to an easily operated handle, which is used by the cleaner inside the cargo holds and also at heights with using special climbing equipment to wash out the hard-to-reach areas (under deck constructions, upper part of bulkheads, top side tanks, pipe guards etc.).
During washing, the cleaner should ensure that all parts of the hold are thoroughly washed and that any cargo residues remaining on the hold surface (under deck and coaming frames, behind the frames, pipes and pipe guards, ladders, platforms, top side plantings and lower hoppers, stools, etc.) are removed. During proper washing, the paint flakes and rust scales to be removed, as well. It must be taken into consideration that poor dry cleaning and poor chemicals’ application will lead to hardening or sticking of cargo residues during wet works.
If the cargo residues or cargo stains are still visible after HPM washing then these areas should be rewashed again, in worse case, the chemicals should be applied locally again with manual brushing of problematic holds area and further HPM blasting from close range.
After HPM washing, with use of seawater and rinsing by fresh water is completed, then it is highly recommended to check holds condition after several days, since water caught behind paint and scale can later dislodge the rust and paint scales. In any case, the holds should always be checked numerous times prior arrival at the port of loading to ensure that there are no any defects or debris have appeared as a result of the vessel’s passage and hull vibration.
Once the washing is deemed successful and all cargo residues have been removed, the holds and hatch covers should be rinsed with fresh water to remove dried salts formed on the surface after previously used seawater. Fresh water is supplied through the vessel’s freshwater system, so the volume of available fresh water be taken into consideration.
The level of rinsing by the fresh water depends on the next cargo. For example, if the next cargo is steel products, it is very important to rinse the surface as much as possible, as any condensate can generate the salt water, which affects the corrosion of the steel.
Fortuna International Ltd. provides HPM washing services of cargo holds in all countries of the world. The mobile brigade (cleaning team) will quickly arrive at the destination to perform a high-quality cleaning of the holds.