Publish Time: 2023-12-28 Origin: Site
Oil Tanker washing will bring risks to the ship and the marine environment, prone to casualties and maritime accidents, so it is necessary to do a good job of risk control of oil tanker washing to ensure the safety of personnel and the marine environment.
The size of the risk of tank washing depends mainly on the oil already discharged from the tanker, the quality of the crew and the state of the ship. The standard of tank washing depends on the next cargo load of the oil tanker. Risks that may be encountered in bunker washing include: fire, explosion, radiation generated by oil, corrosion to human skin and eyes, toxic gas injury to human body, asphyxiation due to lack of oxygen, pollution of the marine environment and so on. How to take proper measures against the above risks to ensure safety?
To ensure the feasibility of the wash program, the crew members involved in the wash work must be qualified personnel who have received professional training, and all participants should be clear about the methods, steps, purposes and requirements of the wash, as well as specific measures to cope with fire prevention, explosion prevention and prevention of casualties. The first officer should consider the impact of the previous cargo on the washing work and the requirements of the next cargo on the cargo hold when making the washing plan. The plan takes into account all the risks involved in the wash, risk assessment and preventive measures.
Cabin gas control is one of the key safety washing tanks, usually oil tanker are equipped with inert gas system, the oxygen content of inert gas in the cabin should be 5% -8%, when the oxygen content of the inert gas is more than 8%, you should immediately stop washing the tanks, filling inert or replace the existing inert gas, to be restored to the required standard of oxygen content of inert gas in the oil tanker , and then continue to wash the tanks.
The seawater for washing the bilge should be heated, generally the seawater is put into the oil pollution cabin to be heated, and then through the heater into the bilge pump to pump the water into the bilge washing line, and the pressure of the water is used to drive the bilge washing machine. The higher the temperature of the wash water, the better the effect of washing the tank, but take into account the high temperature limit of the valve rubber.
Oil tanker washing, caused by many factors of static electricity, such as oil in the pipe flow, oil from the pipe mouth spray, wash water and water vapor high-speed jet and so on. Wash tank static electricity protection precautions and measures:
Oil Tanker Steam Cleaning
1. The valve leading to the main steam pipe on the main deck must be a stop check valve;
2. Before steaming the cabin, carefully check the breathing valve and vent pipe in the cabin to make sure it is smooth, and isolate all the pipelines with other oil tanks, and the hatch cover of the rest of the oil tanks must be closed tightly except for the oil tanks to be steamed;
3. Before steaming the cabin, first fill water in the cabin, the amount of water and just submerged heating coil is appropriate, and then through the heating coil heating, so that the water temperature rises to 60-70 degrees.
4. Steam cabin initial 20min into the cabin saturated steam pressure shall not be greater than 0.2Mpa, slowly through; 20min, steam pressure control in 0.4-0.5Mpa, shall not use the hose to the cabin jet steam;
5. The oil tanker at the end of steaming should immediately close the steam valve, 30min before putting into the washing equipment.
1. The rubber hose connecting the cabin washer and the water supply pipe should be made of conductive rubber hose with reliable connection.
2. If the washer is fixed on the deck, it should have good contact with the hull of the ship; if the washer is suspended in the oil tanks, before the washer is put into the tanks, it should be confirmed that the connection between the washer, the rubber hose assembly and the fixed water supply hose is tight and has electrical continuity. Tank washers can only be suspended in the cargo oil tanks with natural fibers, do not attack the tank structure, the system is strong and reliable.
3. Several grounded metal wires can be set up in the oil tanks.
4. When loading ballast water, the initial stage of controlling the flow rate of water in the tube does not exceed 1m/s, ballast water must be full of silo, in order to prevent the dirty oil water because of the ship shaking caused by static electricity.
5. When washing the cabin, do not recycle the wash water, nor use chemical additives, and strictly prevent any metal objects from falling into the cabin.
6. The wash water should not exceed 60 degrees in general and 80 degrees in winter.
7. When washing the cabin, the water in the cabin must be discharged continuously, otherwise the cabin washing should be stopped immediately.
8. When washing with water pistol, it should be ventilated and de-aerated first.
9. After washing the tanks, the tank washing machine should be put forward carefully, and then dismantle the hose first, and then dismantle the grounding wire.
10. When ventilating the tank after washing, it is forbidden to use steam jet siphon ventilator.
For oil tanker washing operators, safety awareness training should be strengthened to make them fully recognize the hazards of static electricity and master the basic knowledge and skills of static electricity protection. In the actual operation process, should strictly abide by the anti-static operating procedures to ensure the safety of themselves and others.