Oil Discharge Monitoring and Control System | ODMCS | Oil tanker | Merchant Navy Knowledge

Summary

The Oil Discharge Monitoring and Control System (ODMCs) is a crucial maritime technology designed to ensure compliance with environmental regulations. It consists of components in hazardous and non-hazardous areas, including an analyzing unit, sample feed pump, converting unit, and a computer unit in the cargo control room. The system measures oil concentration in discharged water using a light beam and photodiodes, converting the optical data into electrical signals for processing. If oil discharge exceeds regulatory limits, the system triggers alarms and automatically adjusts valves to prevent overboard discharge. It also records and prints data such as oil discharge rate, content in ppm, total quantity discharged, and ship's speed, ensuring transparency and compliance.

Takeaways

• 📍 The Oil Discharge Monitoring and Control System (ODMCs) is designed to ensure compliance with regulations regarding the discharge of oil from ships.
• 🔍 ODMCs components are strategically placed in both hazardous and non-hazardous areas for safety and operational efficiency.
• 🛠️ The analyzing unit, which includes a sample water measuring unit and various connections for sample water and cleaning, is installed in the pump room.
• 🚀 A sample feed pump is mounted in the engine room bulkhead to facilitate the flow of sample water to the analyzing unit.
• 🔌 The electrical drive motor for the sample feed pump is also located in the engine room for easy access and maintenance.
• 🔄 The converting unit, which includes Zener barriers and a container for cleaning liquid, is installed in the engine room for signal conversion and sample cleaning.
• 💻 The system's computer unit, responsible for processing and controlling the system, is installed in the cargo control room for centralized management.
• 🚫 The system is initially operated with the overboard valve closed and the slop tank return valve opened to stabilize before operation.
• 🌐 The ODMCs uses infrared light scattering to measure oil concentration in the water, which is then detected by photodiodes and converted into an electrical signal.
• ⚠️ The computer unit activates alarms and closes the discharge valve when oil discharge rates exceed regulatory limits, ensuring environmental protection.
• 🔄 In case of ODMCs failure, the computer automatically closes the overboard valve and opens the return valve to the slop tanks, activating alarms as a safety measure.
• 📈 The computer uses data from the flow meter, oil concentration (ppm), and ship's speed to calculate the oil discharge rate and total quantity discharged.
• 🖨️ Regular automatic printing of key data, including oil discharge rate, oil content, total quantity discharged, time, date, and ship speed, ensures documentation for regulatory compliance.

Q & A

What are the two main areas where the components of the Oil Discharge Monitoring and Control System (ODMCS) are located?

The components of the ODMCS are located in two main areas: hazardous and non-hazardous areas.

Where is the analyzing unit of the ODMCS typically installed?

The analyzing unit of the ODMCS is typically installed in the pump room.

What is the purpose of the sample feed pump, and where is it mounted in relation to the ship's structure?

The sample feed pump is responsible for taking a sample of the water being discharged and is mounted in the engine room bulkhead.

What is the role of the converting unit in the ODMCS, and where is it installed?

The converting unit processes the optical information into electrical signals and is installed in the engine room.

How is the fresh water supply provided to the analyzing unit for automatic flushing of the measuring cell?

A fresh water supply is provided either from the ship's fresh water service piping system or a small freshwater header tank, supplied by a check valve to the analyzing unit.

What does the converting unit consist of, and what are its main functions?

The converting unit consists of two sections: one with Zener barriers for intrinsically safe signals and various electrical components, and the other with a container for cleaning liquid and a pump for feeding it to the measuring cell at controlled intervals.

What signals are used by the computer unit to calculate the oil discharge rate in liters per nautical mile?

The computer unit uses the processed ppm (parts per million) information, discharge flow rate, and the ship's speed to calculate the oil discharge rate in liters per nautical mile.

What actions does the computer take when the oil discharge rate exceeds the permissible value?

When the oil discharge rate exceeds the permissible value, the computer activates audible and visible alarms, closes the discharge valve, and opens the slop tank return valve.

How does the ODMCS ensure that the overboard valve is closed and the slop tank return valve is opened during initial operation?

The ODMCS uses an interlock mechanism to ensure that the overboard valve is closed and the slop tank return valve is opened during initial operation, allowing the system to stabilize.

What information is printed out by the computer printer at regular intervals, and how often is this done?

The computer printer automatically prints out information such as the discharge rate of oil in liters per nautical mile, oil content in ppm, total quantity of oil discharged, time and date, ship speed, effluent flow rate, position of the discharge valve, oil type, alarms or warnings, and any failure at regular intervals, for example, every 10 minutes.

What is the purpose of the light beam infrared light path in the measuring cell of the analyzer unit?

The light beam infrared light path in the measuring cell is used to detect oil particles in the water sample. Oil particles scatter the light, and the amount of light scattered is proportional to the oil concentration.