Cargo Hold Cleaning Process
Technical Overview
At Seachios Marine Services, our cargo hold cleaning process is grounded in a detailed pre-inspection, which identifies the type and extent of contamination in the holds. This inspection encompasses all critical structural elements, including the hatch coaming, vertical strake of topside tank plating, sloping plating of topside tank, brackets, side shell frame, hopper tank sloping, tank top, bulkheads, lower stool, and bilges.
Contamination Assessment and Cleaning Strategy
The initial step involves assessing residues left by previous cargoes, commonly including substances like petcoke, metcoke, and clinker. These materials are known for their persistent and abrasive nature, requiring targeted cleaning solutions. By referencing the vessel’s last cargoes list, we confirm the contaminants present, which informs our cleaning approach. For instance, high-pressure hydrojetting with freshwater at 500 bar may not suffice for removing petcoke or clinker residues, necessitating the use of chemical agents.
Chemical Agents Utilized
Alkaline Degreasers
Alkaline degreasers are employed to break down and remove oily and greasy residues, which are prevalent in holds previously carrying cargoes like petcoke or metcoke. These degreasers are selected for their ability to interact with hydrocarbon residues, facilitating effective removal.
Corrosion Inhibitors
After the removal of contaminants, corrosion inhibitors are applied to prevent oxidation and rust formation on metal surfaces. This step is essential, particularly when the holds will be exposed to humidity or when preparing the vessel for sensitive cargoes that require clean, rust-free surfaces.
Rust and Chloride Removers
In cases where holds exhibit rust or chloride deposits from previous exposure to seawater, specific rust and chloride removers are utilized. These chemicals are designed to dissolve and eliminate such deposits, ensuring that the surface is adequately prepared for any subsequent treatment or inspection.
Deoxidizers and Neutralizers
Deoxidizers and neutralizers are applied post-cleaning to eliminate any residual acidic compounds that may have been introduced during the cleaning process. This ensures that the holds are chemically neutral, making them suitable for the next operational phase, such as painting or loading.
Acid Descalers
For removing mineral scale or lime deposits, acid descalers are used. These agents effectively dissolve inorganic deposits, which are common in holds exposed to seawater or certain dry cargoes, ensuring the surfaces are clean and smooth.
Post-Cleaning Procedures
Following the chemical cleaning, further treatment may include applying anti-corrosive coatings to protect the hold surfaces from future rusting, particularly when preparing the holds for grain cargoes that require adherence to specific cleanliness standards. Additionally, a protective paint layer may be applied based on the upcoming cargo requirements.
Application Across Vessel Types
The cleaning procedures described are applicable across a range of vessel types, including Panamax, Kamsarmax, Ultramax, and Post-Panamax vessels, each with unique cargo hold configurations. The cleaning strategy is adjusted accordingly to ensure thorough decontamination and preparation for the next cargo, adhering to industry standards and regulations.
This technical approach ensures that each step of the cleaning process is methodically executed, with a focus on the specific chemical and mechanical needs of the vessel’s cargo holds, resulting in a state of readiness for subsequent operations.
