Second STEP
Chemical Application
Chemical cleaning
Chemical cleaning is an important, and sometimes simply necessary, step in the cleaning of the cargo hold before the next load. The use of chemicals will significantly speed up the CARGO HOLD WASHING process and improve the HOLDS CLEANLINESS. Cleaning cargo holds with chemicals is a complex process, which requires a high qualification from the employees who carry it out. It is necessary:
- to choose the correct chemicals based on the type of contamination
- to know and follow the rules for applying of chemicals
- to carry out preliminary preparation of cargo holds’ surface before cleaning
- thoroughly to carry out the application process
- to observe strictly the safety precautions during works with chemicals
The process of chemical cleaning of cargo holds
It should be taken into account, that the application of any ship chemicals is carried out only on the dry surface of the hold. The use of chemicals on a surface, which was previously washed by sea water, reduces its effectiveness for 40%.
If holds surface has previously been washed by sea water, then chemicals should be applied on a desalinated and dry surface, as salt build-up will not provide the necessary conditions for the active chemical agents to work and a positive result will be reduced. Wash-out of chemicals can be done either by seawater or freshwater.
Preparation for chemical application is carried out on board of the vessel and the concentration of fresh water is determined according to the level of the hold contamination. The dilution proportion, as recommended by the manufacturer, must be also considered. Sometimes acceptable to use undiluted chemicals if the level of contamination is very high. Reapplication should be considered to achieve the best result.
Features of cleaning after coal, coke
For cargoes such as coal and petroleum coke, which leave greasy stains and marks, it is necessary to use strong alkaline chemicals, which are being applied in the form of emulsion, for a certain time, and washed-out by seawater. To remove stubborn stains, it would be necessary to apply the chemicals more than once. During the active phase, the alkali begins to foam, indicating a normal reaction process between the solidified cargo residues and the chemical.
Also, chemicals based on calcium chloride-hypochlorite (chlorine) are used for such cargoes; when applied, it does not has any color and emits a specific odor.
Cleaning the cargo holds surfaces by acid
For cargoes such as cement and cement clinker, various ores, etc. which often leave a residue trace on the holds surface, diluted acid chemicals must be also used for their removal. The most used is hydrochloric acid, which is also known as muriatic acid. The diluted acid is applied directly to the cargo remains, allowed to work, and then washed-out. Where the residue is stubborn, multiply acid application may be required, in the worst case, the residue must be physically removed. When acid reacts with the cargo residues, it begins to change color to a green tint and release the steam.
Important: Do not allow the chemical to dry on the holds surface, in practice the working time of the chemical is 15 to 30 minutes, depending on ambient temperature and relative humidity
Safety precautions
You must know that during chemicals application you should pay attention to the safety precautions for specific chemicals, at least ,before starting to work, all unprotected body parts and respiratory tract must be protected with special personal protective equipment. Depending on chemicals type, the appropriate face mask, filters, gloves, boots, suits, other consumables to be used.
Fortuna International has the capacity, knowledge, and experience to carry out chemical cleaning of cargo holds. We are ready to perform any type of cargo hold cleaning services anywhere in the world.
( Fortuna International knows how to carry out the chemical cleaning of cargo holds and performs it with proper safety precautions. We are ready to perform any type of cargo hold cleaning services anywhere in the world. )